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Inventors at Work 

With Chapters on Discovery 

By George lies 

Author of “ Flame, Electricity and tha Camera 

•Copiously Illustrated 

New York 

Doiibled;iy, Page & Company 

Published October, 1906 

All rights reserved, including that 
of translation into foreign Ian- 
guages. including the Scandinavian 











Form as important as substance. Why a joist is stiffer 
than a plank. The girder is developed from a joist. Rail- 
road rails arc girders of great efficiency as designed and 
tested by Mr. P. H. Dudley . • . 5 


Roofs and small bridges may be built much alike. The 
queen-post truss, adapted for bridges in the sixteenth cen- 
tury, neglected for two hundred years and more. A truss 
replaces the Victoria Tubular Bridge. Cantilever spans at 
Niagara and Quebec. Suspension bridges at New York. 

The bowstring design is an arch disguised. Why bridges 
are built with a slight upward curve. How bridges are 

fastened together in America and in England i8 




Why supports are made hollow. Advantages of the arch 
in buildings, bridges and dams. Tubes in manifold new 
services. Wheels more important than ever. Angles give 
way to curves 39 


Ships have their resistances separately studied. This leads 
to improvements of form cither for speed or for carrying 
capacity. Experiments with models in basins. The Viking 
ship, a thousand years old, of admirable design. Clipper 
ships and modern steamers. Judgment in design .... 52 



Shapes to lessen resistance to motion. Shot formed to move 
swiftly through the air. Railroad trains and automobiles 
of somewhat similar shape. Toothed wheels, conveyors, 
propellers and turbines all so curved as to move with ut- 
most freedom 65 


Light economized by rightly-shaped glass. Heat saved by 
well-designed conveyors and radiators. Why rough glass 
may be better flian smooth. Light is directed in useful 
paths by prisms. The magic of total reflection is turned to 
account. Holophanc Globes. Prisms in binocular glasses. 
Lens grinding. Radiation of heat promoted or prevented 
at will 72 

Tools and implements shaped for efficiency. Edge tools old 
and new. Cutting a ring is easier than cutting away* a 
whole circle. Lathes, planers, shapers, and milling ma- 
chines far out-speed the hand. Abrasive wheels and presses 
supersede old methods. Use creates beauty. Convenience 
in use. Ingenuity spurred by poverty in resources ... 89 


Form in aboriginal art, as affected by materials. Old forms 
persist in new materials. Nature’s gifts first used as given, 
then modified and copied. Rigid materials mean stiff pat- 
terns. New materials have not yet had their full effect on 

modern design log 



Heavenly bodies large and small. The earth as sculptured 
a little at a time. The farmer as a divider. Dust and 
its dangers. Models may mislead. Big structures econom- 
ical. • of atoms. Advantages thereof. Dust re- 
pelled by light 


Food nourishes. Weapons and tools are strong and lasting. 
Clothing adorns and protects. Shelter must be durable. 
Properties modified by art. High utility of the bamboo. 
Basketry finds much to use. Aluminium, how produced and 
used. Qualities long unwelcome or worthless arc now gain- 
ful. Properties created at need . 





Producing more and better light from both gas and elec- 
tricity. The Drummond light. The Welsbach mantle. 
Many rivals of carbon filaments and pencils. Flaming arcs. 
Tubes of mercury vapor 154 


Steel: its new varieties are virtually new metals, strong, 
tough, and heat resisting in degrees priceless to the arts. 
Minute admixtures in other alloys are most potent . . .163 


Glass of new and ffiost useful qualities. Metals plastic un- 
der pressure. Non-conductors of heat. Norwegian cooking 
box. Aladdin oven. Matter seems to remember. Feeble 
influences become strong in time . . . • 180 


Properties most evident are studied first. Then those hid- 
den from cursory view. Radio-activity revealed by the elec- 
trician. A property which may be universal, and of the 
highest import. Its study brings us near to ultimate ex- 
planations. Faraday’s prophetic views 197 


Methods beginning in rule-of-thumb proceed to the utmost 
refinement. Standards old and new. The foot and cubit. 

The metric system. Refined measurement as a means of 
discovery. The interferometer measures inch. A 


light-wave as an unvarying unit of length 208 


Weight, Time, Heat, Light, Electricity, measured with new 
precision. Exact measuremeiit means interchangeable de- 
signs, and points the way to utmost economies. The Bureau 
of Standards at Washington. Measurement in expert plan- 
ning and reform • 219 


Forces take paths of least resistance. Accessibility decides 
where cities shall arise. Plants display engineering prin- 
ciples in structure. Lessons from the human heart, eyes, 
bones, muscles, and nerves. What nature has done, art may 
imitate, — in the separation of oxygen from air, in flight, in 
producing light, in converting heat into work. Lessons 
from lower animals. A hammer-using wasp 245 



Knowledge as sought by disinterested inquirers. A plente- 
ous harvest with few reapers. Germany leads in original 
research. The Carnegie Institution at Washington ... 267 


What to look for. The eye may not see what it docs not 
expect to see. Lenses reveal worlds great and small other- 
wise unseen. Observers of the heavens and of seashore life. 
Collections aid discovery. Happy accidents applied to profit. 
Popular beliefs may be based on truth. An engineer taught 
by a bank swallow 279 


Newton, Watt, Ericsson, Rowland, as boys were construc- 
tive. The passion for making new things. Aid from imag- 
ination and trained dexterity. Edison tells how the phono- 
graph was born. Telephonic messages recorded. 1 faiK;^- 
writing transmitted by electricity. I low machines imitate 
hands. Originality in attack 299 


. Self-acting devices abridge labor. Trigger effects in the 
laboratory, the studio and the workshop. Automatic tele- 
phones. Equilibrium of the atmosphere may be easily up- 
set i . . . 329 


Simplicity always desirable, except when it costs too dear. 
Taking direct in.stead of roundabout paths. Omissions may 
bc*gainful. Classification and signaling simpler than ever 
before 340 


Educated guessing. Weaving power. Imagination indis- 
pensable. The proving process. Theory gainfully directs 
both observation and experiment. Tyndall’s views. Dis- 
cursiveness of Thomas Young 355 


Analogies havC value. Many principles may be reversed 
with profit, 'i contrary of an old method may be gain- 
ful. Judgment gives place to measurement, and then passes 
to new fields 366 









Newton, the supreme gcncralizer. Faraday, the master of 
experiment. Bell, the inventor of the telephone, transmits 
«oeech by a beam of light 387 

Bessemer a man of golden ignorances. His boldness and 
versatility. 'Phe story of his steel process told by himself. 
Nobel’s heroic courage in failure and adversity. His tri- 
umph at last. Turns an accidental hint to great profit. In- 
ventors to-day organized for attacks of new breadth and 
audacity 401 


An aid to the miner, quarryman and sculptor.' An actu- 
ator for pumps. Engraves glass and cleans castings. Dust 
and dirt removed by air exhaustion. Westinghousc air- 
brakes and signals 417 

Pouring and ramming are easier and cheaper than cutting 
and carving. Concrete for dwellings ensures comfort and 
safety from lire. Strengthened with steel it builds ware- 
houses, factories and bridges of new excellence .... 429 


Improvements in steam practice. Mechanical draft. Auto- 
matic stokers. Better boilers. Superheaters. Economical 
condensers. Steam turbines on land and sea 446 


Producer gas. Mond gas. Gas engines. Steam and gas 
engines compared. Diesel engine best heat motor of all. 
Gasoline motors. Alcohol engines. Steam and gas motors 
united. Heat and power production together. District 
steam heating. Isolated plants. Electric traction. Gas for 
a service of heat, light and power 457 




Why cities gain at the expense of the country. The factory 
system. Small shops multiplied. Subdivided labor has 
passed due bounds and is being modified. Tendencies 
against centralization and monopoly. Dwellings united for 
new services. Self-contained houses warmed from a 
center. The literature of invention and discovery as pur- 

veyed in public libraries 478 

INDEX 489 


■ Professor Alexander Graham Bell Frontispiece 

Bell Homestead, Brantford, Ontario facing 2 

Lens of ice focussing a sunbeam 5 

Rubber strip suspended plank-wise and joist-wise 7 

Board doubled breadthwise and edgewise 7 

Telegraph poles under compression. Wires under tension. . 8 

Rubber cylinder, flattened by compression, lengthened by 

tension 9 

Rubber joivSt compressed along top, extended along bottom. . 10 

Girder cut from joist 10 

Rubber I-beam suspended flatwise and edgewise lo 

Girder contours simple, built up, in locomotive draw-bars ... Ii 

Steel ore car 12 

Bulb angle column. New York Subway 12 

Strap rail and stringer, Mohawk & Hudson R. R., 1830. ... 13 

Plimmon H. Dudley facing 14 

Dudley rails 16 

Steel cross-ties and rails 17 

King-post truss ^ 18 

Frames of four sides , 19 

Cross-section Arctic ship “Roosevelt” 20 

Pair of compasses stretch a rubber strip 20 

Queen-post truss • 21 

Upper part of roof truss, Interborough Power House, New 

York 21 

Two queen-post trusses from a bridge 22 

Palladio trusses 22 

Burr Bridge, Waterford, N. Y 23 

Howe and Pratt trusses 24 

Baltimore truss 25 



Whipple Bridge 25 

Simple cantilevers 26 

Victoria Bridge, Montreal, original form 27 

Victoria Bridge, Montreal, present form 28 

Cantilever Bridge, near Quel)ec 29 

Kentucky River Cantilever ]>ridgc 30 

Arch Bridge, Niagara Falls 31 

Bovv^string Bridge, rhiladel])hia 32 

Williamsburg Bridge, New York City 33 

Continuous Girder Bridge, T^achinc, near Montreal 34 

l^uhber strip supported at 4 points, and at 2 points 34 

Plate girder bridge 35 

Lattice girder bridge, showing rivets 36 

Bookshelf laden and unladen, showing camber 36 

Pin connecting parts of bridge 37 

Bridge rollers in section and in ])lan 38 

Girder sections in various forms 39 

Rubber cylinders solid and hollow compared in sag 40 

Handle bar of bicycle in steel tubing 40 

A sulky in steel tubing 41 

Pneumatic hammer in steel tubing 41 

Fishing rod in steel tubing 41 

Bridge of steel pijX' 41 

Arch bridge of steel pipe 42 

Spiral fire-lighter 42 

Spiral weld steel tube 42 

Largest stpnc arch in the world, Plauen, Germany 43 

Church of St. Remy, Rbeinis, France 43 

Curve of suspended chain 44 

Dam across Bear Valley, California 44 

Ferguson locking-bar 43 

Hand-hole plates, P>ie City water-tube boiler 46 

Bullock cart with solid wheels 47 

Ball thrust collar bearings 

Rigid bearings for axles of automobiles 48 

Hyatt helical roller 1 )caring. Ditto supporting an axle 49 

Treads and risers of stairs joined by curves 49 

Corner Madison Square Garden, New YorK 50 


Two pipes with funnel-shaped junction 50 

Model Basin, U. S. Navy, Washington, D. C facing 54 

Viking Ship 56 

Clipper ship ‘‘Young America” 58 

Steamship Kaiser Wilhelm IT 6 q 

^Cargo steamer 61 

U. S. Torpedo-boat destroyer 62 

Cross-sections of ships 63 

Racing automobile. Wedge front and spokeless wheels 66 

Bilgram skew gearing 67 

Ch'ain elevator 68 

Robins conveying belt 68 

Ewart detachable link belting 69 

Curves of turbines 70 

Steel vanes of windmill 70 

Pelton water wheel and jet 71 

Lux for prism 74 

Fresnel lens 74 

Lamp and reflector a unit 75 

Inverted arc-light 75 

Sacramento perch totally reilected in aciuarium 77 

Diagram illustrating total reflection 78 

Ilolophane globe, sections 79 

Holophane globe, diffusing curves 80 

Holophane globe, three varieties 80 

Holophane globe, and Welsliach mantle 8 t 

Wire shortened while original direction is resumed. . ., 81 

Four mirrors rellect a ray in a line parallel to first path 82 

Prisms for Zeiss binocular glasses'. 81 

Sections for Zeiss binocular glasses 83 

Tools for producing optical surfaces ^ 84 

Bi-focal lens for spectacles 85 

Canadian box-stove 86 

Canadian dumb-stove 86 

Tubing for radiator 87 

Gokrs electric heater - 87 

Stolp wired tube for automobiles 87 

Corrugated boiler 88 



Pipe allowing contraction or expansion 88 

Carving chisels and gouges 90 

Lathe cutters 90 

Ratchet bit brace 90 

'Eskimo skin scraper 91 

Double tool drill cutting boiler plate 91, 

Common drill compared with ring drill 92 

Twist drill 93 

How a tool cuts metal 94 

Dacotah fire-drill 94 

Lathe, with parts in detail 95 

Compound slide rest 96 

Blanchard lathe 96 

Turret lathe, with side and top views. 97 

Ericsson’s Monitor 98 

Iron planer , . ^ 99 

Iron shaper gg 

Milling machine , 100 

Milling cutters with inserts Th ' loo 

Milling cutters executing c*y, ; > ; loi 

Emery wheels.. 102 

Carborundum wheel edges.. 102 

Rolls to reduce steel in thicknt .s , . 104 

Gourd-shaped vessel, Arkansas 108 

Gourd and derived pottery forms 109 

J\)ino basket 

Bilhoola basket uq 

Bilhoola basket, a square inch of m 

A free-hand scroll : same as woven m 

Yokut basket bowl jj2 

Sampler on c/irdboard 

Bark vessel and derived form in clay 115 

Vase from tumulus, St. George, Utah 116 

Wooden tray. Clay derivative 116 

Shell vessel. Earthen derivative uQ 

Electric lamps in candle shapes jjy 

Notre Dame de Bonsecours, Montreal 118 

New Amsterdam Theater, New York ./.facing 118 


Cinders large and small on hearth. 120 

Cube subdivided into 8 cubes 121 

Cube built of 27 cubes 122 

Two rubber strips, varying as one and three in dimensions, 

compared in sag 127 

Air bubbles rising in oil 128 

Dvorak sound-mill 132 

Beam of light deflects dust 133 

Dr. Carl Freiherr Auer von Welshacii facing 156 

Boivin burner for alcohol 157 

Alcohol lamp with ventilating hood 158 

Wclsbach mantle 159 

Tantalum lamp 160 

Tungsten lamp of Dr. Kuzel 160 

Hewitt mercury-vapor lamp l6l 

Sections Pearlite and Steel facing 164 

Cleaning Cars by the ‘Vacuum’’ Method facing 164 

Open hearth furnace 165 

Professor Ernst Abbe facing 182 

Bliss forming die 184 

Bliss process of shell making 184 

Mandolin pressed in aluminiuni 185 

Pressed seamless pitcher 185 

Barrel of pressed steel 185 

Range front of pressed steel 186 

Pressed paint tube and cover 186 

Norwegian cooker » 189 

Aladdin oven 190 

Mayer’s floating magnets 193 

Alum crystal, broken and restored 194 

Marble before and after deformation by pressure 195 

Professor Ernest Rutherford facing 202 

Professor A. A. Michelson facing 214 

Michelson interferometer 215 

Light-wave distorted by heated air 216 

Ancient Egyptian balance • 219 

Rueprecht balance 220 

Earnshaw compensated balance wheel 223 



Riefler clock 224 

Photometer 227 

Compass needle deflected by electric wire 230 

Compass needle deflected by electric coil 231 

Maxwell galvanometer 231 

Weston voltmeter 232 

Micrometer caliper measuring i/iooo inch 236 

Plug and ring for standard measurements 237 

Two lenses as pressed together by Newton 237 

Newton’s rings 238 

Flat jig or guide 239 

Deciduous cypress 247 

Deciduous cypress, hypothetical diagram 248 

Section of pipe or moor grass; of bulrush 251 

Pluman hip joint 252 

Valves of veins 252 

l>uilt-up gun 253 

Achromatic prisms and lens 255 

Three levers 256 

Arm holding ball 256 

Heaver teeth 258 

Narwhal with twisted tusk 259 

Lower part of warrior ants’ nest, showing dome 260 

Wasp using pebble as hammer 260 

Cuban firefly 263 

Du. R. S. Woodward faciiij^ 276 

Perforated^ sails for ships 292 

Edison phonograph 312 

TeleOiRaimionk 314 a//f/ facijiiT 314 

Gray Telautograph 315 and 318 

Hussey’s mower or reaper 321 

IMergenthaler linotype, justifying wedges 323 

Schuckers’ double-wedge justifier 324 

Two wedges partly in contact, and fully in contact 325 

Polarized light shows strains in glass 327 

Sto])-motion 330 

Dexter feeding mechanism 331 

Schumann’s “Traumerei” in musical score and on Pianola roll . 334 


Mechanism of Pianola 335 

Automatic Tellfuonk 336 and facing 336 

Blenkinsop’s locomotive, 18 ii 345 

Notes on loose cards in alphabetical order 350 

Sectional bookcase, desk and drawers 351 

C]urke telegraphic code 353 

Burke simplified telegraphic signals 354 

Pupin long-distance telephony 367 

Water-gauge direct and reversed 370 

Thomas Alva Edison facing 374 

Cube-root extractor ' 376 

Square-root extractor 377 

Sturtevant ventilating and heating apparatus 380 

Bicycle suspended from axle 382 

Telephones receiving sound through a beam of light. 395 

Selenium cylinder with reflector 398 

Perforated disc yielding sound from light 399 

Sir PIenry Bessemicr facing 402 

P'irst Bessemer converter and ladle 406 

New Ingcrsoll coal cutter 418 

Drill steels 418 

Sculptor at work with Pneumatic Chisei facing 4:8 

Ilaeseler air-hammer 419 

Rock drill used as hammer 420 

Little Giant wood-boring machine 420 

Water lifted by compressed air 421 

Harris system of pumping by compressed air t 422 

Hardie nozzle for painting by compressed air 423 

Vacuum renovators for carpets and upholstery 424 

Injector sand-blast, Drucklieb’s 425 

Vertical receiver, inter- and outer-cooler 426 

Concrete silo foundation 431 

Concrete silo 432 

Mansion in Concrete, Fort Thomas, Kentucky, ./tiem o' 432 

Wall of two-piece concrete blocks 434 

Ransome bar for concrete * 436 

Corrugated steel bar 436 

Thacher bar 43 ^ 



Kahn bar 437 

Hennebique armored concrete girder 437 

Monier netting 437 

Expanded metal diamond lath 438 

Tree box in expanded steel 43^ 

Royal Bank of Canada^ Havana facing 438 

Locl^: -woven wire fabric 439 

Column forms for concrete, Ingalls Building, Cincinnati 440 

Section of chimney, Los Angeles, Cal 441 

Coignet netting and hook 442 

Section of conduit, Newark, N. J 442 

Water culvert 443 

River des Peres Bridge, Forest Park, St. Louis 444 

Memorial Bridge, Washington, D. C 444 

Francis vertical turbine wheeL 446 

5000 Horse- Power Allis-Ciialmers Steam E'sgine. facing 448 

Smoke- jack 449 

Power House, Interhorough Co., New York, ex- 
terior facing 450 

Schmidt superheater 451 

Power House^ Interborough Co., New York, in- 
terior facing 452 

De Laval steam turbine, sections • 453 

Westinghous£:-Parsons Steam Turbine facing 454 

Combustible gas from a candle 458 

Taylor gas-producer 460 

Four-cyclef gas engine 463 

Fire syringe 467 

Sturtevant fan wheel, without casing 472 

Sturtevant Monogram exhauster and solid base heater 473 

New York Central R. R. Electric Locomotive with 
Five-Car Train facing 476 


Aid in writing this volume is acknowledged in th" course of its 
chapters. The authors grateful thanks are rendered also to 
Dr. L. A. Fischer, of the Bureau of Standards at Washington, 
who has revised the paragraphs describing the work of the 
Bureau ; to Mr. C. R. Mann of the Ryerson Physical Laboratory, 
University of Chicago, who corrected the paragraphs on the inter- 
ferometer ; to Mr. Walter A. Mitchell, formerly of Columbia 
University, New» York, who revised most of the chapters on 
measurement. Mr. Thomas E. Fant, Head of the Department 
of Construction and Repair at the Navy Yard, Washington, D. C., 
gave the picture of the model basin here reproduced. Mr. Walter 
Hough of the National Museum, Washington, D. C., contributed 
a photograph of the Porno basket also reproduced here. Mr. John 
Van Vleck and Mr. Henry G. Stott of New York, Mr. George R. 
Prowse and Mr. Edson L, Pease of Montreal, have furnished 
drawings and photographs for illustrations of unusual interest. 
Mr. George F. C. Smillic, of the Bureau of Engraving, Washing- 
ton, D. C., Mr. Pcrcival E. Fanslcr, Mr. Ernest Ingersoll, and 
Mr. Ashley P. Peck, of New York, have read in proof parts of 
the chapters which follow. Their, corrections and suggestions 
have been indispensable. 

Professor Bradley Stoughton, of the School of Mines, Colum- 
bia University, New York, has been good enough fo contribute a 
brief list of books on steel, supplementing the chapter on that 
theme written with his revision. Had it been feasible, other chap- 
ters would have been supplemented in like manner by other 
teachers of mark. In 1902 the American Library Association 
published an annotated guide to the literature of American his- 
tory, engaging forty critics and scholars of distinction, with Mr. 




J. N. Lamed as editor. It is hoped that at no distant day guides 
on the same helpful plan will be issued in the field of science, duly 
supplemented and revised from time to time. 

In the present volume the author has endeavored to include in 
his survey the main facts to the close of May, 1906. 

New York, September, 1906. 




I NVENTORS and discoverers are justly amon^ the most 
honored of men. It is they who add to knowledge, who 
bring matter under subjection both in form and substance, who 
teach us how to perform an old task, as lighting, with new econ- 
omy,* or hand us gifts wholly new, as the spectroscope and the 
wireless telegraph. It is they who tell us how to shape an oar 
into a rudder, and direct a task with our brains instead of tugging 
at it with our muscles. They enable us to replace loss with gain, 
waste with thrift, weariness with comfort, hazard with safety. 
And, chief service of all, they bring us to understand more and 
more of that involved drama of which this planet is by turns the 
stage and the spectator’s gallery. The main difference between 
humanity to-day and its lowly ancestry of the tree-top and the 
cave has been worked ouf by the inventors and discoverers who 
have steadily lifted the plane of life, made it broader and better 
with every passing year. 

On a theme so vast as the labors of these men a threshold book 
can offer but a few glances at principles of moment, to which 
the reader may add as he pleases from observations and ex- 
periments of his own. At the outset Form will cfigage our 
regard : first, as bestowed so as to be retained by girders, trusses 
and bridges; next, as cmlxKlicd in structures which minimize 
friction, such as w’cll designed ships ; or as conducing to the effi- 
ciency of tools and machines; or deciding how bCvSt heat may be 
radiated or light diffused. A word will follow as to modes of 
conferring form, the influence on form of the materials employed, 
and the undue vitality of old forms that should long ago have 
bidden us good-by. Structures alike in shape may differ in 
size. Bigness has its economies, and so has smallness. Both will 
have brief attention, with a rapid survey of new materials which 



enable a buifder to rear towers or engines bolder in dimensions 
than were hitherto possible. 

Substance, as important as form, ^ will next receive a glance. 
First a word will be said about the properties of food, raiment, 
shelter, weapons and tools. Then, the properties of fuels and 
light-givers will be considered, as steadily improved in their ef^ 
fectiveness. How properties are modified by heat and electricity 
will be remarked, with illustrations from steels of new and aston- 
ishing qualities, and from notable varieties of glass produced at 
Jena. A few pages will recount some of the striking phenomena 
of radio-activity displayed by radium, thorium and kindred sub- 
stances, plienomena which are remolding the fundamental con- 
ceptions of physics and chemistry. 

A survey of form and properties, however cursory, must in- 
volve measurement, otherwise an inventor cannot with accuracy 
embody a plan in a working machine, or know exactly how strong, 
elastic, or conducting a rod, a wire, or a frame is. Measuring 
instruments will be sketched, their use delineated, and the results 
of precise measurement noted as an aid to the construction of 
modern mechanism, the interchangeability of its parts, the econ- 
omy of materials and of energy in every branch of industry. 
Next will follow a chapter noting tasks which Nature has long 
accomplished, and which Art has still to perform, as in convert- 
ing at ordinary temperatures within the human body fuel energy 
into work. Plainly, a broad field opens to future invention as it 
copies the function of plants and animals ; functions to be first 
carefully qbserved, then explained and at last imitated with the 
least possible waste of effort. 

The equipment and the talents for invention and discovery' are 
now touched upon. First, knowledge, especially as the fruit of 
disinterested inquiry; Observation, as exercised by trained intel- 
ligence calling to its aid the best modern instruments; Experi- 
ment, as an educated passion for building on original lines. Then, 
in the mechanical field, we bestow a few glances at self-acting 
machines, at the simplicity of design which makes for econom}^ 
not only in building,, but in operation and maintenance. Either 
in designing a new machine, or in reaching a great truth, such as 
Universal Development, there is scope for Imagination upon 






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the Home of the Bell Telephone Memorial Association. 


which we next pause for a moment. A succeeding chapter out- 
lines how theories may be launched and tested, how analogy may 
yield a golden hint, the profit in rules that work both ways, or 
even in doing just the opposite of what has been done without 
question for ages past. 

, From this brief consideration of method we now pass to a few 
men who have exemplified method on the loftiest plane ; we come 
into the presence of Newton, the supreme generalizer, and ob- 
serve his patience and conscientiousness, as remarkable as his 
resourcefulness in experiment, in mathematical analysis. ^ Even 
greater in experiment, while lacking mathematical power, is 
Faraday, who next enlists our regard. This great man, more 
than any other investigator, laid the foundations of modern elec- 
trical science and art. Moreover he distinctly saw how matter 
might reveal itself in the ‘radiant' condition now engaging the 
study of the foremost iiKiuircrs in physics. 

Electricity has no instrument more useful in daily life, or in 
pure research, than the telephone. Now follows a narration by its 
creator. Professor Bell, of his photophone which transmits speech 
by a beam of light. This recital shows us how an inventor of the 
first rank proceeds from one attempt to another, until his toil is 
crowned with success. Next we hear the story of the Bessemer 
process from the lips of Sir Henry Bessemer himself, affording us 
an insight into the methods and characteristics of a mind in- 
genious, versatile and bold in the highest degree. An inventor 
of quite other type is next introduced, — N(d)cl, who gave 
dynamite to the quarryman and miner, smokeless powder to the 
gunner and sportsman. His unfaltering heart, beset as he was 
by constant peril, marks him a herb as l)rave as ever fought 
hazardous and dreary campaigns to a victorious close. 

Many advances in mechanical and structural art h^jvc been won 
rather through a succession of attacks by one leader after another, 
than by a single decisive blow from a Watt or an Edison. A great 
band of inventors, improvers, adapters, have accomplished notable 
tasks with no record of such a feat as Bessemer witli Ins con- 
verter, or Abbe with Jena glass. A brief chapter deals with some 
of the principal uses of compressed air, an agent of steadily in- 
creasing range. As useful, in a totally different sphere— that of 


building material — is concrete, especially as reinforced with steel 
A sketch of its applications is offered. Then follows the theme 
of using fuels with economy, of obtaining from them motive 
powers with the least possible loss. This field is to-day attracting 
inventors of eminent ability, with the prospect that soon motive 
powers will be much cheapened, with incidental abridgment of 
drudgery, a new expansion of cities into the country, and the 
production of light at perhaps as little as one-third its present 
cost. A page or two arc next given to a few social aspects of in- 
vention, its new aid and comfort to craftsmen, farmers, house- 
holders comparatively poor. It will appear that forces working 
against the undue centralization of industry grow stronger ev^ry 

A closing word gives the reader, especially the young reader, a 
hint or two in case he wishes to pursue paths of study the first 
steps of which are taken in this book. 

In 1900 was published the author’s ‘Tlamc, Electricity and the 
Camera,” in which are treated some of the principal applications 
of heat, electricity and photography as exemplified at the time of 
writing. That volume may supplement the book now in the 
reader’s hands. 



Form as important as substance . . / Why a joist is stiffcf than a plank . . 
The girder is developed from a joist . . . Railroad rails are girders of 
great efficiency as designed and tested by Mr. P. H. Dudley. 

O NE January morning in Canada I saw a striking experiment. 

The sun was shining from an imdouded sky, while in the 
shade a Fahrenheit thermometer stood at about twenty degrees 
below zero. A skilful friend of mine had moulded a eake of ice 

A lens of ice focussing a sunbeam. 

into a lens as large as a reading glass ; tightly fastened in a wood- 
en hoop it focussed in the open air a sunbeam so as to set fire 
to a sheet of paper, and char on a cedar shingle a series of zigzag 
lines. There, indeed, was proof of the importance of form. To 
have kept our hands in contact with the ice would have frozen 
them in a few minutes, but by virtue of its curved surfaces the 
ice so concentrated the solar beam as readily to kindle flame. 



Clearly enough, however important properties may be, not less 
so are the forms into which matter may be fashioned and dis- 
posed. Let us consider a few leading principles by which de- 
signers have created forms that have economized their material, 


time and labor, and made their work both secure and lasting. We 
will begin with a glance at the rearing of shelter, an art which 
commenced with the putting together of boughs and loose stones, 
and to-day requires the utmost skill both of architects and en- 


Building in its modern development owes as much to improve- 
ment in form as to the use of stronger materials, brick instead 
of clay, iron and steel instead of wot)d. A stick 
as cut from a tree makes a capital tent-pole, 
and will serve just as well to sustain the roof 
of a cabin. For structures so low and light it is not worth while 
to change the shape of a‘ stick. By way of contrast let us glance 
at an office building of twenty-five stories, or the main piers of 
the new Quebec Bridge rising 330 feet above their copings. To 
compass such heights stout steel is necessary, and it must be dis- 
posed in shapes more efficient than that of a cylinder, as we shall 
presently see. 

In most cases strength depends upon form, in some cases 
strength has nothing whatever to do with form; if we cut an iron 
bar in two its cross-section of say one square inch may be round, 
oblong, or of other contour, while the effort required to work the 
dividing shears will in any case be the same. But shearing 
stresses, sruch as those here in play, are not so common or import- 
ant as the tension which tugs the wires of Brooklyn Bridge, or 
the compression which comes upon a pillar beneath the dome 
of the national capitol. When we place a lintel over a door or 
a window, we arc concerned tliat it shall not sag and let down the 
wall above it in ruin : wc ensure safety from disaster by giving 
th<i lintel a suitable shape. When wc build a bridge we wish its 
roadway to remain as level as possible while a load passes, so that 
no hills and hollows may waste tractive power : levelness is 

secured by a design which is rigid as well as strong. If a rail- 
road has weak, yielding rails, a great deal of energy is uselessly 
exerted in bending the metal as the wheels pass by. A stiff rail, 


giving way but little, avoids this waste. To create forrtis which 
in use will firmly keep their shape is accordingly one of the chief 
tasks of the engineer and the architect. 

Forms of this kind, well exemplified in the steel columns and 
girders of to-day, have been arrived at by pursuing a path opened 
Ipng ago by some shrewd observer. This man 
noticed that a plank laid flatwise bent much Plank and 
beneath a load, but that when the plank rested Joist, 

on its narrow edge, joist fashion, it curved much less, or hardly 

Rubber strip suspended plank-wise, and joist-wise. 

Board doubled breadthwise through 
small semi -circle AB, then edge- 
wise through large semi- 
circle CD. 

at all. Thus simply by chang- 
ing the ])osition of his ])lank 
he in effect altered its form 
v/ith reference to the strain to 
be borne, securing a decided 
gain in rigidity. l.^t us re- 
peat his experiment, using 
material much more yielding 
than wood. We take a piece 
of rubber eight .inches long, 
one inch wide and one quarter 
of an inch thick, riacing it 
flatwise on supports close to 
its ends we find that its own 
weight causes a decided sag. 
We next place it edgewise, 
taking care to keep it perpen- 



dictilar throughout its length, when it sags very little. Why ? Be- 
cause now the rubber has to bend through an arc four times 
greater in radius than in the first experiment. Suppose we had a 
large board yielding enough to be bent double, we can see that 
there would be much more work in doubling it edgewise than flat- 
wise. The rule for joists is that breadth for breadth their stiff nej>s 
varies as the square of their depth, because the circle through 
which the bending takes place varies in area as the square of its 
radius. In our experiment with the rubber strip by increasing 
depth four-fold, we accordingly increased stiffness sixteen-fold; 
but the breadth of our rubber when laid as a joist is only one- 
fourth of its breadth taken flatwise, so' we must divide four into 
sixteen and find that our net gain in stiffness is in this case four- 

Here let us for a moment dwell upon the; two opposite ways in 
which strength may be brought into play, as cither compression 
or tension is resisted. An example presenting 
Girders. both is a telegraph . pole, with well-balanced 
burdens of wires. Its own weight and its load 
of wires, compress it, as we can prove by measuring the pole as 

Telegraph poles under compression. Wires under tension. 


Stretched upon the ground before being set in place, and then 
after it is erected and duly laden. Should this downward thrust 
be excessive, the pole would be crushed and broken down. The 
Strung wires are not in compression, but in the contrary case of 
tension, and are therefore somewhat lengthened as they pass 
fr<c)m one pole to the next. Now observe a mass first subjected 
to compression, and next to tension. In bearing a pound weight 
a rubber cylinder is compressed and protrudes ; 
when the weight is suspended from this cylin- 
der, the rubber is lengthened by tension. In 
each case the effect is vastly greater than with 
wood or steel, because rubber has so much less 
stiffness than they have. 

Both tension and compression arc exhibited 

Rubber cylinder. 

by compression. 

by tension. 

in our little rubber joist, which illustrates the fainiliar wooden 
support beneath the floors of our houses. This form in giving 
rise to the girder has liccn changed for the better. Let us sec how. 
As the rubber joist sags between its ends, we observe that its 
upper half is compressed, and its lower half extended, the two 
effects though small being quite measurable. As we approach 
The central line, A B, this compression and tension gradually fall 
to zero; it is clear that only the uppermost and undermost layers 



Rubber joist in 

section, compressed along the top, extended 
along the bottom. 

call forth the strength of the material, the inner layers doing 
y ii'ffio flirif tVipv mav be rc- 

Girder cut from joist. 

moved with hardly any loss. 
Hence if we take a common 
joist and cut away all but an 
upper and lower flange, leav- 
ing just web enough between 
to hold them firmly together, 
wc will have the I-beam which 
among rectangular supports is 
strongest and stiffest, weight 
for weight. In producing it 
the engineer has bared within 
the joist the skeleton which 
rigidity, stripping oil 
An I-beam made of rubber 
much ; when 
how due form 


ill useless aud burdensome clothing, 
when laid flatwise over supports at its ends will sag 
aid edgewise it will sag but little, clearly showing 
md disposal confer stiffness on a structure. 

Rubber I-beam suspended flatwise, and edgewise. 

Girders of steel are rolled and riveted together at the mills i 
a variety of contours, each best for a specific duty, as the skeleto 
of a floor, a column, or a part of a bridge. Their lengths, if di 



sired, may far exceed those possible to wood. Their principal 
simple forms are the I-bcam; T, the tee; L, the angle; C, the 
channel ; and the Z-bar. Of these the I- 
I T L C T- beam is oftcnest used; its two parallel 

Simple girder contours, flanges are at the distance apart which 

^ practice ajiproves, they are united by a 

web just stout enough not to be twisted or bent in sustaining its 

Gilder contours simple and built up. 

12 FOBM 

burdens. Crank shafts of engines, to withstand severe strains, are 
built in girder fashion ; so arc the side-bars of locomotives and the 
braces of steel cars. Plates riveted together may serve as com- 
pound girders or columns of great strength and rigidity. In the 
New York subway the riveted steel columns which support the 

100,000 pound steel ore car built by the Standard Steel Car Co., 
Pittsburg, for the Duluth, Alissabe & Northern R. R. 

Of structural steel throughout. Weight 
unloaded, 32,200 pounds. 

roof have a contour wliich enlarges at the extremities. 

b — m(Aes ■ 

Sectioil of standard bulb angle coltunn, New York 



By all odds the most important girder is the rail in railroad 
service. Let ns glance at phases of its development in America, 
as illustrating the importance of a right form to 
efficient service. At the outset of its operations, The Rail, 
in the Mohawk & Hiulson Railroad, now 

part of the New York Central & Hudson River Railroad, employed 
a rail which was a mere strap of iron two and one half inches 
wide, nine sixteenths of an inch thick, with upper corners rounded 
to a breadth of one and seven eighths inches; it was laid upon a 


Strap rail and stringer, Moliawk & Hudson R. R., 1830. 

pine stringer, or light joist, six inches square, and weighed about 
14 pounds per yard. Tliin as this rail was, its proportions were 
adequate to bearing a wheel-flange wliich protruded but half an 
inch or even less. Wliere the Iniilders of that day sought rigidity 
and permanence was in the foundations laid beneath their 
stringers. ICxcept upon embankments there were for each track 
two pits each two feet square, three feet from centre to centre, 
filled with broken stone upon which were placed stone blocks each 
of two cubic feet. On the heavy embankments cross-ties were laid ; 
these were found to combine flexibility of superstructure with 
elasticity of roadbed, so that they were adopted throughout the 
remainder of the track construction and continue to this hour 
to be a standard feature of railroad building. 

It was soon observed that the surface of a track as it left the 
track-maker’s hands, underwent a depression more or less marked 
when a train passed over it. With a strap-iron rail this depression 
was so great that engines were limited to a weight of from three 
to six tons. Before long the strap form was succeeded by a rail 
somewhat resembling in section the rail of to-xlay. Year by year 



the details of rolling rails were improved, so that sections weigh- 
ing thirty-five to forty pounds to the yard came into service. 
These at length united a hard bearing surface for the wheel- 
treads, a guide for the wheel-flanges, and a girder to carry the 
wheel-loads and distribute them to the cross-ties. Thereupon the 
weights of engines and cars were increased, leading, in turn, to u 
constant demand for heavier rails. In 1865 a bearing surface was 
reached adequate for wheel-loads of 10,000 to 12,000 pounds, the 
rail weighing fifty-six to sixty pounds to the yard. But the metal 
was still only iron, and wore rapidly under its augmented bur- 
dens. Then was introduced the epoch-making Bessemer process 
and steel was rolled into rails four and one-half inches high, of 
fifty-six to sixty-five pounds to the yard, of t#n to fifteen- fold 
the durability of iron. In design the early steel rails were limber 
so that they rapidly cut the cross-ties under their seats, pushing 
away the ballast beneath them. Because they lacked height they 
had but little stiffness, one result being that the spikes under the 
rails were constantly loosened, exaggerating the deflection due to 
passing trains. Throughout the lines every joint became low, and 
the rails took on permanent irregularities under the pounding 
of traffic, dealing harmful .shocks to the rolling stock. 

This was the state of affairs in 1880, when Mr. Plimmon II. 
Dudley invented his track-indicator. This apparatus, placed in 
a moving car, records by ever-flowing pens 
Dudley's Tiack paj)cr every irregularity, however slight, in 
the track over which it passes. When railroad 
engineers *first saw its records, they belie ed that the thing to do 
was to restore their roads to straightness by the labor of track- 
men. It was abundantly proved that the real remedy lay in using 
a rail of increased stiffness, that is, a rail higher and heavier.. 
Mr. Dudley, in the light of records covering thousands of miles 
of running, added fifteen pounds to a rail which had weighed 
sixty-five pounds, and gave it a height of five inches instead of 
four and one half, while he broadened its upper surface. At a 
bound these changes increased the stiffness of the section sixty 
per cent., the gain being chiefly due to added height. IVoof of 
this came when his improved rail was found to be much stiffer 
than that of the Metropolitan Railway, of London, which weighed 

Phcltojjrnph l>y I''. M. Soim;rs, Ciiiciiui<iti| O. 


OF New Yoriv. 


eighty-four pounds to the yard and had a base of six and three 
eighths inches, but a height of only four and one half inches. In 
July, 1884, the Dudley rail was laid in the Fourth Avenue via- 
duct, New York; so satisfactory did it prove that in less than 
two years five-inch rails were in service on three trunk lines. 
"Jhen followed their introduction throughout America, their 
smoothness and stability as a track giving them acceptance far 
and wide. 

The performance of the Dudley rail so impressed Mr. William 
Buchanan, Superintendent of Motive Power for the New York 
Central Railroad that in 1889 he planned his famous passenger 
engine, No. 870, which entered upon active duty in April, 1890. 
It carried 40;ooo pounds upon each of its two pairs of driving 
wheels, instead of 31,250, as did its heaviest ])redeccssor ; its truck 
bore a burden of 40,000 pounds more; its loaded tender weighed 
80,000 pounds, making a total of 100 tons, an advance of forty 
per cent, beyond the weight of the heaviest preceding engine and 
tender. Mr. Buchanan’s forvvard stride has been worthily fol- 
lowed up. Since 1890, passenger locomotives have nearly doubled 
in the weight borne upon their axles, while tractive power has 
increased in the same degree. Through express and mail trains 
have more than doubled in weight, eind their speeds have increased 
thirty to forty per cent. The tonnage of an average freight train 
has been augmented four to six-fold, with reduction of the crews 
necessary to keep a given amount of tonnage in motion. This 
economy is reflected in a reduction of rates which are now in 
America the lowest in the world, and which steadily^ fall. In 
capacity for business united with stability of roadbed, mainly 
due to stronger and stiffer rails and to adapted improvement in 
rolling stock, railroad progress in the past fifteen years is equal 
to that of the sixty years preceding. With rails increased to a 
weight of TOO pounds to the yard there is shown, even in passing 
over the joints, an astonishing degree of smoothness as con- 
trasted with the jolting action of rails comparatively low and 
light. Stiffness of rail reduces the destructive action of service, 
originally enormous, upon both equipment and track, lowering in 
a marked degree the cost of maintenance. Size of rail as well 
as form plays a part in this economy. A passenger train weigh- 



ing 378 tons has required 820 horse power on 6s-pound rails, and 
but 720 horse power on 8o-pound rails, the speed in both cases 
being 55 miles an hour; it is estimated that with 105-pound rails 
620 horse power would have sufficed. In freight service Dudley 

rails have reduced the resistances per ton from between 7 and 
8 pounds to one half as much; a further reduction, to 3 pounds, 
is in prospect. In passenger service, with rails of unimproved 
type the resistance at 52 miles an hour is 12 pounds per ton; 
with Dudley rails this resistance for heavy trains is not aug- 
mented when the speed rises to 65 or 70 miles an hour. Dudley 
rails, and rails derived from their designs, are now in use on 
three fourths of all the trackage of American railroads, effect- 
ing a vast economy. Seventy-five years ago the DeWitt Clinton 
locomotive and tender weighed only five sixths as much as the 
main pair of driving wheels, boxes, axle, and connecting rods of 
the present Atlantic type of engine. That such an engine can 
haul a heavy train at seventy miles an hour largely depends upon 
the production of that simple and important clement in rail- 
roading, its rail.^ 

^ Mr. Dudley’s rails, and those of other designers, are fully illustrated 
and discussed in “Railway Track and Track Work,” by E. E. Russell 
Tratman. Second edition. New York, Engineering News Publishing Co. 


Continued. BRIDGES 

Roofs and small bridges may be built much alike . . . The queen-post 
truss, adapted for bridges in the sixteenth century, was neglected for 
two hundred years and more ... A truss bridge replaces the Victoria 
Tubular Bridge . . . Cantilever spans at Niagara and Quebec . . . Sus- 
pension bridges at New York . . . The bowstring design is an arch 
disguised . . . Why bridges are built with a slight upward curve . . . 
How bridges are fastened together in America and England. 

R ails are girders used by themselves : girders arc often com- 
, Lined in trusses; of these much the largest and most im- 
portant are employed for bridges. There is now under construc- 
tion near Quebec a cantilever bridge whose channel span of i,8oo 
feet will be the longest in the world. See 
Roofs and Bridges 29. It will take US a little while to 

Much Alike. understand how so bold a flight as this was 
ever dared. We will begin with a glance at a truss of the simplest 
sort, such as we may find beneath the roof of an old-fashioned 
barn. A pair of rafters, AB and AC, are inclined to each other 
at an obtuse angle, and are fastened to the horizontal beam, BC, 

at B and C. Their apex, 
A, is joined to BC by the 
king-post, AK, which binds 
the three strongly and firm- 
ly. This whole structure 
makes up a triangle, and so 
does each of its halves, 
ABK and AKC. No other 
shape built of straight 

King-post truss. AK, king-post. form 

under strain. Take in 

proof say four pieces of 
lath and unite them with a freely turning pin at each corner to 
make the frame, ABCD ; it is easily distorted by a slight pull or 










push; but insert cross-pieces, AC and BD so as to divide the 
square into triangles, and at once the 
frame resists any strain not severe 
enough to break the wood or crush 
its fastenings. As the roof presses 
cfbwn the frame ABC, its sides, AB 
and AC, tend to slide away at their 
lower ends, B and C, but this is pre- 
vented by the horizontal beam, BC, 
which while it holds them in place is 
itself so stretched as to be held level 
and straight. This calling into play of 
tension constitutes the chief merit of 
the truss, and enables it in roofs and 
bridges to span breadths impossible to 
simple beams bending downward un- 
der compressive strains. Not only in 
houses, but in sliips, the truss has 
great value; it was introduced in this 
held by Robert Seppings of Chatham, 
in England, about 1810. To resist the 
pressure of grinding ice, the “Roose- 
velt’^ is built with trusses of great 
strength. She sailed in 1905, under 
Commander Peary, for a voyage of 
Arctic discovery. 

Were our barn roof flat instead of 
sloping to form a truss, its supporting timbers, under compression, 
would have a decided sag from which BC is free. When we 
fashion a small model of a king-post truss, its sides, AB and AC, 
must be of metal or wood because they will be in compression ; 
the king-post, AK, and the base, BC, which will be under tension, 
may be of rubber or cord. Always as in this case the parts of a 
truss exposed to compression must be of rigid material. When a 
part may be of cord, rope or wire, we know that it is resisting 

model easily put together illustrates the truss iu its simplest form. 
Take a pair of wooden compasses, each half of which is 15 inches long, 

rigidity diagonals are 
needed, AC, BD. 



Cross-section of the “Roosevelt,” Commodore Peary’s 
new Arctic ship. Reproduced by permission from 
the Scientific American, New York. 

Wrought iron exerts about as much resistance to compression 
as to tension; so docs steel. For this reason, and on account of 
their great strength, they have immense value in building. Cast 

such as are sold for blackboard use by the Milton Bradley Co., Spring- 
field, Mass., at 50 cents. At each tip fasten, by the ring provided vvitli 
the compasses, a chair castor such as may he had at any hardware store. 
Join the tips of the castors by a rubber strip. Holding the 
upright, and applying pressure from the hand, they will extend until the 
rubber will be so stretched as to become almost perfectly horizontal. 
Various weights may in succession be suspended from the compass- joint, 
r^T^lacing manual pressure, and serving to measure the exerted tensions. 



iron can bear only about one sixth as much tension as compres- 
sion, so that it is useful as foundations, for the becl-platcs of en- 
gines and machinery and the like, but is unsuitable for girders. 
Wood is much stronger under tension than compression ; in white 
pine this proportion is as eight to one. In designing timber 
bridges the strains are, therefore, as far as possible, arranged for 

Let us now enter another barn, about one half wider than the 
first, and look upward at its rafters. We see its roof sustained by 
timbers disposed as DCMH, 
to avoid the undue weight 
necessary for a design re- 
sembling that of our first 
roof, ABC. Instead of one 
itpright post, AK, as in that 
case, we have now two, DE 
and HO, called queen- 
posts, sustaining the hori- 
zontal beam, CM. In 
large modern roofs the 
simple queen-post is modified and multiplied, as in the main power 
house of the Interborough Rapid Transit Company, West 59th St., 
New York. Returning to our simple queen-post design, let us 

DE, 1 10, quccn-posts. 

imagine a creek flowing between w^alls spanned by DCMH ; that 
truss and a mate to it, parallel at a distance of say ten feet, would 
easily carry a roadway and give us a bridge. A truss for a bridge 

SMN4 *'^‘51 ON 

I iBitANY 


must be much stronger than for a roof of equal span, because a 
bridge has to bear moving loads which may come upon it sud- 

Two qneen-post trusses form a bridge. 

denly, giving rise not only to serious strains but to severe 
vibrations, all varying from moment to moment. 

The queen-post truss was remarkably developed by Palladio, a 
famous Italian architect of the sixteenth century. Two of his 
designs, here given in outline, are from his 

Negletted T°usl architecture published in 1570; their 

contours, little changed, are in vogue to-day. 
Strangely enough thc trusses of Palladio, for all their merit, passed 
out of notice until their principles were revived and improved by 

Palladio trusses. 


Theodore Burr, in 1804, a wooden bridge over the Hudson at 
A^aterford, New York. This bridge had spans respectively of 
;54*, 160 and 180 feet, stretches impossible to single wooden beams. 

D H 

DO, HE, struts. DE, HO, ties. DIIEO, panel. 

Professor J. B. Johnson, an eminent engineer, says that this is the 
most scientific design ever invented for an all-wooden 'bridge ; 
during fifty years it stood unrivaled as a model for highway pur- 
poses in this country. The Burr bridges were usually covered in, 
so as to resemble the roofs we began by inspecting. In a truss 
bridge each part bounded by two adjacent uprights, as DOEH in 
the queen-post figure on page 21, is a panel; every part under 
compression, as DO, HE, is a strut, post, or column; every part 
subject to tension as DE, HO, is a tie. 

In 1830 as the first American railroad train sped on its way, a 
new era dawned for the bridge builder as well as for his neigh- 
bors. At once sprang up a demand for bridges longer and stronger 
than those which in the past had served well enough. A score of 
wagons laden with wheat or potatoes were a good deal lighffer 
than a locomotive followed by a train of- loaded freight cars. A 
market-wagon, too, could easily be taken aboard a ferry-boat, but 
for an engine and its cars a bridge was imperative, if the stream 
were not so wide as to forbid all opportunity to the bridge builder. 
Elis response to the demands of the railroad was two-fold. First in 
the use of metal instead of wood, beginning with iron rods to 
bind together frames of timber. As iron became cheaper and its 
value more and more evident, he employed it for additional parts 
of his structure until at last he built the^ whole bridge of iron. 

To-day good steel is so cheap that railroad bridges are seldom 
reared of anything else. Besides using stronger materials, the 



designer has gradually improved the form of his structure, not 
only in its parts but as a whole, so that to-day, strength for 
strength, a bridge may be only one tenth as heavy as a bridge of 
fifty years ago. Advances in form have been due to experience 
as one type has been compared with another; meanwhile the 
mathematicians have carried their analysis of strains as far a^ 
the extreme complexity of their problems will allow, greatly to 
the betterment of designs. 

Tn building a bridge, as in rearing many other structures, gir- 
ders of various contours arc used. In bridge building the I- 
beam is most employed. When the roadway proceeds on the top 
chord, as DH, in the cjueen-jxist figure, page 21, we have a deck 
bridge; when it is built on the bottom chord, as CM, we have a 
through bridge. 

The Burr bridge of 1804, already mentioned, included an arch 
and 'was in part sustained by struts projecting from abutments. 

These features were omitted by William Howe 
The Burr Bridge bridge which he patented in 1840, and 

Simplified by which was, as far as is known, the first suc- 
Howe and Pratt, ecssor to a design of Palladio in employing a 
simple truss for long spans. The Plowe truss 


was built of wood, except its terminal tic-rods, which were of 
iron; it has been repeated thousands of times throughout the 


world. In 1844 Thomas W. and Caleb Pratt patented a bridge 
which in design was the converse of Idowe's. Its diagonals of 
iron were used in tension, while its vertical struts of timber were 
in compression ; in the Howe pattern the diagonals were in com- 
pression, the verticals in tension. This plan, by shortening the 
struts, diminished the cross-section necessary in a truss. When 
wrought iron took the place of wood for bridges, the Pratt 
design became the most popular of all, combining as it did more 
desirable features than any of its rivals. To-day for long spans 

the Baltimore truss is much in favor. Its stresses, that is, its re- 
sistances to change of form under strain, are readily ascertained ; 
the shortness of its panels means .strength ; and its diagonals have 
the inclination which wide and varied experience has shown most 
desirable. The roadway, it will be observed, is upheld by sub- 
verticals, that is, by verticals which reach the floor from half the 
height of a panel. 

An important study concerns itself with the intensity and dis- 
tribution of strains, first in girders, next in trusses, and lastly, in 
bridges as units, all with intent to ensure the best possible designs 
throughout. In this field of inquiry the pioneer was Squire 
Whipple, a maker of mathematical instruments in Utica, N. Y., 
who published in 1847 analysis of the strains in a truss bridge 
duetto its own weight and to its moving loads. With the laws of 
these strains in mind he devised several bridges of great merit. 

Whipple Bridge. 



the most noteworthy being reared in 1852 on the Rensselaer & 
Saratoga Railroad, seven miles north of Troy, which did service 
until 1883 ; its sides or web system had tics extended across two 
panels in double intersection 

In a long truss bridge, which in its entirety may be regarded 
as a girder of the utmost size, the cross pieces between the main 
beams of the structure are much less heavy than if continuous 
plates, of no more strength. The original form of the Victoria 
Bridge at Montreal was that of a continuous tube of iron, square 
in section ; it has given place to a truss bridge of five times greater 
capacity which weighs only twice as much. (Illustrations of both 
on pages 27 and 28.) 

Thus to lessen weight in comparison with strength is a matter 
of great importance in a suspended structure, which must not 
only bear its own weight, but carry heavy moving loads. 

In most cases a bridge crosses a valley or a river in a place 
which permits the engineer to erect scaffolding to support his 

Advantages of the united and become 

Cantilever, Arch, self-sustaiiiing. In sonic places this course is 

and Bowstring denied ; a river such as the Ohio or the Missis- 
Designs. sippi may have to be spanned at a point where the 

Simple cantilevers. 

FG, HI, are first separate; then in contact; last are joined by a 
plank laid above them. 


Rebuilt with trusses. 




waters in a single day may rise forty feet, bearing along trees and 
timbers with destructive violence. As a rule the difficulty is met by 
employing cantilever spans which require no scaffolding for their 
construction. To understand their principle let us suppose that 
on opposite banks of a creek we roll out to meet each other the 
joists FG and HI, taking care that the parts over the water shall 
always be lighter than the parts on land. When the joists at last 
touch they are secured to each other as a continuous roadway. Or, 
while they are at a moderate distance apart they may be joined 
by a third timber laid across the gap from one to the other. In 
practice the simple principle thus illustrated is developed and 
varied in many ways, but in every application the one rule is that 
the trusses as they stretch out from the two sides of a pier shall 
balance each other, the shore ends l)cing duly weighted down or 
safely anchored to solid rock. And thus, at length, we come to 
the wonderful bridge, six miles west of Quebec, whose channel 
span of 1, 800 feet will be the longest ever reared. See illustration, 
page 29. From the cantilever arms, DA and BE, will be suspended 
•the central truss, AB, of 675 feet. A cantilever span may be much 
longer than a simple truss because on a pier, as D of this bridge, 
a part, DA, of the whole span, DE, is balanced either, as in this 
case, by a shore span, CD, or by a corrcsixmding part of the next 

<\ ,(>30 

Kentucky river cantilever bridge 


span should that span not extend to the shore but pass from one 
pier to another. 

The first cantilever bridge in America was designed by C. 
Shalcr Smith for the Cincinnati Southern Railroad, to cross the 
Kentucky River; it was built in 1876-7. 

• Spanning the gorge of Niagara, close to the Falls, is an arch 

bridge of 840 feet in its central span, which, in its construction 
during 1898, followed the plan originated by James B. Eads in 
building the St. Louis bridge nearly thirty years before. As scaf- 
folding was out of the question in lx)th cases, each bridge was 
built out from its piers on the cantilever principle. An arch is 
sometimes disguised as a modified, bowstring, as in the Burr de- 
sign of 1804, a horizontal tic connecting the extremities of the 
arched rib and taking its thrust, dispensing with the abutments 
demanded by an arch. In the chords of such a pattern the strength 
comes as near to uniformity throughout as practical considera- 
tions permit, avoiding the losses of early days when one part of a 
bridge might be twice as strong as another. The bowstring was 
adopted for the great span of 542^2 feet over the Ohio at Cin- 
cinnati built in 1888, and for the span of 546^4 feet erected at 
Louisville in 1893. A bowstring 533 feet long, forming part of 
the Delaware river bridge of the Pennsylvania Railroad, built in 
1896, in Philadelphia, is outlined on page 32. At Bonn, on the 
Rhine, there was completed in 1904 a bridge whose central span 
is a bowstring 6i6;4 feet long. 



Bowstring Bridge, Pennsylvania R. R., Philadelphia. 

If wc take the design of an arch bridge and turn it upside down 
we have a contour such as that of the Williamsburg Suspension 
Suspension Bridges f opened in 1903 between Brooklyn and 

and Continuous ]\lanhattan, depicted on page 33. l'"or the ut- 
Girders. most length this is the only available .span; it 
brings into play the tensile strength of wire, the strongest form 
that steel can take. A steel cable of suitable diameter, if it had to 
support only itself, might safely be three miles long. A suspen- 
sion bridge has another advantage in employing an anchorage to 
bear strains which would break down a simple truss resting on 
piers. As first erected suspension bridges were liable to extreme 
and harmful vibration, in many cases being shaken to pieces by 
storms of no great violence. It was found that this vibration was 
checked and that safety was ensured by introducing stiffening 
trusses which, at the same time, benefited the bridge by distribut- 
ing tlie load uniformly throughout the sustaining cables. 

At Lachinc, about eight miles west of IMontreal, on the line of 
the Canadian Pacific Railroad, a remarkable bridge crosses the 
St. Lawrence river. Its design is that of a continuous girder of 
four spans, the two side spans being 269 feet each in length, and 
the two others each 408 feet. This type is discussed by Mr. Mans- 
field Mcrriman and Mr. Henry S. Jacoby in Part IV, page 30, of 
their work on Roofs and Bridges. One of the advantages pre- 
sented is that deflection under live load is less, and stiffness 
greater than for simple, discontinuous girders, the harmful effect 
of oscillation being thus diminished. Furthermore, less material 
is required than for simple, discontinuous spans. Both these 



Continuous girder bridge, Canadian Pacific R. R., Lachine, 
near Montreal. 

elements of gain are brought out in placing a strip of rubber, AD, 
upon four equidistant points- of support, when we find that BC, 
the central third of the strip sags less than either AB or CD, the 

Rubber strip supported at 4 points, and at 2 points. 

first or last third. Cutting ofif one-third of the whole strip we 
deprive the removed piece, at its surface of separation, of the 
cohesion which dkl much to keep the whole strip, before cutting, 
almost horizontal at that point. W e take AB, our short removed 
piece of rubber, and lay it at its ends on two points of support ; 
it now serves in a rough-and-ready way as a model of a simple 
truss, all by itself; its decided sag shows it much less rigid than 
when it formed a part of an unbroken and longer structure. 
Continuous girders despite their advantages are seldom ‘em- 
ployed; they are liable to serious difficulties; among these may 
be mentioned that changes, often unavoidable, of level in piers 


and abutments cause them to suffer great reversals of stress, al- 
ways a source of danger; furthermore, variations of length due to 
changes of temperature are, of course, , much greater and more 
troublesome to provide against than in the case of discontinuous 

^Vhether spans are long or short, engineers are fairly well 
agreed as to the best proportions for girders and panels. They 
consider that a girder should have about one- 
twelfth to one-tenth as much depth as span ; f^^s^rn^s-^A^SUght 
and that the weight of a web should be about Upward Curve is 
equal to that of its flanges. They usually give Gainful. Pins or 
panels twice as much depth as length, with a Fastening 

tendency to increase the proportion of depth to length, in order 
to minimize the deflections and oscillations which shorten the 
life of a structure. For definite lengths of span, particular types of 

Plate girder bridge. 

construction* are preferred; usually for lengths of from 20 to 125 
feet, plate girders are chosen; for spans of 125 to 150 feet riveted 
lattice trusses are built ; for .spans of 150 to Goo feet pin-connected 
trusses are empjoyed. Here we reach the economical limit of a 
length for simple trusses ; beyond 600 feet the engineer is obliged 
to have recourse either to a cantilever or a suspension bridge. 



Part of lattice girder bridge, showing rivets. 

Whatever the breadth of the stream or the chasm over which 
he is to build a roadway, each case must be studied in the light of 
its special circumstances. There must be due regard to business 
as well as to engineering considerations ; the designer will bear in 
mind that types of parts customarily turned out at great steel 
works arc procurable in less time, and at less cost, than novel types 
reciuiring to be manufactured to order. Then, in speed of con- 
struction, he will remember that a pin-conuected bridge can be 
built much faster than a riveted structure. Furthermore, every 
part must be vastly stronger than ordinary duty requires. Tem- 
pests and floods may suddenly arise ; at any instant a derailment or 
a collision may create a strain of the utmost severity; and even 
under ordinary circumstances it must not be forgotten that train 
loads grow constantly heavier because economy lies that way. 

Upper shelf, unladen, has upward curve or camber. 
Lower similar shelf is straightened by its load. 



One detail of bridge design is worth a moment’s attention. 
When a book-shelf is a thin board, quite straight as manufactured, 
it sags in the middle when fully burdened. This downward dip 
may be avoided by making the shelf at first with a slight curve 
which brings the middle a little higher than the qnds. In bridge 
building a like curve, or camber, is given to eacli span so that when 
fully loaded it will be level or nearly so. In a span of 500 feet 
it is found that a rise of half a foot at the centre is sufficient. In 
suspension bridges, for the sake of strengthening the structure, 
the camber far exceeds this ratio. 

In fastening together the parts of a bridge the usual American 
practice, already mentioned, is to employ pins which pass through 
eye bars. In England riveting is preferred, as shown in the figure 
of the lattice truss, page 36. This difference in methods arose 
through the use of materials 
which differed. In the con- 
struction of bridges the 
English engineer started 
with the flanged girder of 
cast or rolled iron, or some 
other form of stiff beam, 
and as bridges increased in 
size so as to require the 
framing of a truss, his 
whole effort was directed 
toward making that truss as 
much like the original 
flanged or box girder as 
possible. The American en- 
gineer, on the other hand, had at first little or no iron or steel to 
work with, and of necessity used wood. As the necessary bridges 
were of considerable span, the only feasible method was to pin 
together small pieces of wood so as to form a connected series of 
triangles. To make rigid joints in wood was impracticable, and 
indeed rigid joiilts were not desired, because tlie strength of wood 
IS slight when strains arc applied in any direction other than that 
of the fibres of the piece, and the pin joint insures just this line of 
action. As a rule a riveted bridge requires more metal than a pin- 



connected design, takds more time to build, but demands some- 
what less skill. To i:)rovide for changes in length as a bridge is 
subjected to variations of tcihpcraturc, friction rollers are used 
to support its extremities. In the first suspension bridge at 
Niagara Falls, built by Roebling, a little cement accidentally cov- 
ered the friction rollers arid 
prevented them from turning; 
fortunately the structure 
escaped the destruction to 
which it was thus exposed. 

We have now taken a rapid 
survey of some of the methods 
by which the designer of 
bridges plans a structure 
which is at once safe and to 
the utmost extent economical 
of material. Step by step he 
has discovered how little steel 
he may use for designs all the 
bolder because his hand is so 

Bridge rollers in section and plan. Sparing of weight. His SUC- 
New York, Pennsylvania & Ohio R. R. cess began in adopting the 

girder, which we have seen to 
be in cfTect the working skeleton long concealed within the com- 
mon joist; the cantilever span near Quebec, which compasses 
1, 800 feet in its flight, has been dissected out of preceding burden 
bearers in the same way. Its metal stands forth as so much sheer 
muscle kept to the most telling lines, unencumbered by a single 
pound of idle substance. A designer of such a fabric is an artist 
skilled in disengaging from masses of material every ounce that 
can be wisely removed. In some cases, as when Roebling linked 
together New York and Brooklyn, a bridge is created as much a 
thing of beauty as of use, as graceful as it is strong.^ 

^ Mr. David A. Molitor has a chapter, copiously illustrated, on the 
esthetic design of bridges, beginning page ii in the ^Theory and' Practice 
of Modern Framed Structures,” by Mr. J. B. Johnson and other aruthors, 
New York, John Wiley & Sons. Fighth edition, revised and enlarged. 



Why supports are made hollow . . . Advantages of the arch in buildings, 
bridges and dams . . . Tubes in manifold new services . . . Wheels 
more important than ever . . . Angles give way to curves. 

H aving glanced at methods by which forms, judiciously 
chosen, economize the materials of buildings and rails,^ of 
bridges diverse in type, we pass to further consideration of these 
and like shapes, to find that they effect a saving in material while 
they make feasible a new boldness of plan, and introduce new 
elements of beauty. We will also remark that judicious forms 
prevent waste of energy as structures arc either set in motion, or 
serve to convey moving bodies. Incidentally we shall see that 
well chosen shapes insure a structure against undue hurt and 

In lofty structures, the box girder is frequently employed as a 
column or, a beam because it has even greater rigidity than thf' 
I-beam; usually it has four sides, but it may 
have eight, sixteen, or more, and thus step by Columns 

step we come to a hollow cylindrical coluinn 
which has, indeed, the best form that can be bestowed on sup- 

Square Octagonal i6-Sidcd Round 

Girder sections. 

porting material. Chinese builders learned its economy on the 
distant day when they adopted the bamboo for their walls and 



roofs. Comparison with a solid stick of timber of like weight and 
substance will show that an equal length of bamboo is decidedly 
preferable. The inner half of a round solid stick does com- 
paratively little in holding up a burden ; to remove that half is 
therefore as gainful as to strip from a joist the timber surround- 
ing its working skeleton. At first the journals or axles of cngiiK's 
and large machines, as well as the axles of railroad cars and the 
shafts of steamships were solid ; to-day, in a proportion which 
steadily increases, they are hollow. The advantage of this form 


Solid rubjc'r cylinder sa^s much. 
Hollow rubber cylinder sags less. 

comes out when we take two cylinders of rubber, alike in length 
and weight, one solid, the other hollow. Supporting both at their 
ends, the hollow form sags less than the solid form, proving it- 
self to be the more rigid of the two. 

With like advantage seamless tubing is adopted for a broad 
variety of purposes. Tl builds bicycles and sulkies which far out- 

S])eed vehicles of solid frames ; it is 
worked tip into elevator cages, 
mangle rolls, pneumatic tools, fish- 
ing-rods, magazine-rifle tubes, ink- 
ing rollers, farm machinery, poles, 
masts and much else where strength 
and lightness are to be united. Steel 

Handle-bar of Incycle 
in steel-tubing. 


tubini:^ is readily bent into any needed contour, even when of 
considera])le diameter. Mr. Egbert P. Watson has pointed 
out its availability for. 
highway bridges of about 
forty feet span, no profes- 
liional bridge-builders being 
needed for their construc- 
tion. Near Saxonville, 

Massachusetts, a pipe-arch 
bridge, eighty feet long, 
provides a roadway across 
the Sudbury River, while 
carrying within its pipe a 
stream which forms jiart of 
the Boston water system. A 
bridge of similar form, 200 
feet long, spans Rock Creek 

in the City of Washington. The Eads bridge crossing the Missis- 
sippi, at St. Louis, emiiloys for each span eight steel tubes of nine 
inches exterior diameter. 

Tubes large and small have 
been strengthened by adojit- 
ing the model of an old- 
fashioned fire-lighter, or 
spill, a bit of paper rolled 
spirally as a hollow tube. 

Blow sharply into it and you but tighten its joints. In like man- 
ner tubes and pipes of metal are all the tighter when their seams 

A pneumatic hammer, steel tul)ing. 

Fishing-rod in steel tubing. 

Bridge of steel pipe. 



are spiral instead of longitudinal. An eager quest for combined 
strcngtli and lightness in the bicycle has ended in the choice of 
tubes spirally welded. * 

Arch bridge of steel pipe, 
Sudbury River, near Saxondale, Mass. 

Spiral fire-lighter. 

Spiral weld steel tube. 

When builders of old began to rear masonry they repeated in 
stone or brick the forms they had constructed in wood. Accord- 
ingly the lintels of their doors and windows 
Arches. were flat. It was a remarkable step in advance 
when the arch was invented, probably by a 
bricklayer, spanning widths impossible to horizontal structures. 
A flat course of stone or brick presses downward only; an arch 
presses sidewise as well as downward. It is this sidewise thrust, 
calling into play a new resource, that gives the arch its structural 
advantage. In modern masonry the boldest arch is that of the 
bridge at Plauen, Germany, with its span of 295)^ feet. Of 


pointed arches the chief sustain the walls of Gothic cathedrals; it 

Longest stone arch in the world, Plauen, Germany. 

was to counteract the outward thrust of these arches that ex- 

ternal buttresses were reared, 
cither solid, as at St. Rciny in 
Rheinis, or flying, as at Notre 
Dame in Paris. The Saracenic 
arch, offering more than half 
of a circle, is not so strong as 
the Roman arch, but it has a 
grace of its own, fully re- 
vealed in the Alhambra, and 
in the incomparable mosque 
at Cordova. A chain of small 
links, a watch-chain, for ex- 
ample, freely hanging between 
two iKDints of support strikes 
out a catenary curve ; this Ga- 
lileo suggested as the outline 
for an arch in equilibrium; it 
is adopted for suspension 

‘The arch,'^ says Mr. Wil- 
liam P. p. Longfellow in 
“ The Column and the Arch,’’ 
was the great constructive 
factor in the architecture of 
the Roman Empire; it added 

Church of St. Rcmy, Rheims, France. 
Section across buttressed choir. 

enormously to the builder’s re- 

sources in planning, and to his means of architectural effect. 



It gave him the means of spanning wide openings, and 
when expanded into the vanlt, of covering great spaces; it 
habituated him to curved lines and surfaces. Helped by it, and 

Curve of suspcuclcd chain. 

Spurred by the new wants of the complex Roman civilization, he 
enlarged the scale of his buildings and greatly increased the in- 
tricacy of their plans. Ife used his new combinations with a bold- 
ness and fertility of invention that have been the wonder of the 
world from that age to ours, constructing on a scale that dwarfed 

Dam across Bear Valley, San Homardino County, California. 



everything that had gone before except the colossal buildings oi 
Kgypt. Under a new stimulus, and with new means of effect, 
Roman building greatly outstripped that of the Greeks in extent, 
in variety, and magnificence.” 

An arch built on its side, with its convexity upstream, and its 
eifds braced against rocky banks, serves admirably as a dam. It 
has in many cases withstood floods much higher than those ex- 
pected by its designers. Such dams must not be too long, or 
what is saved in thickness is more than lost in length. Arclies 
inverted are used in many places as gulleys for drainage. Near 
Bristol, in England, they anchor the cables of the Clifton Sus- 
pension Bridge, at a depth of cighty-two feet below the surface 
of the ground. Many tunnels finished in masotiry have outlines 
which are two arches united, the lower arch being inverted. The 
Cloaca Maxima, the famous sewer at Rome, is of this pattern; 
it is twenty-six feet high, sixteen feet broad, and is now in its 
twenty-fifth century of service. 

From arches, built of parts of circles, let us pass to the circle 
itself, and glance at the use of tubes of circular section as we be- 
gin to consider how resistances to motion may 
be minimized. The use of the bamboo not only Other 

for building, but for the carriage of water, be- 
gan in the remote past. As structural material it was light and 
strong as we have noticed ; laid upon the ground it was a read}''- 
made water pipe of excellent form. When 
trees were hollowed out to convey water, 
when clay was modeled into tubes, the 
hollow cylindrical shape of the bamboo 
was in the mind of the Asiatic artisan, to 
i)c faithfully copied. That form has de- 
scended to all modern pipijig for water, 
steam, and gas, because the^ best that a 
pipe can take. No other shape has, pro- 
portionately to capacity, so little surface 
lor friction inside or rust outside. A lock- 
ing-bar water pipe, devised by Mephan 
Berguson, of Perth, Australia, is made of 
two plates of equal width, curved into 
senii-circles which arc pressed at their ends into channel bars 

Ferguson locking-bar 
pipe. East Jersey 
Pipe Co., Pater- 
son, N. J. 


§oft Steel. As the lockin^^-bars and joints are opposite each other, 
their joints can be tightly closed by a simple machine which exerts 
pressure in a straight line. This construction may be used not 
only for pipes, but for hydraulic cylinders, air receivers, mud and 
steam drums, tubular boilers and boiler shells where high pres- 
sures are to be withstood. * 

A steam boiler or other vessel under severe internal strains had 
best be spherical if equality to resistance is particularly de- 
sired. l.'^sually a cylindrical shape is much more convenient, and 
no other is given to simjdc steam boilers or to the tubes of water- 
lube or fire-tube boilers. Tubes comparatively narrow, are readily 
manufactured without seam, so that they may be quite safe though 
thin ; large boilers of jdates riveted togetlier, must be built of thick 
metal. It was estimated by ]\fr. V, Reuleaux, the eminent en- 
gineer, that if such boilers could be made in one continuous piece 
of metal by the Mannesmann process, so successful in tu])c-mak- 
ing, an economy in weight of at least one third would be feasible. 

In water-tube boilers a gainful 
departure from the circular form in 
a detail of their design is worthy of 
notice. In order that their tubes 
may be kept sound and clean they 
arc rendered accessible by hand- 
holes which pierce the front- and 
back of the boiler. Usually these 
hand-holes and their covers are 
round, a form whicli makes it iieces- 
sary to ])ut the cover outside the 
boiler where even a«good joint, well 
stayed, may leak or give way undet* 
a pressure whicli tends to force 
apart the cover and its seat. In 
the Eric City boiler the covers arc 
elliptical ; they arc readily passed 
through the hand-holes so as to rest 
not on the outside, but on the inside, 
of the boiler, where the steam pres- 
sure makes their joints all the tighter. A further advantage i-s 

Iland-liole plates. 

Erie City water-tube boiler. 



that each elliptical plate is large enough to give access to two 
tubes instead of one, lessening the lines of juncture along which 
leakage may occur. 

It was a memorable day when first a round log or stick was 
thrust und^r a bur{lcn, casing its motion and leading to the wheel 
Wy piecemeal improvements. A section cut off 
from the end of a round log is to-day the wheel Wheels, 
for ox-carts in China and India. In its crudest 
form a roller enables a man to drag a load instead of carrying it, 
and he can readily drag much more than he can carry. Wheel- 

Bullock cart with solid wheels. 

wrights of old soon found that a wheel need not be solid, that 
strong spokes, a sound rim, and a metal tire embody the utmost 
strength and lightness. Roller and ball bearings much extend 
the benefits gf simple wheels; they lessen friction in the best 
typewriters, bicycles, and elevators ; in wagons, carriages, and 
automobiles roller bearings are so helpful that their use should be 
uniyersal. Of notable efficiency is the Hyatt bearing, formed by 
winding a steel strip into a spiral roller. This device has a flex- 
ibility which enables it to conform to irregularities of motion 
much better than can a solid cylinder. 

For machinery the wheel is indispensable. The hand docs its 
work chiefly in moving to and fro, as in .sawing and whittling. 
Machines outdo manual toil by moving swiftly and continuously 



in a circle: instead of the 
smoothing iron we have the 
mangle, boards are ])laiicd 
by rotary knives, timber is 
divided by circular saws, 
and the steam turbine ts 
displacing the steam engine 
which every moment has to 
check the momentum of 
huge reciprocating masses. 
Noteworthy in this regard 
is the ])erfecting press 
which prints a newspaper 
from a continuous roll, as 
contrasted with the old 
machine which demanded 
for each im]M-ession a dis- 
tinct series of to and fro 
movements. The Harris 
Rotary Press for job print- 
ing is of like nltxlcl. It 
feeds itself with 6,500 
sheets an hour, printing 
from a stcrcot\'pc or an 
electrotype curved upon its 
cylinder, "idic lathe, simple 
enough a century ago, has 
been developed into mach- 
ines of great comi^lexity, 
IKnver, and variety, all with 
the original rotary mandrel 
as their essential feature. 
Willing machines, steadily 
gaining more and more 
importance, employ rotary 
cutters which dispense with 
the manual chip])ing and filing of former days. 

W ood as commonly hewn, sawn, and planed ; bricks as usually 

Section— A B 

1 thrust collar licariiig. 
ball bearing Co., 

Rigid hearings for driving axles 
of aiitoniohiles. 

r>all bearing Co., Philadelphia. 



molded ; stone as it leaves an ordinary hammer, all have flat sides 
and square ed^c^cs. Hence it has been easiest to 
build walls and floors which meet at ri,i;ht Angles Replaced 
anodes, aiiri to leave sharp corners on outer by Curves, 
walls, windows, doorways, and chimneys. This 
is being changed for 
the better ; in stair- 
cases the boards on 
which we tread and 
those which join them 
together now meet in 
smooth curves ; so do 
the walls of rooms as 
they reach ceilings 
and floors, conducing 
to case and thorough- 
ness in sweeping and 
cleansing. In outer 

walls, in doorways Treads and risers joined by curves, 

and windows, similar 
curves reduce liability 


to hurt and harm. A wagon wheel easily knocks pieces from an 
angle of brickwork ; it makes little impression on bricks retiring 
from the street line in a sweeping curve, as in the Madison 
Square Garden, New York. Factory chimneys have long been 

built round instead of square ; 
to-day in the be§,t designsi-the 
ducts to a chimney are also 
freely curved. In blast fur- 
naces this is the rule for every 
part of the structure, ensuring 
gain in strength, lessening re- 
sistance to the flow of gases, 
and thus saving much fuel. 
When waterpipes varying in 
diameter are joined, the junc- 
tion should be a gradual curve, 
otherwise retarding eddies 
will arise, wasting a good deal 
of energy ; the same precau- 
tion is advisable in laying pipes for steam or gas. The elbows of 
pipes for gas, steam or water exert the least possible ffiction when 
* given the utmost feasible 

radius. All the various 
parts of heavy guns are 
curved, since any sharpness 
of angle at a joint brings in 
a hazard of rupture under 
Two pipes with funnel-shaped junction. tremendous strains of 


hhnbossing and stamping machines may cither decorate a sheet 
of note paper or make a tub from a plate of steel. Whatever their 
size these machines have the edges of their dies nicely rounded, 
vSO as to avoid tearing the material they fashion. To ensure the 
utmost strength in the machines themselves they are contoured in 
ample curves. In hydraulic presses, subjected to strains vastly 
greater, the same shaping is imperative, otherwise a cylinder may 
part abruptly with disastrous effect. So, too, in the manufacture 
of magnets and electro-magnets, their terminals are well rounded 

Corner Madison Sfpiarc Garden, 
Madison Avenue and 26th Street, 

New York. 


to ensure the closest possible approach to uniformity of field and 
of working effect. 

A glance at a warship discovers her varied use of curves in de- 
fence; to deflect assailing shot and shell, her plates arc given 
bulging lines, her turrets are built in spherical contours, and her 
cfsemates are convex throughout. On much the same principle 
fortifications are rendered bomb-proof, or rather bomb-shedding; 
while outworks are so inclined that 1x)mbs fall to distances at 
which they do little or no harm. As in war so in peace; there is 
gain in building breakwaters with an easy curve; to give their 
masonry and timbers a perpendicular face would be to invite 
damage, whereas a flowing contour like that of a shelving beach, 
slows down an advancing breaker and checks its shock. In rear- 
ing lighthouses to bear the brunt of ocean storms the outline of a 
breakwater is repeated to the utmost degree feasible. Often, how- 
ever, the base supporting a lighthouse is too small in area for such 
an outline to be possible. 


FORM— Continued. SHIPS 

Ships have their resistances separate!}^ studied . . . This leads to improve- 
ments of form either for speed or for carrying capacity . . . Experiments 
with models in basins . . . 'I'hc Viking ship, a thousand years old, of 
admirable design . . . Clipper ships and modern steamers. Judgment 
in design. 

I N givinj^ form to a ship a designer has a three-fold aim,— 
strength, carrying capacity and speed. Strength is a matter 
of interior hiiild as much as of external walls; it is conferred by 
girders, stays and stiffeners which we have already considered, 
so that we may here i)ass to the general fonii 

Forms of Ships \m\\, which decides how much freight a 

Adapted to Special . . , ^ ^ ^ ^ i 

o ^ sliii) may carry, and, to a certain extent, how 

Resistances. i > 

fast she may run. A ship is the supreme 
exanijile of form adaiited to minimize resistance to motion; its 
lesson in that regard will he the chief theme of this chapter. Un- 
til the close of the eighteenth century the resistance to the progress 
of a ship was regarded as a single, uncompounded clement, plainly 
enough varying with the vessel’s speed and size. It was Marc 
Ileaufoy, who first in in l^ondon, jiohitcd out that a ship’s 

resistance has two distinct components; hist, friction af the shell 
or. skin with the water through which the \essel moves, dependent 
111)011 the area of that skin ; second, resistance due to the forma- 
tion of waves as the ship advances, dependent upon the speed of 
the vessel aiul the shape of her hull. ( 3 ther resistances have since 
been detected, but these tw'o arc much the most important of all ; 
each varies independently of the other as one ship differs from 
another in form, or as in the same ship one speed is compared with 
another. To take a simple : a ship’s model of a certain form, 
of perfectly clean skin, is towed at various speeds and the pull of 
the tow-line is noted; then the same model with its skin rough- 



ened and covered with marine growths is towed at the same 
speeds, and much greater pulls are observed in the tow-line. The 
wetted surface is the same in the two series of experiments, the 
speeds correspond throughout, and the increase of resistance due 
to a roughening of surface can only mean that the friction be- 
tv^en the water and the submerged skin has increased. Next we 
take a model of certain form and definite size, and a second model 
having the same area of wetted surface but a different form; 
we tow both models at the same speed to find that one requires a 
decidedly stronger pull than the other. This difference cannot 
be due to frictional resistance of surface, for this is the same in 
both models, therefore it must be due to the increased resistance 
offered by the water as it is jnishcd aside, a resistance measurable 
in the created waves. Mr. Edmund Froude, an eminent English 
authority, says : 

“For a ship A, of the ocean mail steamer type, 300 feet long 
and 31^ feet beam and 2,634 tons displacement, going at 13 
knots an hour, the skin resistance is 5.8 tons, and the wave re- 
sistance 3.2 tons, making a total of 9 tons. At 14 knots the skin 
resistance is but little increased, namely 6.6 tons ; while the wave 
resistance is nearly double, namely, 6.15 tons. IMark how great, 
relatively to the skin res^istajicCi is the wave resisiance at the 
moderate speed of 14 knots for a ship of this size and of 2,634 
tons weight or displacement. Tn the case of another ship P>, 300 
feet long, 46.3 feet beain, and 3,626 tons displacement —a broader 
and larger ship with nO parallel middle bod}', but with fine lines 
swelling out gradually — the wave resistance is much more 
favorable.^ At 13 knots the skin resistance is rather more than 
in the case of the other ship, being 6.95 tons as against 5.8 tons; 
while tliQ wave resistance is only 2.45 tons as against 3.2 tons. 
At 14 knots there is a very remarkable result in this broader ship 

' The entrance is that part of the ship forward where it enters the water 
f.nd swells out to the full breadth of the ship; the run is the after part 
ftom where the .ship begins to narrow and extending to the stern. A 
ship may consist of only entrance and run ; it may have a middle body 
of parallel sides between the entrance and run. Such a middle body is 
discussed by Lord Kelvin in “Popular Lectures and Addresses,” Vol. Ill, 
Navigation, p. 492. 

54 FOlt$f--StoS 

with its firie lines, all entrance and run and no parallel ' middle 
body at 14 knots the skin resiltance is 8 tons as agahist 6.6 
tons in ship A, while the wave resistance is only 3.15 tons as com- 
pared with 6.15 tons. The two resistances added together are 
for B only 11.15 tons, while for A, a smaller ship, they amount to 
12.75 tons.” f 

These figures show that a designer must bear in mind the speed 
at which this ship is to run ; they prove that he may choose one 
form to minimize friction, or another form if 
he particularly wishes to bring wave-making 
resistance to the lowest possible point. Forms 
of these two kinds are readily studied when represented in models 
12 to 20 feet in length towed through tanks built for the purpose. 
Experiments of this kind were undertaken as long ago as 1770, in 
the Paris Military School ; the methods then inaugurated and 
copied in London at the Greenland Docks were greatly improved* 
by Mr. William Froude in a tank which he constructed at Tor- 
quay in England, in 1870. His modes of investigation, (July 
adopted by the British Admiralty, and after his death continued 
by his son, Mr. Edmund Froude, have created a new era in ship 
design. To-day in Europe and America there are eleven such 
tanks as Mr. Froude^s, all larger than his and more elaborate in 
their appliances. In addition to learning the behavior of models 
diverse in type, Mr. Froude worked out the rules which subsist 
between the performance of a model and that of a ship of like 
form; these he brought to proof in 1871 when he towed Her 
Majesty’s Ship Greyhound, and verified his estimates in towing 
its model. The rules concerned^ known as those of mechanical 
similitude, are given in detail by Professor Cecil H. Peabody in 
his ‘ Naval Architecture,” page 410. While experiments become 
more and more valuable as one refinement succeeds another, there 
is always much wdl worth knowing to be learned from the actual 
behavior of a vessel as she takes her way through a canal, a shal- 
low river, or the storm-beaten stretches of the sea. ' 

The experimental tank of the United States Navy at Washing- 
ton, is 470 feet long, 44 brpad, and 14J4 deep; it is arranged 
for ^ models 20 feet in length. See the' page opposite. The 
towing carriage is a bridge spanning the tank just above the 




water; it is a riveted steel girder. The towing mechanism, of 
massive proportions, is driven by four electric motors of abundant 
power. A double set of brakes brings the carriage gradually and 
quietly to rest from a high speed. A self-acting recorder meas- 
ures both speed and resistance. Ship builders may have models 
buil^by the Bureau in charge, that of Construction and Repair 
of the United States Navy Department, and have these models 
towed at any desired speeds, paying simple cost. 

It was in 1880 that the lessons of towing experiments with 
models began to be adopted in practice. As a result the forms 
of steamers have been greatly improved. Originally their lines 
were taken from those of sailing vessels but, as dimensions grew 
bolder and speeds were increased, it became clear that steamers 
demanded wholly different lines of their own. These lines, for- 
tunately, may be plainly disclosed in experiments with a model, 
because a steamer usually runs on an even keel, in which position 
a model is ^easily driven through a tank. A sailing vessel, on the 
contrary, is nearly always heeled over by the wind so that it sel- 
dom runs on an even keel ; tank experiments, therefore, avail but 
little for the improvement of its lines. Even were the model in- 
clined at various angles in one test after another, sails must be 
omitted, with their influence on steering, their lifting and bury- 
ing effects, often extreme. 

A thousand years ago the Vikings of Norway roved the seas 
in boats of a form which is admired to-day. To those hardy ad- 
venturers swiftness and seaworthiness meant 

nothing less than life and victory, their, eyes A Viking Ship a 
r 1 . . 1 . c. 1 Thousand Years 

perforce were keen to note what craft sped 
fastest through the water, what new curves 
kept waves from coming aboard. Perchance as they refined upon 
keel and rib they took golden hints from the shapes of gulls and 
fish. To be sure, long before science was dreamt of, they had to 
work by rule-of-thumb, but the thumb was joined to brains that 
did honor to human nature. On page 56 is illustrated the Viking 
Ship unearthed early in 1880 at Godstad, near Sandef jord in Nor- 
way, in a mound where, accordii g to tradition, a king and his 
treasure had been buried. It is ihe most complete and the best 
oreserved vessel of ancient d'' *xistence. It is fullv described 



and pictured in 'The Viking Ship,” by Mr. N. Nicolaysen, a 
work published in 1882 by Mr. Albert Cammcnncyer, .Christiania. 
Mr. Nicolaysen regards the vessel as having been built about A. D. 
900, for use in war by the great chieftain whose tomb it be- 
came. The ship was 65 feet, 10 inches long, on the keel ; with 
an^ extreme length over all of 78 feet, i inch ; amidships it was 
16 feet, 9 inches; its depth amidships from the top of the bul- 
warks to the keel was 3 feet, ii^ inches. The material through- 
out was pine. The helm, a plank shaped like a broad oar, was 
fastened to the side of the vessel. In accordance with the number 
of its oars and shields this ship must have had a crew of sixty- 
four, besides these came the steersman, the chieftain and prob- 
ably a few more of his companions, making a total, in all likeli- 
hood, of seventy to be carried by her. Says Mr. Nicolaysen: “In 
the opinion of experts this must be deemed a masterpiece of its 
kind, not to be surpassed by aught which the shipbuilding craft 
of the present age could produce. Doubtless, in the ratio of our 
present ideas, this is rather a boat than a ship ; nevertheless in its 
symmetrical proportions, and the eminent beauty of its lines, is 
exhibited a perfection never attained until after a long and dreary 
period of clumsy unshapcliness, when it was once more revived 
ill the clipper-built craft of the nineteenth century.”^ 

Thirty to sixty years ago much of the world's commerce was 
borne by clipper ships. In all likelihood as good lines as ever 
went into a vessel of this kind were displayed 
in the Young America, outlined on page 58, « Ships and 
built in 1853 Tor the California and East India 
trade. She pnee ran from New York to San Francisco in 103 
days, and from San Francisco to New York in 63 days, records 
which have never been excelled. Her deck length was 235 feet ; 
her depth of hold 25 feet, 9 inches; her moulded beam was 40 
feet, 2 inches; her displacement was 2,713 tons. The lines 
worthiest of remark in her design are the diagonals and buttocks, 
together with her easy entrance and run. Most clipper ships were 
fuller forward than aft ; this had two advantages : first, when 
forward burdens, anchors and the like, tended to an undue settling 

detailed description of the Viking Ship is given in the ^‘Transactions 
of the Institute of Naval Architects” (London), Vol. XII, p. 298. 



clown at the head, it was well to increase the buoyancy forward ; 
second, towini:^ experiments ])rove that a form slightly fuller for- 
ward than aft offers less resistance than the reverse. This shape 
was hit upon by the old-time designers, doubtless as a result of 
many a siirewd experiment. 

tn the early days of steamships, hollow or somewhat concave 
water lines forward were in favor. F.xperiments with models 
have demonstrated that for boats so full in section as to be nearly 
square, it is best to have forward lines which are straight or nearly 
so. Recently it has been shown that at high speeds, with a mid- 
ship section nearly semicircular, resistance is a little lessened 
by very slightly hollowing the water lines forward. 

If a steamer is to have the utmost speed, as the Kaiser Wil- 
helm IT, outlined on page 6o, her design will be very unlike that 
of a vessel recjuired to carry as much cargo as possible at a 
moderate or low speed, as in the case of iTTIi steamship sketched 
on page 6t. The dimensions of the Kaiser Wilhelm II are: 
—length over all, 7o6>^ feet; beam, 72 feet; depth, 29 feet, 
inches; dis])lacement, 29,000 tons; speed, 23^ knots; indicated 
horse power, 3<S,ooo. iVs we compare with her details of form 
the general features of our cargo carrier, ]>age 6t, we observe in 
this freighter the full form of its water linos, its almost straight 
and blunt entrance forward; we also notice that the lower part 
of the bow has been cut away to avoid a reversal of curves which 
would create an eddy witli its consequent increase of resistance. 
Further we may remark the squareness of the midship section, 
which means carrying capacity at its maximum, together with 
the long ])arallcl middle body, little resisted by the water, ending 
aft in buttocks and water-lines (juickly turned. Tins is a twin- 
screw ship : of length 358 feet, 2 inches ; l^eam, 46 feet ; draft, 
23 feet ; depth from shelter deck, 34 feet, 8 inches ; displacement, 
8,270 tons; speed, 9 to 10 ‘knots. 

A good designer has an easy task in drawing lines for a 
freighter in which the weight of hull, machinery and coals may 
be only 40 per cent, of the displacement, leaving 60 per cent, for 
earning space. Contrast this with an Atlantic flyer, where but 
5 per cent, may remain for cargo. Here the designer’s problems 
are difficult indeed, and the chief way out of them is to enlarge 





his ship as much as he dares, for the bigger his vessel, its form 
and speed unchanged, the less will be its resistance as compared 
with displacement. But to an increase of size there are hard and 
fast bounds; first, those imposed by the shallowness of channels 
and harbors ; while the depth of a ship is thus restricted, its length' 
ina^ be somewhat extended with safety and gain ; to increase of 
beam there are distinct and moderate limits, to overpass them 
means that the ship will follow the wave contour of a heavy sea 
so closely as to have a quick, jerky and dangerous motion. 

To design a ship in this case and every other is plainly a matter 
of compromise, a quest of the optimum by a balancing of demands 
for safety, strength, speed, capacity, handiness, 

Judgment m Ship 

a sea- wav, so that each in- 


vested dollar may in the long run earn the 
largest return possible. Itxccllent examples of judicious design are 
the best passenger steamers plying between Europe and New York. 
LTsually their section amidships is like that of a cargo vessel, but 
for a special reason. Within the freighter’s walls the greatest 
feasible cross-section must be created, so that the shape is box- 
like; in a high-speed passenger ship the form is also square, be- 
cause harbors arc shallow; were they less shallow the designer 


Cross-sections of ships 



would choose a midship section somewhat semicircular In con- 
tour. Were our harbors deepened, the easy sections of the first 
transatlantic steamers could be repeated in their gigantic suc- 
cessors of to-day, with increased speed for each horse power 

What a designer can do when his aim is swiftness at the cx- 
j)cnsc of all other considerations,, is shown in the lines of the 
torpedo-boat destroyer, page 62. Its length over all is 246 feet; 
length at water level, 240 feet, 10 inches; beam, 22 feet, 3 inches; 
mean draft, 6 feet, ij/2 inches; displacement, 489 tons; speed, 
30 knots. It is interesting to contrast, on page 63, the cross-sec- 
tion amidships of this vessel, with similar lines of three other 
typical vessels described in this chapter.^ 

^In writing those pages on the forms of ships I have been much in- 
debted to Mr. Harold A. Everett, Instructor in Naval Architecture, 
Massachusetts Institute of Technology, Boston. G. 1. 



Shot formed to move swiftly through the air . . . Railroad trains and 
automobiles of somewhat similar shape . . . Toothed wheels, conveyors, 
uropcllcrs and turbines all so curved as to move with utmost freedom. 

W HILE ships arc much the largest vStructures built for 
motion, and therefore meet resistances which the designer 
must lessen as best he may, other moving bodies, small as com- 
pared with sliips, encounter resistances so extreme that their re- 
duction enlists the utmost skill and the most 
careful study. Speeds vastly higher than those Projectiles and 
of ships are given to projectiles. A ball Icav- ^^^Pattern 
ing a gun muzzle with a velocity of 3,410 feet 
a second, as at Sandy Hook in January, 1906, suffers great at- 
mospheric resistance, overcome in part by the shot having a 
tapering or conoidal form. Indians long ago stuck feathers 
oblicpiely into arrows so as to keep flight true to its aim by giving 
shafts a spiral motion ; an attendant advantage being to lengthen 
flight. The same principle appears in rifling, that is, in cuttings 
spiral grooves in the barrels of firearms large and small, a mis- 
sile receiving a spinning motion through its base, a thin pro- 
truding disk of soft metal, forced into the grooves by the ex- 
plosive. At first the grooves in firearms were straight with in- 
tent to preclude fouling; spiral grooves were introduced by 
Koster of Birmingham about 1620. Delvigne, a Frenchman, de- 
vised a lengthened bullet narrower than the bore so as to enter 
freely, under the pressure of firing it completely filled the bore, 
rotating with great velocity as it sped forth. 


Now that railroad speeds are approaching those of projectiles, 
the outlines of trains are resembling those of shot and shell. In 
the experiments with very fast trains at Zossen, in Germany, 
October, 1903, each car had a paraboloidal front, much diminish- 

Racing automobile. Wedge front and spokeless wheels. 

ing the resistance of the air. Racing automobiles are usually en- 
cased in a pointed vShcll which parts the air like a wedge; their 
wheels, too, are supported not by spokes, but by di.sks having no 
projections. As electric traction becomes more and more rapid 
in its interurban services, the cars will undoubtedly be shaped to 
lessen atmospheric resistance. Especially is this desirable in a 
tunnel service, such as that of the New York Subway, where the 
resistances are extreme for the same reason that a boat in a canal 
is harder to draw than if in water both broad and deep. Just as 
in ship-design, it is in sharpening the front and rear of a car or 
a train that most economy is feasible ; the friction at the sides can- 
not be much lessened except, in the case of a train, by joining 
each car to the next by a vestibule such as that of the Pullman 

Electric traction finds gain in a track having in places a decided 



inclination. In the monorail line between Liverpool and Man- 
chester a downward dip in the line at each terminal quickens de- 
parture, and in arrival aids the brakes by checkin speed on the 
up-grade. In the swift motion of ordinary machinery the resist- 
ance of the air is a source of considerable loss. By encasing a 
hcafy flywheel in sheet iron so as to present a smooth surface to 
the atmosphere, M. Ingliss has saved 4.8 per cent, of the energy 
of a 630 horse power engine. 

In the simplest machines motion may be transmitted by wheels 
in contact, faced with adhesive leather, rul)l)cr, or cloth. Teeth, 
however, arc usually employed ; as wear takes 
place they permit a little play, a slight loose- (^n^eyors 
ness, which contact wheels altogether refuse, 
fl'oothed wheels have, the further advantage that they do not slip, 
their motion is positive. How teeth may best be contoured in- 
volves nice questions in geom- 
etry. They should always 
push and never grind each 
ether, and should move with 
the least possible friction. In 
some ingenious designs the 
teeth of any one particular 
wheel of a series will enmcvsh 
Avith the teeth of any other 
wheel, no matter how much 
larger or smaller. Bevel gears 
cut by Mr. Hugo Bilgram, of 
Bhiladelphia, turn with hardly 
any friction whatever, al- 
though in some wheels the 
teeth run askew, or arc sec- 
tions of cones which do not 
meet at their apices. The Bil- 
gram gear cutter, and the Fellows’ gear shaper which turns out 
plain gear, exert a to and fro planing action. Ordinary gears are 
cut on milling machines by rotary cutters, or may be manufactured 
on a Bliss press without cutting the original lines of fibre. The 
importance of accurate and easy-running gears increases steadily ; 

Bilgram skew gearing. 


they are, for example, applied to steam turbines whose velocity 
must be reduced in the actuation of ordinary machines. Auto- 

Grain elevator. 

mobiles and bicycles also demand reducing gear running with 
the utmost freedom. 



Ewart detachable link belting. 

The grain elevator, invented many years ago, is the parent of 
manifold conveyors of coal, lime, ore or aught else. Their re- 
ceivers have links shaped so as to extend for hundreds of feet 
as continuous belts. Link belting may be had in detachable sec- 
tions, fitting each other at secure hinges which allow free motion. 

Tile Augustin B. IVolvin, a typical ore-carrier on the great 
lakes, is 56 feet in depth; 
its hold is curved to allow a 
clam-shaped bucket to seize 
ten tons of ore at each dip. 

It is probable that at no 
distant day rapid transit in 
cities will employ contin- 
uous moving platforms, 
just as conveyors and tel- 
pherage systems are taking 
the place of the discontin- 
uous transport of grain, 
coal, cotton, ore, and heavy merchandise. 

The screw, an inclined plane wound about an axis, forms the 
propeller for steamships and many steamboats. There is a good 
deal of debate as to the principles which should 
decide its best lines. Here evidently is a field Propellers, 
which will handsomely repay thorough in- 
vestigation. The power expended in steamships, whether fast 
or slow, is prodigious ; any marked improvement in the contour 
of screws will mean either a saving of fuel or an increase of 
speed. Of equal importance with water-propulsion is the setting 
in motion of air. In blast furnaces enormous volumes of air are 
forced at high pressure into the fuel and ore : the fans are care- 
fully molded in screw form, any departure from tlie best curves 
entailing serious loss. Fans' for less important services are seldom 
shaped with care and usually waste much energy. 

Allied to screws are turbine wheels, much the most efficient of 
water motors. Tht shaping of their vanes as volutes minimizes 
the loss of energy in shock as, the water comes 
in^ and lessens to the utmost the velocity of Turbines, 
the stream as it leaves the wheel. Now that 


steam turbines are scoring a success both on land and sea the 
contouring of their vanes with extreme nicety is an important 

problem of the engineer. A 
perfected form means the 
highest economy. 

It is interesting to note 
how the screw propeller, the 
fan, and the turbine wheel 
have each led to a converse 
invention. Mr. Edwin Rey- 
nolds, of Milwaukee, has 
devised a pump in screw 
form of capital efficiency 
under low heads. The fan 
has long had its converse 
in the windmill, now more 
popular throughout Amer- 
ica than ever before, mainly 
because shaped with new 
excellence. In the best 
models, built of steel, the 
sails arc each a section of a 
volute carefully designed 
to discharge the wind 
just as in the parallel case of emission from a water 
such as the Worthington pump. This capital pump is 

Its impeller and diffusion vanes 

Curves of tiirl)iiics. 
Niagara Power Co. 


simply a turbine wheel reversed, 
take up w^ater from rest, lift it to a height which may be as much 
as 2,000 feet, and then deliver it at rest, with little loss from in- 
ternal eddies or slippage. 

Steel vanes of wind-mill. 
Fairbanks, Morse & Co., Chicago. 



The Pelton wheel, pre-eminent among water-motors of the 
impulse type, owes its economy chiefly to each bucket being 
divided in halves and curved with the utmost nicety. 



Why rough glass may be better than smooth . . . Light is directed in 
useful paths by prisms . . . The magic of total reflection is turned to 
account . . . Holophane globes . . . Prisms in binocular glasses . . . 
Lens grinding . . . Radiation of heat promoted or prevented at will. 

T hese are times when an inheritance, such as the window 
pane, venerable though it be, is freely criticized and shown 
lo be far from perfect. We find, indeed, that surfaces and forms 
long given to the glass through which light passes, or from which 
light is reflected, arc faulty and wasteful. This 
A Shrewd Observer nieaiis that sunshine can be turned to better ac- 
Improves Windows count than ever before, that artificial light can 
be employed with an economy wholly new. A 
few years ago when we provided a window with plate glass, 
smooth enough for a mirror, nothing better seemed possible. 
‘ Thanks to the late Edward Atkinson, of Boston, we know to-day 
that in many cases glass may be too smooth to give us the best 
service, that often we may get much more light from panes of 
rough, cheap make than from costly plate glass. He tells us: 
“In 1883, when I inspected a large number of English cotton 
mills, I found them glazed with rough glass erf rather poor qual- 
ity, the common glass of England being inferior to our own from 
the general lack of good sand. On asking why rough glass was 
used instead of smooth I was told that rough glass gave a uniform 
and better light. To my astonishment I found this true. The 
interior of a mill so lighted had the aspect of diffused illumination. 
This led me to reason on the subject, I looked into the construc- 
tion of the Fresnel lens, in which a combination of lenses and 
curved surfaces concentrates rays of light into a single far reach- 




ing beam. I reasoned that if one set of angles or curves could 
thus concentrate light, then by reversal of such angles or sur- 
faces, light could be diffused.’’ 

Mr. Atkinson proceeded to gather specimens of glass not only 
of common rough surface, but also in ribbed and prismatic 
foigns. These he handed for examination and comparison to 
Professor Charles L. Norton of the Massachusetts Institute of 
Technology, Poston. Ilis report says: “The Jiopelessness of 
trying to get something for nothing, that is, to get a sheet of 
window glass to throw into a room more light than fell upon it, 
appeared so plain to me that I made all my preparations to meas- 
ure not a gain but a loss of light in using Mr. Atkinson’s samples. 
The results of the tests may be briefly stated : In a room thirty 
feet or more deep we may increase the light to from three to fif- 
teen times its present effect by using Factory Ribbed’ glass in- 
stead of plane glass in the upper sash. By using prisms we may, 
under certain conditions, increase the effective light to fifty times 
its present strength. The gain in effective light on substituting 
ribbed glass or prisms for plane glass is much greater when the 
sky-angle is small, as in the case of windows* opening upon light 
shafts or narrow alleys. With the use of prisms a desk fifty feet 
from a window has been better lighted than when but twenty feet 
from the same window fitted with plane glass. . * . . ‘Ribbed’ 
and ‘Maze’ glass are of very great value in softening the light, 
especially when windows arc directly exposed to the sun, aside 
from their effectiveness in strengthening the light at distant 
points. With the ‘Maze’ glass the artist may have, in all weathers 
and in all directions, what is in effect a much-desired north light. 
l"he same glass provides the photographer with light as well 
diffused as when^cloth screens or shades arc employed and of 
much greater intensity.” 

Plate prism glass is now manufactured with its outer or street 
surface ground and polished like plate glass, with its prisms ac- 
curate and smooth. In dimensions which may reach fifty-four by 
sixty inches it affords surfaces easily kept clean, and transmitting 
much more light than glass held in frames of small divisions. 

Whence the gain in thus exchanging plane glass for glass 
rough, ribbed, or prismatic ? Rays streaming through an ordinary 



window strike nearby surfaces of wall, ceiling, and floor; from 
these they are reflected in large measure and return through the 

glass to outer space. 
Rough, ribbed, or prismatic 
glass throws the rays much 
further into the room, hence 
they strike so much larger 
an area of wall, ceiling, and 
floor that in being reflected 
again and again the light 
is well diffused, and but lit- 
tle is sent forth again into 
outside space. The form 
of the glass gives the enter- 
ing light its most useful di- 
rection, so that the new 
panes serve better than the 
old. This effect is most 
striking when prisms are carefully adapted to a particular case in 
both their angles and their placing. In traversing glass, light is 
absorbed and wasted, so that the shorter its path the better. In 

Lnxfcr prism. 

Fresnel lens. 

the compound lens devised in 1822 for lighthouses by Augustin 
Jean L'rcsnel, light is as effectively bent by the part of the glass 
shown in dark lines as if the whole lens were em{)loyed. 

This brings us to means for the best use of artificial light. 
Within the past tliirty years the standard of illumination, thanks 
to electricity, has steadily risen. More important than ever, there- 
fore, is it that light should be employed pleasantly and effectively. 
This in the main is a question of placing the sources of light 
judiciously, and of .so reflecting and refracting their rays that 
they will be of agreeable quality, and arrive where they are 



wanted with the least possible loss. Reflectors rightly shaped and 
kept clean economize much light. For lack of them in streets and 
squares we may sometimes observe half the rays from a lamp 
taking their way to the sky where they do no good. Tn shop win- 
dows ribbed reflectors throw full illumination on the wares dis- 
played, while the sources of light 
are out of view. The same method 
is employed in art galleries 
and in museums. A parabolic 
reflector sends forth as parallel 
rays the powerful beam of a light- 
house, a locomotive, or a search- 
light. An incandescent lamp of in- 
genious design is silvered on its 
upper half so that none of its light 
is wasted. Recause the arc lain]) is Lamp and reflector a unit, 
the cheapest of all ilium in ants it is 

adopted for out-of-door lighting where its unpleasant glare is tem- 
pered by distance. Tn factory lighting its brightness is excessive and 

Inverted arc-light. 


harmful unless moderated. A capital plan is to employ an ordinary 
continuous current and place the positive carbon, with its brilliant 
centre, below the negative carbon ; beneath these two carbons a 
good reflector throws the rays to the ceiling, whence they descend 
with agreeable diffusion and much less loss, than when globes of 
ground glass surround the arc. A common white ceiling when 
quite flat is an excellent reflector; indeed, a sheet of white blotting 
paper returns light nearly as well as a polished mirror, and for 
many purposes it serves better; the mirror sends back its beam in a 
sharply defined area which may be dazzling, the paper scatters 
light with thorough and agreeable effect. 

Usually a mirror is a sheet of highly polished metal, or a plate 
of glass with a quicksilver backing; preferable to either is clear 
glass, all by itself, so formed as totally to reflect an impinging 
beam of light. To understand the principle involved in its usq we 
will for a little while bid good-by to lamps of all kinds. 

A hall of delights is the New York Aquarium, in the historic 
Castle Garden at the Iiattery. Its tanks disi)lay a varied and 
superb collection of fish, whose beauty of form 
Delight and Gain heightened by swift and graceful 

as We Watch a motion, favSciiiates the eye as no museum of ‘ 
Fish in Water, dead things, however splendid, ever does. When 
a tank is still, or nearly still, and a gold-fish or 
a perch is quietly resting near the surface of the water, one may 
see its form reflected from that surface as perfectly as if by a 
mirror. The point of view must be close to the tank, with the eye 
somewhat lower than the fish. So perfect, at times, is this mir- 
roring that young folks are apt to suppose the reflection to be 
a second fisli, and *thcy are puzzled to remark how strangely ii 
resembles its mate just below. What cxjflains this reflection? A 
ray of light can always pass from a rare medium, such as air, into 
a dense medium, such as water, because it is bent toward their 
common perpendicular. But a ray cannot always ])ass from a 
dense into a rare medium, from, let us say; \vatcr into air, for if 
the ray were to be bent away from the common perpendicular 
more than 90° it would altogether fail to emerge from the water. 
No luminous ray can pass from water into air if it makes a 
greater angle with the perpendicular than 48° 35', Suppose. AB 



(page 78) to be the water level of a tank. A ray leaving F will be 
bent so as to reach C, a ray from G will reach D, a ray from H 
will reach E; but a ray from L will be bent so much as to pass 
along the surface of the water as OB, and a ray from I will be 
bent so as to return beneath the surface of the water to I. Rays 

Sacramehto perch totally reflected in aquarium. 
A, surface of water. 

such as I, undergoing total reflection, afford us our second image 
of a fish at rest near the surface of water : to observe this kind of 
image we need not journey to the New York Aquarium; with 
patience we may behold jt in a small home aquarium with flat 
sides of clear glass, waiting until the water is quiet and a fish 
comes close to the surface. 

Every dense transparent substance has this ability to yield 
images by total reflection, each substance having a critical angle 
of its own; we have just seen that for water this angle is 48° 35'. 
Glass is made in many varieties, each with a special critical angle, 
nevtsr much different from that of water. A right-angled prism 



of glass, which any optician can supply, serves as a capital mirror 
for rays striking its surface at ninety degrees. Such prisms are 




AB water level. 1% (1, IF, 1. are refracted to C, D, E, B. 
T is totally renocted to T. 

employed in opera glasses, in hand telescopes, in reflectors for 
light-houses, and in the Ilolojdiane globes we are about to 
examine. The efficiency of these ]:)risms may be as much as 92 
per cent., whereas that of the best silvered mirrors never exceeds 
90 per cent. The loss in a prism is due to a slight reflection by 
the surface on which the rays first fall, and by the absorption of 
light in the glass itself ; this second loss, of course, increases with 
the thickness of the i)rism. 

Now that we understand the principle of total reHcction, let uS 
sec how it is applied to increasing the effectiveness of a Wels- 
bach mantle or an electric lamp. And first let 

Total Reflection in’’^ Uglit Upon a small 

Artificial Lighting mainly in a single direction, as downward 
Holophane Globes, upon a desk or. reading-chair. Or, in a quite 
different manner, if we are to ilhiminatc a wide 
space such as that of a large parlor. These rccjuiremcnts- arc 
fulfilled by the Holophane globes, devised by M. Blondcl and M. 


Psaroudaki, which are made in many shapes, each adapted to a 
specific duty. The upper 
half of each globe is 
formed into prisms of such 
angles that, zone by zone, 
thf^ glass totally reflects im- 
pinging rays in just the di- 
rections desired. The con- 
touring is accurate to the 
thousandth part of an inch. 

With this thorough reflec- 
tion is combined diffusion 
as thorough, the interior of 
the globe being shaped as 
ribs. Thus, with the least 
possible waste, the upper Holopliane globe, vertical section, 

half of the source of light 

is utilized. What of the lower half? Its rays pass through prisms 
formed so as to refract imj)inging light into desired paths with 

Section of ITolophanc globe. 

Ray A is refracted as A', C as C'. B, totally reflected, then re- 
fracted, emerges as B'. D takes a similar course, 
emerging as D'. 


but little loss. As a whole, therefore, these globes furnish a beau- 
tiful means of illumination with all but perfect economy, special 
forms of them sending light in any direction desired. 

Diffusing curves. 
Holophanc globe. Rays arc split 
into b, c, reflected, then as e, 
f, g, refracted; and 
into b, c, cl, ' 

Class A, Class B, Class C, 

Hoi oph an e globe, throw- rays mainly directed casting rays chiefly in a 

ing rays mainly down- at an angle of 6o°. lateral direction, 




Section of Holophanc globe and Welsbach mantle, 
showing distribution of light. 

Each typical ray as refracted is marked by a letter of its own. 

In the Zeiss Works at Jena, in Germany, optical instruments 
of the highest excellence are manufactured; many of these take 
advantage of the principle of total rellection we 
have been considering. When the task was Total Reflection in 
assumed of producing a new and improved Binocular Glasses, 
telescope, it was observed that an ordinary 
telescope, built up of lenses, is inconvcnichlly lung and heavy in 
comparison with its magnifying power. The question arose 
whetlicr it was possible to construct short instruments of a magni- 
fying power of four to twelve (.liameters. Porro, an Italian, about 
the middle of the nineteenth 
century suggested totally rc- 
Hccting prisms so placed that 
while the total travel of a ray 
would be the same as in an 
ordinary telescope, the two 
ends of the luminous path would be near together, while the whole 

ITow a wire may be shortened while 
its original direction is resumed. 



would be more effective than if four mirrors were employed. 

His idea may be repre- 
sented by a wire one meter 
long so bent that its ends 
are much less than one 
meter apart. In an ihus- 
tration of a field-glass as 
manufactured at the Zeiss 
Works, on the Porro prin- 
ciple, it will be remarked 
that the entering ray 

Pour mirrors, T, 2, 3, 4, rcHoct a ray in 
a line parallel to its original path. 

passes through lenses which are farther apart than the lenses 
which form the eye-pieces. Thus a much wider field is viewed 

Prisms for Zeiss binocular glasses. 

than that of an ordinary glass, while as the two images received 
from the two eye-pieces differ more than those observed in direct 
vision, the perception of depth is increased in a notable degree. 
Id’.is constrncti(^n is adapted to sporting, marine, and opera-, as well as to field-glasses. 

Lenses r.evertheless continue to be much more important than 
prisms, and the proper shaping of their surfaces involves high 
reaches of both science and art. The properties 
of the glass, of course, count for most in pro- 
ducing combinations free from color for tele- 
scopes, microscopes, and cameras. Jena glass, described in an- 
other chapter of this book, with its extraordinary range of re- 
fractive and dispersive qualities has brought optical instruments 

Lenses Still 
Much Used. 



to virtual perfection. Meanwhile the arts of Icns-grincling leave 
little to be expected in the way of future improvement. It is 

Zeiss liinocnlar p; 
longiUulinal and cross-sections. 

astonishing that a lens forty-t^YO inches wide can be so truly 
curved as to focus the image of a star as an immeasurable dot. 

Let us look at some of the instruments designed by a master for 
shaping glass discs into lenses. Some of the liest telescopes 
in existence arc from the hands of Air. John 
A. Jlrashear, of Allegheny, Penn.sylvania. The^Production 
The grinding tools Ite em])loys lie has con- 
toured in such wise as to produce desired 
curves free from error. The first polishers arc of the ordinary 
form with scptarc or circular facets ccpially distrihuted over the 
surface of the tool, as in Figs. IT and 8. When the polish is 
brought to its best, the glass is allowed to coi:)! slowly to a normal 
temperature, and is then carefully studied as to its defects. These 
are removed and the surfaces finished with iron tools, of the same 
diameter as the surface to be worked, each tool being laid off into 


six sections, as in Figs. 3, 4, 6, 7. The tool being warmed, 

l)itch is spread over its leaf-like spaces, which are given the proper 
curve by being pressed down on the previously wetted concave 
surface; the pitch and tool arc next quickly cooled with water. 
In the sliaping of these spaces rests success. The zone, a,* a, in 
the first figure, needing the greatest amount of abrasion, meets 

a a b c c b 

Tools for producing optical surfaces. 
John A. Brashcar, Allegheny, Pa. 

the widest part of the leaflet, but in order that no zonal error may 
be introduced, as in b, c, c, b, of the second figure, it is gently 
tapered in each direction, the amount of taper being governed by 
the lateral stroke given to the polisher, as well as by the afnount 
of departure of the zone from the normal curve. 

But after all the astronomers aided by lenses thus carefully 
shaped arc few, while millions of people suffer from defects of 
sight which are overcome by suitably formed spectacles. 



In this field a recent minor improvement is worthy of mention. 
Benjamin Franklin many yeais ago made a pair of spectacles in 
which the upper half of each glass was ground 
for far seeing, the lower half for near seeing. Bi-focal 

To-day such bi-focal spectacles are not made in Spectacles, 

halves, with an unpleasant broken line across them. In each of 
the new eyeglasses toward the base a small lens of dense quality 



Bi-focal lens for spectacles. 

.s enclosed; through this lens a wearer looks at objects nearby; 
through the upper part of the eyeglass he looks at distant objects. 
The joining of the three parts is effected so skilfully as not to be 

From light we pass to its twin pliasc of energy, heat, for a 
glance at the forms of devices which enable us to use heat with 
economy. When w^e wish a furnace, crucible, 
or eexfleing vessel to maintain the highest pos- 
sible temperature, we give it as little surface 
as possible. On the contrary when a warming apparatus is de- 
vised, its surface is freely extended. The traditional fireplace, 
for all its cheerfulness’, yields but little heat. Benjamin Franklin 

of Heat. 



copied its form in the stove which bears his name; as it stands 
out from a wall it warms the air all around itself, instead of on 

one side only. This model is 
familiar in gas stoves, whose 
heat thoroughly radiated and 
convccted far exceeds thsX de- 
rived from fireplaces. In 
Canada forty years ago it was 
usual, especially in the coun- 
try, to set up gallows-pipes 
and dumb-stoves, or drums, 
bulky, hollow structures of 
sheet iron, which obliged the 
heated products of combustion 
to take a roundabout course as 
they passed to the chimney. 
To be sure as thus cooled the 
gases were less effective as 
draft makers, but we must re- 
member that one of the most 
wasteful uses of fire is in 
warming air or other gases 
■ them in motion. In modern factories, cen- 
tral lighting stations, and the like huge installations, mechanical 
draft sends a cpiick current through a short 
chimney, saving much fuel. Excellent in de- 
sign are the tile, stoves of Germany and Hol- 
land. Their gentle heat does not parch the 
air ; in moderately cold weather they render it 
unneocssarv to light furnaces which develop, 
at such times, unduly high temperatures. 

In factories the heating coils filled with 
steam or hot water were at first fastened to 
the door. Then came attaching them^to the 
ceiling whence their heat is gently radiated; 
on the floor the coils may gather dust and dirt 
with risk of lire; with the other plan there is 
a saving of floor space, and accidental leaks 
arc at once in evidence. 

Canadian box stove with gallows-pipe, 
for the sake of i)Uttin: 





Tubes for warming are specially effective when dented or 
buckled in directions at right angles to each other and to the axis 

Tubinj? for radiator. 

Dalham Works, Alanchestcr, England. 

of the tube. This form gives the heating water or steam a swirl- 
ing motion which causes it to part more rapidly with its heat than 
docs a cylindrical tube of the same surface,. Gold’s electric heater 

for street-cars, bath-rooms, and the like, is a spiral of resistant 
alloy, hung in a light metallic frame, the whole presenting a large 
surface to the air. Automobiles driven ])y heat engines require 

Stolp wired tube for automobiles. 

coils of the utmost possible surface whereat cooling can take 
place; in many cases this cooling is furthered by the action of a 
quick fan. In like manner the condensers of steam-engines, espe- 
cially aboard ship, are made up of slender tubes presenting to 
the steam a chilling area of vast extent. 


Inventors have long addressed themselves to the difficulty 
caused by ’the expansion and contraction of structures as tem- 

Corrugated boiler. 

peratures change. For years the cylindrical fire-boxes of marine 
boilers have been corrugated, so as to allow them a certain play 

Pipe so bent as to permit 

without breaking from their fasten- 
ings, or tearing their seams, when 
heated or cooled. This form is adopted 
with success for the Morison fire- 
boxes of the Vanderbilt locomotives. 
In (|uite different situations metal 
pi])ing, in a length of let ns say lOO 
feet, is provide’d against trouble from 
shrinkage or expansion by a U bend. 

contraction or expansion. When the diameter of the pijxi is 

twelve inches, this bend is usually 
about ten feet in extent; for a six inch pipe, a bend six feet long 

suffices. Another difficulty due to heat is the limitation of speed 
imposed by the heat which friction creates. A new type of cir- 

cular saw has a hollow arlx)r through which flows cold water, so 

that motion may be faster than ever before. The same arbor ap- 
pears in various other machines with like advantage. 



Edge tools old and new . . . Cutting a ring is easier than cutting away 
a whole circle . . . Lathes, planers, shapers, and milling machines far 
outspeed the hand . . . Abrasive wheels and presses supersede old 
appliances . . . Use creates beauty . . . Convenience in use . . ■. Ingenu- 
ity may be spurred by poverty in resources. 

W E have just reviewed, all too briefly, how light and heat are 
econo^nized by structures of judicious form. At this point 
we will bestow a rapid glance at the economy of work as promoted 
by sound design in tools and implements, in the machines which 
embody these for tasks far beyond the personal 
skill or power of the strongest and deftest Tools and 

When of old a savage tcxik up a stone to serve as a rude knife 
or chisel, we may be sure that he chose the sharpest flint he could 
find. If he could better its shape by knocking it into something 
like a wedge, what task was easier? Our museums display an im- 
mense variety of stone hammers, axes, knives, and arrowheads, 
showing how art long ago improved the forms of simple tools and 
weapons offered by nature. Modern tools and weapons, for all 
their immense diversity, were every one prefigured in the rude 
armory of primitive man. 

Descended from his flint knife is the abounding variety of steel 
cutting tools all the way from the razor, concave on both sides, 
to the axe, doubly convex. As the arts have become more special- 
ized, as artificial power has been introduced, the contrasts of 
the form of one tool with another have grown more and more 
striking. The bar which slices metal is stout of build, and rec- 
tangular in section, while a lancet is little wider or thicker than a 




Carving chisels and gouges. 

man to exert ^great leverage, 
formerly more in use than to-day. 
with gimlet points they break their own paths. 

blade of grass. The knives 
which divide leather, rubber, 
and rope, differ much from 
one another; the knife which 
separates the leaves of a 
bo<3k serves best when dull. 
Gouges for carving are 
nicely adapted to the pro- 
files they are to cut; while 
the exigencies of the power- 
lathe require its tools to 
be designed of particu- 
lar strength and rigidity. 
Among revolving hand-tools 
the brace is the im- 
portant, enabling the work- 
A minor tool, the gimlet, was 
Now that screws are made 

Lathe cutters. 


Ratchet bit brace. 



From the beginning’ tool-makens have shown skill in fitting a ' 
tool to the hand, as in the Eskimo skin- 
scraper; this simple adaptation may 
have arrived in copying the effect of 
wear. Other good hints have come 
from observing an implement after its 
work is done. At the ])laces wlierc 
mild clung to a plowshare the plow- 
maker was long ago told at what points 
to raise his metal ; ccuiverscly, wlien a 
cutter of any kind is unduly worn at 
any part of its side, there the metal l^skimo skin scraper, 
asks to be soiiicwhat narrowed down. 

A circle of say two feet in diameter, may be readily cut from a 
boiler plate by two cutters, one at each end of a horizontal bar, 

the bar being siqiported by a central upright 
axis receiving the motive power. lE'cause the 
cut is narrow, but little metal is wasted as chips. 



A cut of this ring-shape effects a desirable saving even when the 

circle to be swept is but an inch 

trouble tool drill cutting boiler plate, 
gineer in quest of bed-rock, to 

so in width instead of several 
feet, \\dien an auger takes 
its way through a i)lank it 
renunx's as chips all the 
wood within the circle of 
its range : a drill, of com- 
mon form, as it pierces 
stone or metal acts in a 
similar manner. Motive 
power is greatly econo- 
mized when a drill is tubu- 
lar, with the further ad- 
vantage that wdthin the 
ring cut a solid cylinder re- 
mains to be broken off at 
intervals and lifted out, its 
core informing to the en- 
^ prospector of mines or oil- 



fields, or to the geologist who reads at a glance the composition 
of a mineral, the forces which have impressed it age after age. 
Such drills, set with bortz diamonds, have accomplished remark- 

A common drill removes a A ring drill removes much less 
whole circle of stone. stone with the same effect. 

able feats. In boring out 260 columns surrounding the dome of 
the capitol at Springfield, Illinois, . cores 22^ inches in diameter 
were removed from holes 24 inches wide; without sacrifice of 
strength there was a saving in weight of three-fifths. At the 



Ellcnwood coal mine, Kingston, Pennsylvania, a core 17 feet, 5 
inches in breadth was taken from a bore only five inches wider. 
When the engineers in 1896 were planning the foundations for 
the Williamsburg P)ridgc, New York, the deepest of their 22 
Ijorings was 112 feet below high water. Steel drills had indicated 
bed-rock 12 to 20 feet higher than was the actual ease; the 
diamond drill showed the supposed bed-rock to be merely a de- 
])osit of boulders. No other known means could have accom- 
plished these results. In the same way steel guns of large calibre 
have been drilled so as to leave a core of much value, while in this 
as in all other such tasks, the boring demanded less energy and 
proved less straining than if all the metal within the sweep of the 
drill had been reduced to fragments. All these tools were pre- 
figured in a simple ring drill used two thousand years ago on 
the banks of the Nile ; hollow reeds were employed, with sand as 
a cutter. 

Twist drills are superseding flat drills as stronger and better in 
every way. A twist drill is made with a slight taper toward the 
shank end. Its cross-section is 

Twist Drills. not quite round, the diameter 
being reduced from a short di.s- 
taiicc behind the cutting edge, so as to diminish 
friction and- give the .sides of the drill as much 
clearance as possible. The advanced edges of 
the flutes arc all full circle, so as to maintain the 
diameter of the drill and keep the tool steady. 

The advantage of the twist drill is that its cuttings 
find free egress, while it always runs true, with- 
out reforging or retempering. The cutting edges 
are usually ground to an angle of sixty degrees 
to the center line of the drill : for brass work the Twist drill. 

angle should be fifty degrees. 

The manner in which a lathe tool cuts metal is shown in an 
outline which represents a tool feeding a cut along a piece of* 

wrought iron. The removed metal, ^in its di- 
ameter and openness, tells the expert operator 
both the quality of his cutter and how it is 

Lathe and 
Planer Tools. 

being affected by wear. The principal consideration, says Mr. 

94 form— LATHES 

Joshua Rose, in determining the proper shape of a cutting tool, 
for use in a lathe or a planer, is where it shall have the rake, or 

ITow a tool cuts metal. 
Beginning a second cut. 

inclination, to make it keen enough to cut well, and yet be as 
strong as possible; this is governed, in a large degree, by the 
nature of the work. 

Ill g’iving' form to wood and metal cheaply and lapidly, ma- 
chine-tools have within recent years risen to great importance. CM 
these the lathe is one of the chief. It seems 
Machine Tools: descended from tlie bow drill, the tool 

« Lathes. whirled by a cord wrapped round it, 

or it may be, that under another sky, the lathe was deiived from 
the potter^s wheel whose axle was changed from a vertical to a 

horizontal plane. I' or cen- 
turies all lathes had their cut- 
ting’ tools simply laid on a bar, 
or rest, just as in the hand 
cutting lathe of to-day. While 
this afforded opportunity to 
.skill it did not lend itself to 
large or uniform production. 
Henry Maudslay, about a cen- 
tury ago, immensely broad- 
ened the machine in scope by 
devising the slide rest whicli 
firmly grasps the cutting tool, 
and automatically moves it to- 

Dacotah fire-drill. 

Lathe: a, work; b, tail-stock; c, hand-tool rest; d, dead-centre; 
e, live-centre; f, face-plate; g, live-spindle; h, dead-spindle; k, head- 
stock; m, cone-pulley; ii, driving-pulley; o, belt; p, treadle; r, treadle- 
hook; s, shears; t, treadle-crank. 

turning a pencil cavSe, the granite columns for a cathedral, or the 
propeller-shaft of an ocean steamer. 

The lathe has been develo])e(l in many ways until it has become 
one of the most complex of all machines, adapted to tasks which 
even twenty years ago seemed impossible. ( hily two of its varieties 
can here be noticed, the Blanchard lathe for cutting irregular 
forms, and the turret lathe. An illustration, taken from an old 
engraving shows the Blanchard lathe as originally built for shoe- 


lasts. A pattern-last and the block to be carved are fixed on the 
same axis and are revolved by a pulley. On a sliding carriage 
are fastened pivots from which arc freely suspended the axles of a 


Cotnpotincl slide rest. 

C, shears; K. tool carriage; IT, cross slide; K, cross 
slide handle; L, cross feed handle; P, tool post; T, tool; 
D, driver; W, work. 

Blanchard Lathe. 

A, frame; B, carriage; C, gun stock; D, former; E, cutter- 
head; F, guide wheel; G, swinging frame; H, feed motion; 
K, shaft for revolving stock and former. 


cutting wheel, and a friction wheel, equal in diameter. The cutting 
wheel turns on a horizontal axle, and bears on its periphery a series 
of cutters. The friction wheel is in contact with the pattern-last 
and presses against it while in motion. During revolution, the 
pattern, irregidar in its surface, causes the^axis to approach or 

Turret lathe : an early Brown & Sharpe model. 

C, carriage; T, turret; L, hand lever; F, face plate; D, jaw 
chuck; F, tool. 

recede from this friction wlieel; the cutting wheel in its corre- 
sponding motion removes wood from the block until a duplicate of 
the pattern appears. This lathe much im- 
proved and modified now turns not only 
gun-stocks, axe-handles and the like, but re- 
peats elaborate carvings with precision. 

Ornaments for Pullman cars arc produced 
by this machine. 

The turret lathe, equally ingenious, has a 
turret or capstan, which carries let us say 
eight different tools, one on each of its 
eight faces. In its turn each tool operates 
on the work in its forward traverse ; it then 
retires while the turret automatically moves 
through one-eighth of a circle, when the 
next tool emerges for its task, and so on.^ 

Lathes have given rise to planers, now 
built of great strength and in highly com- 

' I he turret principle is embodied in drills and a variety of other 
niachincs. It was adopted in remarkable fashion by John Ericsson in his 


plicated designs. In a lathe the object turns upon centers against 
a tool ; a planer carries its tool in a revolving cylinder, the work 
being fed in a straight line. A shaper, with much the same essen- 
tial construction, moves along its work, the wood or metal operated 
on remaining stationary. With a planer or a shaper the size airl 
uniformity of the work depend upon the skill of the operator. The 
planer has led to the invention of a machine which dispenses with 
this skill. Uramah, in i8ii, employed a revolving cutter to plane 
iron, adapting to metal the familiar mechanism for planing wood. 
This was the beginning of the milling machine, now so remark- 
ably developed and improved. A skilled mechanic sets the ma- 
cliinc and the chucks which hold the work ; an unskilled hand can 
continue the operations, his ])roducts being uniformly of the di- 
mensions and forms desired. Intricate shapes arc easily executed, 
quite impracticable on any other machine. At first the revolving 
mechanism and its cutters were a single piece of metal; to-day 
cutters of costly quality are inserted in cheap metal ; these in- 
serted cutters when worn out arc easily replaced. 

Monitor, launched in 1862 for service in the Civil War. Because this 
vessel had to navigate shallow streams, its draft was limited to eleven 

Ericsson’s Monitor. 

feet. As it was thus impossible to carry the hurden of armor necessary 
to protect a high-sided vessel, he was obliged to design a sunken hull 
Guns and gunner were protected within a covered cylindrical turret which 
as it turned on its vertical axis, delivered an all-round fire while the 
Monitor stood still, l^ricsson’s original turret, and its later modification? 
in the leading navies of the world, are described in the Life of John 
Ericsson, by William Conant Church, New York, Scribner, 1890. 

Iron planer; a, b, c, d, lixed cutting- tools; M, moving bed 
Niles-Bemciit-Pond Co., New York. 


Milling machine, R. K, Lc Blond Machine Tool Co., Cincinnati. 

A, tabic ; B, overhanging arm ; C, cutters ; D, spindle ; E, feed box. 

In many cases the milling machine ousts the planer as much 
more economical. At the shops of the Taylor Signal Company, 
BuflFalo, a miller of the Cincinnati Milling 
Machine Company docs nine-fold as much 
work as a planer. It takes a first cut 
inch deep across a full width of 12 inches, 
makes 60 revolutions per minute, feeds .075 
inch per turn, giving a table travel of 
inches per minute, with an accuracy limit of 
.001 inch. 

Now for a glimpse of what a great in- 
ventor had to suffer because he lived prior 
to the era of machine tools, before the days, 
indeed, of that indispensable organ of the 

Milling cutters with 
inserted teeth. 
Cincinnati Milling 
Machine Co. 



lathe, its slide rest. The first steam engines of James Watt, built 
at the Soho Works, near Birmingham, are thus described:— 
cast iron cylinder, over i8 inches 
in diameter, an inch thick and 
weighing half a ton, not perfect, but 
without any gross error ’was pro- 
cured, and the piston, to diminish 
friction and the consecpient wear of 
metal, was girt with a brass hoop 
two inches broad. When first tried 

the engine goes marvelously bad; it Milling cutters executing 
made eight strokes per minute ; but complex curves, 

upon Joseph’s endeavoring to mend Brown & Sharpe, 

it, it stood still ; and that, too, Providuict, R. I.^ 

though the piston was helped with 

all the appliances of hat, papier inachc, grease, blacklead powder, 
a bottle of oil to drain through the hat and lubricate the sides, and 
an iron weight above all to prevent the piston leaving the paper 
behind in its stroke— after some imperfections of the valves were 
remedied, the engine makes 500 strokes with about two hundred 
weight of coals.’' In another month or two, with better conden- 
sation, it ^hnakes 2,000 strokes with one hundred weight of coals.” 

Emery, carborundum and alundum wheels arc developed from 

the grindstone of the distant past. That stone gives a straight- 

line finish or edge to the surfaces submitted to 

it ; and as the work is shifted in front of the Emery and 
, , . , 1 Carborundum 

Stone these surfaces tnay take a curved or other Wheels 

contour. But a grindstone, let it ])e as hard as 

can be found, is not hard enough to take and keep any other than 

a cylindrical form. Its successors of to-day, the carl)orundum 

wheel especially, can be of varied shapes, and transfer these to 

metal with celerity and economy. 

Carborundum, a compound of silicon and carbon, is produced 
at Niagara Falls, New York, by a process devised by Afr. E. G. 
Acheson. In an electrical furnace arc placed granulated coke, 
sand, a little salt, and some sawdust to keep the mixture porous 
and allow generated gases to escape freely. The crystals of 

Emery and 

carborundum thus produced require seven horse-power hours 
fpr each pound: in hardness they are excelled by the diamond 



Emery wheels. 

only. United under severe hydraulic pressure by a vitrified 
bond they arc ei^ht times as efficient as emery in abrasion. Car- 

Carborundum Co., Niagara Falls, N. Y. 
Carborundum wheel edges. 

borundum wheels are re- 
placing lathes as a means 
of finishing axles, piston- 
rods and rolls; their accur- 
acy is unsurpassed, while 
they demand but one third 
the time needed by a steel 

At the very dawn of art 
moist clay was molded into 
useful plates and bowls. 
This foreran not only all 
that the potter has since 
accomplished, but all that 
has been achieved in the 
foundry and the mint. In 



making bricks, tiles, and terra cotta, the first task is to make the 
clay plastic, then advantage is taken of its plasticity. In like 
manner we heat a metal to fluidity, and then pour it into a mold 
to make a fence rail, a stove plate, or a car 
wheel. An electric bath refines upon this Form in 
process. Copper, let us say, dissolves in a Plastic Arts, 
tank, and concurrently its particles are deposited on a mold from 
which the metal can be readily stripped, avoiding the distortion 
inevitable when heat has come into play. 

Within the past ten years concrete has grown into much import- 
ance as a building material, especially as nun forced with steel, it 
is a great deal easier and cheaper to pour a wall into molds than 
to lay courses of brick, or cut and dispose stone-work. Elsewhere 
in this book a few pages arc given to reinforced concrete, and its 

Pressing, like molding, has of late years much extended its 
range of forms. In germ it goes back to the distant day when 
seals were impressed upon clay tablets, and 

coins or medals were struck from hard ma- Pressing and 

, Stamping, 

trices. In glass manufacture the i)rcss has been 

used for centuries. Cheap pressed tumblers and bowls have long 
been accompanied by cheap metal pots and pans, plates and basins, 
stamped by machinery. To-day much enlarged and improved, 
such machinery, as a Bliss press, makes a kitchen sink from a 
sheet of steel, forms gears an<l piniv)ns from round bars of metal, 
and executes the intricate curves of a mandolin in a plate of 
aluminum. For a good while the spinning lathe gave us from thin 
metallic sheets a variety of cups, saucers, dishes, parts of kettles, 
lamps, and the like. To-day each of these articles is produced by 
a single blow of a die, proving that metals arc plastic in a degree 
unsuspected in former days. Thus it comes about that the scams 
necessary to the tinman and the cc ppersmith, with all their liability 
to leaks and uncleanliness, have been largely dismissed and may 
soon be wholly banished. Pressing is illustrated on pages 184 to 
186 of this book. 

To-day we are rich in old and new facilities for the bestowal 
of form. To confer shape by division we have an immense variety 


Means of Con- 
ferring Form. 

of knives, scissors, saws, axes, hatchets and shears. These, to- 
gether with haniiners, chisels and gouges enable us to disengage 
from a mass not merely a simple rail, panel, or 
Old and New table-top, but a carving or a statue. Surfaces 
arc smoothed with a rasp, a file, a plane; sand 
is rubbed on abrasively, or falls front a height, 
or is forcibly blown with a blast of steam or air. Emery either 
spread on paper, or glued upon a wheel, grinds with an accuracy 
and speed new to art ; and all that emery can do is outdone by car- 
b'orundum and alundum, which slice away metal as if chalk, be its 
hardness what it may. Terforation is accomplished with rotary 

drills, or by a sandblast, or 
on occasion by corrosive 
acids— a final resource in 
treating refractory stone. 
Rolls of tremendous power 
reduce iron and steel in 
thickness, .and, when suitably 
shaped, confer form on rail- 
road rails, girders and the 
like. Every tool and imple- 
ment, old or new, is now em- 
bodied in machines of gigan- 
tic force, or multiple effect, so that the skill of an earlier genera- 
tion is either not in demand at all or passes to tasks of a delicacy 
never attemi)te(l before. Tt is by virtue of presses, enormous in 
power, that lo-day shapes arc bestowed on metals in successful 
rivalry witli the ancient art of the founder himself. Indeed the 
art of conferring form by poimng a licinid into molds is at this 
hour largely exercised in work where heat plays no part what- 
ever,— as in tile tasks of the builder in concrete, the labors of the 
electrician as he employs a bath to separate a metal from its or(', 
or to plate a surface with silver or gold. 

In strong contrast with the varied resources 
of modern toil are the simple tools and imple- 
ments of prehistoric skill which, modified mucli 
or little, arc at this hour still indispensable to the mechanic, the 
builder, the engineer. These simple aids early became ad- 

Diagram of rolls to reduce steel in 

Use Creates 


niirable in form so as to be all the more useful. Says Mr. George 
Bourne : — 

“The beauty of tools is not accidental but inherent and essential. 
The contours of a ship’s sail bellying in the wind arc not more in- 
evitable, nor more graceful, than the curves of an adze-head or of 
a plowshare. Cast in iron or steel, the gracefulness of a plow- 
share is less destructible than the metal, yet pliant, within the 
limits of its type, ft changes for different soils ; it is widened out 
or narrowed ; it is deep-grooved or shallow ; not because of caprice 
at the foundry or to satisfy an artistic fad, but to meet the tech- 
nical demands of the expert plowman. The most familiar ex- 
ample of beauty indicating subtle technique is supplied by the ad- 
mired shape of boats, which is so variable, says an old coast- 
i>uardsman, that the boat best adapted for one stretch of shore 
may be dangerous if not entirely useless at another stretch ten 
miles away. And as technique determines the design of a boat, 
or of a wagon, or of a plowshare, so it controls absolutely the 
fashioning of tools, and is responsible for any beauty or form they 
possess. Of all tools, none, of course, is more exquisite than a 
fiddle-bow. But the fiddle-bow never could have been ])erfected, 
because there would have been no call for its tapering delicacy, its 
calculated balance of lightness and strength, had not the violinist’s 
technique reached such, marvelous fineness of ])owcr. For it 
is the accomplished artist who is fastidious as to his tools; the 
bungling beginner can bungle with anything. The fiddle- 
bow, however, affords only one example of a rule which is 
equally well exemplified by many humbler tools. Ouarry- 
nian’s pick, coachman’s whij), cricket-bat, fishing-rod, trowel, 
all have their intimate relation to the skill of those who use them ; 
and like animals and plants adapting themselves each to its 
own place in the universal order, they attain to beauty by force 
of being fit. That law of adaptation which shajies the wings 
of a swallow and prescribes the poise and elegance of the 
branches of trees, is the same that demands symmetry in the 
corn-rick and convexiiy in the barrel; and that, exerting itself 
with matchless precision through the trained senses of hay- 
makers and woodmen, gives the final curve to the handles of 
their scythes and the shafts of their axes. Hence the. beauty of 



in the Use of 

a tool is an unfailing sign that in the proper handling of it tech- 
nique is present.'’^ y 

In the course of a judicious review of the mechanical engineer- 
ing of machine tools, Mr. Charles Griffin has this to say regarding 

“A tool is an investment, the interest which it earns depending 
on the amount of work it turns out in a given time. This depends’ 
largely on its convenience of manipulation, in- 
convenience volving a study of levers, handles, wheels, 
knobs and other auxiliary devices, their shape 
and place with reference to the best adaptation 
to the average human frame, the ease and extent of their motions, 
and the rapidity with which these motions may be accomplished. 
The position of the operator, his natural tendencies, the motions 
he will go through, all have to be imagined in view of the attain- 
ment of his maximum convenience. 1'his study, in the absence 
of any counterpart of the proposed machine, often forces a resort 
to rough models, or in lieu of this, a full-size .])lackboard sketch, 
extending to the floor, upon which the location of parts may be 
tried for convenience.’’ 

In the National Museum, at Washington, the visitor as he in- 
spects examples of American aboriginal art is astonished at its 

Resources Rich beauty. Toat and paddle, 

or Meagre as Spear and hook, basket and vase, arc as ad- 

Affecting mirahic in form as useful in traveling, fishing. 

Invention. gj- carrying corn or water. How far an ab- 
original designer may go largely turns upon what variety of re- 
sources Nature offers him. No few score families on a lonely islet 
of the Pacific can possibly rival the cloths and carvings displayed 
by tribes ranging a Pennsylvania, or a California, abounding with 
diverse minerals, plants and animals. When skill and invention 
occupy so rich a land they flower into the highest creations of ab- 
original art. And yet it may be that the very fewness of a de- 
signer’s resources but spurs him to all the more ingenuity. It 
depends upon who the man is. As we look upon a collection of 
Eskimo harpoons and knives, coats and kayaks, wc marvel that 

^ Cornhill Magazine, London, September, 1903. 

* Engineering Magazine, New York, May, 1901, 


all these should be produced with so much excellence and variety 
from a scanty store of bones and teeth, sinews and hides, with but 
little iron or none at all.^ 

^Two unrivalled hooks on aboriginal invention have been written by. 
Mr. Otis T. Mason, Curator of the Department of Ethnology at the 
National Museum, Washington :—'‘Woman’s Share in Primitive Culture,’* 
New York, D. Appleton & Co., 1894; “The Origin of Inventions,** 
London,, Walter Scott Publishing Co., and New York, C. Scribner’s Sons, 
190.'^. Loth volumes arc fully illustrated. 

The annual reports of the Bureau of Ethnology, Smithsonian Institution, 
Washington, describe and illustrate American aboriginal art so fully and 
admirably as to be indispensable to the student 



Nature’s gifts first used as given, then modified and copied . . . Rigid 
materials mean stiff patterns . . New materials have not yet had their 
full effect on modern design. 

S O multiplied are the resource.^ of modern industry that de- 
sired forms are created at will, almost without regard to the 
material employed. It is not so in primitive art, to which for a 
brief space we will now turn so that our survey of form, though 
all too cursory, may he refreshed by a contrast 
of old with new. Let us begin with a glance at 
some of the aids with which man first provided 
himself, taking the gifts of nature just as they were offered. In 
large areas of the Southern States, and of C’entral America, the 

Gourd-shaped vessel from Arkansas: 
^Tottery of the Ancient Pueblos.” 
W. H. Holmes. 

gourd for ages has been a 
common plant, and has long 
served many Indian trilies as 
a Avater pitcher. On sea- 
shores, where the gourd did 
not grow, conch-shells wxu'e 
used instead, their users 
breaking away the outer 
spines and the inner whorls, 
leaving Avithin a sjiace ck'an 
and clear. Loth gourds and 
shells gave their forms tn 
the clay vessels which suc- 
ceeded them. 

In Zuni land, says Mr. F'. 
H. Cushing, the first vessels 
for water were sections of 
cane or tubes of Avood. Wc 
may infer that the wwdea 




tubes were copied from the cane stems. What at first was pas- 
sively accepted as nature gave it, was afterward changed a little, 

Gourd and derived forms. “I’otlery of the Ancient Pueblos.’ 
W- II. Holmes. 

and then was step by step changed miieli, so that at length there 
grew up processes of manufacture. There was, for example, in 
California a wealth of osiers, reeds, and roots well suited for mak- 
ing baskets ; these at last were perfected as water-tight receptacles 
neither brittle like a shell nor liable to a gourd’s swift decay, be- 
ginning probal)ly in mere wattling, in the rude plaiting of mats 
and roofs, the weaver came gradually upon finer and stronger 
materials than at first, with equal pace rising to new delicacy of 
finish and beauty of design. At the National Museum in Wash- 

Pomo basket. National Museum, Washington. 

ington, the Hudson collection of Indian baskets from California 
includes the finest specimen in the world, a Porno basket. Its 
sixty stitches to the running inch were possible only through 

110 form— BASKETRY 

using the carex root, easily divided into threads at once blender 
and strong.* 

It is interesting to observe the limitation imposed upon a 
primitive designer by the cpialities of the leaf, shell, or cane in his 
hands, the way in which these qualities point him to the forms in 
which he may excel. Of this we have capital examples in the 
basket-work of the North American aborigines as described by 
Mr. Otis T. Mason, in the report of the Smithsonian Institution, 
1883-84. lie says: “Along the coast of British Columbia the 

Bilhoola liaskc t of vvo'hmi cedar bast. work of North 

American Aliorigincs.” Otis T. Mason. 

gTcat cedar {'Fkiija i^^ii^antca) g;rows in the f^rcatest abundance, 
and its bast fiirnislics a textile material of the greatest value. 
Here in the use of this pliable material the savages seem for the 
first time to have thiiught of checker-weaving. Mats, wallets, 
and rectangular ba.skcts are produced by the plainest crossing of 
alternate strands varying in width from a* millimeter to an inch. 
(Ornamentation is effected both by introducing different-colored 
strands and by varying the width of the warp or the woof threads. 
. . . It is not astonishing that a material so easily worked 

should have found its way so extensively in the industries of this 

’ Many of the handsomest baskets at the National Museum, as well as 
baskets from other great collections, are illustrated, partly in color, in 
"Indian Basketry,” by Otis T. Mason, curator of the ethnological depart- 
n.ent of the National ^luscuin. The publishers are Doubleday, Page & 
Co., New York. 


stock of Indians. Neither should we wonder that the checker 
pattern in weaving should first appear on the west coast among 
the only peoples possessing a material 
adapted to this form of ornamentation.” 

Referring to the water-bottles of the Pai 
Utes, Mr. Mason says: “This style can be 
made coarse or fine, according to the 
material and size of the coil and outer 
threads. If two twigs of uniform thickness 
are carried around, the stitch will be hatchy 
and open; but if one of the twigs is larger 
than the other, or if yucca or other fibre 
replace one of them and narrower sewing 
material be used, the texture will be much finer.” Basket? and 
rain-hats, as woven by TIaidas and many other tribes, are water- 
proof when wet, owing to the closeness of their texture. 

When reeds or somewhat rigid fibres are woven, they compel 
a straightness of edge in patterns and designs. . A wave has to be 
suggested by ste])j.)cd or broken lines, and so 
we have a rectilinear meander or fret, in con- 
trast with its free-hand form as developed in 
a woven fabric. Under the constraint of her material a squaw 
as she weaves a design into a basket, must give squareness to a 

A square inch of the 
Bilhoola basket. 

•Idiom of 

A free-hand scroll. The same developed in a 

woven fabric. 

*Torm and Ornament in Ceramic Art.” W. II. Holmes. 

contour which would be somewhat rounded were it executed in 
delicate threads. This is clear in the human figures of the Porno 
basket shown on page I09;'and in those of a Yokut basket bowl, 
also in the National Museum in Washington, illustrated on the 
next page. 

112 form— BASKETRY 

Stone and Ijrick-work, in their rectilinear shapes, impose a rigid- 
ity in architectural design from which modern bricks, in their rich 
variety of flat and curved surfaces, have wrought emancipation. 

Yokiit basket l)owl. 

“.Basket Work of Nortli American Al>()ri!:’'incs.” Otis T. Mason. 

In the now residential streets of St. Louis, for example, the archi- 
teetnre owes mneli of its freedom and beauty to the new shapes 
in which brick is now mamifactiired. Even wider liberty than 
now falls to the lot of the brick-maker has always been enjoyed 
by the potter. In his hands clay lends itself to any desired imita- 
tion, to any fresh design however fanciful; what is more it in- 
vites those modifications of old forms in which art takes its chief 
forward strides. All but infinite are the variations which Jap- 



anese potters have played on the shapes of vases, jars, kettles, 
and basins, each clearly true to its type, while at the same time 
original in a pleasing way. IIow the Japanese artist in clay has 
rejoiced in his freedom is exemplified in the collection of Jap- 
anese pottery at the Ahtseum of Fine Arts, in l]oston. Says Mr. 
I^dward S. Morse, who brought this collection together: “Uten- 
sils for every day life, terra cotta funeral urns, large terra cotta 
howls, weights for fishing nets, brush handles, and even clothes- 
hooks are in Japan made of pottery. Where we use silver and 
other metals, or glass, in making articles for daily use, the Jap- 
anese use i)ottery.’' He adds: “Fhe prehistoric ]K)ttery of Japan 
was modeled by hand, and to-day in various parts of the empire, 
this ancient art is continued in its ])rehistoric form. There are 
many potters in Jai)an who are still at work iising only the hand 
in making bowls, delicate tea-pots, and dishes of various kinds. 
Uic pottery vessels offered at Shinto shrines are usually made 
without the use of the wheel and are unglazed. The potter’s 
wheel was brought to Japan from Korea. The first was probably 
the kick-wheel used in Satsuma and other southern ])rovinccs.” 

'fhe Japanese employ not only clay but wood in methods that 
richly repay study. .Says Mr. Ralph Adams Cram: — “In one 
respect Japanese architecture is unique : it is a style developed 
from the exigencies of wooden construction, and here it stands 
alone as the most perfect mode in wood the world has known. 
i\s such it must be judged, and not from the narrow canons of 
the West that presu])])ose masonry as the only Imilding material. 
. . . Perhaps the greatest lesson one learns in Ja]^an is that of 
the beauty of natural wood, and tlie right method of treating it. 
The universal custom of the West has been to look on wood as a 
convenient medium for the obtaining of ornamental form through 
carving and joinery, the quality of the^ material itself being sel- 
dom considered. In Jaj)an the reverse is the case. In domestic 
work a Japanese builder shrinks from anything that would draw 
attention fnan the beauty of his varied woods. lie treats them 
as we do precious marbles, and one is forced to confess that under 
his hand wood is found to be quite as wonderful a material as 
our expensive and hardly worked marbles. In Japan one comes 


to the final conclusion that stains, paints, and varnish, so far as 
interior work is concerned, arc nothing short of artistic crimes/'^ 

In strong contrast with the art of Japan is that. of Egypt; on 
the hanks of the Nile the first buildings were of limestone, suc- 
ceeded l)y huge structures reared from Syenc granite, with no 
little loss in delicacy of ornamentation. It was only when marble, 
all but plastic under the chisel, was adopted by the Greek sculptor, 
that tlie frieze of the Parthenon could spring into life. 

Here William Morris should be heard. In '‘Hopes and Fears 
for Art,” he says : "All material offers certain difficulties to be 
overcome and certain facilities to be made the most of. Up to a 
certain point yon must be master of your material, but you must 
never be so much the master as to turn it surly, so to say. You 
must not make it your slave, or presently you will be its slave 
also. You must master it so far as to make it express a meaning, 
and to serve y(nir aim at beauty. You may go beyond that neces- 
sary point for your own pleasure and amusement, and still be in 
the right way; but if you go on after that merely to make people 
stare at your dexterity in dealing with a difficult thing, you have 
forgotten art along with the rights of your material, and you will 
make not a work of art, but a mere toy; you arc no longer an 
artist, but a juggler. The history of art gives us abundant ex- 
amples and warning in this matter. First clear, steady principle, 
then playing with the danger, and lastly falling into the snare, 
mark with the utmost distinctness the times of the health, the 
decli]ie, and the last sickness of art.” Fie illustrates this in detail 
from the history of mosaic in architecture. 

While the modern artist duly respects the idiom of his new 
materials, their diversity and refinement, in granting him the ut- 
most freedom, enable him to attain a truth of execution unknown 
before to-day. I^'or writing on papyrus a brush had to be used; 
on vellum or paper, a pen or pencil' may also be employed, tracing 
lines no wider than a hair. G)ur grandmothers were fond of sew- 
ing on a perforated card a motto or a flower in silk thread; such 
a sampler always had an unpleasant straightness in its outlines. 

Impressions of Japanese Architecture and tfie Allied Arts,” by Ralph 
Adams Cram. New York, Baker & Taylor Co., 1905. 


Sampler on cardboard, exe- 
cuted in silk thread. 

When in weaving silk or linen there may be two hundred threads 
to the running inch instead of ten, the designer can introduce 
curves almost* as flowing as if he 
were a painter. So too in archi- 
tecture: the log hut was perforce 
straight in its every line ; stone and 
brick made possible the arch; iron 
and steel are bringing in a free 
choice of the best lines, whether 
straight or curved, all with a new 
sprightlincss, as witness the best of 
our oflice-buildings in New York, 
such as the Whitehall, Trinity, and 
Empire Ihiildings. 

Art in its early stages seldom displays any outright invention; 
with all the force of habit the savage artist clings to old familiar 
shapes, and it is interesting to remark how 
dealing with a new material may lead or even Old Forms 
oblige him to modify a tradituMial form. The 
Algonquins inhabit a country in which the birch 
is common. They cut and fold its bark into vessels which, when 
imitated in pottery, have an unusual rcctangularity. In many 

Indian tribes it was custom- 
ary to use as a water-holder 
the paunch of a deer or a 
buffalo; many ancient urns 
of Central America have an 
aperture at an U])pcr ex- 
tremity, copied from the 
paunch, in every case with a 
simplification of outline. Winged troughs of wood were un- 
doubtedly in the mind of^ the man who made the earthen vessel 
illustrated on the next page, found in an ancient grave in Arkansas. 
As usual the borrower put something of himself into his work, 
reminding us that the law of evolution is descent with modifica- 
tion. An earthen vessel, illustrated on the next page, was 
plainly copied from a shell vessel such as the specimen found not 
far off, in Indiana. When the Clallam Indians, of the State of 

Bark vessel, and derived form in clay. 
“Form and Ornament in Ceramic 
Art.” W. II. Holmes. 


W-'.sIiiiisloii, iK'gan to weave baskets, they imitated the forms of 
their rude wicker fish-traps. The like persistence was shown by 

the Haida squaws when 

# lau«^ht l)y the missionaries to 

make mats from rags; they 
repeated their ancient twined 
model, long employed for 
mats and hats of vegetable 
fibres. As in America, so 
also in Europe ; when the 
makers of celts passed from 

tiiey repnxluced the old 
forms, and only gradually 
Vase from tiiniiilns. St. George, Utah. p-irned to economize metal, 
“l^iltorv of tlie Ancient i'licblos.^’ , ^ . 

' W II I [i.)inies much stronger tlian stone, 

nnd so much harder to get, 
by narrowing and llattening their new weapons and tools. 

Albdern manufacture in its designs gives us a kindred per- 
sistence of old forms in new 

Vase from tiimiilns. St. George, Utah, 
“l^ittery of the Ancient ihieblos.'’ 

^ W. II. Holmes. 

things. For electric illumi- 
nation we have bulbs which 
recall the shape of a candlc- 

. „ X, ,, , blaze, or surmount an old- 

Art. W. II. Holmes. i n • i 

fashioned candlestick; a gas- 

burner, popular for fifty years, repeats in milky porcelain the 

whole length of a candle, (ia.s-grates, in uncounted thousands 

Wooden tray. Clay derivative, 
“borm and Ornament in Ceramic 

Shell vessel made from a Earthen vessel, imitation of 

Busy con pcrvcrsiim, found shell, Missouri, 

at Ritclicrsville, 


From W. IL Holmes* “Art in Shell of the Ancient Americans.” 


throughout our cities every winter, offer us flames which flicker 
and leap over asbestos and clay molded into the semblance of maple 
or charcoal. Nor is the engineer himself, for all his sternness of 

Electric lamps in candle shapes. 

discipline, quite free from ])rolonging the reign of the past, even at 
r.nwarrantable cost. When steel was first used for steam boilers 
there was a period of hesitation during whicli the metal was used 
unduly tliick, as if to maintain the long familiar massiveness of 
iron structures. When automobiles w^crc invented, they at first 
closely resembled common carriages. I'o-day, designers have de- 
; irted from tradition, and provide us with horseless vehicles which 
1 espond to their new needs in ways wholly untrammclcd by in- 
herited ideas. In an automobile, driven by steam or gasoline, 
there must be due disposition of fuel, of machinery, of cooling 
ajiparatus, all so combined as to bring the center of gravity as 
low as may be best, affording ready access to any part needing 
lubrication, repair, or reneival; throughout there must be the 
minimum of dead weight, of friction, and of liability to derange- 
ment; all with means of easy, quick, and certain control. Why 

118 form-inherited. 

should these requirements be deferred to repeating the model of 
a carriage drawn by a horse? In Europe, to this hour, the rail- 
rf)ad carriages are an imitation of the old ,road"Coaches, horse 
carriages slightly modified. America, fortunately, from the first 

Notre Dame de Bonsccours, Montreal. Before restoration. 

has had cars directly adapted to railroad exigencies, with a thor- 
oughfare extending the whole length of a train, avoiding the 
]x)x-likc coinpartnicnts which may give the lunatic or the mur- 
derer an opportunity to work his will. 

Sometimes an inherited form taken to a new home proves to 
be faulty there, and is discarded. When Normandy sent forth 
its children to Canada, they built on the shores of the St. Law- 
rence just such high-pitched roofs as had sheltered them in Caen 
and Rouen. An example remains at Montreal in the roof of 

KEW AMSTERDA:M theatre, new YORK. 

Xo pillars obstruct a full view of the stage. 


Notre Dame de Bonsecoiirs. Biit in Montreal and Quebec the 
snowfall is much heavier than in Northern France, and the Nor- 
man roofs at intervals from December to March were wont to let 
loose their avalanches with an eflfect at times deadly. To-day, 
therefore, in French Canada many of the roofs, especially in 
towns and cities, arc flat or nearly flat, while the best models 
quite reverse the old design. In breadths somewhat concave they 
catch the snow as in a basin, and allow it to melt slowly so as to 
run down a pipe through the center of the building. 

Under our eyes, day by day, iron and steel arc taking the place 
of stone and wood in architecture and engineering; yet the force 
of habit leads us to continue in metal many troublesome details 
which were imperative in the weak building materials of gencra- 
tions^past. It was as recently as the autumn of 1903 that the first 
large American theater was opened having no columns to olistruct 
views of its stage. The architects of the New Amsterdam 
Theater, New York, simply by availing themselves of the strength 
of steel cantilevers have shown that henceforth all large audi- 
toriums may be free from obstructions to a view of the stage, 
pulpit or platform. See facing page 118. 

Modern architecture, in the judgment of an eminent critic, has 
lot yet fully responded to its new materials and methods. Says 
Mr. Russell Sturgis, of New York, in “How to Judge Archi- 
tecture” “Every important change in building, in the past, has 
been accomplished by a change in the method of design, so that 
even in the times of avowed revival there was seen no attempt 
to stick to the old way of designing while the new method of 
construction was adopted ; now in the niileteenth century, anti in 
what we have seen of tlie twentieth century, our great new sys- 
tems of building have flourished and developed themselves with- 
out effect as yet upon our methods of design. We still put a 
simulacrum of a stone wall with stone window casings and pedi- 
ments and cornices and great springing arches outside of thin, 
light, scientifically combined, carefully calculated metal — the 
appearance of a solid tower supported by a reality of slender 
props and bars.” 



Heavenly bodies large and small . . . The earth as sculptured a little at 
a time . . . The farmer as a divider . . . Dust and its dangers . . . 
Models may mislead . . . Big structures ecoftoniical . . . Smallness of 
atoms . . . Advantages thereof ... A comet may be more repelled by 
the sun’s light than attracted by his mass. 

B uildings, carriages, structures of all kinds, whether 
reared by art or iiatirre, often resemble one another in form 
while varying much in size." Differences of dimensions are of 
importance to the inventor and discoverer, and will be here briefly 
considered, beginning with a few of their obvious and elementary 

One frosty evening I sat with three young pupils in a room 
warined by a grate-fire. Sbaking out some small live coals, I 
bade the boys observe which of them turned 
l)lack soonest. They were (juick to see that 
the smallest did, but they were unable to tell 
why, until I l)roke a large glowing coal into a score of fragments, 
which almost at once turned black. Then one of them cried, 

“Why, smashing that 
coal gave it more sur- 

Ciiiders large and small on hearth. 

face!’^ This young 
scholar was studying 
the elements of as- 
tronomy that year, so 
I had him give us 
some account of how 
the planets differ 
from one another in 
size, how the moon 
compares with the 
earth in volume, and 
how vastly larger 



than any of its worlds is the sun. Explaining to him the fiery 
ongin of the so ar system, I shall not soon forget his delight- 
m which the others presently shared— when it burst upon him 

A cube as subdivided into 8 cubes of 4 times 
more surface. 

that because the moon is much smaller than the earth it must be 
uci cooler, that indeed, it is like a small cinder compared with 
a arge one. It was easy to advance from this to understanding 
w y Jupiter, with eleven times the diameter of the earth still 
glows faintly in the sky by its own light, and then to comprehend- 
ing that the sun pours out its wealth of heat and light because llio 

122 SI^ 

immensity of its bulk means a comparatively small surface to 
radiate from. 

To make the law concerned in these examples definite and clear, 
I took cig-ht blocks, each an inch cube, and had the boys tell me 
how much surface each had— six square inches. Building the 
eight blocks into one cube, they then counted the square inches 
of its surface— twenty-four : four times as many as those of each 
separate cube. With twenty-seven blocks Iniilt into a cube, that 
structure was found to have a surface of fifty-four square inches 
— nine times that of each component block. As the blocks under- 
went the building process, a portion of 
their surfaces came into contact, and 
thus hidrlen could not count in the outer 
surfaces of the large cubes. The outer 
surfaces of these large cubes I then 
painted white ; when each was separ- 
ated into its eight or twenty-seven 
blocks, we saw in iTn])aintcd wood how 
surfaces were increased by this 
separation into the original small 
cubes. Observation and comparison 
brought the boys to the rule involved 
in these simple experiments. They 
wrote: Solids of the same form vary 
ill surface as the square, and in contents as the cube, of their like 

This elementary law I traced that year in a variety of illustra- 
tions presented in Class in Geometry,^^ published by A. S. 
Barnes & Co., New York. Our excursions, since extended, are 
here given as an example of the knitting value of a pervasive rule 
kept constantly in mind. 

Our planet in diverse ways illustrates the law, just stated, of 
surfaces and volumes. Forces of unresting activity quietly trans- 
form the hills and plains, the sea coasts and 
Earth Sculpture, lake shores of the world, and so gradually that 
in many cases detection proceeds only by noting 
the changes wrought in a century. For the most part these forces 

Cube built of 27 cubes of 9 
times more surface. 


break up large masses into fragments, or slowly wear away the 
surfaces of rocks into dust. A lichen takes root on a granite 
ledge, and in a few years reduces the rock to powder. Rain al- 
ways contains a little acid, so that in time Hint itself is consumed, 
for all its liardness. Water soaking through soils to form under- 
ground streams has hollowed out vast caves, as notably in Vir- 
ginia and Kentucky. Limestones and sandstones are of open 
texture, and take up much moisture into their pores ; in cold 
weather this freezes, and in expansion wedges off thin flakes of 
stone. In the North one sees the ground strewn with such 
s])lintcrs when the warm April sun has melted the snow from be- 
side a limestone fc.nce. Watch the rills as they descend a hillside 
during a rainstorm and just afterward. They are dark with mud, 
and on steep declivities they carry down pebbles and bits of 
broken stone, building up valleys at the expense of high ground.- 
I'ed on a huge scale by such mud, the Alississippi River hears in 
suspension to the Gulf of ItTexico a little more than a tx)und of 
solid matter in every cubic yard, a prime example of how the 
waters of the globe gain upon the land. The halls of Niagara 
have retreated several miles frotn their original plunge ; the carv- 
ing of their channel has been wrought much less by the rushing 
waters than by their ]>urden of abrading earth and sand. The 
ceaseless churning of water at the f(X)t of the Falls cuts back 
into the rock, undermining its u])per layers, so that ever and anon 
tliey break off from the brink of the cataract, with the effect that 
the stream steadily retires. 

Throughout the ocean arc strong currents to be constantly sur- 
veyed and charted on the mariner’s behalf. These currents tran.s- 
port fine mud, and organisms living and dead. Corals flourish 
best where such currents fetch an abundant supply of food, just 
as plants thrive best in rich, loose soil. Life in the sea just like 
life on land is thus dependent on forces which divide large masses 
into small, and distribute these small masses over wide areas, 
chiefly by water carriage. 

Inventors have taken a hint from nature as she carries a burden 
of mud and pebbles in a rapid .stream of water. A modern method 
of deepening a water course is to reduce to fine silt the surface 


of its bed, and then remove this silt with a powerful stream. 
Water in swift eddies both lifts and bears away not only clay, 
but stone and gravel when these arc small cn()U.e:h. In placcr- 
minini^ streams of water much more powerful are directed against 
hill-slopes of earth and stone, which disappear 
Breaking Earth ^ great deal faster than In^ means of .spades 
for Removal (),iy of oiir iVorthwcstcrn rail- 

* ' roads runs for some miles along the base of a 

steep ridge, from which at times heavy rains wash down masses 
of earth, sand and gravel to the track. A powerful steam pump 
forcing a stream throngli hose removes the ol^slriiclions from the 
line with amazing ra])idity. Work a good deal commoner and 
vastly more important consists in taking a process begun by na- 
ture and carrying it many steps further, so as to break up masses 
of earth again and again. The plow, the harrow, the sharp- 
todthed cultivator, divide and subdivide the soil of farm and gar- 
den so as to offer rootlets new surfaces at which rain may be 
drunk in with its nourishing food. When a garden patch is to 
be fertilized by bcuies, these serve best when reduced to meal, 
so as to be (juickly and widely absorbed. 

fn earth-scul])ture one of the busiest agents is the wind, 
est)ecially as it seizes ocean waves and dashes them upon beach 
and cliff, grinding large stones to pieces, and 
reducing these at last to mere pebbles and sand. 
On land the gales take hold of sand and dust 
with efiects even more tdling: sand ihing against the hardest 
quartz or granite will bring it to ])owder at last. Sand dunes, 
shifting under the stress of high winds, have spread desolation 
around Provincetown, iMassachusetts, and in many another region 
once fertile enough. This process of nature immemorially old has 
been copied in mcMlern invention, by the sandblast devised by the 
late General Tilghman of Philadelphia. In its simplest form, 
sand from a hopper falls in a narrow stream upon window panes, 
glassware and the like, to be roughened except where protected 
by a paper pattern. Had sandstone in lumps, as large as playing 
marbles, been dropped on tlie glass, there would have been harm- 
ful fracture ; as each particle of sand weighs too little in pro- 

’ Work of the 

DUST 125 

portion to its striking surface to do more than detach a tiny chip, 
we have a bombardment wholly useful. 

Primitive man achieved an incomparable triumph when first he 
kindled fire by swiftly twirling one dry stick up'On another, drop- 
ping the tiny s})arks on finely divided tinder, 
quick to catch fire because it presented much ^^^gnhion^ 
surface to the air. l\'at, a fuel common in 
many parts of the world, easily dug from bogs and marshes, can 
be readily dried if chopped into fragments and exposed to the 
wind ill open sheds. Cliarcoal easily produced from wood of any 
kind, is often used to absorb harmful gases in boxes of preserved 
meats and in household refrigerators. Its effectiveness is due to 
its minute pores, presenting as they do a vast area of capillary 
attraction. Charcoal, of course, burns faster when powdered 
than when unbroken ; and gunpowder, into which charcoal largely 
enters, is molded into cakes either big, if it is to burn somewhat 
slowly, or is pressed into fine grains, when an explosion all but 
instantaneous is desired. 

Common dust surrounds us always, entering the tiniest chink 
of wall and ceiling to show its path by a defacing mark. In dry 
seasons it abounds to a distressing degree, and 
accumulates rapidly at considerable heights Dust Common 
from the ground. Observe a roof of the kind and Uncommon, 
that slopes gradually toward the street, with a 
trough running along tlie cornice to carry off the rain or melted 
snow. When such a gutter is undisturbed for a few months it 
is clogged with mud due to the dust which has been lifted by 
winds to the roof, and swejit by successive showers into the 
gutter. Dust particles, because tlicy have so much surface for 
their mass, are readily caught up and borne to lieights far ex- 
ceeding those of the highest roofs. The terrific explosion of the 
volcano at Krakatoa, in the Sunda Strait of Java in 1883, shot 
more than four cubic miles of dust into the up])er levels of the 
atmosphere, encircling the globe with particles which fell so 
slowly as for months to color the sunsets of New York and 
Canada, ten thousand miles away. 

Wheat like other grain is combustible, hence as food it sustains 



bodily warmth. Under stress of necessity wheat, corn, and barley 
have been burned as fuel when coal and wood have been lacking. 
In the process of flOur-making wheat is ground to a powder so 
line that when its particles arc diffused through the air of a mill, 
there is a liability to explosion because the in- 

Inflammable flammable dust comes so near to contact with 
tlie atmospheric oxygen that at any moment 
they may unite. At IVIinneapolis, frightful disasters were brought 
alx)ut in this way until specially devised machines removed the 
dust. In coal mines, too, coal may fill the air with a dust so fine 
that explosions take place, with serious loss of life. In Austria it 
has been found that the fineness of the dust has more to do with 
the violence of such explosions than has the chemical composition 
of the particles. 

In mining, let us observe, the whole round of work consists in 
separations which bring masses from bigness to smallness, again 
and again, r'irst of all the solid walls and floors are broken up 
by pick, or drill, or ])()wdcr, or all together. Irqn ores as hoisted 
to the surface of the earth are taken to breakers whicb crush them 
into pieces suitable for the blast furnace. When the ores carry 
gold, copper, lead, or tin, this crushing is followed by stamping 
to facilitate the final process by which metal is separated from 
worthless rock. 

Spinning and weaving, remote as they arc from mining, arc 
equally subject to the law of surfaces and volumes. It is in fur- 
thering adhesion by giving tlieir thread a multi- 
Dimensions in pHed surface that the spinner and weaver 
Woven Fabrics. manufacture cloth at once strong and durable. 

The best linens and silks arc spun in exceed- 
ingly fine threads; canvases and tweeds have threads compara- 
tively coarse, i'^rom the cut edge of a piece of fine silk fabric it 
is hard to pull out a lengthwise thread ; the task is easy with saik 

From observation let us turn to experiment as we further con- 
sider the law of size. Inventors, especially young inventors, arc 

The Dimensions underrate the difficulty of supplying an 

of Models. want in a new and successful way. In their 

enthusiasm they may lose sight of principles 
which oppose their designs, as for instance, the rules which gov- 



ern the plain facts of dimensions. Mr. James B. Eads, in planning 
his great bridge at St. Louis, chose three spans instead of one 
span. Why? For the simple reason that if built in one sp^n 
the weight of the bridge would have been twenty-seven times 
that of a span one-third as long, while only nine times as strong, 
assuming that both structures had the same form. Two pieces of 
rubber will clearly exlhbit the contrast in question. One piece 
is three feet long, one inch wide, one inch thick; the other piece 
is one foot long, and measures in width and thickness one-third 
of an inch. Placing each on supports at its ends we sec how 
much more the longer strip sags than the shorter. The longer 
has twenty-seven times the mass of the other, but only nine times 

The upper strip of rubber is thrice as long, wide and deep as ‘the . 
lower, which sags less. 

its strength. Many an inventor has ignored this elementary fact 
and built a model of a bridge, or roof, which has seemed ex- 
cellent in the dimensions of a model, only to prove weak and 
worthless when executed in full working size. 

We have glanced at a few cases of invention where it has been 
remembered that the larger a mass of given shape the less its 
surface as compared with its bulk. Let us note 
how this rule enters into the tasks of the ship- Why Big Ships 
builder. We take a narrow vial of clear glass, Best, 

nearly fill it with white oil or glycerine, cork 
it, and shake it smartly. Holding the vial upright we observe 
that the largest bubbles of imprisoned air come first to the top 
of the liquid, because in comparison with bulk they have least 
surface to be resisted as they rise. For a parallel case we visit 
the docks of New York, and note a wide diversity of steamers. 
Here is the ‘‘Baltic,’' of the White Star Tdne, with a length of 
726 feet, and a displacement of 28,000 tons. Less than a mile 



away is a small steamer trading to Nova Scotia, having a length 
of but 260 feet, and a displacement of only 1,000 tons or so. We 
recognize at once why the quickest ships are always among the 
biggest. It is simply the case of bubbles small 
and great over again ; the biggest vessels in pro- 
portion to size have least surface whereat to re- 
sist air and sea, so that they can run fastest be- 
tween port and port. As with ships, so with their 
engines; economy rests with bigness; the largest 
engines have pr(q)ortionately least surface at which 
to lose heat by rad ia cion or by contact, or for re- 
sistance by friction as they move. Indeed in de- 
signing ocean steamers of the greyhound type it 
is imperative that the utmost possible dimensions 
be adopted. The “ Mauretania’' and the '‘Lusi- 
tania” just built for the Ciinard Company, to be 
driven by steam turbines at 25 knots an hour, will 
each demand 70,000 horse-power. They are 790 
feet in length over all, 88 feet in beam, 6oy^ feet 
in depth, with a displacement of 45,000 tons. Mr. 
\\'illiam 1 ", Durand, in his work on the resistance 
and jM'opulsion of shi])s, considers three vessels 
less huge and swift than these Cunarders and 
able to cross the Atlantic in say seven days. The 
5,ooo-ton ship coidd ])arely make the trip with no 
Air bubbles rising ^ i6,ooo-ton ship would be able to 

in oil. carry 3,000 tons of freight, while a 20,ooo-ton 
shi]:) could carry 4,200 tons of carg*o. Burdens of 
hull, machinery, and coal do not increase as rapidly as gross 
tonnage when the dimensions of a ship arc enlarged. 

Now we begin to realize how great is the boon of cheap steel, 
much stronger than iron, of which ships and engines may be built 
bigger than at any earlier period. Steel of 
great strength has made feasible, too, the Eift'el 
Tower in Paris, nearly a thousand feet tall, the 
office-buildings of New York thirty stories in height, and steel 
will soon cross the St. Lawrence near Quebec with a single span 
of 1,800 feet. In 1904, at Schenectady, N. Y., the New York 

Bigness Needs 
Strong Materials. 



Central & Hudson River Railroad Company began comparisons 
between an electric locomotive of 201,000 pounds, shown opposite 
page 476, and a steam locomotive so huge that with its tender it 
weighed no less than 342,000 pounds. Steel, as the material of 
engines and tools of all sorts enables us to build in dimensions 
bolder than ever before ; or, if old dimensions are not surpassed, 
we are free to employ velocities quite out of the question with 

It is a long' time since adventurers first entrusted themselves to 
floating logs, afterward tied together as rafts, and slowly im- 
proved until they became boats moved by paddles or oars. Thus 
far little else than failure has attended the inventors who have 
sought to navigate the air as easily as river, lake or sea. A stride 
toward success was however distinctly taken when the strongest 
known alloys, those of steel and nickel, gave the aeronaut a 
stronger boiler, jiound for pound, than he ever had before, with 
wings lighter in proportion to their power than those of earlier 
experiments. Let the burden of his apparatus be further re- 
duced, and by one-half; then we may expect him to reign in the 
air as securely as the sea-gull. The original resource of the aero- 
naut, his balloon, suffers from a permanent disability. Air has 
but 'j/jjo the specific gravity of water, so that a balloon must be 
enormous to have any carrying capacity worth while. And what 
would become of a balloon, its rudder and ropes, if caught in a 
hurricane of eighty miles an hour? 

Let the aeronaut continne his wistful and envious gaze at the 
birds in the sky while we turn our attention to mother earth, there 
to note how every day trade surrounds us with 
further illustrations of the law of size, of the A Store 
gains which may attend bigness. We enter a 
department .store, displaying a varied stock of 
foods, clothing, shoes, furniture, and so on. As we cast our eyes 
alxHit its counters, shelves, and floor we see cans of vegetables, 
fruit, and fish; jars of olives and vinegar; boxes of rice, soap and 
crackers ; paper sacks of flour and meal. Outside the door are 
piled kegs, barrels, and packing cases. Plainly the cost of paper. 

glass, tin, and lumber for packages must levy a large tax on re- 
tailing. Once more is recalled our old lesson with the inch- 



cubes ; the bi^j^ger a jar, box, or sack, the less material it needs in 
proportion to its capacity. Wholesale packers of merchandise 
save money as they form ])ackagcs of the largest size. The con- 
tents of each box, crate, and sack tell the* familiar story once 
again. The coffee is ground from the bean that it may be readily 
infused in the coffee-pot; wheat is reduced to flour, oats to fine 
meal, that they may be quickly cooked; sugar is crushed that it 
may rapidly dissolve in the tea cup. This very tasjv began long 
ago with the mastication of food by the teeth, diminishing the size 
of morsels while nioistening them for digestion before they 
reached the stomach. 

During a visit to the country one smiimcr, we observed new 
examples of our familiar rule. When we compared the dimen- 
sions of a small sectional cabin with those of 
Summer Holiday large house, we saw the principal reason why 

the cabin was hard to ‘keep cool in July, and 
hard to keep warm in l^ecember. We noticed tasks which de- 
pended upon giving wood, cloth or other material as much sur- 
face* as possible, whether new forms were like old ones or not. A 
neighboring sawmill was busy cutting up logs into thin boards; 
these' were piled in o])en tiers, so that the drying winds might 
.speedily finish their work. Tn the same way we noted a laundress 
spreading out by itself each table-cloth and apron fully to catch 
the wind, instead of leaving the linen as a solid heap in her 
basket, where only the edges would be dried. When the farm- 
hands went haymaking they hdlowed the same rule; they tedded 
‘out their gavels to give them the utmost supply of sun and air; 
when all was as dry as a bone they reared a haycock of compact 
form so as to expose the least possible surface to rain and snow. 

So much for things to be observed in a country ramble, in a city 
.store, or at the docks of a busy port. Apart from all such things 

is a world unseen, standing beneath the visible 
Dimensions , , , „ , . i xt 

Molecular. voudd, and equally worthy of study. Here 

knowledge is based upon inferences, upon what 
lawyers call circumstantial evidence. The chemist by means 
purely indirect studies the molecule and the atom, objects that far 
elude his microscope. A molecule is a part of a compound so 
small that it cannot be divided without becoming something 



simpler. Thus a sugar molecule is made up of carbon, hydrogen, 
and oxygen atoms; were these disjoined, the sugar, as such, 
would cease to be, just as a brick wall no longer exists when its 
bricks and their several slices of mortar are parted from one an- 
other as separate units. Small as molecules are they have not 
escaped the measuring rod of the physicist. Some years ago Lord 
Kelvin experimentally arrived at the estimate that the average 
molecule has a diameter of 1/760,000, (XX) inch. Such molecules 
when compared with masses of like form, and of a diameter of 
one inch, have 760,000,000 limes as much surface. In the trans- 
mission of motion, with adhesion in play, surfaces count for much, 
as when a wheel in. motion is brought into contact with a wheel at 
rest. Here may be an explanation of why electricity is conducted 
through a wire with a velocity far exceeding any speed we can 
mechanically impress upon the metal, because the molecules cf)n- 
cerned have incomparably more surface than the wire as a mass. 

By virtue, also, of its minuteness the molecule as a reservoir of 
energy can far excel a mass of visible dimensions. Let us com- 
pare two rotating spheres, one of them of seven 
times the radius of the other. We spin both at 
the same peripheral rate, and gradually increase 
this speed : which will be the first to break apart under centrifugal 
strain? The larger, and why? Because the cohesion of a sphere 
is in proportion to the area of its great circle, which varies as the 
square of its diameter, while centrifugal strain under swift rota- 
tion varies as the cube of that diameter, or as the volume of the 
sphere. From this it follows that we may safely spin our small ♦ 
sphere with a circumferential velocity seven times that given the 
large sphere ; therefore as containers of energy small sjdiercs are 
more effective than large, and this inversely as their diameters. 

* .Spheres, or bodies of any other form, if reduced in dinieiisious to 
1/760,000,000111, would as reservoirs of energy gain 760, 000,000- 
fold. Thys we open a door of explanation regarding the stupend- 
ous contrast between chemical energy and mechanical work. 
Chemical processes are exerted by molecules and atoms, mechan- 
ical work takes place among masses conqiaratively enormous in 
bulk. It may require a hundred blows from a ponderous steam 
hammer to raise the temperature of an iron bar ten degrees ; that 

Reservoirs of 



bar melts in ten seconds when plunged into a flame produced by a 
few ounces of hydrogen and oxygen gases. 

Recent experiments by Professor Joseph J. Thomson point to 
tlie proljability that the atom of the chemist while a unit, is in part 
built of electrons each but one-thousandth part the size of a 
hydrogen atom. An electron, by virtue of its infinitesimal minute- 
ness, becomes able to hold proj)ortionatcly much more energy than 
is possible to an atom moving as a whole. This brings us to some 
comprehension of the astonishing powers of radium, an element 
which maintains itself at a temperature 3° to 5° Centigrade higher 
than that of its surroundings, probably through the collision with- 
in each atom of its comi)onent parts. 

Water-waves as they strike a shore or the sides of a basin exert 
a thrust, or a re])elling action, which may easily be observed. 

That sound-waves act in similar fashion is 
Repulsion by proved by a little sound-mill devised in 1883 by 
Professor V. Dvoiak, of the University of 
Agram in Austria. It consists of four vanes, 
each a small card slighty curved, mounted on a spindle. In a 
sounding-box nearby is a tuning-fork which may he struck through 
its stem F. A Helmholtz resonator has its wide opening turned 

Dvorak Sound-mill. 

toward this box, its narrow opening toward the mill. A stroke on 
the tuning-fork emits vibrations which send tiny jets of air against 
the sails of the mill, which accordingly rotate at a pace propor- 
tionate to the loudness of the sound. 



Professor Ernest F. Nichols of Columbia University, New 
York, and Professor Gordon F. Hull of Dartmouth College, in 
the Journal of Astrophysics, Chicago, June, 1903, describe their 
apparatus for measuring the radiation pressure of light, a phe- 
nomenon analogous to that studied by Professor Dvorak in the • 
field of sound. In the same number of that Journal they detail an 
experiment to show light exerting a driving action on very tenuous 
])articlcs. They burned a putf ball 
of lycoperdon to charcoal spherules 
of about one-sixth the specific grav- 
ity of water. 'Fhese spherules, with 
some fine emery sand, they placed in 
a glass tube shaped like an hour- 
glass; this tube was then exhausted 
of its gases until a mere fraction re- 
mained which could not be removed. 

With the sand and charcoal in its 
upper half the tube was held upright, 
while a beam of light twenty to forty 
times as strong as sunshine was 
thrown on the tube just below its 
neck. I>y tapping the glass a stream 
of sand and charcoal descended; the 
sand fell through the beam without 
deflection ; the charcoal particles were 
driven away from the stream as they 
fell through the light. Part of this A beam of light deflects dust, 
effect was due to the slight remnant 

of gas left in the tube which, warmed by the light, produced a 
motion resembling that of a Crookes' radiometer ; the remainder 
of the effect was caused by the drive or repulsion of the luminous 
beam. It is argued tliat this repulsion by light is probably one of 
the causes why the sun seems ; ) drive away the tail of a comet, 
whose particles being extremely minute have much surface and 
little bulk, so that they are more repelled by the light of the sun 
than they are attracted by his mass. To approach cometary con- 
ditions in an experiment* it would be necessary to intensify sun- 
light no less than i,6oo-fold, because on the surface of the earth 

134 SIZE 

its own gravitation is i,6oo times greater than that which is there 
exerted by tlie siin. 

1'he law tliat a given shape when enlarged increases much more 
^ai)idly in volume than in surface has, in our brief survey, bound 
together a wide diversity of facts in astronomy, 
A Law as a .geology, geography, navigation, engineering. 
Binding Thread.- mechanics, physics, and chemistry. A good 
many times I have brought it before young 
folks as a means of linking together everyday observations and 
])rinciples of swee])ing comprehensiveness. Boys and girls are 
apt to tliiiik tliat there is a formidable barrier between science and 
common knowledge. No such barrier exists. The sun, his 
l)lanets and their moons ; the forces which carve mountains and 
valleys; the arts of shipbuilders, of designers of bridges, office- 
buildings, and lighthouses; the plans of the inventors of ma- 
chinery ; till* rides discovered by investigators who pass from ap- 
])earances to the underlying reality of molecule and atom, are all 
within the sway of the elementary law we have, been studying, 
'riiere is a gain in thus jHirsuing a connecting thread of classifica- 
tion, c('»nferring order as it does on what might else be an assem- 
blage of things collected at random. A law such as that *of size 
links into unity, and fastens in the memory a vast array of ob- 
servations and experiments wdiich otherwise would have no asso- 
ciating tie, no common illumination. 



Food nourishes . . . Weapons and tools arc strong and lasting . . . Cloth- 
ing adorns and protects . . . Shelter must be durable . . . Properties 
modified by art . ... High utility of the bamboo . . . Basketry finds 
much to use . . . Aluminium, how produced aiul utilized . . . Unwel- 
come qualities turned to profit . . . Properties long worthless are now 
gainful , . . Properties may be created at need. 

M aterials arc valued for their properties as well as their 
forms. We now pass to a rapid kirvey of properties as 
observed in gifts of nature, as modified l)y art, as turned to ac- 
count in many ingenious ways, as studied by the investigators who 
would fain know in what particulars of ultimate form, size and 
motion, properties may really ci.uisist. 

We go to market with a few different coins : one of them is 
worth a hundred times as much as another of about the same size, 
because gold is more ])eautiful than nickel, does not tarnish, may 
be hammered into leaves of extreme thinness, or Unites with 
copper as an alloy which withstands abrasion for vears after it 
leaves the mint. When we build a house we wish strength in its 
foundation and 'jvalls, so we jiay a higher price for granite than 
for limestone; and choose for joists, floors and rafters well 
seasoned wood in preference to newly sawn lumber liable to 
warp and crack with heat in summer, with cold in winter. So 
with raiment : silk is preferred to cotton or wool because hand- 
somer, stronger, more lasting. Hut food comes before shelter, 
raiment or any other need of mankind, and (jualities of nourish- 
ment and palatability mark off nuts, fruits, grain and roots as 
suitable for food. In this regard all living creatures exercise 
discrimination under penalty of death. 



A score of sparrows arc flitting about a door-yard; strew 
a handful of crumbs on the gravel before tliem ; at once the 
birds begin picking up the bread, leaving the 
Food. gravel alone. They know crumbs, good to 

eat, from stone, not good to eat. The earliest 
races of men, immeasurably higher than birds in the scale of 
life, have eaten every herb, root, grass, and fruit they could find. 
Experiment here was as wide as the world, and bold enough in 
all conscience. In many cases new and delicious foods, thor- 
oughly wholesome, were discovered. At other times, as when 
the juice of the pojijiy was swallowed, sleep was induced, with 
a hint for the escape from pain in artificial slumber. In less 
happy cases the new food was poisonous ; yet even this quality 
was pressed into service. In Mendocino County, California, to 
this day, the Indians throw soap root and turkey mullein, both 
deadly, into the streams ; the fish thus killed are eaten without 
harm. These same Indians make acorns and buckeye horse 
chestnuts into porridge and bread, pounding the seeds into a 
fine- flour and washing out its astringent part with water. These 
and other aborigines use for food and industry many plants 
neglected by the white man, taking at times guidance from the 
lower animals. One of the early explorers of South Africa, Lc 
Vaillant, says that the Hottentots and Bushmen would eat noth- 
ing that the baboons had left alone. Following their example 
he would submit to a lame baboon new plants for acceptance or 
rejection as food. 

As with food so with other resources almost as vital. Long 
ago the savage learned that hickory makes good bows and 

, arrows, that as a club it forms a stout and 
Weapons and , , i- i i . 

Tools. lasting weapon. He discovered, too, that m 

these qualities soft woods are inferior and 
the sumach altogether wanting. Thus, too, with the whole 
round of stones from which as a warrior or a craftsman he 
fashioned knives, chisels, arrowheads, axes; it was important 
that only tough and durable kinds should be employed. No 
lump of dry clay ever yet served as a hammer or an adze ; happy 
were the tribes, such as those of ancient Britain, who had at hand 


j, goodly beds of flint from which a few well directed blows could 
furnish forth a whole armory of fools and weapons. 

In the eating of foods simply as found, in the use of materials 
for clothing or building just as proffered by the hand of nature, 
much was learned as to their qualities; some 
were found good, others indifferent, still others Properties 

bad. Then followed the art of modifying these Modified, 

qualities, so as to bring, let us say, a fibre or a thong from 
stiffness, to pliability and .so make it useful instead of almost 
worthless. The progress of man from downright savagery may 
be fairly reckoned by his advances in the power to change the 
qualities of foods, raiment, materials for shelter, tools, and 
weapons. These arts of modification go back very far. At 
first they may have consisted simply in taking advantage of 
the effects of time. In the very childhood of mankind ft must 
have been noticed that fruit harsh and sour became mellow with 
keeping, just as now we know that a Baldwin apple harvested 
in October will be all the better for cellarage until Christmas, 
the ripening process continuing long after the apple has left 
its bough. Grains and seeds when newly gatliered are usually 
soft and, at times, somewhat damp ; exposed to the sun and dry 
air for a few days they become hard and remain sound for 
months or even years of careful storage. In warm weather 
among many Indian trilxis such food was the only hind 
that remained eatable; all else went to swift decay, except in 
parched districts such as those of Arizona, so that roots, fruits, 
the flesh of birds, beasts, and fish had to be consumed speedily, 
a fact that goes far to account for the glfittony of the red man. 
His stomach was at first his sole warehouse; that filled, any 
surplus viands went to waste. In frosty weather this havoc 
ceased; as long as cold lasted there was no loss in his larder. 
A few communities, as at Luray, Virginia, or at Mammoth Cave, 
Kentucky, in their huge caverns had storehouses which would 
preserve food all the months of the twelve. In New Mexico 
and other arid regions the air is so dry that meat does not fall 
into decay. How it was discovered that smoke had equal virtue 
we know not. Probably the fact came out in observing the 



Properties in 

accidental exposure of a liaiinch of venison as the reek from a 
camp-fire sank into its fibres. Salt, too, was early ascertained 
to have ^rcat value in preservings food. Suppose a side of buffalo, 
or horse, to liave fallen accidentally into brine in a pool or kettle, 
and staved there long- enough for saturation, its keeping sweet 
afterward would give a hint seizable by an intelligent housewife. 
PresiMwation bv burial in silos began in times far remote, and 
was fullv described by Pliny in the first century of the Christian 

Phe skin just taken from a sheep, the hide when removed from 
an ox, are both as flexible as in life. But they soon stiffen so 
as to be uncomfortable when worn as gar- 
nn'uts. Wetting the ])clt is but a transient 
r(“source ; satisfactory, because lasting, is the 
effect of rubbing grease, fat, or oil into the texture of the hide. 
Peary in (ireenland found that pelts in small ])ieces, and bird- 
skins, were softened by the JCskimo women chewing them for 
hours together. 

Wetting was as notable an aid- to handicraft of old as today. 
Boughs, roots, withes, osiers, or the stems of fibrous plants, when 
thoroughly saturated with water became so soft as to be easily 
worked, yielding strands, as in the case of hemp, separated from 
worthless pulp. I lence the basketmaker, the wattlcr, the builder, 
the potter, the weaver of rude nets and tra])s, long ago learned 
to wet their materials to make them ])lastic. Bake now the 
reverse process of drying, which toughens wood, and the sinews 
used as jirimitive thread. Leaves when dried become hard and 
brittle of texture, hence the necessity that when woven and inter- 
laced as roofs the work shall jiromptly follow upon gathering 
the material. In plaiting coarse mats and sails may have begun 
the textile art which to-day gives us the linens of Belfast, the 
silks of Lyons and Milan. 

A good and serviceable imitation of silk is due to a simple 
and ingenious treatment of cotton. In 1845 John Mercer, a 
Lancashire calico printer, one day filtered a 
Strengthened solution of caustic soda through a piece of 

and Beautified. 0 ( 4 ton cloth. He noticed that the cloth, as it 

dried, was strangely altered : it had shrunk 
considerably both in length and breadth, had become stronger, 



with an increased attraction for dyes. This was the beginning of 
the merccrization which to-day produces cotton fabrics almost as 
strong and handsome as if silk. The cloth, preferably woven of 
long Sea Island staple, is immersed in a solution of caustic soda, 
and afterward washed in dilute sulphuric acid and in pure water. 
As it enters the caustic bath the cotton is pure cellulose, as it 
leaves the bath the fabric is hydrated cellulose, with new and 
valuable properties. The structural change in the fibre is decided. 
The original filament of cotton is a flattciif ’ tube, the sides of 
v/hich arc close together, leaving a central cavity which is en- 
larged at each edge of the surrounding tube. It is opaque and 
the surface is not • smooth. The fibre has also a slight twist. 
The tube after treatment becomes rounded into cylindrical form ; 
its cavity is lessened and the walls of its tube thicken; the sur- 
face becomes smooth and each fibre assumes a spiral form. 
Effects like these of mcrcerization arc produced in paper as well 
as in cotton cloth, yielding vegetable parchment, a familiar 
covering for preserve jars and the like. 

Some sandstones, such as arc common in Ohio and Indiana, 
soft when hewn in the quarry, soon harden on exposure to 
wind and weather; materials of this kind in 
early times afforded shelter more lasting than 
tents of boughs or hides. Ihit the building 
art was to know a gift vastly more important^ 
when an artificial mud was blended of clay and water, with a 
steady improvement both in the strength and durability of the 
product. It was a golden day in the history of man when first 
a clayey paste was patted into a pot, a bowl, a kettle : then was 
laid the foundation of all that the potter, the brick maker, the 
tile molder have since accomplished. Another remarkable dis- 
covery, needing prolonged and faithful experiment, was reached 
when pottery was found to-keej) its form better when broken 
potsherds and bits of flint were mingled with its clay. A dis- 
covery of equal moment was that of mortar, probably approached 
in the daubing of mud or clay into chinks of stones, with the 
admixture first of one substance and then another until the 
right one was found, and the binder and the bound became of 
one and the same hardness. The Romans, a deliberate race, took 
two years in making a batch of mortar; that bond to-day pro- 

Properties in 


triulcs from their walls as more resistant to the tooth of time 
than stone itself. ' 

But if water did much to modify properties, flame did infi- 
nitely more. A block of blue limestone thrust into a fire was 
liurned to whiteness, and became lime, which. 
Flame and Elec- mixed with water, proved a biting compound 
tricity as slippery feel, — an alkali indeed. This same 

wonderful flame caused water wholly to dis- 
apjiear from a heated kettle; or could dissipate almost the whole 
of an ignited brand or lump of fat. By cooking a food, it gave 
a new relish to the poorest dish, banishetl from such a root as 
tapioca its poison, and when a yam was baked it remained eatable 
for a twelvemontli. Fire enabled man to melt metals as if they 

were wax, to soften iron or copper which a deftly swung hammer 
shaped as he willed. TTere, too, opened the whole world of 
chemistry, one of its first gifts the power to take an ore worthless 
when unchanged, and gain from it a battle-axe, a knife, an arrow- 
head. Even in this day of electricity it is fire which the en- 
gineer must evoke to create acids, alkalis, sugars, alcohols, from 
substances as dilTerent from these as iron is from iron ore. 

Electricity as a modifier of properties in turn throws flame 
into ecli])se. Take an example : a strip of ferro-nickel is fast 
dissolving in an alkaline bath ; attach one end of the metal to 
the negative pole of a battery or a dynamo, the other end to 
the positive pole ; at once solution ceases and the metal begins 
to pick out kindred particles from the bath, adding them to itself. 
Electricity has completely reversed the wasting process ; what 
was eaten away is now growing, what was a compound is now 
shaken into its elements, one of wdiich rapidly increases in mass. 
Nothing in the empire of heat is as striking as this process — 
familiar in renewing the energy of a storage battery. Many a 
union or a parting im])Ossible to fire is wrought instantly by the 
electric wave. 

When Mr. Edison devised his electric lamp, his first successful 
filaments were fibres of bamboo; they glowed more brilliantly 
than anything else he could find, they were tenacious enough to 
withstand intense heat for weeks together. A single gift oi 
nature/ such as the bamboo, may be so many-sided that its appli 



cations greatly enrich human life. A task of interest would be 
to trace the vast indebtedness of modern science and art to car- 
bon, iron, or silver, in their various forms. But the bamboo is 
cheaper and more abundant than any of these, 
so that it will be worth while to glance at the xhe Bamboo 
many wants it has satisfied, at the creations it Rich in Utilities, 
has suggested to ingenuity. In Ceylon, India, 

China, Japan, the Malay archipelago, it is the chief item of 
natural wealth, the main resource for the principal arts of life. 
First of all it provides food. More than one case is recorded 
where its abundant seeds have staved off the horrors of famine; 
these seeds, too, are commonly fermented to produce a drink 
resembling beer. Many .sj^ecics of bamboo have shoots whicli 
when young and tender are a palatable and nourishing -food. 
As a building material it is strong, durable and easily divided. 
Its sizes are various enough to provide a lishing-rod for a boy, 
or a column for a palace. 

“To the Chinaman, as to the Japanese,'’ says Mr. Freeman- 
Mitford, in “The Bamboo Garden,” “the bamboo is of supreme 
value; indeed it may be said that there is not a necessity, a 
luxury, or a, [)lcasurc of his daily life to which it does not 
minister. It furnishes the framework of his house and thatches 
the roof over his head, while it supplies paper for his windows, 
awnings for his sheds, and blinds for his verandah. Flis beds, 
tables, chairs, cupboards, his thousand and one small articles 
of furniture are made of it. Shavings and shreds of bamboo 
stuff his pillows and mattresses. The retail dealer’s, measure, 
the carpenter’s rule, the farmer’s waterwheel and irrigating pipes, 
cages for birds, crickets, and other pets, vessels of all kinds, 
from the richly laccpicrcd flower-stands of the well-to-do gentle- 
man down to the humblest utensils of the very poor, all come 
from the same source. The* boatman’s raft, and the pole with 
which he punts it along; his ropes, his mat sails, and the ribs 
to which Hiey arc fastened; the palanquin in which the stately 
mandarin is borne to his office, the bride to lier wedding, the 
coffin to the grave ; the cruel instruments of the executioner, the 
beafity’s. fan and parasol, the soldier’s spear, ciuivcr, and arrenvs, 
the. scribe’s pen, the student’s book, the artist’s brush and the 



favorite study for liis sketch; the musician's flute, the mouth- 
organ, plectrum, and a dozen various instruments of strange 
shapes and still stranger sounds — in the making of all these the 
bamboo is a first necessity. Plaiting and wickerwork of all kinds, 
from the coarsest baskets and matting down to the delicate filigree 
which encases porcelain, are all of bamboo fibre. The same 
material made into great hats like inverted baskets protects the 
coolie from the sun, while the laborers in the rice fields go about 
looking like animated haycocks in waterproof coats made of the 
dried leaves of the bamboo sewn together." 

In North America the Indians have had no such resource as 
the bamboo, but with tireless sagacity they have laid under con- 
tribution either for food or for the arts every 
Materials for the soil. In seeking materials for bas- 

Basketry. kctr}% for example, they have surveyed the 
length and breadth of the continent, testing 
in every plant the c|ualities of root, stem, bark, leaf, fruit, seed 
and gum, so far as these promised the fibres or. the dyes for a 
basket, a wallet, a carrier. With all the instinct of scientific 
research they have sought materials strong, pliant, lasting and 
easily divided lengthwise* for refined fabrics. In his work on 
^‘Indian Ikisketrv” Air. Otis T. Mason has a picture of a bam- 
shi-bu coiled basket, having a foundation of three shoots of 
Hind’s willow, sewn in the lighter i)ortions with carefully pre- 
jxired roots of kahum, a sedge; while its ornamental designs arc 
executed in roots of a bulrush, the tsuwish. Often a basket, as 
in this case, is built of materials found miles apart, each requiring 
l)atient and skilful treatment at the artist's hands, 

A few trees, the cedar in particular, lend themselves to the 
needs of tlie basketinaker with a generous array of resources. 
Mats of large size made from its inner bark are common among 
the Indians of the Northern Pacific Coast. From the roots of 
the same tree hats are woven as well as vessels so close in texture 
as to be watertight. When the roots are boiled so as to be 
readily torn into fibres, these are formed into thread, either woven 
with whale-sinews or with kelp-thread as warp. Among the 
handsomest of all Indian baskets are those of the Porno tribe, 
one of which is shown on page 109. The splints for their creamy 



groundwork arc made from tlic rootstock of the Care.v harharac, 
which are dug from the earth with clam shells and sticks, a 
woman securing fifteen to twenty strands in a day. These she 
places in water over night to keep them flexible, and to soften 
the scaly bark which is afterward removed. To make a basket 
watertight the Indians of Oregon weave the inner bark of their 
maple with the utmost closeness. In otlier regions a simpler 
method is to apply as water-pro(ding the gum the ])ihon, the 
resins of pines, or mineral as])halt. hTpial diligence and sagacity 
mark the Indians as users of stone. The^Shastas heat a stone of 
such cpiality that in cooling it splits into flakes for weajxms and 
tools. They ])lace an obsidian ])ebble on an anvil, and with an 
agate chisel divide it as they wish ; all three being chosen from a 
vast diversity of stones which must have been tried and found 

T^'rom Indian handicrafts, developed by aboriginal skill, patience 
and good taste to remarkable triiini])hs, let ns turn to an achieve- 
ment of a modern chemist who, calling electric- 
ity to his aid, bestowed a new metal upon Aluminium and 
industry, making ])ossible new economies in a Its Uses, 
wide sisterhood of arts. Aluminium was dis- 
covered in 1828 by Wohler, a (lerman chemist, who noted its 
lightness, toughness, and ductility. y\t the Centennial Exhibition 
at Philadelphia, in 1876, a surveyor's transit built of aluminium 
was shown, but the metal at that time was six-fold the ]u*icc of 
silver, so that the instrument for .some years remained uncopied. 
Of course, engineers and mechanics were uuich interested in a 
metal only about one-third as heavy as brass or co])i)er, of white 
lustre, and with as much as five-eighths the electrical conductivity 
of copper. All that hindered the extensive use of the metal was 
its high cost. If that cost could be lowered, at once co])per, and 
even silver, would face a rivak After many unsuccessful because 
expensive processes for obtaining the metal had been devised, 
a method was found at once sim])le and inexpensive. 

This method of separating aluminium ffom its compounds 
was devised by Charles M. Ifall, while an undergraduate student 
at Oberlin College, Ohio. ITis success turned on his knowledge 
of the properties of related metallic compounds. He recognized 



the probable value of aluminium in the arts, could it be produced 
in large quantity at low cost. He believed that electrolysis would 
prove the most convenient, thorough and inexpensive method; 
but there was at that time no process known by which it could 
be applied to this element. His problem was to find a form of 
electrolyte rich in aluminium which should be Comparatively easy 
to separate into its elements, and to discover a substance for the 
solvent which should prove a satisfactory bath. This latter sub- 
stance must, furthermore, be a good conductor of electricity, must 
readily dissolve the proposed electrolyte, and must have a higher 
resistance to electrolytic disruption than the electrolyte. To dis- 
cover the needed substances for electrolyte and solvent involved 
the examination of all available compounds of aluminium, the 
study of the various possil)le solvents for the compound selected, 
and the determination of electric conductivities. By virtue of 
rare familiarity with the chemistry and physics of the subject, 
with the properties of every substance concerned, the search was, 
after a time, rewarded, with complete success. Tt.was found that 
bauxite — the oxide of aluminium, alumina, in fact — is dissolved 
by molten cryolite, the double silicate of aluminium and sodium, 
and that the latter, while dissolving the bauxite freely and serving 
as an ideal solvent, also itself' breaks up under the action of the 
electric current at a much higher voltage than alumina. So far 
as known, these arc the only substances in nature which stand 
to each other in such relation ^is to permit the commercial pro- 
duction of the metal. 

Aluminium as constructive material has disappointed some of 
its earlier advocates. It is difficult to work, gumming the teeth 
of files and resisting cutting and drilling tools by virtue of the 
very toughness which makes it desirable for tubes, columns, and 
the like. Its excellences, however, are manifold : the German 
army on investigation found that helmets of aluminium, as light 
as felt, turned the glancing impact of a bullet. ' For soldiers’ use 
it ‘now forms not only helmets, but cooking vessels, cartridge 
cases, buttons, sword and bayonet scabbards. It gives the photog- 
rapher as well as the surveyor instruments which unite strength 
with lightness. It has furthermore the quality which has long 
given value to the lithographic stone of Hohenlofen in Bavaria. 



Aluminium takes a sketch as perfectly as docs the stone, with 
the inestinlable advantages that the metal may be readily curved 
for a cylinder press, that it is compact, and light in storage, while 
without the brittleness whicli has made stone so costly a servant 
to both artists and printers. To produce a deep color from stohe 
it may be necessary to print one impression over another again 
and again; from aluminium a single impression is enough, as 
severe pressure may be safely applied. 

Aluminium has so great an affinity for oxygen as to play a 
conspicuous part in the metallurgy of other metals. In the cast- 
ing of iron, steel or brass, the addition to each ton of two to five 
pounds of aluminium greatly improves the product ; the aluminium 
by combining with the occluded gases reduces the blowholes and 
renders the molten metal more fluid and therefore more homo- 
geneous. A second use for aluminium turns on the same quality ; 
it was devised by Dr. Goldschmidt for producing high tempera- 
tures, and is especially useful in welding steel rails and pipes. 
A mixture of iron oxide and aluminium finely divided is ignited 
by a magnesium ril)bon ; a very high temperature results as the 
aluminium combines with the oxygen derived from the iron oxide. 

Aluminium by reason of its lightness occui)ies a large field in 
naval and military equipments, in motor-car construction, and 
the like, where the reduction of weight is of paramount im- 
portance. For cooking utensils the use of aluminium is con- 
stantly extending; the metal is*a capital conductor of heat, is 
not liable to deteriorate in use, and gives rise, if dissolved, to 
harmless compounds. The chief objection to aluminium is its 
low tensile strength, which, for the cast metal is only 10,000 to 
16,000 pounds per square inch. An improvement is effected by 
adding as an alloy a small quantity of some other metal, such as 
nickel or copper. When one part of aluminium is joined with 
nine parts of copper we have aluminium bronze, the strongest 
and handsomest of copper alloys, much resembling gold in its 

Aluminium is finding acceptance as an electrical conductor. 
An installation of this kind in Canada unites Shawinigan Falls 
with Montreal, 84.3 miles c|jstant. Three cables arc employed, 
each composed of seven No. 7 wires. The total loss in the 



transmission of 8,ooo-Iio-rse power, at 50,000 volts at the generat- 
iiig station, is about eighteen per cent. Comparing equal con- 
fluctors, in round numbers the cross-section of an aluminium 
cable is one-and-a-half times that of a copper cable, the weight 
])cing one-half and the tensile strength three-quarters. Every- 
thing considered wlien aluminium is 2 i/io the price of copper, 
the investor is e([ually served by both metals as conductors. This 
is true only where the conductors are bare. Where insulated 
cables arc needed, the increased diameter of an aluminium con- 
ductor entails extra cost for insulating material. 

At first the lightness and weakness of aluminium were much 
against it ; these, as we have seen, were soon overcome by alloy- 
ing the metal with copper or nickel. But by 

Properties at 
First Unwelcome 
are Turned to 

giving aluminium forms of utmost stiffness, 
by reinforcing these forms with steel wires, 
the metal is (juite strong and rigid enough for 

cu])S, plates, cameras and other instruments 

for which lightness is most desirable. Ju many another case a 

material or a characteristic at first unwelcome has been turned to 

excellent account. Smokiness in a fuel is not a quality mentioned 
in its advertisements, and yet smokiness is just what is sought in 
the twigs, stubble, or coals set on fire to give q)lants a cloud 
])rotccting them from unseasonable fro.sts. It is astonishing how 
little fuel will serve in such cases, especially if the atmosphere is 
calm, so as not to carry the smoke where it is not needed. Many 
another instance might be given of a ([uality objectionable for 
one service and then turned to satisfying a new want. Some- 

times, too, ofi'ensive (|ualitics are most useful. Jlluminating gas, 
as at first manufactured, had a distressing odor, which gave 
])rom])t and unmistakable notice of a leak. When water gas came 
into use, m()st harmful when inhaled, the chemists were puzzled 
to know how to give it an offensive siiTcll ; they found that a 
quality long complained of was really an advantage in disguise. 

S(') in the electrical field, when an unsought quality has in- 
truded itself, and proved unwelcome, the question 1ms arisen, what 
service can we enlist it for? Not seldom the answer has been 
gainful in the extreme. Dr. Oliver^J. Lodge tells us that a bad 
electrical contact was at one time regarded simply as a nuisance, 



because of the singularly uncertain and capricious character of the 
current transmitted by it. Professor Hughes observed its sen- 
sitiveness to sound-waves, and it became the microphone, which, 
duly modified, brought the telephone from the whisper of a 
curious toy to the full tones which ensured commercial success 
the world over. This same '‘bad” contact turns out to be sensitive 
to electric waves also, forming indeed nothing else than the 
coherer of the wireless telegraph. 

Many an electrician has been perplexed and thwarted by the 
small bubbles of air which jdace themselves on a metallic surface 
immersed in an electric bath, interrupting the attack sought to 
be carried to a finish. Happily there is a task* which these very 
bubbles perform as if they had been created for no other purj)ose, 
namely, the re-sharpening of files. First the dull and dirty files 
are placed for twelve hours in a -fifteen to twenty per cent, 
solution of caustic soda; they arc then cleaned with a scratch- 
brush and a five per cent, .soda solution. Next they arc placed 
in a bath of six parts of forty per cent, nitric acid, three parts 
sulphuric acid, and lOO parts water, each file being connected 
to a plate of carbon immersed close to it, by means of a copper 
plate connecting at the top all the carbons and the files. This 
j^roduces a short-circuited battery generating gas at the surface 
of the files; the bubbles which adhere to the points of the files 
protect them from being eaten away, while the rest of the metal 
is being etched. Every five minutes the files are taken out and 
washed in water to remove the oxide which collects on their 
surfaces. When sufficiently etched they arc placed in lime-water 
to remove any adherent acid, dried in sawdust to prevent rusting, 
and rubbed with a mixture of oil and turpentine. Indispensable 
in the whole process is the protection afforded by the bubbles 
of air. 

For a long time its creation of sparks kept electrical machinery 

out of mines liable to fire-damp, which might be exploded by 

these sparks. In many other places they 

worked evils quite as serious, setting fire to Thou 

^ My Good. 

shavings, cotton and such like. To-day these 

very sparks are applied t^ touching off the ' charges of gas 

and air in gas-engines of all types, whether stationary, or for 



automobiles and motor-boats. Tn another respect the automobile 
sliould be provided with a means of creating what is usually 
considered a nuisance, namely, a noise. Moving rapidly as it 
does on thick rubber tires, it gives no warning to hapless way- 
farers. In Canadian cities, where in winter deep snow may muffle 
the tread of horses, every sleigh, under severe penalty, must be 
furnished with efficient bells. 

Sometimes an important property has unwelcome effects which, 
in ])articular cases, cannot be a])plied to advantage, and must be 
counterbalanced with as much care as possible. 

Compensating y!;my pieces of mechanism from the qualities 
of their materials arc subject to deviations 
which must be com])ens^itcd by introducing equal and opposite 
action. Tasks of this kind proceed upon an intimate acquaintance 
with the properties of substances common and uncommon. From 
the first making of clocks there was much trou])le due to changes 
of temt)erature which affected the dimensions of pendulums, and 
consequently their rate of going. This difficulty. is overcome by 
taking advantage of the fact that heat expands zinc about two- 
and-a-half times as mueh as it expands steel. Accordingly the 
two-second pendulum of the great clock at Westminster is built 
of a steel rod 179 inches in length, and a zinc tube, less massive, 
126 inches long; they arc joined at their lower ends only and 
are parallel. As tem])eratures vary, the fluctuations in length 
of the steel compensate those which occur in the zinc. Another 
mode of effecting the same purpose is to employ a cylinder partly 
filled with mercury; as this rises when warmed it exactly com- 
jiensates 'for the lengthening by expansion of its supporting rod 
of steel. 

Gravity, that universal force at which wc have just glanced as 
it swings a pendulum, cannot be banished, but its downward 
push may be balanced by an equal upward thrust. In a re- 
markable feat Plateau poured oil into a blend of water and 
alcohol, adding alcohol until he produced a mixture having the 
same specific gravity as the oil — which now became a sphere, 
taking its place in the middle of the diluted spirits. Pie then 
introduced into the oil a vertical disc which he rotated; very 
soon spherules of oil separated themselves from the parent mass, 



and as , satellites moved in the same direction as the primary 
sphere, because immersed as they were in the diluted alcohol, 
they shared the direction of its motion: the whole afforded a 
remarkable illustration of how nebulae may become planets, 
moons, and suns. 

On somewhat the same principle as Plateau’s model are the 
liquid compasses for ships. Their needles are disposed within 
hollow metallic holders of the same specific gravity as the im- 
mersing liquid, in which therefore they move with perfect free- 
dom on their sapphire bearings. Sometimes it is desired to use 
compass needles so poised that they will respond to the slightest 
magnetic influence. To this end one needle is placed above 
another, the north pole of the first over the south pole of the 
second; the astatic needle formed by this union is much more 
sensitive than a simple needle. The astatic needle, for all its 
ingenuity, is little used; of incomparably more importance is 
that other magnetic device, the telephone. No s(X)ner had it en- 
tered into business than a serious fault was found with its mes- 
sages*; they arrived blurred and mingled with m^iny sounds and 
noises, as if the conveying wire had caught every audibility of a 
neighborhood. The difficulty is remedied by using two con- 
ductors instead of one, and so arranging them that the currents 
induced on one conductor arc exactly c(iual and opposite to those 
induced in the other. 

If properties at first unwelcome have at last been turned to 
account, so also have properties which were long deemed utterly 
useless. A big and interesting book might be 
filled with the story of how by-products, long Properties Long 
thrown away as worthless, have rewarded care- l^eemed Useless 
fill study with great profit. Thus for ages was Gainful, 
bran discarded in fiour-mills : to-day it may 
afford all the miller’s profit,^ or even more than that profit. In the 
Southern. States until a generation ago cotton seed was regarded 
as valueless. At present that product, so long wasted, is the basis 
of a great industry, a ton of seed yielding about 1089 lbs. of 
meat to 20 lbs. of lint; out of this meat 800 lbs. are cake and 
meal; the remainder, 289 lbs., forms an oil which furnishes a 
substitute for olive oil and lard. Until a few years ago glycerine 



was thrown away as produced in candle-works and soap factories. 
It is now so valuable that manufacturers adopt just that method 
of preparing fatty acids which yields most glycerine from neutral 
fats. So in paper-making, the soda which formerly was sent into 
creeks and rivers to the pollution of sources of water-supply, is 
now used over and over again, largely increasing the net results 
of manufacture. No industry has shown of late years so large 
utilization of products formerly wasted as the iron and steel 
manufacture. Its slags arc made into bricks, cement, and glassy 
non-conductors of heat and electricity. Its gases are used for 
engines develoj)ing immense motive powers, or they arc in part 
condensed for valuable acids or other compounds. In these CEvSes 
and thousands more the ciuestion has been. What arc the prop- 
erties of these by-products? How can they be made useful? 

Let us note how diverse substances are separated from 
one another by taking hold of differences in their properties. 

When a handful of grain which has just passed 
Separation a flail is thrown upward in a breeze, its 

Turns on chaff is blown much farther tlian the grain ; 
Properties. difference in breadth of surface, joined to 

a difference in density, enables the wind to 
effect a thorough separation. A common fanning mill, with its 
([nick air current, works much better than the fitful wind, because 
continuously. Hiat simple machine, like every other which takes 
a mixture and sejiarates its ingredients, seizes upon a difference 
in properties. In Edison’s apparatus for removing iron from 
sand or dust, a scries of powerful magnets overhang a stream 
of .sand or [lowdcred material, deflecting the iron particles so that 
they fall into a bin by themselves, while the trash gees into an 
adjoining larger bin. The Hungarian process of Hour-milling 
first crushes wheat through rollers; the various [iroducts are then 
separated by pnx'csses which lay hold of differences in specific 
gravity — often but slight. 

A feat more difficult than that of the Hungarian mill would 
seem to be the division of diamonds from other stones. It has 
been accomplishccj by ^Ir. hVederick Kersten of Kimberley, wSouth 
Africa. He noticed one day at his ellxiw a rough diamond and 
a garnet on a board. He raised one end of this board, and while 



the garnet slipped off, the diamond remained undisturbed. What 
was the reason? He observed that the wood bore a coating of 
grease, which possibly had held the diamond while the garnet 
had slipped away. He took a wider board, greased it, and dropped 
upon it a handful of small stones, some of which were rough 
diamonds. He found that by inclining the board a little, and 
vibrating it carefully, all the stones but the diamonds fell off, 
while the diamonds stuck to the grease. He forthwith built a 
machine with a greasy board as its separator, and scored a 

On quite a different plan is built the coal washer which sepa- 
rates coal from slate. Pulses of water are sent upward through 
a sieve so as to strike a broken mixture of coal and slate, making 
a quicksand of the mass. Because the slate is heavier than the 
coal it is not carried so far, and is therefore caught in a separate 
stream and thrown away. 

Separations, such as we just considered, turn itpon obvious 
differences in density. Properties not obvious, yet highly useful, 
come into view year by year as observers grow 
more alert and keen, as new instruments are properties Newly 
devised for their aid, as measurements bc'come Discovered and 
more refined, so that matter is constantly found Produced, 
to he vastly richer in properties than was for- 
merly supposed. We have long known that carbon has forms 
which vary as widely as coal, graphite and the diamond. Many 
other elements are detected in a similar masciueradc. Iron, for 
instance, takes three forms, alpJia^ beta, and <e;auima. Alpha iron 
is soft, weak, ductile and strongly magnetic ; beta iron is hard, 
brittle and feebly magnetic; s^ajiima iron is also hard and feebly 
magnetic, yet ductile. Joule, tlic famous English experimenter, 
])repared an amalgam of iron with mercury; when he distilled 
away the mercury, the remaining iron took fire on exposure to 
the air, proving itself to be' different from ordinary iron. Mois- 
san has shown that similar effects follow when chromium, manga- 
nese, cobalt and nickel arc released from amalgamation with 

At first steel was valued for its strength and elasticity; to-day 

we also inquire as to its conductivity for heat or electricity, its 



behavior in powerful magnetic fields, its capacity to absorb or 
Voflect rays luminous or other. As art moves onward we* enter 
upon new powers to change the properties of matter, compassing 
new intensities of heat and cold, each with new effects upon 
tenacity, elasticity, conductivity. So also with the extreme pres- 
sures, possible only with modern hydraulic apparatus, which 
jjrovc mar])lc to be plastic, and reduce wood to a density compar- 
able with that of coal, explaining how anthracite has been con- 
solidated- from the vegetation of long ago. 

And one discovery but breaks the path for another, and so on 
indefinitely. Coming upon a new property, the sensitiveness of 
silver compounds to light, meant a new means of further dis- 
covery, the photographic plate. That plate, responsive to rays 
which fall without response upon the retina, reveals much to us 
otherwise utiknown and unsuspected. Of old when an observer 
saw nothing, he thought there was nothing to see. We know 
better now. Thanks to the sensitive plate we have reason to 
believe that properties, once deemed exceptional, are really uni- 
versal. Phosphorcvscencc, for ages familiar in the firefly, in 
decaying logs and fish, now declares itself excitable in all sub- 
stances whatever, although usually in but slight measure. The 
case is ly])ical : the polariscope, the spectroscope, the fluoroscope, 
the magnetometer, the electroscope, each employing as its core 
a substance of extraordinary susceptibility, detects that quality 
in everything brought within its play. Thus from day to day 
matter is disclosed in new wealths of properties, and therefore 
in new .and corresponding complexities of structure. In ages 
past mankind was on nodding terms with many things, and had 
no intimate knowledge of an3^thing. 

Wdth materials before him richer in array than ever before, 
and better understood than of old, the inventor asks. What 
properties do I wish in a particular substance? Then, he pro- 
ceeds to make, if he can, a dye of unfading permanence, an 
ir.siilator resistant to high temperatures, an alloy winch when 
su])jecte(l to heat or cold remains unaltered in dimensions, fie 
finds materials much more under command than a century ago 
cnuUl have been imagined, as the glass manufacture, the alloying 
industry', the making of artificial dyes, abundantly prove. 


Mr. Edison, for aid in finding just the substance he needs for 
a new purpose, has at his laboratory in Orange, New Jersey, i\ 
large store-room filled with materials of all 
kinds. He may wish a particularly high degree Edison’s Ware- 
of elasticity, liardncss, abrasive power, or what house as an Aid. 
not ; to provide these he has gathered a wide 
diversity of woods, ivories, fibres, horn, glass, porcelain, metals 
pure and alloyed, alkalis, acids, oils, varnishes and so on. Take 
one example from among many which might be given from his 
shelves ; he finds that a sapphire furnishes the best stylus where- 
with to cut a channel on a phonographic cylinder. Hard, flinty 
particles from the air are apt to enter the wax, so as to blunt a 
cutting edge. Diamonds would be best as chaimelers, but their 
cost obliges him to choose sapphires as next best; they arc pur- 
chasable at reasonable prices and last ten years under ordinary 
conditions of wear. 

ciiaptj^:r XII 


Producing more and better light from both gas and electricity . . . The 
Drummond light . . . The Welsbach mantle . . . Many rivals of carbon 
lilameiits and pencils . . . Flaming arcs and tubes of mercury vapor. 

M r. EDISON has achieved triiiniphs not only in giving sound 
its lasting registration, but in producing an electric light of 
new economy. Doth exploits proceeded upon a masterly knowl- 
edge of properties. A century ago candles provided illumination 
both to rich and poor, the sole difference being 
Ldght Giving shone in the palace and tallow in the 

hut. ddie oil lamps which glcaincd in the light- 
houses of ICngland and America, for all their bigness, were plainly 
of kin to the Fkskimo saucer tilled with blubber, edged with moss 
as wick. Yet for ages, from every hearth in Christendom, there 
had been the promise of better things as bituminous coals, or 
sticks of wood, had cheered as much by their light as by their 
warmth. We owe much to James Watt, who imj^roved the steam- 
engine and gave it essentially the form it retains to the present 
hour. We pwe also a weighty debt to an assistant of his, Wil- 
liam Murdock, wIk'j, thanks to a suggestion from Lord Dun- 
donald, attentively observed the process by which coals produce 
light. He saw that under stress of intense heat the solid fuel 
emitted streams of gas which burned with great brilliancy. Here 
gas-making and gas-burning went on at the same moment in the 
same place ; might the ])rocess be separated, so that gas might 
be made here, and burned elsewhere at any convenient time? An 
experiment proved the ])roject to be feasible, and forthwith th(,‘ 
Soho Works, near Birmingham, in which Watt’s engines were 
built, were lighted by gas. Such was the beginning of an industry 
now imi)ortant in many ways. To-day gas not only yields light, 




but heat and power, while, especially in metallurgy, fuels are more 
and more used after reduction to the gaseous form. 

Early in the day of gas-making it was noticed that gases of 
various kinds differed much in light-giving quality. It was 
presently shown that their light depended on 
the carbon brought to incandescence in a llame ; the Gas 

in the absence of that carbon, as when a jet of ^nvente^^ 

pure hydrogen was consumed, extreme heat 
was accompanied by no light whatever. Then came a capital dis- 
covery, namely, that lime introduced within a burning jet of 
hydrogen became intensely luminous while itself but slowly con- 
sumed. Adopting lime for the core of his apparatus, Captain 
Thomas Drummond, of the Royal Engineers, in 1835 devised the 
lime light. Upon a block of pure, compressed quick lime, he 
directed a jet of burning gas, obtaining a beam of great vividness 
still employed in stereopticons and in theatres. For modern types 
of the Drummond lamp a twin jet of hydrogen and oxygen is 
used. Lime has many sister substances having light-giving qual- 
ity when highly heated, and among them arc many rare earths, 
(jxides of uncommon elements. These strange substances were 
destined to play a prominent part in the battle between gas and 
electricity as illuminants. When hklison in 1878 perfected his 
incandescent bulb, it seemed as if electricity were soon to be the 
sole illuminator of houses. But the gas engineers were to be 
rejoiced by the invention of a mantle which quadrupled the bril- 
lancy of a gas flame, withstanding the rivalry of electricity in a 
notable degree. This mantle was invented by Dr. Auer von 
Welsbach, a chemist of Vienna, who virtually adiopted the prin- 
ciple of the Drummond light. His efforts give us an admirable 
example of an inventor passing from a hint to a test, day after 
day meeting new difficulties with unfailing courage and resource- 
i Illness. 

In 1880 Dr. von Welsbach took up the study of rare earths, 
mainly with a view to ascertaining their value as illuminants. As 
he brought one specimen after another to melting heat on bits of 
platinum wire, he found that the little beads formed were un- 
favorable in shape to the production of light. Then came into 
his mind an idea of that golden quality which occurs only to the 



mail who earns it : Why not soak cotton with solutions of salts of 
rare earths, burn the cotton and leave behind an earthy skeleton 
of slight thickness and much surface? Experiment proved that 
the idea had promise, but the skeletons crumbled to dust with 
the least tremor. P"or success a fair degree of cohesion was im- 
perative, but to secure that cohesion demanded skill, resource, and 
])aticncc. After a long scries of trials a mantle was made with 
lanthanum oxide; immersed in flame its beam was particularly 
bright, now for the first time suggesting that the rare earths 
might yield light on a large scale. I.>ut trouble was at hand, to 
be overcome only at the end of much toil. 

During an absence of several days, the inventor left a mantle 
of lanthanum oxide locked up in his laboratory. When he re- 
turned it had fallen to powder, having attracted from the atmo- 
sj^herc both moisture and carlxm dioxide. Evidently this harm- 
ful attraction must be avoided by adding an ingredient to keep 
the mantle dry and preserve it from union with carbon dioxide. 
For this purpose magnesia was chosen; the resulting coin])ound 
proved to be dural)lc, and gave an agreeable light of moderate in- 
tensity. lUit, alas, after glowing about seventy hours, the mantle 
failed in its radiance, becoming of glassy and translucent texture, 
'riiiis impeded, the untiring inventor turned to mixtures having 
zirconium as a basis ; these not only giive a steady beam, but ex- 
tended to hundreds of hours the life of a mantle. Still bent on 
getting more light if he could. Dr. von Welsbach tested thorium 
oxide with gratifying results; yet, strange to say, when he had 
purified this material to the utmost, his light fell off in an unac- 
countable fashion. What could be the matter? Surely in the 
purifying process some invaluable element had been cast aside. 
This element, in the researches of an associate, Mr. Ludwig Hai- 
tingcr, proved to be cerium in minute quantity. Here was a dis- 
covery of the highest moment; at the end of many experiments 
it was determined that one per cent, of cerium and ninety-nine per 
cent, of thorium oxide arc the best proportions for a mantle such 
as we use to-day. Why these proportions are best nobody knows, 
any more than why one per cent, of carlx)n added to us 

a steel incomparably better than iron for many ^ ^ Wel^actr - 

mantle has good points apart from its econom Its com- 

Dr. carl I'RlLliniRR AUlCR von WlvLSRACH 
OF Vienna. 



bustion is thorough, so that it throws into the air a much lower 
percentage of injurious products than docs an ordinary gas flame. 
It never smokes, and its light is so steady as to be available for 
work with the microscope and other exacting demands. It has 
one defect which may yet be removed: its light 
has a somewhat unpleasant tinge of green. In 
another chapter of this took, producer gas, much 
cheaper than common illuminating gas, is de- 
scribed. Dowson producer gas, with a Wclsbach 
mantle, yields a light of 8 to lo candle-power 
with a consumption of 4.5 to 4.8 cubic feet per 

Thus far no successful mantle for a petroleum 
lamp has been devised. With alcohol a mantle 

yields a brilliant flame. A lamp with a Toivin 

burner and a WeLs])ach mantle has given a light 
of 30.35 candle-power for 57 hours and 5 minutes 
in consuming one gallon of alcohol, almost twice 
as much light as given by a Miller lamp with a 
round wick and a central draft, burning a gallon 
of kerosene. In the United States on January i, 

1907, there will cease to ])e an excise tax on 
alcohol used in the arts, a denaturalizing process 
rendering the Ii([uid unfit to drink. As this 
alcohol may be easily produced from grain or Boivin burner 

potatoes at 20 to 25 cents a gallon, a capital for alcohol, 

ilium inant will be available for the public, as well attachable 
as ail excellent fuel and a substitute for gas or 
gasoline in motors. 

As f^yst manufactured, gas-mantles were 
woven, they are now knitted,— a change for the better in close- 
ness and firmness of textur-c. Nearly all the thorium used for 
mantles is' found in the monazite sands of the provinces of Bahia 
and Espirito Santo, along the coast of Brazil. These sands were 
for a long time valuable only for the zinc they contained. To- 
day the thorium they carry is of vastly more account ; for chemical 
treatment this is sent to Germany whence the manufactured 
product is borne to every quarter of the globe. 



While the Welsbach mantles have been constantly improved 

in quality, and given new and inverted forms of special value, 

the inventors in the field of electric lighting 

Improvements Jiavc not stood still. For interior illumination 

m Electric Light- Edison incandescent bulb still holds its own 
mg: Incandescent ^ 

Lamps. despite many a threat of dispossession. Since 

i88i its details of manufacture have been 
steadily bettered and its price much reduced, while its consump- 
tion of current has fallen from 5.8 watts per candle to 3.1. This 

advance, marked as it is, leaves a 
long path ahead of the inventor 
whose estimate is that were the 
whole of an electric current trans- 
formed into liglit. a candle would 
cost us but .11 of a watt, that is, but 
one twenty-eighth part as much as 
when we set a carbon filament aglow. 
In electrical terms a horse-power 
yields 748 watts, representing, were 
there no waste in conversion, no less 
than 425 lamps each of 16 candle- 

It is this immense margin for ini- 
]>rovement that has sjnirrcd in- 
genuity to attack the problem of 
electric lighting from .iiany new 
sides. The Genera' Electric ("oni- 
pany produces a carbon filament ol 
one fifth greater efficiency than an 
ordinary untreated filament. Fibers 
of the usual cellulose kind are cn 
closed in a carbon box, placed in a carbon-tube resistance furnace 
heated to between 3,000° and 3,700° C. This converts the filanieiii 
into a graphite of increased luminosity which, furthermore, 
blackens its enclosing glass much less than a common filament 

In the early days of electric lighting a good many experiment' 
were tried with threads of platinum, but witliout success. Tha 

ventilating hood. 



metal remains iinnielted at a very high temperature, but as a 
light-giver its quality is poor. Of late years investigators have 

Wcisbach mantle. 

turned to other metals, of high melting’ points, and with results 
so remarkable that we may expect some of them to be in general 
use in the near future. Tantalum, a rare and costly metal, has 
been found to give a candle-power with as little as two watts and, 
in specially favorable circumstances, with only 1.85 watts. 



Osmium, in the hands of Dr. Auer von Welsbach, reduces this 
figure to 1.5 watts. Dr. Hans Kuzel,.of Baden, Austria, has em- 
ployed filaments of tungsten in lamps which 
he claims demanded only one watt per candle. 
From among these new lamps it seems 
highly probable that as soon as methods of 
manufacture are settled and standardized 
the world will be given an electric light, in 
small units, much cheaper than ever before. 

For large s])aces indoors and for out 
of doors the arc-lamp maintains its popu- 
larity in much the form 
originally devised by New Arc Lamps.' 
Air. Charles b\ Briisb of 
Cleveland. But, as in the case of the in- 
Tantaliim lamp. candescent bulb, many a rival is now dis- 
puting the field, so that supersedure may be 
close at hand. In what are known as flaming or luminous arcs 
the carbon pencils arc impregnated with salts of the calcium 
group of elements, of extreme luminosity. 

In these lamj)s the electric arc itself is the 
chief source of light, instead of the 
glowing end of the ix)sitive carbon as 
in a common arc lamp. As the calcium 
salts volatilize into gases they provide 
a path of less resistance than air for the 
passage of the current, so that the elec- 
tnxlcs may be drawn apart to a distance 
which may be as much as 2^2 inches. These 
lamps require free ventilation, so that they 
must be open. Their economy is extraor- 
dinary, a candle-power being afforded for 
•353 watt, as against 1.78 watts for an en- 
closed arc lamp, a five- fold gain in ef- 
fectiveness. To renew the carbons, which 
waste rapidly, a new device provides 
fresh pencils, cartridge fashion, as re- 
quired. Without this aid, trimming is often 

Tungsten lamp of 
Dr. Hans Kuzel. 


trtr.Wl'I'T . „t the carbons 

,totbebigbcf Vexpertocnt 

1 this 5nct joiner another hne oxides- 
necessary- m their nse. ^ ^ith . o-«er 

»' r. ■ 

He«M mcrcttry-''aP°' ^ 

nt higher eftcrencres 

, ;t is expected that j^^^itt enters the 

watt, at| I’eter Coope ^ .^gtcai o 

"'pi nnh*^ iSoidiliajng^iScw tube giiy 


is sealed, ai tilling 

temaffls nneo 



Its rays arc greenish, so that where normal colors arc desired, it 
is well to use supplementary lamps of carbon filaments to furnish 
red rays. J^'or strcf'ls, squares, freight-sheds and the like, the 
Hewitt light is capital just as produced, its rays being widely 
diffused and casting no heavy sliadows. Its high actinic power 
makes it specially useful to photographers, while in factories, 
drafting rooms, com])osing nxims and so on, its color is unob- 
jectionable. Its cost is small, as a c:mdle-powcr is produced in 
large tubes with but 0.55 of a watt. A Hewitt lamp of automatic 
tyjie, recently devised, has a small solenoid or magnet on the sus- 
pension bar just above the holder. On closing the circuit the cur- 
rent fknvs through this solenoid which instantly tilts the tube and 
starts the light. This lamp is iiarticularly suited to places, such 
as the lofty ceilings of foundries, where it would be difficult to 
tilt the tube by hand. Hewitt lamps use cither a direct or an 
alternating current. 

•In an earlier chapter we glanced at reflectors and refractors, 
newly invented, which give light its most useful paths with as 
little avoidable loss as possible. These devices, applied to Wels- 
bach burners and the new electric lamps, greatly economize 
modern illumination in comparison with that of former times. 

* In kobriiar}', 1906, the llhnninating- loigineerinj? Society was established 
in New \ ork. Its socrolarv is A. It. 4 Irving Place, New York. 

I he Society publishes its proceedings and discussions. 



I Is new varieties are virtually new metals, strong^, tough, and heat re- 
sisting in degrees priceless to the arts . . . Minute admixtures in other 
alloys are most potent. 

I ^ROM a brief consideration of ilhiminants let ns pass to a 
rapid survey of a most important g^ronp of structural mate- 
rials, the steels. Here, as always, we shall find how abundant are 
the harvests reaped in a searching- study of properties. Within 
the past fifty years new steels have been produced in so ample 
and rich a variety that wc have gained what are virtually many 
new metals of inestimable qualities. 

In 1781 Professor Torbern Bergman, of the University of 
Upsala, in Sweden, showed that steel mainly differs from iron 
in containing alxnit one fifth of one per cent, of plumbago, or car- 
bon, as wc would say now. Steels may contain all the way from 
one tenth to one and a half per cent, of carbon; 
the lower this percentage, the more nearly does 
the steel approach wrought iron in softness; 
as the proportion of carbon increases up to one per cent, the 
steel increases in tenacity, beyond one per cent, tenacity dimin- 
ishes and brittleness is augmented. Hardness depends upon the 
])crcentagc of carbon a steel contains. Physical conditions arc 
almost as important as chemical comix)sition ; a mass of red-hot 
steel, carefully hammered 'or pressed is thereby strengthened, an 
effect due either to minimizing the process of crystallization, or to 
breaking up crystals as fast as they form. The microscope re- 
veals many details of structure in steel, and has enabled the 
analysts greatly to economize the manufacture of desired 
varieties. Under the microscope steels much resemble crystalline 
rocks in structure, with constituents differing widely. Of these 


Steels for 


the most important is ferrite, a pure' or nearly pure metallic iron, 
soft, weak, ductile, of high electric conductivity. Next in im- 
portance is cementite, an iron carbide (FesC), harder than glass 
and nearly as brittle, but probably very strong under gradually 
and axially applied stress. A third constituent, austenite, is a 
solid solution of carbon, or perhaps of an iron carbide, in gamma 
allotropic iron (there being also alpha and beta irons). Austen- 
ite is hard and brittle when cold,, is stable at high temperatures, 
and ‘is slowly transformed by reaction into compounds of ferrite 
or cementite. Several other ingredients of importance, as pearlite, 
illustrated on the opposite page, have also been studied.^ 

While carbon is the most decisive element. in admixture, other 
ingredients have marked influence, silicon and manganese espe- 
cially. The process invented by Bessemer, described by himself 
in another chapter of this book, as introduced in 1855, revolution- 
ized the steel manufacture by its directness, cheapness and §peed. 

It consists in burning out from pig-iron, by a hot air blast, all 
or nearly all its carbon. Then spiegcleisen, or other mixture, 
containing a definite quantity of carbon and manganese, is added 
to the molten mass, yielding steel of the quality desired. This 
method produces more rails for railroads than any competing 
method ; in other fields it is being rivalled more and more severely 
by the open hearth process. 

Steel making by the open hearth process is chiefly due to the 
late Sir William Siemens. In a gas producer he gave his fuel 
the gaseous form, in which it is more easily 
controlled and more efficient than when solid. ^ 
Of more importance were his regenerators, 
chambers of brickwork, heated by the products of combustion, and 
then employed to warm incoming currents of air and gas on their 
way to the furnace. The Siemens furnace has been modified in 
mafiy ways and much improved in its details. A good example 
df an open hearth furnace, as planned by the late Mr. Bernard 
Dawson, is shown on page 165. It centers in a large hearth built 
of refractory materials, upon which the metal is melted as flames 
play over it. At each end are two regenerators filled with checker 

^ Henry Marion Howe, “Iron, Steel and Other Alloys.” Second edition. 
Published by Albert Sauveur, Cambridge, Mass., 1906. 




firebricks through which air or gas passes on its way to the fur- 
nace, and through which, at due intervals, the products of com- 
bustion emerge as they pass to the stack. On each side, one of 
the regenerators is for air, the other for gas; between them is 

Open hearth furnace. 

a substantial wall to prevent any mixing before their currents 
reach the hearth. It is in the regenerator, which utilizes heat which 
otherwise would be wasted, that the open liearth displays its best 
feature. Its products vary in composition as its raw materials 
vary, whether pig-iron of a specific kind, a particular ore, or 
scrap; and just as in the Llessemer process, a harmful element, as 
phosphorus, is removed almost wholly by the addition of a suit- 
able ingredient, such as lime. In excellence and uniformity of 
quality open hearth steels are preferred t(’) those of the Uessemer 
converter, even for railroad rails which for years were made 
solely by the Bessemer process. 

A remarkable improvement in blast-furnace jiractice, cheapen- 
ing cast or pig-iron, and therefore lowering the cost of derived 
steels, is the dry-blast process due ta Mr. James 
Gayley, of Pittsburg. It has long been known Gayley 

that blast-furnaces ask more fuel in warm and Dry-Blast 
, 11- Process, 

clamp weather than in cold and dry weather; 

beginning with this familiar fact Mr. Gayley proceeded to dry the 

air blown into his furnaces, by passing it around large coils of 


iron pipes throrgh which a freezing mixture circulated, melting 
the snow as formed by passing hot brine through the pipes, a few 
of them at a time. The air tints dried was then heated by being 
sent through hot blast stoves in the usual mode. This simple 
drying of the blast saves about 19 per cent, of the fuel, and makes 
the action of the furnace much more regular than when ordinary 
air is used. It lowers the temperature of the gases which escape 
from the top of the furnace, and raises their percentage of carbon 
dioxide, symptoms of the great increase in fuel efficiency. Atmo- 
si)heric moisture has a cooling effect on the lower part of a fur- 
nace, just where the highest temperature is needed to melt the 
iron and slag, remove the sulphur and deoxidize the silica. A 
comjxaratively small increase of temperature by broadening the 
margin of effective heat, which margin at best is narrow, has the 
astonishing effect of economizing fuel to the extent stated, 19 
per cent.‘ 

What is chiedy sought in .steel is tensile strength, next in value 
is elasticity ; in some cases hardness is indispensable. By varying 
the proportions of the carbon, silicon and man- 

Steels to Order. gaiicse added to his iron, the steel-maker pro- 
duces an alloy with the tenacity, elasticity or 
hardness he wishes. Nickel, as a further ingredient, in certain 
proportions yields an astonishing gain. A steel containing tifteen 
pel cent, of nickel has shown a tensile strength of 244,000 pounds 
to th-e scpiare inch, four times as much as before admixture ; the 
clastic limit also was much increased. Hardness and strength 
tend to exclude ductility, but nickel steel is at once strong, hard 
and extremely ductile ; hence its use for armor plale, great guns, 
and the barrels of small arms. Nothing but the high price of nickel 
prevents these alloys from having wide utilization, for they mean 
lighter and therefore more economical machines and engines tlian 
those of ordinary steel. jMany turbines actuated by water, steam 
or gas, arc best o])erated at speeds forbidden to common steel, 
which would fly to pieces under the centrifugal stress exerted, 
yet these speeds are quite feasible and safe when nickel steel is 
employed. This alloy brings nearer the day of mechanical flight, 

MTcnry Marion Howe, ‘‘Iron, Steel and Other Alloys.” Second edition. 
Cambridge, Mass., Albert Saiiveiir, 1906. 



first promising to transportation on lantl and sca'cngincs increased 
in po\Ver while mucli diminislied in weight. In exceptional cases, 
where the expense may be borne, we nia}' expect soon to sec nickel 
steel used for higher towers, longer bridge-spans, thinner boilers, 
than those of to-day. ]*art of the bridge crossing lllackweirs 
Island, New York, is built of nickel steel. INx'ii with costs at 
their present plane, it is worth while for the designer of machinery 
to rcmeml)er that friction is reduced when masses become smaller, 
power for ])Ower. It is found jirolitahle, for instance, to use 
nickel steel for the cylinders of automobiles of high ])ower. 

In many tools and implements two ililTerent kinds of steel are 
united with decided gain. Thus the cutting edge of a cold chisel 
is hard and brittle,’ while its shank, much less hard, is tough and 
able to resist the shocks it receives. So also a projectile is hard- 
ened at its point and nowhere else. Plowshares are often- made 
very hard on their surfaces, with a hacking which is com])aratively 
soft hut elastic enough to suffer no harm in the blows dealt by 
rough ground and stones. One of the drawbacks in the use of 
steel is its liability to eajrrosion. i\n alloy of 30 ])er cent, nickel 
and 70 ])er cent, steel has ])roved to he corrodible in hut slight 
measure, affording a material of great \alue to the arts. 

While the chemical com])osition of a steel is of ]n*imc im]M)r- 
tance, the quality oi the steel will next (U^pend upon its heat treat- 
ment in manufacture. The temperature to 
which heating is carrie<l, the i)eriod during Heat Treatment, 
which it is maintained, the rate at which cool- 
ing takes ])lace, and the circumstances of cooling, each has its 
effect on the character of the ])roduct. It ‘is chielly in this field 
that the steel-maker within wide limits is able to turn out an alloy 
either hard of soft, brittle or ductile, tenacious or weak, at pleas- 
ure. While much has been learned within the ])ast few years as 
to the proper treatment of steel by heat, much still remains to be 

To quote typical instances from Ih'ofessor 1 fenry Marion Ilowc, 
of Columbia LIniversity, New York: — '‘In the case of steel with 
less than 0.33 per cent, of carbon the temperature from which slow 
cooling occurs appears to have little influence on the tensile 
strength; but it is the general belief that if that temoerature ap- 



proachcs the melting-ix)int, the tensile strength decreases. In 
the ease of higher-carbon steel, the tensile strength at first in- 
creases as the tcni{ 3 craturc from which slow cooling occurs rises 
to 800°, or even to 900° or 1000° C. Then, after varying some- 
what, it falls off very abruptly in the case of steel of 0.50 per cent, 
of carbon, when that temperature approaches 1400°.”^ 

For rock drills, cold chisels, milling and other tools it is neces- 
sary to use steel carefully tempered, so that brittleness is greatly 
reduced while considerable hardness and cut- 

Tempering and power remain. Other changes of proper- 

Annealing. . , , , ... ^ . 

ties, as remark^^blc, follow upon subjecting 

steel to greater heat than that used for tempering. Says Profes- 
sor Roberts-Austen “Three strips of steel identical in quality 
are taken. By bending one it is shown to be soft; if it is heated 
to redness and plunged in cold water it will become hard and 
will break on any atteniiit to bend it. The second strip, after heat- 
ing and rai)id cooling, if again heated to about the melting point 
of lead, will at once bend readily, but will , vS])ring back to a 
straight line when the bending force is icmovcd. The third piece 
may be softened by being cooled slowly from a bright red heat, 
and this will bend easily and remain distorted. The metal has 
been singularly altered in its ])ropertics by comparatively simple 
treatment, and all these changes, it must be remembered, have 
been t)ro(.luced in a solid metal to which nothing has been added, 
and from which nothing has been taken away.^’ 

It is the cohiparative slowness of cooling in oil, the greater 
slowness of cooling in air, that make these by far the best tem- 
pering processes, because the molecular re-arrangement, in which 
tempering consists, requires time. Often the critical temperature, 
at which a desired re-arrangement takes place, is declared by the 
metal losing all power of response to a magnet : this fact affords 
the steel-maker welcome aid ; he has only to shut off heat as soon 
as his steel ceases to attract a magnet and plunge the steel into 
water in order to obtain the hardness he wishes. 

The comple.x phenomena of heat treatment in steel manufacture 

* In his *dron, Steel and Other Alloys.” Second edition. Published by 
Albert Sauveur, Cambridge, ^lass., 1906. 

INVAR 169 

are fully discussed by Professor H. M. Howe, in his ^'Iron, Steel 
and Other Alloys,’’ second ctUtion, 1906. 

In another chapter of this book a word is said as to the form 
of rails at which Mr. P. PI. Dudley has arrived as the outcome 
of years of experiment. Pie* thus describes the 
properties which the steel should possess by 
virtue of due chemical composition and proper 
heat treatment:— 

“Ductility to ensure power to resist the shock of the driving* 
wheels, so that the steel may not break ; resistance to abrasion, 
that it may not wear out ; and high limit of elasticity, that it may 
not take a permanent set and be bent into a series of waves be- 
tween its supporting ties, by the enormous pressures wliich the 
wheels of to-day throw upon it. The best composition is carbon 
0.55 to 0.60 per cent., silicon o.To to 0.15, manganese 1.20, sulphur 
under 0.06, phosjihorus under 0.06; with 50,000 to 60,000 granular 
tions to the .square inch. ]\'Iore granulations, or fewer, mean an 
increase of brittleness in the steel.” ^ 

While the great strength of steel makes it of ])rc-cminent 
value in the arts, steel in the huge dimensions of modern roofs 
and bridges has the demerit of expanding with 
heat and contracting with cold in a troublesome Invar : A Steel 
degree. A notable case is that of the steel Invariable in 
rails on the elevated railroad of New York. , 

Jf this fault, common to all metals, can be or Cooled, 
materially reduced or abolished, then steel 
enters upon a new field of golden harvests. Here, by dint of 
acumen and skill the goal has licen reached by M. Charles 
PMouard Guillaume, of the International Ihircau of Weights and 
Measures in Paris. A few years ago he began investigating the 
singular magnetic qualities of nickel-steels. Then in studying 
expansibility by heat he discovered that when the nickel was in- 
creased to 36.2 per cent, the alloy was almost indii'fcrcnt to 
changes of temperature, expanding but one part in one million 
when warmed from zero to 1° Centigrade. Pecausc of this in- 

^ Henry Marion Howe, “Iron, Steel and Other Alloys.” Second edition, 
knblishcd by Albert Sauveur, Cambridge, Mass., 1906. And a note from 
^Ir. P. H. Dudley to the author, ^lay 2, 1906. 



sensibility, the alloy at the siigfgestion of Professor Thury is 
named invar, Jn observations of invar which extended through 
six years, an elongation of one part in 100,000 was detected; 
subsecjiiently its changes of length each year seemed less than 
one-millionth. This slight inconstancy may be overcome by 
further experiment; in the meantime while invar is not available 
for standards of length of the first order, such as those of the 
liurcau of Standards at Washington, there is a vast and useful 
field for the alloy. Tt offers itself for secondary standards, to be 
compared at intervals with primary standards at Washington or 
other cajiitals o*f the world. 

A leading application will be in surveying. Already wires of 
invar have been employed by the Survey of P'rance with the ut- 
most success, dispensing with the burdensome apparatus for- 
merly needed in compensating variations due to temperature. 
With invar wires ten men have advanced at the rate of five 
kilometers a day ; ten years before, with ordinary steel meas- 
ures, fifty men advanced one half a kilometer, that is, with but 
one fiftieth as much efficiency. 

In time-keeping invar is likely to be as valuable as in survey- 
ing. At the Pureau of Standards and the Naval Observatory 
at Washington, pendulums of invar have been adopted with 
gratifying results. In ordinary watches and clocks the alloy will 
banish the com])ensating devices now recjuisitc, of brass and steel 
which ex])and with heat and shrink with cold. I'or chronometers 
of the highest grade it is desirable that invar be improved with 
respect to its stability, an improvement wliich appears to be highly 

(hie other discovery by M. Guillaume deserves a word. PTe 
has found a nickel-stecl which when warmed has the same ex- 
pansibility as glass, so that it may disj^lace platinum wire in lead- 
ing an electric current into an incandescent lamp, a Crookes' tube 
or similar illuminator. More singular still is another of his 
nickel-steels which shrinks slightly when warmed, holding out 
the hope of finding an alloy which will neither shrink nor ex- 
pand as its temperature rises. With such a substance, of trust- 
worthy stability, the arts would have a working material of in- 
estimable value for theodolites, frames for microscopes and tele- 
scopes, and cameras for exact picturing. 



The mag^nctic properties of steel, to-day of supreme impor- 
tance, have for ag*es excited curiosity. As loiigf ag;o as 1774, Rin- 
man observed that steel alloyed with mau- 
g-anesc is non-mag^netic. Here was a material Manganese Steel, 
for time-pieces which would free them from 
magnetic derangement. In tlie hands of Air. R. A. Tladfield, of the 
Mecla Works, Sheffield, Juigland, manganese steel has been i)r(v 
duced in remarkable varieties. As the propiu-tion of manganese 
is increased, the alloys manifest singular changes in their pn^^ 
erties. When the manganese is four to six per ci'ut., and the 
carbon less than one-half per cent., the alloy is brittle enough to 
be readily powdered by a hand hammer. When the pro])()rtion of 
manganese is doubled, the alloy displays great strength, which 
reaches its maximum when the manganese is fourteen jier cent. 
N'o other material approaches mang'inese steel in its ability to 
resist abrasion; it outwears ordinary steel four times, much re- 
ducing the need for repairs, renewals, or ])auses in work while 
worn-out parts are being replaced. It gives e(iually good service 
as the pins and bushings of dredges of the bucket-ladder type, 
lifting gold-bearing gravels and sands. It is uscul for centrifugal 
])umps in dredging sandy harbors, sli])s, or 1)011 ds, where the grit 
borne in the water plays havoc with ordinary steel surfaces. In 
ore-crushing manganese steel is particularly elTective; a pair of 
jaws built of it have crushed 21,000 tons of ilinty ore and were 
still g'ood for 4,000 to 6,000 tons more, while tlie best cliillc‘d iron 
plates failed to crush as little as 4,000 tons. 

This alloy is so hard that it cannot be machined or drilled by 
ordinjfry means; it must be treated by emery or carborundum 
wheels. Yet it is so malleable that it can be used for rivc'ts when 
headed cold. It is so tough that it may be bent and twisted at 
will without rupture, so that it forms railroad switches, frogs, 
and crossings of great durability. 

Until 1868 the steel tools used in lathes and drills, planers and 
so on, were limited to the moderate pace at which they remained 
ccx)! enough to keep their temper. Reyond tliat 
quiet gait thev l)ecamc worthless, snapped Tool 

apart, or melted as if wax. In 1868 Robert 
Forester Mushet, of the Titanic Steel and Iron Company, Cole- 
ford, England, discovered an alloy of steel, tungsten and man- 


gancsc which took rough cuts at a depth and with a speed tin- 
known l)cforc. This alloy, because hardened simply in air, was 
called “air-hardening’’ or “self-hardening.” Thirty years after- 
ward at the Ijcthlchcm Steel Works, Pennsylvania, a tool of this 
steel was heated to what was feared to be a ruinously high tem- 
])eralure ; exi)erinient proved that the tool could be used at a 
heat, and therefore at a speed, never attained before in the work- 
slujp. J^Vom that hour hundreds of investigators have proceeded 
to combine steel with tungsten in various percentages, adding 
manganese, molybdenum, chromium, silicon, and vanadium. Of 
these ingredients much the most important arc tungsten and 
molybdenum. Particular pains must be taken thoroughly to an- 
neal the alloy when worked into bars. 

As to the gain introduced by high-speed tool steels let Mr. 
J. M. (iledhill testify from the experience of the Sir W. G. Arm- 
strong, Whitworth & Com])any’s works at Manchester : — 

“hormerly where forgings were first made and then machined 
with ordinary self-hardening steel, a production, from bars 
eightec'ii and one half by six and five eighth inches, of eight bolts 
in ten hours was usual. With the new steel forty similar bolts 
from the rolled bar are now turned out in the same time, further 
abolishing the cost of first rough forging the bolt to form. The 
speed is t6o feet a minute, the depth of cut three-quarter inch, 
of feed 1/32 inch, the weight removed from each Ixdt sixty-two 
pounds, or 2,480 pounds per day, the tool being ground only once 
in that time. This is a fairly typical case. Just as striking is the 
behavior (T this steel in twist drills, which supersede the punch- 
ing process by passing through stacks of thin steel plates (ffciite as 
swiftly and economically as a punch, while avoiding the liability 
to distress which accompanies the action of a punch.” 

With the (juickening of pace due to these steels, the designer 
is asked to remodel machine tools so that they may stand up 
against new pressures and speeds. A lathe thus re-patterned is 
mentioned by Mr. Glcdhill : it absorbs sixty-five horse power as 
against twelve formerly, and has a belt trebled in width so as to 
measure twelve inches. Mr. Oberlin Smith expects high-speed 
steel to have other effects on machine design than the conferring 
of new strength : he looks for a rivalry keener than ever between 



rotary and reciprocating tools. In his judgment the milling tool, 
which can be speeded indefinitely, will encroach more and more 
on the planer, limited as the planer is by its movement being to 
and fro. 

When work on cast iron must proceed at the utmost pace, a jet- 
of air, delivered to the chips with force enough to clear them of¥ 
as fast as they are formed, enables the speed to be quickened, 
while, at the same time, the life of the cutter is lengtliened.^ 

In electrical art tlie alloy employed for electro-magnets should 
be permeable by magnetism fully and easily, otherwise dynamos 
and motors will waste energy as their magnet- 
ism is constantly gained, lost, or reversed. Alloys for 
Once more the experimenter is Mr. Rol)ert Electro-Magnets. 
A. Hadfield of Sheffield, who j)roduces an 
excellent alloy by uniting iron with 2.75 per cent, silicon, .08 
per cent, manganese, .03 per cent. suli)hur, .03 per cent, phos- 
phorus. This alloy is improved by being heated to between 900° • 
and 1100° C., followed by quick cooling; then being reheated to 
between 700° to 800° C., and cooled very slowly. 

Iron is largely used as an electrical conductor, so that it is well 
to know how its conductivity is affected by ‘ordinary admixtures. 
In experiments with sixty-eight specimens. Professor W. P. Ilar- 
rett alloyed iron separately with carbon, aluminium, silicon, chro- 
mium, manganese, nickel, cobalt, and tungsten. In every case 
there was a loss of conductivity, and usually in a degree pro- 
portioned to the atomic weight of the added ingredient. I between 
one element and another there was often a wide disj^arity of 
effect."*^ h'or example, in admixtures, each of one per cent., tung- 
sten increased the resistance of a conductor by two per cent., 
while aluminium did seven- fold as much harm. 

We have so long been accustomed to thinking that there must 
be iron in everything magnetic that we hear with astonishment 
diat metals each insusceptible of magnetism, when united strongly 
display this property. Such is the discovery of Mr. Fr. Hcusler, 

' The foregoing pages on steel have been revised by Professor Bradley 
Stoughton, of the School of Mines, Columbia University, New York. He 
contributes at the end of this chapter a brief list of books for the reader 
who may wish to know something of the literature of iron and steel. 



oi I)illcnl)urg, near Wiesbaden. He noticed one day that an alloy 
(jf inani^anese, tin, and copper adhered to a tool which he had 
accidentally magnetized. In the course of ex- 
Magnetic Alloys pcrinicnts Mr. Hcusler found that carbon, sili- 
of Non-Magnetic Con, and phosphorus did not confer magnetism ; 

Ingredients. ^Yl^ilc arsciiic, antimony, and bismuth did 
so, all three metals being diamagnetic, 
lliat is, placing themselves at right angles to a common steel 
magnet above which they arc freely suspended. An alloy of re- 
markable magnetic strength was composed of copper 61.5 per 
cent., manganese 23.5 per cent., and aluminium 15 per cent. This 
ahoy is brittle and considerable changes of temperature but 
slightly alTect its magnetism. When a little lead is added magnet- 
ism disa])pears between () 0 ° and 70° C. This alloy therefore is 
magnetic when placed in cold water; when the water is heated the 
magnetism disa])])ears bebu'c the water boils, only to reappear 
when the water cools. The main interest of these discoveries is 
that the new allo\s bridge the gap betwixt magnetic and dia- 
magnetic bodies, tliat is, they join the iron, nickel, and cobalt 
gron{\ which ])lace themselves along the line of a magnetic field, 
with the diamagnetic elements, bismuth, antimony, zinc, tin, lead, 
silver, and arsenic, which ])lacc themselves at right angles to the 
lines of a magnetic field. We have been accustomed to suppose 
that magnetism is a ])r()])erty possessed by only a few elements; 
these alloNS show us that magnetism may arise as a result of 
grouping atoms, none of which by itself has any magnetism what- 
ever. Indeed it may be possilde to make an alloy more magnetic 
than iron, furnishing the electrician with electro-magnets of new 


\\\‘ have brielly glanced at recent progress in the art of alloy- 
ing in so far as it has produced steels of new strength, elasticity, 
or hardness ; new ability to resist abrasion or 
higli temperatures, new capacity for magnet- 
ism, new indilTerence to changes of tempera- 
ture as ail'ecting dimensions. Alloying has of late years conferred 
other gifts upon industry, of which one example may be citcdi 
from among many of ecpial importance. Friction levies so 
grievous a tax upon the mechanic and the engineer that they are 



quipk to seize upon any material for bearings which reduces 
friction. As the result of extensive experiments Dr. C. B. Dudley 
recommends an alloy of tin, copper, a little phosphorus, with ten 
to fifteen per cent, of lead. He finds the loss of metal hy wear 
under uniform conditions diminishes as the lead is increased and 
the tin diminished. 

We have seen how remarkably the properties of iron are af- 
fected hy minute additions of carbon which may he assumetl to 
enter into chemical union with the metal. The 

properties of other metals may he inlluenced 
hy minute quantities of added elements, al- 
though in quantities so small as to preclude 

Influence of 

the possibility of their *forining ordinary chemical compounds. 

It hy no means follows, however, that tlie atom of an added 

element does not exert a direct influence. Tn Professor Roherts- 

Austen’s lalx)ratory, in T.ondon, two ladles were filled with ex- 
ceptionally pure bismuth ; into one ladle a tiny fragment of tel- 
lurium was placed. The ladles were jxnired each into a separate 
mold, and when the metal became cold it was fractured by a ham- 
mer. The bismuth to which the tellurium was added Iiad become 

minutely crystalline ; while that which remained pure had crys- 
tallized in broad mirror-like ])lanes. One reflected light as a 
mirror; the other, containing the tellurium, scattered the light it 
received. With no guidance but that of mere inspection, one 
would have said that the two substances were distinct elements, 
and yet the only difference was that one contained 1/2000 part of 
tellurium and the other no tellurium at all. 

Submarine telegraphy presents us with- a case as striking: were 
its copper wire to contain but one-thousandth jiart of liisniuth, 
the line would be so much reduced in conductivity as to be com- 
mercially worthless: ([uite as harmful are mixtures of antimony. 
In coining, the addition to gold of one five-hundredth ])art hy 
weight of bismuth produces an alloy which crumbles under the 
die and refuses to take an impression. Tn the manufacture of 
such dies it is necessary to employ a .steel containing 0.8 to T per 
cent, of carbon and no manganese. It is usual, says ITofessor 
Roberts- Austen, to water-hard en and temper it to a straw color, 
and a really good die will strike 40,000 coins without being 



fractured or deformed, but if the steel contains o.i per cent# too 
much carbon, it would not strike lOO pieces without cracking, and 
if it contained 0.2 per cent, too little carbon, it would probably 
be hopelessly distorted and its engraved surface destroyed in the 
attempt to strike a single coin. As in coining so in steam- 
engineering. A little arsenic added to copper improves it for the 
fire-boxes of locomotives. Boilers of old, formed of copper 
slightly admixed with sulphur, lasted longer than modern Ixjilers 
built of copper free from sulphur. Antimony behaves like 
arsenic, and in due proportion strengthens copper; bismuth, on 
the contrary, weakens copper, and a perceptible effect is wrought 
by a mere trace. Nickel is made malleable by adding extremely 
small quantities of phosphorus, magnesium, or zinc. 


Chosen and annotated by Professor Bradley vStoughton, School 

of Mines, (.\dumbia University, New York. (Oraduated Vaie Univer- 
sity, 189J, as J'li. B. In 1896 Assistant in Mining and Metalhirgy at Massachusetts Insti- 
tute of 'rechnology, Boston, where he received the degree of li.S. In 1898-99, metallurgist 
of South Works. Illinois Steel Co., South (diicago. Superintendent in loooof steel foundry, 
Briggs-Seabury Oun and Ammunition Co., Derby, Conn. Manager of Bessemer plant, 
Benjamin Atba iS: Co., Newark, N. J., In 1901. Instructor in metallurgy, Columbia Uni- 
versity, i90..’-cu. Next year became Adjunct IVofessorof IMetallurgy, Columbia University 
and, as consulting nu*.^llurgist, entered the firm of Ilowe Stoughton, New York.) 

r>.\i.r,, Gi<:ok(ik R. Modern imuiulry Practice. Part I, 1902. Part II, IQ06. 

London, Teclinical Publishing Co. 35. 6t/, each. 

An admirable work, the only one covering the w'holc field. The author 
thoroughly understands his snl)ject, and writes most intelligibly. The 
principles underlying every detail of practice arc clearly explained. 

l\'irt I deals wdth foundry ctpiipincnt, materials used, furnaces and 
processes, describes Idow’ers, ladles, cranes, hoists, cupola, air furnaces, 
drying ovens, dry and green sand, the manufacture of chilled castings and 
malleable iron castings. 

Part IT takes up machine molding, physical properties, the effects pro- 
duced by variolas ingredients, the principles of mixing irons, cleaning 
castings. Costs arc considered in conclusion. 


Bell, Sir Isaac Lowtuian. Principles of tlic Manufacture of Iron and 
Steel. London, George Roulledge & Sons, i8tS4. 722 pp. 2Ly. 

A classic. Like “Clieiiiical Phenomena of Iron Smelting,” by the same 
author, now out of print and rare, it will never be replaced by a new 
liook in the metallurgist’s library, although somewhat out of date. Deals 
with principles ever important, while our knowledge of them increases 
constantly. Begins with a brief history, then passes to the direct processes 
for the production of iron and steel. Then follow sections on the funda- 
mental principles of blast furnace operation, and a study of the refining 
of pig-iron, or, in other words, the principles of the conversion of pig- 
iron into wrought iron and steel. Por recent metallurgical practice, some 
later hook is to lie preferred. 

C.Vmimjell, IIaury TIuse. ^lanufacture and Properties of Iron and 
Steel. 2d edition. New York, Engineering and IMining Journal, 1903. 
839 PP. $5-00. 

klr. Campbell is a careful and deep thinker. He is well known as the 
successful manager of a large and important steel works. Out of 
abundant knowledge, gathered in long experience and study, he gives 
in this book much valuable information. Details of the various furnaces 
and their operations are frequently lacking, but as a comparative study 
of leading methods of steel-making, and of the commercial conditions 
involved, this work has no eiiual. 

Harford, F. W. Metallurgy of Steel. With a section on the Mechan- 
ical treatment of .Steel, by b'. W. Hall. Revised edition. London, 
Charles Griffin & Co., 1905. 792 pp. 2Ss. 

This exhaustive treatise is the best of its kind. Abounds with valuable 
information on furnaces and their working, on the effects of different 
impurities in steel. On the shaping of steel mechanically it is the only 
complete treatise. This work de.als, however, chietly with English prac- 
tice, while American practice is larger and more progressive. 

Howe, Henry M. Iron, Steel and Other Alloys. 2d edition, slightly re- 
vised. Boston, A. Sauveur, 1906. j8-b495 pp. $5.00. 

The best and most complete work on the modern theory of the consti- 
tution of steel by the highest living authority. Can be readily understood 
by any one having a slight knowledge of cheniistr\\ In adilition to the 
Hudy of iron and steel as metals, brief but satisfactory chapters in manu- 
facture are included. 

Howe, Henry 1 \T. ^Metallurgy of Steel. Vol. I. 4th edition. New York, 
haigineering and Mining Journal, i8(;o. 385 pp. $10.00. 

Still recognized the world over as the standard authority; every book 
written on its theme since 1890 builds upon this work as the source of 


highest reference. Devoted chiefly to the effects of different impurities, 
and of treatment, on steel. The crucible and Bessemer processes arc de- 
scribed at some length. Not a work for general readers. 

Mkfj.or, J. W. Crystallization of Iron and Steel: an Introduction to the 
Study of Aletallography. Ixmdon and New York, Longmans, Green & 
Co., 1905. 154 pp. $l-6o. 

Reprinted lectures giving an excellent popular account of the consti- 
tution and nature of cast iron and steel. Includes right and wrong 
methods of annealing, hardening and tempering steel, and their micro- 
scopic examination. The information is presented in a terse and at- 
tractive style. Any reader of a scientific turn will find profit in this book. 

Skxton, a. 1 luMJioLDT. Outline of the Metallurgy of Iron and Steel. 
Manchester, Scientiiic Ihiblishing Co., 1902. l6.y. 

'Die best, because most recent of the good elementary text-books 011 
iron and steel. It is behind the times in regard to American practice, 
but contains a great deal of important information, clearly expressed. 
Covers iron ores, their physics and chemistry, construction and working 
of the blast furnace, foundry practice, puddling, forging, the Bessemer, 
open hearth and crucible, special steels, the testing of steel and 
protection from corrosion. Its sketch of the structure and heat treatment 
or iron and steel is very incomplete. 

Swank, Jamf.s 1\T. Short History of the Manufacture of Iron in all 
ages, i)articular]y in the United Stales from 1585 to 1885. 2d edition. 
Philaflelphia, American Iron and Steel Association, 1894. 428 pp. $5.00. 
The best historical account of iron and steel manufacture, written in 
an interesting manner. So carefully systematized that the history of any 
branch of the subject may be studied independently. 

Swank, Ja:uk.s M. Direct(wy of the Iron and Steel Works in the United 
States and Canada, luiibracing a full description of the blast furnaces, 
rolling mills, steel work.s, tin plate and terne plate works, forges and 
hloomaries in the United States; also classified lists of the wire rod 
mills, structural mills, plate sheet and skelp mills, Bessemer steel works, 
open hearth .steel works, and crucible steel works. l6th edition. 
Phi 1 ad('lphia, American Iron and Steel Association, 1004. $10.00. 

A Supplement to this directory contains a classified list of leading con- 
sumers of iron and steel in the United States, corrected to January, 
TQOd- iQfi pp. $5 00. 

The Penton Jhihlishing Co., Cleveland, Ohio, publish a list of the iron 
h-nndries in the Ihiited States and Canada, mentioning plants not listed 
by Mr. Swank, 1906. $to.oo. 


Turner, Thomas. Metallurgy of Iron and Steel. Edited by Prof. W. C. 
Roberts-Austeii. Vol. I, Metallurgy of Iron. London, Charles Griflin & 
Co., 1895. 367 PP* 

If but one book is to be chosen, this is the best on ores, construction and 
working blast furnaces, the properties of iron, the manufacture and 
properties of wrought iron. It also has valuable chapters on foundry 
practice, the history of iron, blast furnace fuels, forging and rolling, and 
the corrosion of iron and steel. 

WoomvoRTir, Joseph V. Hardening, Tempering, Annealing and Forging 
of Steel : a treatise on the practical treatment and working of high 
and low grade steel. New York, Norman W. Henley & Co., 1903. 
j 88 pp. $2.50. 

Treats of the selection and identification of steel, the most modern and 
npproved processes of heating, hardening, tempering, annealing and forg- 
ing, the use of gas blast forges, heating machines and furnaces, the an- 
nealing and manufacture of malleable iron, the treatment and use of 
self-hardening steel, with special reference to case-hardening processes, 
the hardening and tempering of milling cutters and press tools, the use 
of machinery steel for cutting tools, forging and welding high grade 
steel forgings in America, forging hollow shafts, drop-forging, and 
grinding processes for tools and machine parts. 

It is ahiK^st iniiiossible to say which is the best book on the practice 
treated in this book. It has been chosen because it contains much valu- 
able information which has the rare quality of not only being useful in 
the shop, but of being accompanied by the reasons involved. Copiously 
illustrated. Many useful tables. I'or one looking for general knowledge 
it will be found serviceable, h'or the seeker who wishes si)ecial data no 
single book will suffice. 

JoORNAi. OF THE Ir().^«i AND Steel INSTITUTE. IMited by T>ennett H. 
Brough. London. Published by the Institute. Seniianmud. h^acli 
mmiher 16 shillings; mailed by Lcnicke & Buechner, Ji IC. ryth St., New 
York. $4.50. 

Contains many articles of importance, and abstracts of a large part 
of the current literature of iron and steel, dlius almost every metallurgist 
who begins the study of a new subject uses this Journal ; he linds it a 
guide to the latest information which has not yet found its way into 
reference and text books. 

Pevue de Metam.urgie. lulited by Henri Le Chatelier. Paris. Monthly. 
Per annum, 40 francs; mailed by Lemcke & Buechner, 11 E. 17th St., 
New York. $10.00. 

Most valuable for recent literature on the constitution of iron and steel 
and their alloys. Contains bibliographies of works on these subjects. 


PRO P I '.RT I ES —Con tin tied 

Glass of new and most iisefnl qualities . . . Metals plastic under pressure 
. . . Non-conductors of heat . . . Norwegian cooking box . . . Aladdin 
oven . . . Matter seems to remember . . . Feeble influences become 
strong in time. 

A S in the case of the aluminiiini bronzes and nickel steels, 
alloys of the utmost value have been formed by introducing 
new ingredients, often in little more than traces, or by modifying 
but slightly the proportions in which ingredients long familiar 
have been mingled together. An ecpial gain 
has followed u])on varying anew the comi)osi- Jena Glass, 
tion of glass, b'or centuries the only materials 
added to sand for its melting pot were silicic acid, potash, soda, 
lead-oxide, and lime. As optical research grew more exacting 
the (juestion arose, Will new ingredients give ns lenses of better 
qualities? bdrst of all came the demand for glasses which com- 
bined in lenses would yield images in the telescope and micro- 
scope free from color. In a simple lens, such as that of an ordi- 
nary reading glass, wc can readily observe the production of 
c()lor by a common beam of light. The rays of different colors, 
which make up white light, are refrangible in different degrees, 
so that while the violet rays come to a focus near the lens, the 
red rays have their focus farther off; the images, therefore, in- 
stead of being sharply defined, arc surrounded by faint colored 
rings. In a telescope or microscope a simple lens would be of 
no value from the indistinctness of its images. To correct this 
dispersion of color a second lens of opposite action is placed be- 
hind the first, that is, a crown-glass lens is added to a flint-glass 
lens. (See cut, p. 254.) This remedy is not quite perfect for 
the reason that the distribution of the spectrum from violet to 




red varies with each kind of glass, and in such a way that through 
failure of correspondence, color to color, in a compound lens, 
variegated fringes of light, though faint, arc perceptible, much 
to the annoyance of the microscopist, the astronomer, and the 

With a view to producing glasses which united in compound 
lenses should be color free. Rev. V^ernon Ilarcourt, an iMiglish 
clergyman, in 1834 began experinients which he continued for 
twenty-five years. Ry using boron and titanium in addition to 
ordinary ingredients of glass, he j^roduced lenses less troubled by 
color than any that had before been made. Ilis labors, only in 
jxart successful, were in 1881 followed by those of Professor Ernst 
Abbe and Er. Otto .^chott at Jena. With resources provided by 
the Government of l^russia, these investigators were able to do 
more for the science and art of glass-making than all the workers 
who stood between them and the first melters of sand and soda, 
'rhey immensely diversified the ingredients employed, carefully 
noting the behavior of each new glass, how much light it ab- 
sorbed, how it behaved in danij) air, what strength it had, how it 
retained its original (pialities during months of keejdng, and in 
particular how variously colorccf rays were distributed through- 
out its field of dispersion. As in the bk'nding of new alloys it was 
found that many of these novel combinations were useless. Gf 
the scores of new glasses i)roduced some were extremely brittle, 
others were easily tarnished Iw air, or so .soft as to refuse to be 
shaped as prisms or ground as lenses. A more systematic plan of 
experiment was therefore adopted: for the production of new 
glasses there were by degrees separately introduced in varied 
quantities, carefully measured, boron, phosphorus, lithium, magne- 
sium, zinc, cadmiuin, barium, strontium, aluminium, berylium, 
iron, manganese, cerium, didymium, erbium, silver, mercury, thal- 
lium, bismuth, antimony, arsenic, molybdenum, niobium, tung.sten, 
tin, titanium, fluorine, uranium. An early and cardinal discovery 
was that the relation between refraction and disj^ersion may be 
varied almost at will. For examjde, boron lengthens the red end 
of the spectrum relatively to the blue ; while fluorine,, potassium, 
and sodium have the opposite effect. With the distribution of the 
diverse hues of the spectrum thus brought under control, there 



were produced glasses which, when united as compound lenses, 
were almost perfectly color-free, rendering images with a new 
vsharpness of definition. Yet more: in their unceasing round of 
experiments Professor Abbe and Dr. Schott came upon glass so 
little absorbent of light that combinations of much thickness inter- 
cepted only a small fraction of a beam ; they were indeed almost 
perfectly transparent. This achievement is of great importance to 
the photographer, whose planar combination of six lenses may be 
four inches in thickness. At Jena the researchers arc endeavoring 
to perfect another gift for the camera: they seek to produce 
glasses each transmitting but one color, for service in color- 

To microscopy they have recently given lenses which completely 
transmit ultra-violet rays so as to photograph the diffraction discs 
of objects, such as gold particles in colloidal solutions, otherwise 
invisible, because below the resolving ])Ower of the most powerful 
microscope. It is estimated that with this new aid an object but 
T/250, 000,000 of a millimeter in length may indirectly be brought 
to view. 

One ancient art, that of annealing glass. Professor Abbe and 
Dr. Schott greatly improved, eliminating from their products the 
stresses which distort an image. l>y means of an automatic heat- 
regulator, the temperature of a batch of glass could be kept stead- 
ily for any desired period at any point between 350*" and 477° C., 
or allowed to fall uniformly at any prescribed rate. The glass 
was usually contained in a very thick cylindrical copper vessel, 
on which played a large gas flame. The highest temperature 
found necessary to banish stress, that is, to cause softening to 
begin, was 465"^ C. The lowest temperature required to ensure 
complete hardening was about 370° C. Thus the temperatures of 
solidification all lie between 370° and 465°. This fall of 95° was 
s]:)read over an interval of four weeks, instead of a few days as 
formerly, with the result that stress was banished utterly. 

A practical example of the benefits gained in the properties of 
Jena glass is exhibited by its use in measuring heat. A thermom- 
eter of common glass when first manufactured may tell the truth, 
and in a month or two may vary from truth so much as to be 
worthless. The reason is that the dimensions of the glass slowly 

liy Hr.limliih iV '1 us-.'h 




change clay by day, as in a less degree do those of many alloys. 
It was one of the aims of the Jena lalxiratorv to produce a glass 
which should remain constant in its dimensions while exposed to 
varying temperatures, so that, made into thermometers, it would 
be thoroughly trustworthy. Mere, too, success was attained, so 
that thermometers of Jena glass are found to be reliable as are no 
instruments of ordinary glass. This product is available for astro- 
nomical lenses, otherwise liable to serious changes of form as 
exposed successively to warmth anil cold. 

Heat was to be staunchly withstood not only in moderate varia- 
tions, but in extreme degrees. From time immemorial heat sud- 
denly applied to glass has riven it in pieces. Could art dismiss 
this ancient fault? To-day a beaker from Jena may be filled with 
ice and placed with safety on a gas flame. In its many varieties 
this glass furnishes the chemist with clean, transiiarent and un- 
tarnishing vessels for the delicate tasks of the laboratory, all of 
singular indifference to heat and cold. Yet again. Special kinds 
of this glass in chemical uses arc attacked by cold or hot corrosive 
lifjuids only one-twelfth to one-fourth as much as good I Bohemian 
glass, the next best material. 

Not only to heat but to light Jena glass renders a service. Glass 
of ordinary kinds when used for the tubes of a Hewitt mercury- 
vapor lamp, absorbs a considerable ])art of the ultra-violet rays 
upon which photography chiefly depends. A Jena glass free from 
this fault is formed into Uviol lamps (.)f great value in taking 
])hotographs, ph(jto-copying, and photo-engraving. These lamps 
are also employed in ascertaining the comparative stability of inks 
and artificial dyes ; .so intense is their action tliat brief ])erio(Is 
suffice for the tests. Uviol rays severely irritate the eyes and skin ; 
they may prove useful in treating skin diseases. They moreover 
quickly destroy germs. In all these activities reminding us of 

Thus by a bold departure from traditional methods in glass- 
making, the eye receives aid from lenses more powerful and more 
nearly true than ever before swept the canopy of heaven, or 
peered into the structure of minutest life. iMcanwhilc instruments 
rff measurement take on a new accuracy and retain it as long as 
they last. All this while a material invaluable for its transparency 



Power Presses 
in Metal 

is redeemed from brittleness and corrodibility, and given a 
strength all but metallic ; at the same time transmitting light with 
none of the usual subtraction from its beams. 

From glass let us now turn to metals. It is their tenacity that 
chiefly gives them value; this tenacity is usually accompanied by 
a hardness which disposes us to regard nickel, 
for example, as of a solidity quite unyielding. 
lUit the coins in our pockets prove that under 
the pressure of minting machinery they are as 
impressible as wax. In molds and dies, each the counterpart of the 
other, brass, bronze, iron, steel, and tin-plate take desired forms 

as readily as if paste. Solid 
though these metals appear 
they yield under severe 
stress with a semi-fluid 
quality. We have long 
had stamped kitchen ware, 
baking. pans, and the like; 
the principle of their manu- 
facture has of late years 
been extended to ware of 
more importance. Bliss 
powtT* presses are to-day 
turning out hundreds of articles which until recently were either 

Jjliss forming die. 
r>, ])lank-lioldcr. C, 
1), pusli-out plate, 
pressure surfaces. 

A, bed plate, 
drawing punch. 
O, P, annular 

6fh. Operation 
4f/?. Operation 

3d Operation 

2d Operation 
tst Operation 

Sizing or Finishing Die 
Redra^ving Die 

Redro^ving Die 

Redrawing Die 
Drawing Die 

Bliss process of shell making. 


slowly hammered or fipun into form, pieced with solder, or shaped 
by the gear cutter or the milling machine. These presses furnish 
the United States Navy with sharp-pointed pn^jectiles, some of 
them so large as to demand 
a million pounds pressure 
for their production ; they 
make strong seamless drawn 
battles, cylindrical tanks for 
compressed air and other Mandolin pressed in alumininm. ♦ 
gases, and cream separators 

able to withstand the bursting tendency of extremely swift 

Presses less powerful produce scores of ])arts for sewing ma- 
chines, typewriters, cash registers, bicycles, and 
so on ; or, at a blow, strike out a gong .from a 
disc of bronze. Presses of another kind stamp 
out cans in great variety, and even a mandolin 
frame in all its irregular curves. Tubs arc 
quickly pressed from sheets of metal ; a i^air of 
such tubs, tightly joined at their rims ])y a double 
seam, form a barrel impervious to oil or other 
liquid, and hence preferable to a wooden barrel. A i)ress o])erated 
by a double crank may be arranged to supersede the forging of 
hammers, axes, and mat- 
tocks. Another press at a 
blow cuts out tlie front for 
a steel range. Still another 
press invades the foundry, 
producing excellent gear 
wheels for trolley cars, not 
weakened by being cut from 
a casting across the grain of 
the metal. Sometimes the article manufactured rc(|uircs a series 
of operations, as in the case of a kettle cover with its knob. At 
the Lalance & Grosjean factory, Woodhaven, New York, a Pliss 
press makes such covers in a single continuous round., y\nother 
press treats soft alloys, so that a disc one inch in diameter when 
hit by a plunger is forced into the shape of a tube suitable to hold 
paint or oil. 

l>arrcl of pressed steel. 

Pressed Seam- 
less pitcher. 



In lar^e manufacturCvS as in small the hydraulic forge has 
wrought a quiet revolution. If a steel freight car were produced 
by planing, turning, slotting and similar machines, it would be 

much heavier and dearer 
than as turned out to-day 
from ingeniously fashioned 
dies under severe pressure. 
Its girders are molded of 
the same strength through- 
out with no waste of mate- 
rial, and without rivets ; 
corner pieces are avoided; 
stiffeners are built up from 
the plates themselves 
Range front pressed from sheet steel. through the introduction of 

ridges and depressions : and 
in a structure having the fewest possible parts, uniform strength 
is attained Ix'causc dimensions everywhere niay freely depart 
from uniformity. 

In a vast manufactory of vSteel cans, 
of steel structural forms, steam has to 
be conveyed long distances from the 
boilers. Here, as in similar huge Pressed paint tube and cover, 
establishments, or in the heating of 

towns and cities from central stations, it is desirable to lose as 
little heat as possible by the way, for undue waste means 
enormous inroads upon profits. There arc 
other reasons for wishing to keep heat within 
a steam pipe ; much damage may be done to 
fruit, flour and other merchandise unduly warmed. Furthermore 
there is a risk of setting fire to woodwork, ]:)apcr, cotton and the 
like; it has been observed that after a month’s exposure to heat 
from stcampipes, wood takes fire at a temperature which at first 
would not have led to ignition, because then the wood contained a 
little moisture. To guard against loss and danger it has long been 
the practice to cover steampipcs with jackets of non-conducting 
material, such as mineral-wool,— furnacc-vslag blown into sliort 
glassy fibres by a sharp blast of air. Felt, loosely folded, also 


serves well. Many advertised claims for asbestos are not well 
founded; this mineral is incombustilde and is therefore useful in 
thick curtains to separate a sta^e from the au(lit(M‘ium of a 
theatre. But it is a fairly good conductor, and for steampipes 
should be used as a direct covering of the metal simply to keep an 
outer and much thicker coat of felt from being charred. Wliat- 
ever the material chietly cm])loyed, one j^oint is clearly brought 
out by experiment, namely, that the air detained by the fibres of 
a covering greatly aids in obstructing the passage of heat. Hence 
it is well to keep the materials from becoming compacted together, 
as do ashes when moistened. Asbestos fibres, which are smooth 
and glassy, do not take hold of air as do cork and wool. 

Professor J. M. (Irdway, of the Massachusetts Institute of 
Technology, Jioston, tells us that non-conductors should he of 
materials that are abundant and cheap; clean and inodorous; light 
and to ap|)ly; not liable to become conijiacted by jarring or 
to change by long keeping; not attractive to insects or mice; not 
likely to scorch, char or ignite at the long-continued highest tem- 
jierature to which they may be exjxised ; not liable to spontaneous 
combustion when partly soaked in oil; not prone to attract 
moisture from the air; not capable of exerting chemical action on 
the surfaces they touch. No material combines all these de- 
sirable qualities, but a considerable range of substances fulfd 
most of the requirements. 

dVsts of steam-pipe coverings at Sibley College, Cornell Ihii- 
versity, and at Michigan University, have resulted as follows; — 

R».l;itivi‘ Amount of 

Kind of Coverinj^ Ileal 'i'l aiismittcd 

Miked pipe loo. 

1 wo layers asbestos pipe, i inch hair felt, canvas cover 15.2 

I lie same, wrapped with manila i)aper 15. 

I wo layers asbestos paper, 1 inch hair felt 17. 

Hair felt sectional covering, asbestos lined 18.6 

^ hie thickness asbestos board 5f).4 

’ "ur thicknesses asbcsttis paper 50.3 

I wo layers asbestos paper 77.7 

A ool felt, asbestos lined 23.1 

\\ ool felt with air spaces, asbestos lined 19.7 

A ool felt, plaster paris lined 25.9 



Relative Amount of 

Kind of Covering Heat Transmitted 

Asl)CStos molded, mixed with plaster paris 

Asbestos felted, pure long fibre 20.1 

Asbestos and sponge 18.8 

Asbestos and woed felt 20.8 

M.'ignesia, molded, applied in plastic condition 22.4 

Magnesia, sectional 18.8 

MiJieral wool, sectional 19.3 

Rock wo(d, fibrous 20.3 

R(x:k wool, felted 20.9 

I'ossil meal, molded, ^ inch thick 29.7 

In general the thickness of the coverings tested was one inch. 
Sfnne tests were made with coverings of different thicknesses, 
from which it would appear that the gain in insulating power 
obtained by increasing the thickness is very slight compared with 
the increase in cost.^ 

.Some properties of matter seem to have family ties. Tenacity 
and conductivity for heat, as an example, go together; all the 
fciiacious metals as a group are conducting as well. Conversely, 
the non-conductors, — felt, gypsum, and the rest, arc structurally 
weak. If the inventor could lay hands on a material able to with- 
stand high pressure and, at the same time, carry off wastcfully 
hut little heat, he would build with it cylinders for steam engines 
much more eccniomical than those of to-day He would also give 
cooking apparatus of all kinds a covering which would conduce 
to the health and comfort of the cook, while, at the same time, 
heat would be economized to the utmost. One of the advantages 
of electric heat is that it can be readily introduced into kettles 
and chafing dishes surrounded by excellent non-conductors; the 
result is an efficiency of about ninety-five per cent., quite unap- 
proached in the operations of a common stove or range. 

The costliness of electric heat forbids the housekeeper from 
using much of it. Her main source of heat must long continue 
to be the common fuels. These, however, thanks to cheap non- 
conductors, may be used with much more economy and comfort 

' Rolla C. Carpenter, “ITeating and Ventilating Buildings,” p. 229. New 
Aork, John Wiley & Sons, 1905. 



than of old. Take, for example, the Norwegian cooking box, 

steadily gaining favor in P"uropc and well worthy of popularity 

in America. It consists of a box, preferably 

cubical, made of closely fitted thick lx)ar(ls, Norwegian 
, , . , ^ -11 , 1. , Cooking Box. 

with a hd which fits tightly. l>ox and lid arc 

thickly lined with felt or woolen cloth, and filled with hay except 
where pots are placed. These pots, filled with the materials for 
a soup, a stew, a ragout, are brought to a boil on a fire and then 
placed within the box, its lid being then fastened down. For 
two hours^ or so the cooking process goes on witli no further 
a])plication of heat. To be sure the temperature has fallen a little, 
but it is still high enough to complete the i)re])aration of a whole- 
some and palatalde dish, with economy of fuel and labor, without 
unduly heating the kitchen. 

Norwegian cooker. 

On the same principle is the Aladdin oven, invented by the late 
Edward Atkinson of Boston, and manufactured by the Aladdin 


Oven G)ni])any, lirofjkline, Mass. It is built of iron, surrounded 
willi air cell asbestos IxKird, vSo as to maintain a cooking tem- 
])eralure of 4(K)° k'abr. with little fuel or atten- 
tion. hs (Iroj) door when oi)en forms a shelf, Aladdin Oven, 
when cl(jsed it is fastened by a brass eccentric 

catch, ensuring tightness ; its 
w(X)dcn stand has an iron 
top to hold the oven firmly 
in place. This apparatus 
cooks a wide range of dishes 
admirably, retainitig the na- 
tural flavors of meats, fish, 
vegetables and fruits as ordi- 
nary excessive temperatures 
never d(x Mr. Atkinson 
wrote “Tlie Science of Nutri- 
tion,” which sets forth the 
construction and uses of this 

JCvcry pro])erty of matter 
seems universal. The best 
non-conductor of heat trans- 
mits a little heat ; the best 
conductor is ])y no means ])erfect : the two classes of substances 
are joined by iiialerials which gradually ai)])roach one end of tin 
scale or the other. Xothing is so hard but that 
it ui.i\ h(. indented oi engiaved, and wheie Matter Impressec 
iu‘ither a blow nor severe pressure is employed, by Its History, 
we may have, as in the j)h(4ograi)hic i)late, an 
impression which is chemical instead of mechanical, displaying 
itselt to the eye only when treated with a suitable developer. A 
bar ot steel hammered on an anvil is changed in properties; as it 
heconu's closer in textun* its tenacity is increased. When that 
l)ar takes its place in a structure, the work it has to do, the shocks 
it hears, ecjually tell upon its fibres. Stresses and strains leave 
their eliects upon the stoutest machines, engines, bridges; they 

M'uhlislicd hv Daiiirell iS: L'pliani, Boston. $i.oo. 

Al.'iddiii oven. 



arQ never the same afterward as before, and usually their ex- 
perience dqes them harm. Says an eminent engineer, Mr. W. 
Anderson : “The constant recurrence of stresses, even those within 
the elastic limit, causes changes in the arrangement of the par- 
ticles which slowly alter their properties. In this way pieces of 
machinery, which theoretically were abundantly strong for the 
work they had to do, have after a time failed. The effect is inten- 
sified if the stress is suddenly applied, as in the case of armor 
plate, or in the wheels of a locomotive. . . . When considerable 
masses of metal have been forged, or severely pressed while 
heated, the subscfjuent cooling of the mass imposes restrictions on 
the free movement of some if not all the particles, hence internal 
stresses are dcvclo])ed which slowly avssert themselves and often 
cause unexi)ccted failures. In the manufacture of dies for coin- 
age, of chilled rollers, of shot and shell hardened in an unequal 
manner, s]>ontaneous fractures take place without ap])arent cause, 
through constrained molecular motion of the inner particles 
gradually extending the motion of the outer ones until a break 

Sir Benjamin Baker says: — '‘Many engineers ignore the fact 
that a bar of iron may l3C broken in two ways — by a single appli- 
cation of a heavy stress, or by the repeated a])plication of a com- 
paratively light stress. An athlete’s muscles have often been 
likened to a bar of iron, but if 'fatigue’ be in (juestion, the simile 
is very wide (ff the truth. Intermittent action, the alternative pull 
and thrust of the rower, or of the lalx)rer turning a winch, is what 
the muscle likes and the bar abhors. A long time ago Braith- 
waitc correctly attributed the failure of girders, carrying a large 
brewery vat, to the vessel being sometimes full and sometimes 
empty, the repeated deflection, although imperceptibly slow and 
free from vibration, deteriorating the metal, until in the course 
of years it broke. These girders were of cast iron, but it was 
equally well known that wrought iron was similarly affected, for 
Nasmyth afterward called attention to the fact that the alternate 
strain in axles rendered them weak and brittle, and suggested an- 
nealing as a remedy, having found that an axle which would snap 
with one blow when worn, would bear eighteen blows when new 
or just after annealing. We know that the toughest wire car. 



be broken if bent backward and forward at a sharp angle; perhaps 
only t(j locomotive and marine engineers does it appear that the 
sanw result will follow in time even when the bending is so slight 
as to be unseen by the eye. A IcKomotive crank-axle bends but 
1/34 inch, and a straight driving axle but 1/64, under the heaviest 
bending stresses to which they arc exposed, and yet their life is 
limited. I^x])eriencc proves that a very moderate stress alter- 
nating from tension to compression, if repeated about a hundred 
million times, will cause fracture as surely as bending to a sharp 
angle repeated a few hundred times.’’ 

Hence an axle, or other structure, should be tested by just such 
stresses as it is to withstand in practice. A steel bar may satis- 
factorily pass a tensile test applied in one direction, only to break 
down disastrously under alternating stresses each less severe. 

I'bat matter virtually remembers its impressions is plain when 
we study magnetism. Steel when magnetized for the first time 
does not behave as when magnetized after- 
Magnetization. ward. Jt is as if magnetism at its first onset 
threw aside barriers which never again stood 
, in its way. If the steel is to be brought to its original state it must 
be melted and recast, or raised to a white heat for a long time. 
In ([uite other fields of channeled motion we remark that violins 
take on a richer sonority with age; their fibres, under the player's 
hand, seem to fall into such lines as better lend themselves to 
musical e\])ression. 

In iSyS the late Professor y\lfred 1\1. IVIayer of the Stevens 
Institute of Icchnology, Hoboken, New Jersey, published a series 
of remarkable exj^criments in the ‘‘American Journal of 
Science. lie there told and pictured how he had magnetized 
several small steel needles, thrust through bits of cork set afloat 
in water, the sinith ])ole of each needle being upward. As the 
needles repelled each other, or had their repulsion somewhat over-' 
conu* by a large magnet held alx)vc them with its north pole 
-lownward, the needles disjxiscd themselves symmetrically in 
outlines of great interest, which varied, of course, with the nuin- 
tXM of needles alkxat at any one time. Three needles formed an 
equilateral triangle, four made up a square, five disposed them- 
:elves eitlier as a pentagon or as a square with one magnet at its 



centre, and so on in a series of resular combinations, all suggest- 
ing that magnetic forces may underlie the structure of crystals. 

iviaycr s iioatini^ 

One of the rciiiarkable atlrilniles of a crVstal is its ability to 
and act as a unit, as if it liad a life of its own, despite the 
evident variety and i^reat number of its ])arts. 

Take a crystal of alum, break off a corner and t- 
then immerse tb^' broken mass m its mother Plant, 

liquor; at once the crystal will repair itself, 
new molecules buildint^ themselves int('> its structure as if they 
knew where to ^o. This unity of effect may be observed during 
a northern winter on a scale nuicli more striking. In cold 
weather on a large sheet of plate glass ex])osed as a window, a 
frost pattern will extend itself as if a tree, beautiful branches 


spreading- llicmsclvcs from a main stem which may be seven feet 
in height. It is altogether proba])lc that polar forces, such as we 
observe in the magnet, are here at work. Their harmony of effect, 

A B C 

Alum crystal. After a part has Restored by im- 

been l^ndvcii off. mersion in alum 


rroin pboto.nrapbs by Herr IIujau Scbinidt, Hackley School, Tarry- 
town, N. Y. 

in spaces C()ni])arativ(‘ly vast, is astonishing. I'orces of allied char- 
acter rise to a plane yet higher in vegetation, culminating in the 
inagjnlicent secfiioia of ( alifornia, whose life, measured by thou- 
sands of years, goes back almost to the dawn of human civiliza- 
tion. The union of tools, levers, wheels, as an organized machine; 
the co-ordination in research of the parts to be played by ob- 
servers, recorders, depicters, generalizers ; the regimentation of 
soldiers, so that all march, advance and fire as one man under 
the control of a single will, is prefigured in the forces which make 
a unit of every crystal of saltpetre in a soldier’s cartridge- 
box. Of all the characteristics of matter none is more pervasive 
and more marvelous than its ability to form a unit which moves 
and acts as if no ])art were separable from anv other, while mani- 
festing a highly cougilicated structure, with functions at once 
intricate and co-ordir.ate. 

Oualities of matter, much more simple, may now engage our 
attention. First, then, let us note how minute induences, acting 
for long stretches of time, may change the 
(lualities (if metals and rocks. Forces, too 
slight for measurement as yet, are known in 
the course of a year or two to affect steel at 
times favorable, at other times unfavorablv. 

During Long 
Periods Minute 
Become Telling. 



The highest grades of tocd-steel are improved by being kept in 
stock for a considerable time, the longer the better. It seems, 
tliat bayonets, swords, and gnus are liable to changes which may 
account for failure under sudden thrust or strain. Gauges of 
tool steel, which are required to be hard in the extreme, arc 
finished to their standard sizes a year on two after the hardening 
process. Slow molecular changes register themselves in altered 
dimensions. In the Ihircau of Standards at Washington are a 
vard in steel and a yard in brass, at first identical in length ; after 
twenty years they were found to vary by the 1/5000 of an inch. 
I'akc another case, familiar enough to the railroad engineer : in 
a mine, or a tunnel, the rcKif or wall may tumble down a month 
or more after a blasting. The stone which fell immediately uj)on 
the explosion was far from representing all the work done ])y the 
dynamite. A stress was set up in large areas of rock and tins at 
last, beginning in slight cracks, overcame the cohesion of masses 
of huge extent. 

Properties undergo change during the simple flight of time: a 
parallel diversity is worthy of remark. A substance exhibits 
(piitc diverse qualities according to whether the action u]x)n it is 
slow or speedy. iV paraffine candle protruding horizontally half 
way out of a box, during a Xew York summer will at last point 
directlv downward, for all its brittleness. Jf shoemaker’s wax is 
struck a sudden blow, it breaks into bits as might a pane of win- 
dow glass. r>ut place leaden balls on the surface of this same 
wax and in the course of ten or twelve weeks you will find them 
sunk to the bottom of the mass. When sharply smitten, the wax 

I ron tube enclosing marble before 
and after deformation. 

Marble before deformation 
and after. 


is rigid and brittle; to a long continued, moderate pressure the 
wax proves plastic, semi-fluid almost. All this is repeated when 
st(jne is subjected to severe pressure for as long a period as two 
months. At .McOill Ibiiversity, Montreal, a small cylinder of 
marble thus treated by Professor h'rank D. Adams became of 
bulging form, without fracture, but with a reduction in tensile 
strength of one-half. When the pressure was applied during but 
ninety minutes tlu' tensile strength of the resulting mass was but 
one-third that ]n*esented by the original marble; when the experi- 
ment occupied but ten minutes the tenacity fell to somewhat less 
than one-fourth its first degree. These researches shed light on 
the stratifications of rocks often foldetl under extreme pressure 
as if rubber or jiaste. 

d'ake another and quite dilTerent example of how variations in 
time bring about wide contrasts of result : a rubber ball thrown in 
play at a wall reliounds; send it forth from a cannon, with a 
lumdred-fold this velocity, and it pierces the wall as might a shot 
of steel. 



Properties most evident are studied first . . . "fhen those hidden from 
cursory view' . . . Radio-activity revealed by the electrician ... A 
property which may be universal and of the highest import ... Its 
study brings us near to ultimate explanations . . . h'araday’s prophetic 

P roperties afCC after at^c have become more and more in- 
timately known. .^\t first the savage took account solely of 
the obvious strenj>th of an oak, tlie sharpness of a Hint, thc- 
])liability of a sinew. With the first kindling of lire he discovered 
a new round of properties in things long familiar. All kinds of 
wood, esjx'cially when dry, were found combustible, so were straw 
and twigs, as well as the fat of birds, the oil of fish. Then it was 
noticed that the ground beneath a fire remained unburnt and grew 
firm and hard, so that its clay or mud might be used for rude fur- 
naces and ovens. Soon come ex|XM*iments as to the coverings 
which maintain coals at red heat, ashes proving the readiest and 

A century ago the mastery of electricity began to unfold a new 
knowledge of properties, so wide and intimate as to recall the 
immense expansion of such knowledge that long he feme had fol- 
lowed U])on the kindling of fire. The successors of Volta, as 
they reproduced his crown of cups, asked. What metals dissolved 
in what liquids will give us an electric current at least outlay? 
Then followed the further question, What metals drawn into 
wire will bear currents afar with least loss? With the invention 
of the electro-magnet came another query. What kinds of iron 
are most swiftly and largely magnetized by a current; and when 
the current ceases, which of them loses its magnetism in the 
shortest time? Plainlv enough the electrician regards co])per, 
zinc, iron, steel, acids, alkalis from a new point of view ; he dis- 



covers in them properties which until his advent had been utterly 

Among the properties of matter revealed by electricity none 
are more striking than those displayed in tubes containing highly 
rarified gases. The study of their phenomena has led to dis- 
coveries winch bring us within view of an ultimate explanation 
of ])roperlies, an understanding of how matter is atomically built. 
All this began simply enough as IMucker, in 1859, elec- 

tric discharge through a tube fairly wxll exhausted, producing 
singular bands of color, (leissler, afterward using tubes more 
exhausted, produced bands of still higher variegation. In 1875 
Professor William Crookes devised the all but vacuous tube 
which bears his name, through which he sent electric pulses from 
a cathode ixde, revealing what he called ‘‘radiant matter, as 
borne in a beam of cathode rays, as much more tenuous than 
ordinary gases as these are more rare than liquids. In 1894 
Professor JMiilipp Lenard observed that cathode rays paSvSed 
through a thin plate of aluminium, much as daylight takes its 
way through a fdm of translucent marble. Next year came the 
epoch-making discovery of Professor Conrad Wilhelm Rontgen 
that cathode rays consist in part of X-rays which readily pass 
through human flesli, so as to cast shadows of bones upon a 
photographic plate. Cathode rays make air a fairly good con- 
ductor of electricity, while ordinary air is non-conducting in an 
extreme degree. This singular power is also possessed by the 
ultra-violet rays of sunshine, as readily shown by an electroscope. 
In 1897 Rrofessor Joseph J. Thomson, of Cambridge University, 
demonstrated that cathode rays arc made up of corpuscles, or 
electrons, alxmt one-thousandth part the size of a hydrogen atom, 
and bearing a charge of negative electricity. Such electrons form 
a small of every chemical atom, the remainder of which is, 
of course, positively electrified. All electrons are alike, however 
various the “elements” whence they are derived ; as the most 
minute masses known to science they may be among the primal 
units of all matter. 

hTance, as well as Germany and England, was to take a leading 
part in furthering the study of radio-activity. In Paris the fa- 
mous Becquerd family had for three generations devoted them- 



selves to studying phosphorescence. Henri rjccqitercl, third of 
the line, said, “I wonder if a phosphorescent substance, such as 
zinc sulphide, would be excited by X-rays.” He tried the ex- 
periment, causing the sulphide to glow with new vigor. From 
that moment proofs have accumulated that the rays of common 
phosphorescence such as arc emitted by matches, decaying wood 
and fish, are of kin to the cathode rays which the electrician 
evokes from any substance whatever when he employs a high- 
tension current. One day Tvl. nec(tuerel came upon a remarkable 
discovery. lie noticed that com]xnnids of uranium, whether 
phosphorescent or not, affected a photogra])hic plate through an 
opaque covering of black paper, and rendered the adjacent air an 
electric conductor. Compounds of thorium, similar to those used 
for incandescent mantles, were found to have the same proper- 
ties. And here was detected the cause of an annoyance and Joss 
which had kiUg perplexed photogra]diers. Often they had be- 
stowed sensitive ])aper or plates within wrappers of stout paper, 
or card, or thick wood, secluded in dark cu])hoar(ls or drawers. 
y\ll in vain. At the end of a few weeks or months these carefully 
guarded surfaces were as much divscolored as if they had been for 
a few minutes exposed, here and there, to daylight itself. All 
the while each material relied upon as a safeguard had been 
sending forth a feeble but constant beam ; treachery had lurked 
in the trusted guardian. 

At the suggestion of ]\T. Becquerel, M. and TNladame Pierre 
Curie undertook a thorough quest for these effects in a wide 
diversity of substances. They found that several minerals con- 
taining uranium were more radio-active than that element itself. 
Pitchblende, for instance, consisting mainly of an oxide of ura- 
nium, was especially energetic as it approached an electroscope, 
suggesting the presence of an uncommonly active constituent, 
thus far not identified. At the end of a most laborious series of 
separations they came at Iasi to a minute quantity of radium 
chloride displaying extraordinary properties. Another com])ound 
of radium, a bromide, has since been arrived at : radium by itself 
has not yet been obtained. Tn radio-activity radium chloride sur- 
I)asses uranium about one-million-fold. Provided with an electro^ 
scope of exquisite sensibility. Professor Ernest Rutherford of 


Mdiill University, Alontrcal, has discovered seven distinct radia- 
tions from radium, eacli vvitli characteristics of its own. Directed 
uj)on plates of aluminium he finds its gaiinua rays’ to he loo 
limes more penetrating^ than its beta rays, and beta rays loo 
times more penetratinj^- than its alpha rays. Each radiation has 
(jualities as distinct as those of an ordinary chemical element. 
llcla rays behave in all respects like cathode rays, so that here a 
hridj^c* is discerned hetwixt the (jualities of radium and the long- 
familiar i)henomena of the Crookes tube. 

d'he substance ranking next in radio-activity to radium is 
thorium. Professor Rutherford has observed it throwing off a 
substance he calls Thorium X; this radiates strongly for a time, 
the jiarent mass not radiating at all. Gradually Thorium X 
ceases to radiate and the original thorium resumes an emission 
of Idiorium X. b'rom Thorium X emanates what seems a gas, 
condensible l)y extreme cold, which attaches itself to adjacent 
bodies so as to make them radio-active. This emanation in its 
turn produces successively three new and distinct kinds of radia- 
tion. Professor Charles 1 la.skcrville, of the College of the City 
of Xew ^'()rk, has scjiaratcd from thorium two stibstances prob- 
ably elementary, carolinium and berzeliuin. 

Other radio-active substances have each several derivatives: 
actinium has nine, uranium has four. As researchers breiaden 
their range of in(|uiry they .steadily lengthen the list of radio- 
active substances. Minerals of many kinds, water from springs, 
es])ecially those of medicinal value, the leaves of plants, newly 
fallen snow, and even common air, are found to be radio-active, 
although usually in but a sliglit degree, so that the doubt may Ix' 
exiiressed. Is the observed effect due to a trace of some highly 
radio-active material diffused in something else which is nut 
radio-acti\e at all? Should it ])e established that radio-activity 
is really present in all matter it would be no other than a parallel 
to what, at ancHher point in the physical scale, presents itself as 
ordinary evaiioration. 

In a northern winter we may observe in air almost still, the 
wasting away of a large block of ice, so that during a week it 
l('>ses a considerable part of its bulk. The giving forth of vapor 
is t'vidently not restricted to high or to ordinary temperatures, but 



may occur below the freezing point of water. In 1863, Thomas 
Graham, the eminent Scottish physicist, from many experiments 
with metals expressed the opinion that what 

seems to be a solid may be also in a minute 
degree both liquid and gaseous as well. Con- 
firmation of this view was afforded in 1886 

Solids are not as 
Solid as They 

by Professor W. Spring, of Liege, who formed alloys by strongly 
compressing their constituents as powders at ordinary tempera- 
tures. It is probable that a slight pervasive li([iudity gave suc- 
cess to the experiment. * Professor Roberts- Austen once observed 
that an electric-deposit of iron on a clean cojiper plate adhered so 
firmly tliat when they were severed by force, a film was stripjied 
from the copper plate and remained on the iron, signifying that 
the two metals had penetrated each other at an ordinary tempera- 
ture. This interpenetration he found to take place thn)ugh films 
of electro-deposited nickel. In a remarkable round of experi- 
ments he also found that at 100” a temperature much lielow 
the fusing point of lead, gold as leaf is slightly diffused through 
a mass of lead ; when the lead is fluid at 550“^ C., the proportion 
of diffused gold is increased 160,000 times, 'fhis volatility of the 
particles of a heavy metal shows us ])lainly that virtual evapora- 
tion may be alw'ays taking place from metallic surfaces at ordi- 
nary temperatures, — a phenomenon which may be the same in 
kind as the pouring out of a perceptible stream of corpuscles un- 
der strong electrical excitation. The analogy goes further, at 
least in the case of liquids, which exhale a vaj)or usually different 
in composition from the parent body; take, for example, a .solu- 
tion of sugar in water which sends forth, watery vajior only, or 
observe a mixture of much water and a little alcohol as it emits 

a vapor largely alcoholic and but slightly aqueous. 

TTere we are reminded of a striking experiment by Faraday: 
exciting an electro-magnet of gigantic proportions lie showed 
that every substance he brought near to it was 
affected in a definite degree. lie found iron to Every Property 
be pre-eminently magnetic, much as Madame May be Universal. 
Curie has shown radium to be va.stly mfire 
radio-active than any other substance. From Faraday’s time to 
the present hour the whole trend of investigation has built up the 


proljability that every known property in some degree exists in all 
matter whatever. Copper conducts electricity remarkably well, 
and gutta percha conducts remarkably ill; but gutta pcrcha has 
some little conductivity, or thinner sheets of it than those now used 
would suffice to keep within an ocean cable the throbs which pass 
between America and Juirope. In radio-activity many subvStances 
may be as low in the scale as is gutta pcrcha in the list of electric 
conductors; in that case no existing means of detection would 
make the property manifest. 

While radio-activity may be a universal property of matter, to 
be disclosed more and more as means of detection arc refined and 
Radium Reveals hnj)rove(l, radium compounds are to-day in a 
Properties class quite by themselves. Radium bromide 

Unknown Till constantly maintains itself at a temperature of 
Now. ^ higher than that of its surround- 

ings, so that every hour it could boil its own weight of water. Pro- 
fessor Rutherford estimates the life of rac^.iam as i,8oo years, its 
emanations in breaking up through their successive stages emitting 
about three million times as much energy as is given out by the 
union of an eciiial volume of hydrogen and oxygen, mixed in the. 
proportions which form water, a union accompanied by more heat 
than that evolved in any other chemical change. Whence this 
amazing stream of energy? It is probable that each radium atom 
may break into minute parts, or corpuscles, which, moving at a‘ 
velocity of 120,000 miles a second or so, collide so as to cause the 
observed heat. 

h'rom another side the compoiiUvls of radium bid us revise the 
laws of chemical change as taught up to the close of the nineteenth 
century. In the pores of many radio-active minerals may be found 
that remarkable clement, helium, first detected in the sun by 
means of the spectroscope, then afterward discovered in the pores 
of cleveite, a mineral unearthed in Norwa}^ Sir William Ramsay 
and Mr. Frederick Soddy have found helium in the gases evolved 
from radium chloride kept as a solid for some months. The spec- 
irum of helium was at first invisible ; it soon appeared and steadily 
grew more intense with the lapse of time. ‘Tt appears not un- 
likely,’' says PnTessor Rutherford, ''that many of the so-called 
chemical elements may prove to be compounds of helium, or, in 

Phofoy^r.iph by Rice, Montreal. 


McCilLL Univkksity. Montrkal. 


, iher words, that the helium atom is one of the secondary units 
with which the heavier atoms are built up/’^ 

Already the phenomena of radio-activity, although of puzzling 
intricacy, have greatly broadened our conceptions of matter. 
W here we were wont to deem it of simple, structure, it displays a 
baffling complexity, as indeed has long been suggested in so highly 
(liversiffed a spectrum as that of iron. WV find that radiations 
from an ‘'clement” may consist not only in the undulations of an 
ether, but also in an emission of matter as real as the projection 
of steam from a hcnling pot. Newton believed sunshine to be a 
stream of corpuseles : he was wrong with res])ect to sunlight, his 
conception is true of many other kinds of radiation. Until quite 
lately we looked u]Kin atoms as indivisible bodies; to-day we have 
learned that at least some of them may on occasion divide into 
many parts, each part moving with a speed ai)])roaching that of 
light, with energy far exceeding that of any chemical action we 
know. In the field of ray-transmission our knowledge has under- 
gone a like gain in width. Twenty years ago we spoke of the 
opacity of lead, the transi)arencv of (lint glass, as absolute proper- 
ties. To-day we learn that given its accordant ray any substance 
whatever affords that ray free passage, as when oak an inch thick 
transmits pulses from radium. Yet more: ordinary chemical 
changes require us to bring one substance into contact with an- 
other : usually we must also ap])Iy heat or electricity to the bodies 
thus joined ; they are always resi)onsive to ehanges of tenqierature. 
\\"ithin the ]yast six years we have become ac([uainted with changes 
incomparably more energetic than those of the iiK^st violent chem- 
ical action ; many of them ])roceed with aqiparent spontaneity from 
a substance all bv itself. Tn the case of radium neither extreme 
cold nor extreme heat has any perceptible effect upon the radiant 

One of the results of investigation in radio-activity is that it 
shows the alchemists in their attenqits at transmutation to have 
stood on solid ground. Says Professor Rutherford : "There can 
be no doubt that in the radio-elements wc are witnessing the spon- 
taneous transformation of matter, and that the different products 

M^rnest Rutherford “Radio-activity/' Second edition. New York: Mac- 
millan Co.; Cambridge, England, University Press, 1905. 


History of the 
Rewritten in the 
Light of 

which arise mark the stages or haltinj:^ places in the process of 
transformation, where tlic atoms arc able to exist for a short time 
before hreakiii'^ ti]) into new systems.” 

i^adio-activity has a vivid interest far beyond the laboratories of 
clu'inists and ])hysicians. ( )ne of the lonj^ standini^ puzzles of 
t^eoloi^y has been to explain why the tempera' 
ture of the earth has remained fairly constant 
ever since organic life made its appearance. A 
sister problem lias been the maintenance by the 
sun of its vast out])ut of heat and light, age 
after age, with little or no diminution of intensity. Professor 
Rutherford and Air. Soddy believe that the phenomena of radio- 
activity may solve both these ])roblems : an clement like helium 
may furnish a store of energy vastly greater than that of ordinary 
chemical action, and 'much lengthen the cooling process due to 
radiation from either the sun or the earth. 

Radio-activity, furthermore, throws new light upon evolution 
fcgtu'ded in its broadest as])ccts. The corpuscles discovered in 
i 8()7 by Professor J.‘J. Thomson, as he severed atoms in jiieces, 
are all alike whatever chemical element may be the parent body. 
Jlence it is argued that we may have here the jirimal units of all 
matter whatever. Sir Norman Lockyer long ago pointed out that 
helium and hydrogen predominate in the hottest stars, while in 
stars less hot more coni]ilex ty])es of matter appear. He argues 
that these stars as they successively lose heat show a develo])nient 
of what chemists call elements. His views are parallel with the 

suggestion that in the radio-active corpuscle we make acquaintance 
with an ultimate element of all matter, whether observed in a 
laboratory tube or in the squadrons bright of the midnighl 

d'he phenomena of radio-activity revive interest in the prophetic 
views of Michael Faraday. In i8i6, when he was but twenty- four 
years of age, he delivered a lecture at the Royal Institution in 

’ Radio-activity and other physical phenomena recently discovered art 
set fi^rth in “d'lie New Knowledge,’" by Professor Robert Kennedy Duncan, 
published by A. S. Barnes & Co., New York, 1905; and “The Recent 
1 >cvelopnient of Pliysical Science,” by W. C. D. Whetham, published h; 
John Murray, London, and P. Blakiston, Son & Co., Phila., 1906, 


London on Radiant ATattcr. In the course of his remarks there 
occurs this passage 

‘'If we now conceive a change as far beyond vaporization as 
tliat is above fluidity, and then take into acccnint the proportional 
increased extent of alteration as the changes 
arise, we shall perhaps, if wc can form any Faraday’s 
conception at all, not fall short of radiant Prophetic Views, 
matter; and as in the last conversion many 
qualities were lost, so here also many more would disappear. 

“It was the opinion of Newton, and of many other distinguished 
])hilosophcrs, that this conversion was possible, and continually 
going on in the processes of nature, and they found that the idea 
would bear without injury the ap])lications of mathematical rea- 
soning — as regards heat, for instance. 1 f assumed, we must also 
assume the simplicity of matter; for it would hdlow that jdl the 
variety of substances with which wc are ac(iuainted could be con- 
verted into one of three kinds of radiant matter, which again may 
differ from each other only in the size of their ])articles or their 
form. The ])roperties of known Ixxlies would then bc^ supposed 
to arise from the varied arrangements of thl'ir idtimate atoms, and 
belong to substances only as long as their com])ound nature 
existed; and thus va'riety of matter and variety of properties 
would be found co-essential.’’* 

Three years later he returned to this theme in another 
lecture : — 

“Ijy the power of heat all solid ixKh’es have been fused into 
fluids, and there are very few the conversion of which into 
gaseous forms is at all doubtful. In inverting tlie method, at- 
tempts have not been so successful. Many gases refuse to resign 
their form, and .some fluids have not been frozen. If, however, 
we adopt means which depend on the rearrangement of particles, 
then these refractory instances disappear, and by combining sub- 
stances together we can 'make them take the solid, fluid, or 
gaseous form at pleasure. 

“In these observations on the changes of state, I have purposely 
avoided mentioning the radiant state of matter, being purely 

^‘‘Lifc and Letters of Faraday,” by Bence Jones. Vol. I, p. 216. 


hyix^tlietioal, it would not have been just to tlie demonstrated 
parts f)f the science to weaken the force of their laws by con- 
nectiiij^ them with what is undecided. I may now, however, 
notice a progression in pliysical properties accompanyin^i^ 
changes of f(jrm, and which is perhaps sufficient to induce, in 
the inventive and san^-uine pliilosopher, a considerable belief in 
tlie ;ussociation of the radiant form with the others in the set 
of clian^es I have mentioned. 

“As we ascend from the solid to [he ffuid and <^aseous states, 
])]iysical properties diminish in number ancl variety, each state 
havin|4‘ some of those which helon.e: to the precedin.e: state. When 
solids are coiUTrled into fluids, all varieties of hardness and soft- 
ness are necessarily lost, ('rystalline and other sha])es arc de- 
stroyed. Opacity and color frecjuently ,[;ive way to a colorless 
trans]\arencv, and a g'cneral mobility of ])articles is conferred. 

“Massin*.;’ onward to the <;asef)us state, still more of the evident 
characters of bodies are annihilalcal. 'rht‘ immense dilTerences 
in their weiii^lits almost disai)pear; the remains of dilTerencc in 
color that were left, are lost. 'rransi)arency becomes universal, 
and they are all edastic. They now form but one set of sub- 
stances, and tlu‘ varieties of density, hardness, opacity, color, 
elasticity and form, which render the number of solids and fluids 
almost infinite, are now sn])plied by a few slij^'ht variations in 
weight, and some unim])ortant shades (-f color. 

“lo those, therefore, who admit the radiant form of matter, 
no difficulty exists in the sim])licity of the jiropcrties it possesses, 
but rather an ari^aunent in their favor. These ])ersons show vou 
a [gradual resii^nation of ])roperties in the matter we can appre- 
ciate as the matter ascends in the scale of forms, and tbev would 
be surprised if that efre('t w<'r<' to cease at the ti^aseons state, d^hev 
point out the eater exertions which nature makes at each step 
of the change, and think that, consistent Iv, it ouql.t to be <;>'rcatest 
at the passage from the [;ase(U\s to the radiant form.”^ 

Ibis remarkable deliverance recalls what another c^reat ex- 
perimental ])liiloso]dier. Onint Rumforvi, deduced as bv dint of 
ir.eclianical motion he melted ice in a closed and insulated re- 

’ “Life and Letters of Faraday,” by Bence Jones. Vol. I, p. 307. 



cciver. He inferred that the heat thus generated was not a 
material substance, as then generally supposed, but must be in 
essence motion, for only motion had brought it into existence. 
As we follow Faraday’s recital of the successive changes in prop- 
erties which follow upon additions of heat, in other words, of 
mechanical motion, the inference is irresistible that properties 
consist in the distinct motions of masses of definite form and 
size, these very motions, perhaps, deciding both the form and 
size of each mass. 



Methods besinninp: in rule-of-thumb proceed to the utmost refinement . . . 
'fhe fo(U and culiit . . . The metric system . . . Refined measurement a 
means of discovery . . . Idle interferometer measures 1-5,000,000 inch 
... A li^’ht-wave as an unvarying unit of length. 

A C’IIirJ) notices tliat liis bedroom is smaller than the family 
parlor, that to-day is warmer than yesterday was, that iron 
is much heavier than wood and less easily marked by a blow. 
d1ie eliild becomes a well thrown boy before be paces the lenj^th 
and breadth of rooms so as to compare their areas and add to his 
mensuration lesson an example from home. If instead of pacing 
he were to nse a foot-rule, or a ta])e-line, so much the better. 
About this ‘time he may bcji^in to observe the thermometer, notint;' 
that within five hours, let us say, it has fallen ei^ht degrees. y\s 
a child he took account of bigness or smallness, lightness or 
heaviness, warmth or cedd ; now he passes to measuring their 
amount. In so doing he spans in a few years what has required 
for mankind ages of history. When corn and peltries are bar- 
tered, or axes •and calumets are bought and sold, a shrewd guess 
at sizes and weights is enough for the parties to the bargain. Put 
when gold or gems change owners a balance of delicacy must be 
set u]-), and the moral code resounds with imprecations on all who 
lanqier with its weights or beam. Perhaps the halance was sug- 
gested by the children’s teeter, that primitive means of sport 
which crosses one prone tree with another, playmates rising and 
falling at the ends of the upper, moving trunk. In essence the 
most refincil balance of to-day is a teeter still. Its successiv'c 
improvements register the transition from merely considering 
what a thing is, whether stone, wood, oil or what not, to ascer- 
taining just how much there is of it; or, in fonnal phrase, to 
make and use an accurate balance means passing from the quali- 



tative to the quantitative stage of inquiry. Before Lavoisier’s 
(lay it was thought that any part of a substance which disappeared 
in burning was annihilated. Lavoisier carefully gathered all the 
products of ccjinbustion, and with scales of precision showed that 
they weighed just as much as the elements before they were 
burned. He thus laid the corner-stone of uK^dern chemistry by 
demonstrating that matter is invariable in its total ([uantity, not- 
withstanding all chemical unions or partings. Phases of energy 
other than gravity are now measured with instruments as much 
impnn^ed of late years as the balance: tbicy tell us the great truth 
that energy like matter is cotistant in (|uantity, however much it 
may vary from form io form, however many the subtle and 
elusive disguises it may wear. 

flow the foot, our commonest measure, has descended to us is 
an interesting story. The oldest known .standard of length, the 
cubit, was the distance between the point of a 
man’s elbow and the tip of his middle finger. Foot and Cubit. 
In Egypt the ordinary cubit was 18.24 inches, 
and the royal cubit, 20.67 inches. A royal cubit in hard wood, 
perfectly preserved, was discovered among the ruins of iMemphis 
early in the nineteenth century. It bears the date of the reign 
of Ilorus, who is believed to have Ix'come King of h'gypt about 
1657 B. C. The Greeks adopted a foot, ecjual to two-thirds of the 
ordinary Egyptian cubit, as their standard of length. 'Phis meas- 
ure, 12.16 inches, was introduced into Italy, where it was divided 
into twelfths or inches according to the Roman (hiodecimal sys- 
tem, thence to find its way throughout Juirojie. 

Units equally important with the cubit were from of old 
derived from the finger and the fingers joined. The breadth of 
the forefinger at the middle part (d* its first joint became the 
four digits were taken as a palm, or hand-breadth, used to 
this day in measuring horses. Another ancient unit, not yet ob- 
s(detc, the pace, is forty digits; while the fathom, still enijiloyed, 
is ninety-six digits, as spaced by the extended arms from the 
finger tips. The culn’t is twenty-four digits, and the foot is six- 
teen digits, d'hus centuries ago were laid the foundations of the 
measurement of space as an art. A definite part of the human 
body was adopted as a standard of length, and copied on rods 



The Metric 

of wood and slabs of stone. Divisors and multiples, in whole 
numbers, were derived from that standard for convenience in 
measuring lines comparatively long or short. And yet in prac- 
tice, even as late as a century ago, much remained faulty. Stand- 
ards varied from nation to nation, and from district to district. 
Carelessness in cojiying yard-mcasmes, the wear and tear suf- 
fered by lengths of wood or metal, the neglect to take into ac- 
count perturbing effects of varying temperatures on the materials 
employed, all constrained men of science to seek a standard of 
measurement u])on which the civilized world could unite, and 
which might be safeguarded against inaccuracy. 

Tfere the (iovernment of France took the lead; in 1791 it ap- 
])(dnted as a committee Lagrange, La])lacc, Borda, Alonge, and 
Condorcet, five illustrious members of the 
French Academy, to choose a natural constant 
from which a unit of measurement might be 
derived, that constant to serve for comparison or reference at 
need. They chose the world itself to yield the unit sought, and 
set on foot an ex])cdition to ascertain the length of a (juadrant, 
or (juarter-circle of the earth, from the equator to the north pole, 
taking an arc of the meridian from Dunkirk to Barcelona, nearly 
nine and one-half degrees, as ])art of the retiuired curve. When 
the (juadrant had been measured, with absolute precision, as it 
was believed, its ten-millionth part, the jiictrc, was adopted as 
the new standard of length. As the science and art of measure- 
ment have since advanced, it has been found that the measured 
quadrant is alxnit t 472.5 metres longer than as re])orted in 1799 
by the commissioners. Furthermore, the form of the earth is 
now known to be by no means the same when one quadrant is 
comi)arcd with another; and even a specific (juadrant may vary 
from age to age both in contour and length as the planet shrinks 
in ccxding, becomes abraded by wind and rain, rises or falls with 
earthquakes, or bends under mountains of ice and snow in its 
p(dar zones. All this has led to the judicious conclusion that there 
is no advantage in adopting a quadrant instead of a conventional 
unit, such as a particular rod of metal, preserved as a standard 
for comparison in the custody of authorities n^tional or inter- 



What gives the metric system pre-eminence is the simplicity 
and uniformity of its decimal scale, forming part and parcel as 
it does of the decimal system of notation, and lending itself to a 
decimal coinage as in h'rance, Germany, Italy, and S])ain. The 
metre is organically related to all measures of length, surface, 
capacity, solidity, and weight. A cubic centimetre of water, 
taken as it melts in a vacuum, at 4° C, the temperature of maxi- 
mum density, is the i^ram from which other weights are derived ; 
this gram of water becomes a measure of capacity, the millilitre, 
duly linked with other similar measures. Surfaces arc measured 
in stpiare metres, solids in cubic metres. Simple i)refixes are : 
dcci— , one-tenth; ceiiti — , onc-hundredth ; milli — , one-thou- 
sandth; deka— , inultijdies a unit by ten; hecto— , by one hun- 
dred; kilo — , by one thousand; and myria — , by ten thousand. 

As long ago as 1660 Alouton, a Jesuit teacher of Lyons, pro- 
posed a metric system which should be unalterable because de- 
rived from the globe itself. Watt, tbe great imi)rover of the 
steam engine, in a letter of November r4th, 1783, suggested a 
metric system in all respects such as the I'rench commissioners 
eight years later decided to ado])t. 

The nautical mile of 2029 yards has the honor of being the 
first standard based upon the dimensions of the globe. It was 
su])poscd to measure one-sixtieth part of a degree on the equa- 
tor; the sni)t>osition was somewhat in error. 

Lord Kelvin, a master in the art of measurement, an inventor 
of electrical measuring instruments (T the highest precision, as 
president of the I British Association for the 
Advancement of Science in 1871, said: “Ac- Uses of Refined 
curate and minute measurement seems to the Measurement, 
non-scicntific imagination, a less lofty and 
<lignificd work than looking for something new. But nearly all 
the grandest discoveries of science have been but the rewards of 
accurate measurement and patient, long-continued lalxjr in the 
minute sifting of numerical results. The ])opular idea of New- 
ton’s grand discovery is that the theory of gravitation flashed 
upon his mind, and so the discovery was made. It was by a long 
train of mathematical calculation, founded on results accumu- 
lated through prodigious toil of practical astronomers, that New- 



t(jn first demonstrated the forces urj^ing the planets towards the 
sun, determined the magnitude of those forces, and discovered 
that a ff)rce following the same law of variation with distance 
urges tlu‘ moon towards the earth. Then first, we may suppose, 
cam.e to him the idea of the universality of y^ravitaiion ; but when 
he atteinjited to compare the magnitude of the force on the moon 
with the magnitude of the force of gravitation of a heavy body 
of ecjual mass at the earth’s surface, he did not find the agreement 
which the law he was discovering required. Not for years after 
would he pul)lish liis discovery as made. It is recounted that, 
lieing ]n*(‘sent at a meeting of the l^oyal Society, he heard a 
pajier read, describing a geodesic measureinent hy Picard, which 
led to a seri(Uis correction of the jireviously accepted estimate of 
the earth’s radius. This was what Newton re([uircd ; he went 
home with tlie result, and commenced his calculations, but felt 
so much agitated that he haiuled over the arithmetical work to a 
friend ; then (and not when sitting in a garden he saw an apple 
fall) did he ascertain that gravitation keeps the moon in her orbit. 

‘'Paraday’s di.scovcry of s])ccific inductive caiiacity, which in- 
augurated the new ])hiloso])hy, tending to discard action at a dis- 
tance, was the result of minute and accurate measurement of 
electric forces. 

“Joule’s discovery of a thermo-dynamic law, through the 
regions of electro-chemistry, electro-magnetism, and elasticity of 
gases was based on a delicacy of thermometry which seemed im- 
possible’ to some of the most distinguished chemists of the day. 

“.Andrews’ discovery of the continuity between the gaseous 
aud the licjuid states was worked out by many years of laborious 
and minute measureinent of phenomena scarcely sensible to the 
naked eve.’" 

It is with these cxamjdes before them that investigators take 
the trouble to weigh a mass in a vacuum, to watch the index of 
a balance through a telescope at a distance of 




twelve feet, or use an interferometer to space 
out an inch into a million parts. Their one 
desire is to arrive at truth as nearlv as the\ 

can, to bring grounds of disagreement to the vanishing point. 



and ensure exactness in all the computations based on their 
work. As art advances from plane to plane it demands new 
niceties of measurement, discovers sources of error unsuspected 
before, and avoids these errors by ingenious ])recautions. To- 
day observers earnestly wish for means of measurement surpass- 
ing those at hand. Take the astronomer for example. One 
would suppose that the two points of the earth’s orbit which arc 
farthest apart, divided as they are hy about 185,000,000 miles, 
would afford sufficient room between them for a base-line where- 
with to meavsure celestial spaces. Ihit the fact is otherwise. So 
remote arc the fixed stars that nearly all of them seem unchanged 
in place whether we observe them on January 3 or July 3, al- 
though meanwhile we have changed our point of view by the 
whole length of tlie elli])se described by the earth in its motion. 

Then, too, the chemist is now concerned with analyses of a 
delicacy out of the (juestion a century ago. llis reward is in dis- 
covering the great inlluence wrought by admixtures so slight in 
amount as alm(.)st to defy ([uantitative recognition. In the ex- 
jieriments by M. (luillaume, elsewhere recited, his unit through- 
out every research was one-thousandth of a millimetre, or 
1/25,400 inch. y\rgon, a gas about one- fourth heavier than 
oxygen, forms nearly one-hundredth ])art of the atmosphere, and 
yet its discovery by Lord Rayleigh dates only from i8(;4. His 
feat depended not only upon refined modes of measurement, but 
also upon his challenging the traditional analyses of comiiKm air. 
"fhe utmost resources of refrigeration, of s])ectrosc(j])y, and of 
measurement were re([nire(l to detect four elements associated in 
minute quantities with argon, and of like chemical inertness. 
These are helium, having a density of i.q8 as e()m])ared with 16 
for oxygen; neon, of p.qf) density; kryj)ton, of 40.78; and xenon, 
of 64. Argon itself has a density of iq.qO. “Air contains,” says 
Sir William Ramsay, “one or two i)arts of neon jier J 00,000, (Rie 
or two parts of helium per 1,000,000, about one ])art of krypt{)n 
per 1,000,000, and about one ])art of xenon i)er 20,ooo,0(X) ; these 
together with argon form no less than 0.937 of the atmo- 

sphere. y\s a group these elements occu])y a ])Iacc between the 
strongly electro-negative elements of the fluorine group, and the 



very positive electro-positive clenieiits of the lithium group. By 
virtue of their lack of electric i^olarity and their inactivity they 
form, in a certain sense, a connecting link between the two.''^ 

As measurements become more and more ])recise they afford 
an important means of discovery. Sir William Crookes tells 
us; — “It is well known that of late years new 
Precise Measure- ^^(^.nientary bodies, new interesting compounds 

Precise Measure- 
ment as a Means , . , . -11 1 

of Discovery have often been discovered in residual procl- 

ucts, in slags, due-dusts, and waste of various 
kinds. Tn like manner, if we carefully scrutinize the processes 
either of the laboratory (ir of nature, we may occasionally detect 
some slight anomaly, some unanticipated phenomenon which we 
cannot account for, and which, were received theories correct and 
sufficient, ought not to occur. Such residual phenomena are 
hints which may lead the man of discijilined mind and of finished 
manipulative skill to the discovery of new elements, of new 
laws, possibly even of new forces; upon iindrilled men these pos- 
sibilities are sinijily thrown away. The untrained physicist or 
chemist fails to catch these suggestive glimjises. If they appear 
under his hands, he ignores them as the miners of old did the 
ores of cobalt and nickel.”- 

It was a residual effect which led to the discovery of the planet 
Neptune. The orbit of ITanus being exactly defined, it was noticed 
by Adams and Leverrier that after making due allowance for ])er- 
turbations bv all known bodies, there remained a small disturbance 

which they believed could be accounted for only by the existence 
of a ])lanet as yet uiK^bserved. That planet was forthwith sought, 
and soon afterward discovered, proving in mass and path to be 
capable of just the effect which had re(|uircd explanation. 

Tn the measurement of length or moticMi a most refined in- 
trument is the interferometer, devised bv Professor A. A. Michel- 

Refined : the 

son, of the University of Chicago. It enables 
an observer to detect a movement through one 
five-millionth of an inch. The ])rinciplc in- 
volvcvl is illustrated in a simple experiment. If 

* “Gases of tlie Atmo'^plu-re : History of I'lieir Discovery.” Third edi- 
tion, with portraits. London and Xcw York. Macmillan, 1906. 
'Nineteenth Century Mai^azine, London, July 1S77. 

Photrjjfraph by cox, C^!c.'l)^o. 


University of Chicago. 



by dropping a pebble at each of two centres, say a yard apart, in 
a still pond, we send out two systems of waves, each system will 
ripple out in a series of concentric circles. If, when the waves 
meet, the crests from one set of waves coincide with the depres- 

Michelson interferometer. 

sions from the other set, the water in that particular spot becomes 
smooth because one set of waves destroys the other. In this 
case we may say that the waves interfere, if, on the other hand, 
the crests of waves from two sources should coincide, they would 
fisc to twice their original height. Light-waves sent out in a 
similar mode from two points may in like manner either inter- 
fere, and produce darkness, or unite to produce light of double 
i^fi Ilian cy. These alternate dark and bright bands arc called in- 
terference fringes. When one of the two sources of light is 
moved through a very small space, the interference fringes at a 
<^listancc move through a space so much larger as to be easily ob- 
s(Tved and measured, enabling an observer to compute the short 
P^ith through which a light-source has moved. In the simplest 



form of interferometer, from any chosen source, S, is ren- 

(lerc'd api)roximately parallel in its rays by a double convex lens 
at L. 'riie lii;ht fallin^^ nix^n the glass plate A is divided into two 
beams, one of which passes to the mirror M, while the other is 
relk'Cted to Mk 1 'he rays rellected from Mh which pass through 
A, and those returned from A 1 reflected at d, arc reunited, and 
may be observed at I A In order to produce optical symmetry of 
the two luminous paths, a plate C exactly like A is introduced 
between A atid M. When the distance from d to M and to AP 
arc* the same the observer sees with white light a central black- 
spot surrounded with colored rings. When the mirror Md is 
moved parallel to itself either further from or nearer to A, the 
fringes of interference move acn^ss the field of view at E. A 
displacemc'iit of one fringe corresponds to a movement of half a 
wave-length of light by the mirror AlP Ply counting the number 
of fringes corres])onding to a motion of AP we are able to express 
the dis])lacement in terms of a wave-length of light. Where hy 
other means this distance is measurable, the length of the light- 
wave may he deduced. Witli intense* light from a mercury tube 
/( fringes have been counted, amounting to a difference in 
path of about one-fourth of a metre. 

Alany diverse applications of the interferometer have been de- 
veloped, as, for e\am])le, in thermometry, ddie warmth of a 
hand held near a pencil of light is enough to cause a wavering of 
the fringe's. A lighted match shows contortions as here illus- 
trated. When the air is heated its 
density and refractive power diminish : 
it follows that if this experiment 
tried under ccmditicuis which show- a 
iTgnlar and measurable disjdacement ot 
the fringes, their movement wall ia- 
dic'atc the temperature of the air. This 
method has been applied to ascertain 
very high temperatures, such as tla^sc' 
of the blast furnace. Alost metals ex- 
pand one or tw’o parts in 100,000 for a rise in temperature of oia^‘ 
degree centigrade. When a small specimen is examined tin' 
whole change to be measured may be only about 1/10,000 incli. 

i.ight-W'avc (listorU’d in 
I)as^ing ibrongli 
lu-ak-d air. 



space requiring a good microscope to perceive, but readily meas- 
ured by an interferometer. It means a displacement amounting to 
several fringes, and this may be measured to within 1/50 of a 
fringe or less ; so that the whole displacement may he measured 
to within a fniclion of one per cent. Of course, with long bars 
the accuracy attainable is much greater. 

The interferometer has much refined the indications of the 

balance. In a noteworthy ex])eriment Professor Alichelson found 

the amount of attraction which a sphere of lead 

exerted on a small sphere liung on an arm of Application to 

. Weigning. 

a delicate balance. The amount of this attrac- 
tion when two such spheres touch is proportional to the diameter 
of the large sphere,- which in this case was about eight inches. 
The attraction on the small hall on the end of the balance was 
thus the same fraction of its weight as the diameter of the large 
hall was of ^ the diameter of the earth, — something like one 
twenty-millionth. So the force to he measured was one twenty- 
millionth of the weight of this small hall. Tn the interferometer 
the approach of the small ])all to the large one i)roduced a dis- 
placement of seven whole fringes. 

In order that this instrument may yield the best results, great 
care must he exercised in its construction. The runways of the 
frame aKC straightened with exactitude by a method due to Air. 
V, L. O. Wadsworth. The optical surfaces of the planes and 
mirrors in the original designs were from the master hand of 
Mr. John A. l^>rashcar of Allegheny, Pennsylvania. J^kich mirror 
is free from any irregularity greater than i/8(So,ooo inch, and 
the opposite faces of the mirrors must he parallel witliin one sec- 
ond of arc, or 1/1,296,000 part of a circle.^ 

Now for a. word as to Professor Alichelson’s suggestion that 
an unvarying unit of measurement may he found in a certain 
light-wave, as observed in the interferometer. 

Everybody knows that each *chemical element ^ Light-Wave 
burns with colors of its own. When wc see red as an Unvarying 
fire bursting from a rocket we know that Unit of Length, 
strontium is ablaze; when the tint is green it 

^ Interferometers in a variety of designs are manufactured by William 
Gaertner & Co., 5347 Lake Avenue, Chicago. 

218 mkasttrement 

tells ns that copper is on fire, as when a trolley-wheel jumps 
from its electric wire. When these sources of W^ht are looked at 
through an accurate prism of glass in a spectroscope they form 
characteristic spectra, and these spectra in their peculiarities of 
color reveal what elements are allame. In most cases the rays 
from an clement form a highly complicated scries; to this rule 
cadmium, a metal resembling zinc, is an exception. It emits a 
red, a green, and a blue ray; the wave-lengths of these rays Pro- 
fessor iMichcIson proix^scs as a basis of reference for the metallic 
standards of length adopted by the nations of Europe and Amer- 
ica. He says: “We have in the interferometer a means of com- 
paring the fundamental standard of length with a natural unit— 
the length of a light-wave— with a\)out the same order of accu- 
racy as is at present possible in the comparison of two metre- 
bars, that is, to one part in twenty millions. The unit depends on 
the projicrties of the vibrating atoms of the radiating substance, 
and of the luminiferous ether, and is probabl}^ one of the least 
changeable qualities in the material universe. If therefore the 
metre and all its copies were destroyed, they could be replaced by 
new (Uies, which would not differ among themselves. While such 
a simultaneous disaster is ])ractically impossible, it is by no 
means sure that notwithstanding the elaborate jn'ccautions that 
have been taken to ensure ])ermanency, there may not be slow 
molecular changes going on in all tlie standards, changes wdiich 
It would be impossible to detect except by some such method as 
that here ])resented.“ 

11] us, by dint of mechanical relincmcnts such as the world never 
saw before, some of the smallest units rcvealetl to the eye become 
the basis of all measurement whatever, reaching at last those 
cosmical diameters acr(')ss which light itself is the sole messenger, 
in the early days of spectroscopy many doubters said. What 
good is all this? .Since then a full re])ly has been rendered to 
their (|uestion and, at this unexpected point, the spectrosco])io 
examination of an unimportant metal may aflford a measuring 
unit of ideal stability. Cases like this suggest the query, Is any 
knowledge whatever quite worthless? 



Weight, Time, Heat, Light, Llcctricity measured with new precision , . . 
J^:xact measurement means intcrchangeahlc designs, and points the 
way to utmost economies . . . The Bureau of Standards at Washington 
. . . Measurement in expert planning and reform. 

O UR grandfathers siip])oscd that trade began in barter; we 
have been able to go one step further back in history to 
find that barter followed upon the custom of exchanging presents. 
This custom, among shrewd and self-respecting people, came at 
length to a degree of fairness, and led to rough 
and ready modes of weighing, gradually im- Balance in 

proved. In the British Museum, in a paqyrus Measurement. 

Ancient Egyptian balance. 


of Iluniiafer, wlto lived in Efjvpt thirty-tlirce centuries ago, we 
have pictured a well-constructed balance of equal arms, in which 
a feather is outweighing a human soul. In its successive im- 

A Rucprcclit balance. 

provoments the balance registers the progress of many arts aii<l 
sciences, and in its turn has promoted them all. It must be built 
of a metal, or an alloy, hard, durable, and not easily corroded. 
Its centre of motion should be a little above its centre of gravity *, 
its knife edge should have an angle of about 6o degrees. Ap- 
pliances must render it easy to lift the weighing apparatus when 
out of use, so that unnecessary wear of the knife edge may be 



avoided, as well as needless strain throughout the structure. Air 
currents should be kept off by a suitable case, or, better still, the 
instrument should be enclosed in a receiver exhausted of air alto- 
gether. The weights, made with scrupulous care of standard 
metal or alloy, should be guarded from tampering, abrasion, and 
corrosion, from dirt or other accretions. A weighing should be 
slowly performed, the weights placed in the center of one pan, 
the object weighed in the center of the other pan; to eliminate 
errors due to inequality in the length of arms, the article weighed 
and the weights are then made to exchange j^laccs. The platform 
should be of the utmost strength and rigidity, so as precisely to 
maintain its level at all times. 

As long ago as 1798 a balance was erected having an accuracy 
of one part in 1,600,000; fifty years later ten- fold greater accu- 
racy had been attained ; to-day results much more astonishing are 
achieved. A precision balance manufactured by Messrs. y\lbert 
Rueprecht & Son, Vienna, is shown on page 220, as furnished 
in 1902 to the International Bureau of Weights and Measures at 
Sevres, France. It is i)rovided with means for ap])lying the 
smallest weights of platinum from a distance of three to four 
metres, so as to guard against perturbations due to the warmth 
of an operator’s body. The weights may be shifted from one 
])an to the other, and the oscillations observed through a tele- 
scope, at a distance of four metres. This balance will detect the 
1/500 of a milligram when weighing a mass of 500 grams, or one 
part in 250,000,000. Such balances, and those of l^aul lUinge, of 
Hamburg, require ten to twenty months of skilled lalxu’ for their 
completion. The International Bureau of Weights and Measures 
has a balance of extraordinary sensitiveness at the Pavilion de 
Ilreteuil, Sevres, where the work of the J]ureau goes forward. 
I'his instrument measures the difference in the attraction of the 
earth for a mass of one kilogram when that weight is moved 
nearer to or farther from the centre of the earth by as little as 
f’Hc centimetre. Thus ]^)lacing two weights, of common shape, 
^‘J^ch a kilogram, one on top of the other, and two other weights 
in the other pan beside one another, would introduce a note- 
worthy difference in a comparison. 

At the very dawn of civilization, the day, however crudely, was 

divided into parts. These parts, long afterward^ probably in 
Ikdn'lonia, l)ccanie the twenty-four hours which have descended 
t') us. The means of time-keeping came first, in all likelihood, 
fn)m nu'asiiring the simple shadow of a stick, the gnomon, still 
set up as a sun-dial in our gardens. Next 

Measurement eamc an hour-glass with its falling sand; the 
of Time. elepsydra, with its water dropping from a jar; 

tli(‘ burning of candles flefinitc in length. At last came the su- 
preme discovery that a pendulum, of given length, if kept in one 
l)laei‘ oseillatc's in an unvarying period, be its arc of motion long 
or short. Tradition lias it that in Arabia, about the year looo 
A. I)., the ])endulum was used in time-keeping. Granting this to 
be true, we must nevertheless give Galileo credit for his indepen- 
dent discovery as he observed the swaying lamp of the catliedral 
; t i'isa, early in the seventeenth century. Tn 1657 Huygens cm- 
])lo\ed a jiendiilmn in the construction of a clock which, of 
course, displayed a new approach to accuracy. Tn 1792 JTorda 
and C assini had improved their limc-pieccs so as to be correct 
within one ])art in 375,000, that is to one second in 104 hours. 
io)r the sake of jiortability, clocks were gradually reduced in 
size until they became watches. Instead of a pendulum they were 
furnished with its e([uivalent, a balance wheel, Pierre Le I^oy 
i'.aving discovered that there is in every spring a certain length 
wh('re all the viljrations, great or small, are performed in ap- 
jiroximately the same period. Vor actuation, watches were pro- 
vided with mainsjirings which have steadily undergone improve- 
ment in ([uality and in placing. 

Many relhiements have Imnight the time-keeper for the ship, 
the observatory, the railroad, to virtual perfection. Its wheels, 



])inions, balance-staffs are manufactured auto- 
matically, as at AValtham, Massachusetts, to an 
accuracy of 1/5000 inch or even less, thanks to 

that great inventor, ]\lr. Duane H. Church. In modern watch- 

making the most durable materials are used, magnetic perturba- 
tions are avoided by employing alloys insensitive to magnetisin, 
and the effects of ductuating temperatures, are withstood by Earn- 
shaw s compensated balance wheel. This wheel is in halves, each 



nearly semicircular and attached at one end to a stout diameter. 
Its outer rim, being made of brass, when warmed expands more 
than its inner rim of steel. Thus, 
in a rising temperature the wheel 
curves inward with its duly placed 
weights, so that the reduction in 
elasticity of the hair-spring caused 
I)y heat is compensated. Experi- 
ments are afoot which look toward 
a marked improvement in the 
making of time-pieces, by using 
invar, a nickel-steel with prac- 
tically no expansibility by heat. 

This alloy is already employed Earnsliaw conipcnsatod bal- 
for pendulums with satisfactory ance wheel for watche's. ‘ 

results, both at the Naval Ob- 
servatory and at the Bureau of Standards, in Washiiigton. It 
has been described on i)age 169. 

At the Paris Observatory the standard clock, by Winnerl, is in 
a vault twenty-seven metres underground. At that depth the 
temperature changes arc less than one fifth of 
The Best Clocks ‘1 degree during the year, yet the effect of baro- 

in the World. metric changes on the rate of the clock have 
proved to be serious. This difficulty is 
avoided in the Naval Observatory at Wa.shington, by enclosing 
the standard clock in an air-tight case within which the air is 
reduced to a pressure lower than that ever shown by a barometer 
at that level. To avoid risks of air leaking through this case were 
it to be pierced by a moving axle, this clock is actuated by weights 
lifted electrically by a small i)rimary battery. The slight electric 
current required has no perturbing effect on the clock. This time- 
piece, provided with an escapement of great excellence, was 
manufactured by Clemens Rieflcr of Munich. 

At the Observatory of the Case School of Applied Science, 
Cleveland, Ohio, another Richer clock has a mean error of but 
•01 5 second per day. This means that in a year the total error is 
not more than 5.475 seconds, or one part in 5,700,000 of the 365 



(lays. Such errors, minute as they are, give a good deal of 
trouble when thev are irregular, that is, when the clock is some- 

times slow, sometimes fast, in 

Riolk’r cluck. 

a fashion apparently lawless. 
When the divergences arc 
fairly constant they can 
usually be traced to their 
source, making it feasible to 
apply a remedy. 

A pendulum which swings 
once in a second at the base 
of a tall tower will require 
for the same travel a little 
more than a second when 
borne to the top of the tower, 
because then further from 
the centre of the earth. Still 
greater will be the difference 
in its pcrio.ds as it swings 
first at the base of a moun- 
tain and next at its summit. 
A pendulum, therefore, is a 
means of learning the force 
of gravity at a given place, 
and without sacrifice of ac- 
curacy it is well that it 
should be as small as pos- 
vsible. In 1890, Profess(M* 
T. C. Mendenhall, then 
superintendent of the United 
States Coast and Geodetic 
Survey, designed a pendulum 
one fourth the length of those 

previously used, and of ad- 
mirable precision. Afterward pendulums were built of dimen- 

sions further reduced to about two and one 
Fo^r^eTf Gravity! length, with periods of oscilla- 

tion of one fourth of a second. Such pen- 
dulums are easily carried to stations difficult of access, and have 



been employed on the summits of high mountains, including 
Pike’s Peak : their indications agree well witli those of the larger 
and somewhat cumbersome apparatus previously used. 

Mncli the most convenient means of measuring temperature is 
tlie common glass lube filled with merctirv. This metal is chosen 
l ocalise a lic|ui(l, and because it varies extremely 
in bulk when warmed or cooled. Materials of Heat Measured, 
parallel susceptibility are adopted for instru- 
ments which measure the intensity of magnetism or of electricity, 
the working core of the instrument being made of a substance 
highly responsive to magnetism or to electricity. 

A mercurial thermometer, for all its convenience, has its ac- 
curacy assailed on more sides than one. When the barometric 
pressure rises, the bulb is compressed ; when the barometer falls, 
the bulb enlarges by virtue of the diminution in atir.ospheric pres^ 
sure. Further, when its graduated tube is uj)right the .mercury 
exerts a distending pressure which introduces error. At all tem- 
peratures the metal is giving off a va]X)r which has tension, in its 
upper ranges entailing marked inaccuracies. The glass itself of 
which the instrument is made, when of ordinary composition, 
spontaneously undergoes changes of volume. AVhilc this is a 
minor source of error it may be almost ‘completely avoided by 
using a boro-silicate glass from the factory of Schott & (lenossen, 
at Jena. Other substances than mercury are emphwed in thermom- 
eters with gratifying results. ITydrogen gas is found very 
suitable within the interval from — 30° to 200 "" CAntigrade. Pen- 
tane serves in temperatures reaching down to— t8o°. 

P)Ut it is in alliances with electricity that 'the measurement of 
heat has its broadest scope and utmost exactitude. Tt was long 
ago remarked that heating a metallic conductor increases its re- 
sistance to the flow of an electric current; to measure that 
resistance in a platinum wire serves, therefore, to measure its 
temperature. An instrument on this principle is the bolometer of 
the late Professor S. P. Langley, of Washington. Through a 
strip of platinum barely 1/500 inch in widtli, and less than 1/5000 
inch in thickness, a current of electricity flows continuously. 
When radiation, visible or invisible, on occasion from a star, falls 
upon it, the strip when warmed by as little as one millionth of a 


(Ic^^rcc duly records tlie fact. An instriinient, modified irom the 
Crookes radiometer Ijy Professor R. F. Nichols of Columbia Uni- 
versity, New York, is more sensitive still. An exhausted hollow 
metal block has a window of fluorite, a mineral transjiarent to 
ether vibrations of a lon^ef raiii^e of frequencies. Suspended inside 
tlie block is a fine (luartz fibre supporting* a horizontal bar, iiL the 
ends of which are attached thin plates of mica, blackened on one 
side. Kavs i)assiiio- throUL;h the fluorite window strike the black- 
ened side of the mica, which is ]Kirallcl and opposite to it. The 
resultinj,^ rise in temperature causes the vane to revolve against 
the torsion of the ((uartz fibre, ddie ani^le of torsion when thermal 
ef|nilihrium is reached, measures the intensity of the incident 

Another ])rinci])le is adopted in the electrical instruments which 
expose to lK‘at a junction of two different materials, usually 
nu‘tallic, .civint;* rise to an electric current, easily measured. Ex- 
])erience shows that the most satisfactory couples for temperatures 
between 300° C. (570° V.) and iCoo'' C. (2(jOO° F.) arc those 
devised by M. Ee Chatelier, one half cousistino- of pure ])latinuni, 
the other half an alloy of ten per cent, rhoelium and ninety per 
cent. ])lalinum. Such instruments arc indisi)cnsable in the arts 
which employ hii^ii tem])eratures. In producin^q* chlorine by the 
Deacon ])rocess, or in the bakiuq* of porcelain, an undue variation 
of teuq)erature of only twenty degrees may cause a complete 
failure of the operation. 

It is proI)al)le that about one half the electricity from the 
d\'namos of America is sent into lamps, and this is but ])art of 
the whole outlay for light, still chielly i)ro- 
The Measurement duced by petroleum and gas. Hence the ini- 
of Light. ]>ortance of measuring the light from lam])^. 

jets, and tmmtles of variims kinds, and testing 
the elficicncy of shades and First of all comes the dc- 
cisiim as to a standard for C(un])arison. Great Britain has ackq^led 
the llarcourt lain]), consuiniug ])entauc, as a standard for ten 
candle-])ower, referring to the old time candle of spermaceti. 
Cicrmany em])loys the amylacetatc lain]) introduced by Von Hef- 
ner .Mtcneck, as a standard for its llefucr unit of illumination. 
J»oth lamps share in a difficulty which attends all combustion: 



atmospheric conditions which vary from hour to hour, from place 
to place, greatly affect the intensity of a flame. Hence incan- 
descent lamps, which have been compared with these fundamental 
standards, are used as working standards. They can be operated 
by a uniform current of specified voltage, and after a hundred 
hours’ use their constancy of radiation for a considerable period 
is remarkable. 

Having settled upon a standard candle or lamp the measurc- 

Photomctcr. A, standard candle. B, gas Uame. S, sliding frame. 

nient of light demands extreme care, and, at the best, can never 
approach the accuracy of other laboratory measurements. Many 
])hot()nieters have been invented, some of them highly elaborate, 
but the type oftenest used remains in essence the sim])lc instru- 
ment long ago devised by lUmsen. On a frame supported by a 
stand, S, is stretched a sheet of white pa])er in the centre of which 
is a grease six)t. This s])ot allows more light to ])ass through 
it and conserjiicntly rellects less than the unmarked portion of 
the paper. Tf the sheet is m()rc strongly lighted from behind 
than from in fn^nt, it apjx'ars bright on a dark ground. If it is 
illuminated more strongly in front than at the back it will seem 
dark u])on a bright ground. When equal lights fall on both sides, 
the s]Dot becomes invisible, since it can then a]q)ear neither darker* 
Jior brighter than the surrounding paper. In its simplest use the 
screen is placed between a standard candle or lamp at A and the 
light to be measured at B : the screen is moved along its graduated 
slide until the grease spot vanishes. If the screen is twice as far 


from T] as from A when the spot disappears, then B is four times 
as intense as A in light; if the screen were thrice as far from B 
as from A, then B would be nine-fold as bright as A, the intensity 
of light diminishing as the s(juarc of the distance of its source. 

An open-arc lam]), without a reflector, sends to the ground a 
fairly wide ring of brilliant rays; on both sides of that ring the 
illumination is feeble. Other sources of light also vary a good 
deal in the brilliancy of the beams which they emit in various 
planes. It is therefore usual to measure the light from a lamp as 
sent forth in all ]danes, or at least in its principal planes. When 
incandescent lam])s are brought to a photometer they are as a 
rule placed on a spindle turning so swiftly that their mean hori- 
zontal candle-j^ower may be read at once. For measuring the 
mean spherical intensity a ]diotometer devised by Professor Mat- 
thews of I’urdue Fniversity is employed. This apparatus has a 
series of mirrors arranged in a semicircle around a lamp, rv;nect- 
iug all the received light u])on a single surface. 

Ught may have great brilliancy and yet be undesirable from 
its color: we are all familiar with the havoc that gas light may 
])lay with hues of blossom and leaf that in sunshine are beautiful. 
Through ages untold the human eye has been seeing by rays from 
the sun, and from immemorial habit is best served by light of 
similar quality. A simi)le instrument, the spectrometer, casts 
ui)on a screen the spectrum from a mercury tube, a Nernst lain]), 
a Welsbach mantle, or other illuminant, and enables us to com- 
pare it with the spectrum of sunshine. Then, as in placing a light 
pink sh.adc over a Welsbach mantle, we act on the intimations of 
analysis greatly to the relief of the eye. 

An incandescent bulb or mantle may be satisfactory both in 
brilliancy and color, but a furtber quCvStion is, How long will the 
lilament or the mantle last, and at what point in deterioration 
should it be discarded? Tests during the first, the fiftieth, the 
hundredth, and other successive hours will tell us how much 
•the intensity falls off. Just when a bulb or a mantle should he 
dismissed from service depends partly on the rate of deteriora- 
tii’yn, and partly on the prices of bulbs and current, of mantles and 

Hanlly less important than testing sources of light is the 



investigation of their reflectors and shades. As a rule onr lamps 
arc too brilliant, and in many cases they send their light in waste- 
ful directions. It is a general and absurd practice to buy a 
dollar’s worth of light and then kill sixty cents’ worth of it with 
a thick opal or cut-glass shade. Examination with the photom- 
eter has revealed that many popular ]>at terns of reflectors and 
shades are most ineffective, while those of the TIolophanc make, 
when kept scrupulously clean, send the light just where it docs 
most good and at the lowest jiossiblc expenditure of energy. This 
theme has attention on page 78.^ 

The sky has been the su])reme field for measurements more 
refined from age to age. Professor William Stanley jevons, in 
“Principles of Science,” says : “At Greenwich 
Observatory in the ])resent day, the hundredth ^ 

part of a second is not thought an inconsider- Field for - 
able portion of time. The ancient Chaldeans Measurement, 
recorded an eclipse to the nearest hour, and 
even the early Alexandrian astronomers thought it superfluous to 
distinguish between the edge and centre of the sun. P)y the intro- 
duction of the astrolabe, Ptolemy and the latgr Alexandrian 
astronomers could determine the places of the heavenly 
bodies within about ten minutes of arc. But little progress then 
ensued for thirteen centuries, until Tycho Brahe made the first 
great step toward accuracy, not only by employing better instru- 
ments, but even more by ceasing to regard an instrument as cor- 
rect. Tycho, in fact, determined the errors of his instruments, 
and corrected his observations. He also took notice of the effects 
of atmospheric refraction, and succeeded in attaining an accuracy 
often sixty times as great as that of Ptolemy. 

“Yet Tycho and Hcvelius often erred several minutes in the 
determination of a star’s place, and it was a great achievement of 
Roemer and Flamsteed to reduce this error to seconds. Bradley, 
the modern Hipparchus, carrie'd on the improvement, his errors 
in right ascension being under one second of time, and those of ^ 

capital treatise on the subject of lighting, and the measurement of 
ii,u[ht, is Louis Bell’s “Art of Tllumination.” New York, McGraw Publish- 
ing Co., 1902. $2.50. Its author (August, 1906) is preparing a new and 
revised edition. 



(k-clination under four seconds (^f arc according to Bessel. In the 
])rcscnt day the average error of a single observation is probably 
reduced to the half or quarter of what it was in Bradley’s time; 
and further extreme accuracy is attained by the multiplication of 
observations, and their skilful combination according to the 
metlKxl of least squares. Some of the more important constants, 
for instance that of nutation, have been determined within the 
tenth part of a second of arc. 

“It would be a matter of great interest to trace out the depem 
deuce f)f this vast progress iq)on the introduction of new instru- 
ments. The astrolabe of Ptolemy, the telescope of Galileo, the 
j)endulum of (jalileo and Huygens, the micrometer of Horrocks, 
and the telescopic sights and micrometer of Gascoyne and Picard, 
Roemer’s transit instrument, Newton’s and Hadley’s quadrant, 
Dollond’s achromatic lenses, Harrison’s chronometer, and Rams- 
den’s dividing engine— such were some of the principal additions 
to astronomical apparatus. The result is that we now take note 
of quantities 1/7,00.000 or 1/400,000 the size of the smallest ob- 
servable in the time o’f the Chaldeans.” 

As important as the measurements of the astronomer arc those 

of the electrician. 



It was as recently as 1819 that Oersted, a 
Danish ])hysicist, published a discovery which 
became a foundation stone of electrical en- 
gineering, and upon which rises the art of elec- 



trical measurement. He observed that when an electric current is 
passing through a wire, a nearby magnetic needle tends to place 
itself at right angles to the wire, the deflection varying with the 
strength of the current. When instead of a wire, a coil, duly in- 
sulated, is employed to carry the current, effects much more de- 
cided are displayed. At first current-measurers, or galvanometers, 

Compass needle deflected by an electric current borne 
in a coil. 

employed simple compass needles; these proved to be unsatis- 
factory. They were affected by the variations which occur in the 
intensity of the earth\s magnetism; and no matter how carefully 
a needle was made, it varied in strength 
from week to week, from year to year; 
again, a current might l)c so strong as to 
create magnetism overwhelming in com- 
parison with that of the earth, and (|uite 
beyond the measuring power of a com- 
pass needle. A galvanometer on a plan 
due to Professor James Clerk Maxwell, 
employs a permanent magnet, or an elec- 
tro-magnet, which is stationary, between 
the poles of which may freely turn a coil 
hearing the current to be measured. This 
current in the case of an ocean cable is so 
weak that no other means of indication 

will serve. Lord Kelvin’s recording apparatus for such a cable is 
^ galvanoiiieter on this principle. In order to concentrate the lines 

Suspended coil with D, 
soft iron core. N, S, 
magnetic poles. 


of ma^ou‘lic (orce on the vertical sides of the coil, a piece of soJ: 
iron, I), is fixed between the poles of the magnet. This iron be- 
comes magnetized by induction, so as to produce a very powerful 
field of force, in the minute spaces between it and the two mag- 
netic jioles, through which spaces the vertical sides of the coil arc 
free to move. Instruments of this kind, developed by p’Arson- 
val, are known by his name. 

Instruments for electrical measurement, with stationary magnets 
and moving coils, of great excellence, are manufactured by the 
Weston Company, Wavcrly Park, New Jersey. 
Weston 'Jdieir accuracy rests upon several important 

Instruments. . discoveries by Dr. Edward Weston : first, a 

metliod of making a magnet which is really permanent, retaining 
its original strength for a long lime: second, by the prc])- 
aration of a reniarkalde group of ailoys which under ordinary 
variations of tenii)erature manifest scarcely any change in con- 

Weston voltmeter. 

ductivity, and which set up but little thermo-electric action as they 
touch other metals in iin instrument. Let us .see how a Weston 
voltmeter, or measurer of electric pressure, is constructed. 



A light rectangular coil of copper wire, C, is wound on an alu- 
minium frame pivoted in jeweled l 3 carings so as to be free to 
rotate in the ring-likc space between an inner cylindrical soft iron 
core, K, and the pole pieces P and P of the permanent magnet, M. 
A light aluminium pointer, p, is attached to the coil and is free to 
move across the scale, D. The current enters the coil through the 
two spiral springs S and S, which serve also to control the move- 
ment of the coil. When a current passes through the coil the 
dynamic action between the current and the magnetic field tends 
to rotate the coil, and the position of equilibrium between this 
force and the torsion of the springs, indicated by the pointer, 
measures the current passing through the coil. Because the 
magnetic field is practically unvarying throughout, and the torsion 
of the springs is proportionate to their deflection, the scale is vir- 
tually uniform. This is not assumed in their manufacture, how- 
ever, for each instrument is calibrated by direct reference to 
standards. As the aluminium frame moves through the magnetic 
field, slight currents are generated within the metal ; these serve 
to dampen vibrations so that the pointer comes to rest almost in- 
stantly without friction. That the magnetic field may have the 
utmost strength, the air gap in which the coil rotates is made 
as narrow as possible ; this is ensured by workmanshij) of the 
highest skill, and by tools specially designed. The hardened steel 
pivots are ground and centered as in the best watch-making: the 
coil is balanced by means of adjusUdile weights so that none but 
electrical forces may come into play. In a Weston voltmeter of 
regular type, the maximum current required for a full scale- 
deflection is only o.oi ampere. Instruments of much higher sen- 
sibility arc constructed for measuring insulation, requiring but 
0.0006 ampere for the same deflection. So much for the task 
of measuring electrical pressure. 

For measuring electrical currents, which differ from pressures 
as the quantity of water flowing in a pipe differs from the pressure 
of that water as shown in a common gauge, a Weston ammeter, 
or ampere-meter, may be employed. It is similar to the voltmeter 
just described, being in fact a milli-voltmetcr actuated by the 
difference in electrical jx^tential, or pressure, between the ter- 
minals of a standard resistance, the shunt, through which a defi- 


nitc fraction of the current passes. It is as if a known part of 
the how of a river being measured, the volume of the whole 
stream is learned. 

The two principal alloys discovered by Dr. Weston, and used 
in his instruments, are manganin and nickelin. Manganin has 
al)out twenty-five times the resistance of copper, and increases 
in resistance about o.ooooi for each degree Centigrade through 
wliich its temperature rises. Nickelin has about twenty-nine times 
the resistance of copper, and decreases in resistance about 0.00004 
for each degree Centigrade through which its temperature rises. 
These and other alloys used in construction arc carefully worked 
and anncalcfl according to methods perfected in years of ex- 
perience. After a wire for an instrument is drawn, its fibres, 
being in a state of unequal strain, undergo an artificial aging pro- 
cess so that their resistance shall remain unchanged after adjust- 
ment. The Weston instruments arc based on the international 
volt and ampere adopted by the National Bureau of Standards 
at Washington. Instruments of the regular portable type have a 
guaranteed accuracy of one part in 400, while the laboratory 
standard semi-portable instruments are guaranteed to one part in 
1000. Weston voltmeters and ammeters arc constantly being 
checked after years of active service, and are found correct within 
the guaranteed limits of accuracy. 

This remarkable success testifies to the importance of asking, 
What properties are needed in the material of which an instrument 
is to be built? That question duly answered, it becomes a task 
for research to provide these materials, that skill may put them 
together in compact and convenient form.^ 

Whether in the laboratory of the chemist or the physicist, in 
the machine shop or the engine-room, every means of measurement 
must be based on standards created with the 
'^StaE^ards'at^ highest skill and guarded with the utmost care. 

Washington, United States these ultimate standards, 

in full variety, arc brought together at the 

In taking notes for this book the author has visited many factories, 
\vorks, and mills. In design, equipment, and operation the Weston factory 
is the best of them all and quite above criticism. Admirable, too, are 
the educational and social features of this establishment. 



Bureau of Standards at Washington, of which Dr. S. W. Stratton 
is director. Here arc safeguarded copies of the international 
metre and the kilogram adopted by Executive Order in 1893 as 
fundamental units of length and mass; here, too, arc standard 
yards and pounds, bearing fixed legal relations to the international 
metre and kilogram The Bureau is prepared to determine the 
length of any standard up to fifty metres, to calibrate its sub- 
divisions, and to determine its coefficient of expansion for ordinary 
temperatures. To the credit of American workmanship be it said 
that at times the micrometers received from leading manufac- 
turers, for use in workshops of the best class, are so refined in 
their measurements as to tax to the utmost the resources of the 
Bureau. Its precision balances, by Rueprecht of Vienna, and 
Stuckrath of Berlin, weigh a kilogram within 1/200 part of a 
milligram, that is, within one two-hundred-millionth part of its 

In the department of electricity a resistance may be measured 
all the way from 1/100,000 of an ohm to 100,000 ohms. Here arc 
voltmeters, and wattmeters of the best types. Alagnetism, as 
swiftly summoned or dismissed in the cores of dynamos and 
motors, is here measured with the utmOvSt exactitude. In some of 
the instruments fused (ptartz has l)een used as a means of sus- 
pension because its high elasticity and great strengtli allow it to be 
drawn as extremely fine threads. Dr. K. E. (iuthe, now of the 
University of Iowa, while at the head of tlie section of magnetic 
measurements, found that fibres c(jually serviceable may be drawn 
from steatite, or soapstone, such as forms a common kind of 
gas-burner. Thick quartz threads break easily when bent, those 
of steatite do not. 

In thermometry, a section in charge of Dr. Waidner, much work 
goes forward in testing clinical and other thermometers for manu- 
facturers. The whole range of heat measurement is covered by 
instruments adapted to recording the higliest attainable tempera- 
tures until we reach apparatus by which, through observation of 
its light, the absolute temperature of the electric arc has been 
found to be 3720° C. Alcasurcments of light proceed in another 
section. Here a photometer designed by Mr. Edward V, Hyde, 
of the Bureau staff, has reached the hitherto unexampled accuracy 


of one part in 200. The Bureau has an extensive workshop where 
new (lesions for improved apparatus are constantly in hand. For 
services on behalf of the national or any state government the 
Ihircau makes no cliarge; moderate fees are required from firms 
and individuals, fn its new and adequate quarters the Bureau is 
doing work as authoritative as that of any similar institution in 
the world. 

In manufacturing modern tools and machinery, the thousandth 
of an inch is the usual limit of allowable error. A micrometer 
caliper measuring to this limit is here shown. 
Refined Measure- pitch of its screw is 40 to the inch, and 

Improves beveled edge of the screw-thimble is divided 

into 25 parts, so that motion from one division 
to the next takes the screw T/25 of 1/40 of an inch, or i/iooo. 
By carrying refinement a step farther, 1/10,000 of an inch can be 

jMicronu'ter caliper measuring- i-iooo inch, 
lirown & Sharpe, Providence. 

detected. The iM'oduction of a screw siich as this was simply 
impossible by the lathe as used almost up to the close of the 
eighteenth century, its operator holding in his hand a gouge or 
chisel. Of inestimable importance was Henry Maudslay’s inven- 
tion of the slide-rest which firmly holds the tool, moving it auto- 
matically along the wood or metal being cut. See illustration on 
page 96. James Watt, as he endeavored to improve the steam 
engino, before the slide-rest was invented, was sorely vexed 
and thwarted by the ill-shaped containers for steam which served 


him as cylinders. Perhaps the chief task accomplished by the 
lathe has been its own improvement, so that to-day surfaces are 
readily cut by its tools ac- 
curately to within a thou- 
sandth part of an inch. 

Vastly beyond this feat was 
Professor H. A. Rowland’s 
production of a virtually 
perfect screw, which enabled 
him to rule on concave 
gratings 5.9 inches square, 

I TO, 000 lines with such 
precision that the error between any two of the lines is probably 
less than 1/3,000,000 of an inch. These gratings lirought lo view 
spectra much more extended and clear than those observable in 
a spectroscope, h(3wever powerful. The concave plates employed 
by Professor Rowland were made by Air. John A. llrashear of 
Allegheny, Pennsylvania. 

Measurement is greatly indebted to accurate means of enlarging 
the images of objects as viewed in the telescope or the microscope. 
Glass grinding tools are to-day so excjuisitely contoured that a lens 
forty-two inches in breadth shows the image of a star as an im- 
measurable dot. It was in pressing together two lenses of very 
large and known radius that Newton measured the lengths of 
light- waves. With homogeneous rays, such as those of yellow 
light, the successive rings of light and darkness marked the 



Two lenses as pressed together by Newton. 

points at which the intervals between his lenses were equal to 
half a light-vibration or any multiple thereof. ATeasuring these 
intervals, by noting their distances from the common centre of 
his lenses, he found the wave-length of the particular light he 
was studying. 

Plug and ring for standard 


'I'lic cheap duplication of products, so wonderfully expanded 
of late \ ears, had its j^erm long before the Christian era, when in 
J lahylonia a builder first made bricks in a mold. 
Interchangeability -‘’x' c^rc by careful measurement to keep 

Old and New. U) nniforni (limciisions in his output. Because 
anv hrick matched any other from the same 
mold, lie intnjKhiced a new beauty and regularity in architecture, 

he made it easy to extend 
or repair a wall, a gate- 
way, a battlement. So it 
was afterward with the 
tiles, also made in molds, 
which were laid as floors 
or r(x:)fs; and the piping, 
likewise molded, for water- 
supply or drainage. To- 
day when a housekeeper 
replaces her worn-out 
stove-linings, and a printer 
increases his stock of type, 
they enjoy a direct in- 
heritance from the first 
molders of bricks and tiles, 
cups and 1k)w1s, In a modern factory vast sums are expended in 
producing the original patterns, molded or copied perhaps ten 
million limes, so that their cost, in so far as represented in each 
manufactured hook or lever, is next to nothing. Much expense, 
also, is entailed in making the jigs which guide the tools used in 
lathes or milling machines to turn out the cases of voltmeters, or 
a comj)licated valve-seat. A jig may cost a hundred dollars and 
its use may re([nire rare .steadiness of hand, the utmost keenness 
ol eye; all the while the operator’s wife, at home, avails henscll 
oi an aid based on the very .same principle. What else is the 
pa])er pattern according to which she cuts out a collar, an apron., 
a baby's bib? 

In machinery the first introduction of an interchangeability 
jiarts was by (icneral Ciribeauval, in the French artillery service, 
about 1765. He reduced gun-carriages to classes, and so arranged 

Newton’s riii)L»s as produced in 
yellow light. 


many of their parts that they could be applied to any carriage of 
the class for which they were made. These parts were stamped, 
not forged. The next step 
in this direction was taken in 
America and, as in France, its 
aim was to improve instru- 
ments of war. Eli Whitney, 
famous as the inventor of Flat jig, or guide, 

the cotton gin, secured a 

contract from the United States Government for 10,000 firearms. 
These he manufactured almost wholly by stamping. He introduced 
machinery for shaping and, as far as then feasible, the finishing 
of each part. He also employed a system of gauges, by which uni- 
formity of construction was assured for every gun produced. 
Next came J. H. Hall, of Harper's Ferry, Virginia, who in l8i8 
made every similar part of a gun of such size and shape as to suit 
any other gun, improving some details of importance. 

The modern designer of tools, implements and machines takes 
care that the parts upon which wear chieiiy comes are easily re- 
movable so as to be cheaply replaced. A worn out plowshare is 
renewed for a dollar or two, keeping the plow as a whole sub- 
stantially new. Should the pinion of a watch be destroyed by 
accident, it is duplicated from Waltham or hdgin for a few cents. 

To-day rods, wires, .screws, bolts, tubes, nails, sheets of metal, 
are made in standard sizes. Much the. same is true of rails for 
railroads, girders, eye-bars for bridges, and the like. Thus the 
product of any factory or mill may be used to piece out or to repair 
work turned out by any other similar concern. Yet more, if a 
subway or a tunnel is to be built in a hurry, two or more steel- 
works may co-operate in furnishing beams, columns, or aught 
else, with no departure from ordinary gauges. Steel works in 
Pennsylvania have produced every detail for a bridge erected in 
Africa, a factory in Germany, a stamp mill in Canada. At the 
World’s Congress of electricians held in Chicago in 1893, units 
were adopted as international standards, a noteworthy step toward 
adopting universal standards in all branches of engineering. Here 
progress is to some extent held back by firms and corporations 
that produce patterns not always worthy of defence. Standard 




A Test Shows 
How Concrete 
May be Cheaply 

forms and dimensions, especially in manufactures for a world- 
market, arc only decided u^x)!! after thorough discussion, so that 
they are judiciously chosen. Among feasible shapes and sizes for 
rails, columns, girders, and the rest, one is usually best, or a few 
are best. Why not exhaust every reasonable means of ascertain- 
ing which these arc for specific tasks that they may be freely 
chosen? Then if individuality prefers its own different designs, 
let it do so knowing what the indulgence costs. 

Measurements may be conducted in the strict spirit of scientific 
research, not immediately directed to industrial ends. Methods 
thus perfected are more and more being 
adopted for large questions of industry. Let 
an example be presented from the field, briefly 
touched upon in this book, of concrete as a 
material for the builder. Says Mr. C. H. Um- 
stead of Washington, lYmnsylvania : — 

*‘Many thousands of tons of the finer grades of stones from the 
crushers all over the country are rejected by engineers for use in 
concrete foundations and walls, sand being preferred at greatly 
increased cost. I prejiared seventy-two three-inch cubes with 
cjuartz sand and with varying proportions of crushed stone which 
was going to the duiu]) as unfit for foundation work, and sub- 
mitted them to crushing tests at periods of fourteen and twenty- 
eight days. The proportion of Portland cement was constant.” 

From Mr. Ilmstcad’s table of results the following figures are 
chosen ; on comparing those for the first and third cubes they show 
that a gain in strength of forty-three per cent, followed upon 
using six pounds of crusher refuse instead of five and one half 
pounds of sand. 



Compressive Strain 






28 Days 

8.5 11)S. 

4.5 Ihs. 

I lb. 


2850 lbs. per sq. in. 



4.5 " 


3 lbs. 

3120 « “ “ 


3 “ 

4.5 “ 

1. 125 lbs 

6 “ 

3620 “ “ " 



much for 

the value of 

a test in 

the improvement of 

an im- 

portant manufacture. 



Mr. Umstead's full report appeared in 1903, in the third volume 
of bulletins published by the American Society for Testing Mate- 
rials. This Society, whose secretary is Professor Edgar Marburg 
of the University of Pennsylvania, Philadelphia, is affiliated with 
the International Association for Testing Materials, one of the 
most important agencies in existence for providing the engineer 
with trustworthy data. 

Measurement industrially is taking on a new and rapidly ex- 
tending scope. It is of great moment that a railroad or a steam- 
ship, a factory or a mill, should be built of the 
best materials in the most economical way, that industrial Usas 
it should be equipped with the most efficient of Measurement, 
boilers, engines, machines, and lamps : in effect, 
that every dollar be expended for the utmost possible value. 

At Altoona the Pennsylvania Railroad Company has a labora- 
tory for testing the materials which go into its roadbed, bridges, 
tracks, rolling stock, buildings, telegraph, and signal systems. 
Every gallon of oil, each incandescent lamp, car axle, or boiler 
plate accepted by the Company must pass a due test in a con- 
tinuous series of competitive examinations. The huge scale of 
such a Company’s purchases, the strains placed upon its equip- 
ment by a service growing in extent and in speed, make this 
course indispensable. Take another case, this time in New York, 
at the power-house of the Interborough Company in West 59th 
Street. There every day a fair sample of the coal brought to the 
(lock is burned, and its heat-units ascertained as a basis for pay- 
ment. With a consumption which may rise to 1500 tons a day 
this precaution is obligatory.^ 

^ The United States Geological Survey, WavShington, D. C., in 1906 pub- 
lished a report on the coal testing plant at the Exposition, St. Louis, Mo., 
T904. Part I, Field work, classification of coals, chemical work. Part II, 
Boiler tests. Part III, Producer-gas, coking, briquetting, and washing tests. 
This report, with elaborate tables and many illustrations, is of great value. 

The Pennsylvania R. R. Co., Philadelphia, in 1905 published a large 
•ind handsomely illustrated volume, “Locomotive tests and exhibits, St. 
I-ouis, 1904.” $5.00. The locomotives represented the best American 
practice of 1904. Every detail of construction and operation is given in 
the most instructive manner. 

The Company is continuing these tests of locomotives at Altoona, Pa. 


On quite other lines, equally important, the ascertainment of 
values proceeds at laboratories thoroughly organized for the pur- 
pose by staffs at the service of the public. In the United States 
the first in rank of such laboratories are grouped at the Bureau 
of Standards in Washington. At leading universities and techiiu- 
kjgical institutes throughout the Union are other laboratories well 
etjuipped for chemical, physical, and engineering tests. At the 
Massachusetts Institute of Technology in Boston, for example, is 
an iMiiery testing apiiaratus for making compression tests of 
specimens u]) to eighteen feet in length, for tension specimens up 
to thirteen fc‘et. Jn Europe analogous institutions arc supple- 
mented by the I’oard of Trade Laboratories in London, the Labo- 
ratoire ( eniral in Baris, the Reichsanstalt in Berlin. The Electrical 
Testing Lalioratories, a joint-stock concern, has been established 
in New York, at lughtieth Street and EavSt End Avenue, for 
similar tasks in so far as they come within the electrical field. Its 
direction in ability and character is authoritative, tierc is some of 
the best apparatus in the world for tests of the permeability of 
magnet iron, of tlie light from incandescent, arc, or other electric 
lam])s, of gas-])urners and mantles, of the extent to which re- 
flectors and glolies fulfil their jnirpose, and so on. 

It is altogether ])robable that this concern will be copied in 
every other large city of the Union'. When an electrical plant is 
installed it is not enough that the specifications be drawn with 
care, it is necessary that verifications of (piality follow upon de- 
livery of dynamos, motors, lanqis, and all else. Tests should be 
continuous : let us su])])ose that for a s])ecific task of illumination 
Nernst lamps are selected. All very well, but the question is. 
What quality has each lamp? Buyers in cases of this kind are 
more and more referring rival manufactures to tests which settle, 
as in a court of final appeal, differences upon which they them- 
selves are inconqietent to pass. Not only in sale but in production 
these tests arc of the first importance. If a copper refinery turns 
out from the same batch of crude metal two samples which vary 
by a thousandth in electrical conductivity, it is worth while know 
ing every detail which may explain how the better sample was 
jiroduced. So likewise in the dr^iwing of wire, the alloying nt 
lead with other metals for anti- friction bearings, and so on. 



It is altogether likely that recourse to authoritative tests will 
;oon become general. Before many years elapse we may see 
)rivate and public laboratories multiplied for the comparison of 
milding and road-making materials, fuel, boilers, engines, ina- 
:hines, lubricants, finished goods of all kinds. In the textile iii- 
lustry, for instance, much is said about the waste entailed in mix- 
iig sound wool with shoddy, long staple cotton with short inferior 
)rands. Let pure and adulterated fabrics be compared in re- 
;istance to wear; and let the effects of scouring, bleaching, dye- 
ng, and mechanical washing be measured. In another field Pro- 
’essor W. O. Atwater has done much to ascertain the nourishing 
^aluc of foods : his labors might well be extended full circle, not 
miitting tests of i^opular medicaments and common drugs. 

To-day engineers of mark are engaged not only to plan a 
)ower-house, a flour mill, a steel works or other vast installati(5n, 
)Ut also to examine industrial plants estab- 
ished long ago and enlarged from time to Expert Planning 
ime in an unsystematic way. Armed with and Reform, 
scales, pressure-gauges, indicators, voltmeters, 
hey ascertain the cost of a horse-power-hour, of making a pound 
)f flour, copper wire, or aught else. They note how speeds may 
>e heightened with profit, as by using suitable brands of high- 
speed steels. They suggest how a pattern may be adopted in the 
'oundry which will lessen machining; how by-products now 
brown away may be turned to account. They point out how 
[uality may be improved by the adoption of new machines which 
nay, furthermore, demand unskilled instead of skilled attend- 
ince. They may advise, from a wide outlook ’on the whole field 
)f American experience, a method for equalizing output through- 
)Ut the day and throughout the year, as when a central-lighting 
station sells current at a large discount during the hours when 
\o lamps are aglow, so that ice may be manufactured at such 
Kriods, or batteries restored for use in automobiles and motor- 
)oats. Mr. Wilson S. Howell, of New York, a few years ago 
became convinced that a neglected branch of economy in central 
ighting stations was the maintaining a uniform voltage. lie suc- 
'ceded in reducing fluctuations. in many plants to the unexampled 
igure of four per cent. The result was that he lowered the cur- 


rent necessary for an Edison lamp from 3.6 watts to 3.1 watts per 
candle-power, a saving of one seventh. Mr. M. K. Eyre, another 
well-known engineer, once took charge of a lamp factory in Ohio. 
In four months he had reduced cost forty per cent, while pro- 
ducing a lamp of the best quality. An electric lighting and power 
property which for years had been unprofitable was placed in the 
hands of Messrs. J. G. White & Company of New York, an en- 
gineering firm of the first rank. Within a few months the prop- 
erty was earning a substantial surplus; the ratio of operating to 
gross earnings was reduced about thirty per cent., and the gross 
earnings showed an increase over corresponding months of the 
previous year of nearly forty per cent. Economies quite as strik- 
ing have been effected by the firm of Messrs. Dodge & Day of 
Philadelphia. On request investigators of this stamp, whose aim 
is to abolish waste and promote efficiency, go beyond mechanical 
and engineering details. They may point out how needed work- 
ing capital may be obtained, how best to extend sales, and pos- 
sibly how an economical consolidation with other similar plants 
may. be effected. Almost invariably it is found imperative to re- 
cast the bookkeeping methods, especially with regard to ascer- 
taining the cost of production in each department. Drawing 
upon experience recommendations may follow as to premium 
plans of paying wages, and other methods of identifying the 
interests of employers and employed.^ Approved schemes for the 
comfort and welfare of work people are also suggested by coun- 
sellors thoroughly aware that contentment is great gain, that 
Dure air, good light, and the utmost feasible safety, contribute to 
:he balance sheet not less than the quickest lathe tools or the best 
wound dynamo. 

^Mr. T. S. Halsey is a contributor to “Trade Unionism and Labor 
Problems,” published by Ginn & Co., Boston, 1905. He recites (p. 284) 
how a corporation had manufactured a product again and again. Both 
workmen and foreman were positive that the working time was at the 
minimum. The premium plan of payment was introduced, with a reduc- 
tion in time of 41 per cent, as the result 



Forces take paths of least resistance . . . Accessibility decides where 
cities shall arise . . . Plants display engineering principles in structure. 
Lessons from the human heart, eye, bones, muscles, and nerves . . . 
What nature has done, art may imitate, — in the separation of oxygen 
from air, in flight, in producing light, in converting heat into work . . . 
Lessons from lower animals ... A hammer-using wasp. 

B eyond their unending study of forms and properties, their 
constant weighing and measuring, the inventor and his 
twin-brother, the discoverer, have a gainful province which now 
for a little space will engage our attention. This province is 
nothing else than Nature, which begins by offering primitive man 
stones for hammers, arrowheads, knives ; sticks to serve as clubs, 
paddles, harrows or tent-poles. We may well believe that the 
lowest savages have always exercised some degree of choice even 
here; it would be the soundest and sharpCwSt stone that they 
picked up when a rude axe was needed. Should only blunt stones 
be found, then in giving one of them an edge was taken a first 
step in art, rewarded with a tool as good as the axe found ready 
to hand in some earlier quest. Nature is not only a giver of much 
besides stones and sticks, she is virtually a great contriver whose 
feats may incite the inventor to reach her goals if he can; his 
path will probably differ widely enough from hers as he arrives 
at success. 

When one drop of rain meets another, and they join them- 
selves to thousands more on the crest of a hill, they need no 
guide posts to show them the easiest course to 
the valley. They simply take it under the quiet 
pull of gravity. When a bolt of lightning darts Easiest Paths, 
across the sky, its lines, chaotic as they seem, 
are just the paths where* the electric pulses find least obstruction. 
If a volcano, which has boiled and throbbed for ages, at last 



opens a chasm on a hapless shore, as that of Martinique, we may 
l>e sure that at that point and nowhere else the mighty caldron’s 
lid was lightest. A cavern in Kentucky, or Virginia, slowly 
broadening and deepening through uncounted rills which dissolve 
its limy walls, comes at last to utter collapse: the breach marking 
exactly where an ounce tw much pressed the roof at its frailest 
seam. In these cases as in all others, however complex, matter 
moves inevitably in the path of least resistance. To imitate that 
ecoiKJinv of effort is from first to last the inventor’s task. 

Rains, winds and frosts, in their sculpture of the earth have 
each taken the easiest course; in so doing they have incidentally 
marked out the best paths for human feet, have 
Cities and Roads, pointed to the best sites for the homes of men. 

The stresses of defence may rear a pueblo on 
the ])eak of a perpendicular cliff in New Mexico, but Paris and 
London, like Rome, must have all roads leading to their gates; 
and the easier and shorter thcvSe roads, the bigger and stronger 
the city will become. Where New York, Montreal, Chicago, and 
Pittsburg now stand, the Indians long ago had the wit to found* 
goodly settlements. They knew, as well as their white succes- 
sors, the advantages of paths readily traversed, and no longer 
than need be. In this regard there was an instructive contrast at 
the outset of railroad building in hmgland. A leading engineer, 
who planned some of the earliest luiglish railways, had strong 
mathematical pre])ossessions : he endeavored to join the terminal 
of his routes by lines as nearly straight as he could. George 
Steidieuson, for his part, had no mathcmaticed warp of any kind, 
but instead much sound sense; his lines followed the courses ol 
rivers and valleys, and kept, as much as might be, to the chief 
indentations of the sea. His roads deviated a •g(X)d deal from 
straightness, hut the) did so ])rofitably ; whereas the lines of hi^ 
academic rival, disrespecting the hints and indications of nature, 
were much less gratifying from an investor’s point of view. Tf 
a traveler takes the New York Central and Hudson River Rail- 
nxul from New \ork to Ihiflfalo he goes north for 143 miles, to 
•Albany, before he begins to travel westward at all. Yet thi^ 
line, keeping as it does to the well-peopled levels of the Hudson 
and Mohawk Valleys and serving their succession of cities. 



towns, and villages, enjoys the best business, and makes better 
time between its terminals than any rival route, because it passes 
around instead of over its hills and mountains, liy way of con- 
trast we turn to the railroad map of Russia and observe how 
Moscow and St. Petersburg are joined by a line which follows 
the road which .it is said that Peter the Great, with military 
exigencies in view, laid down with a pencil and ruler. 

If the engineer has many a golden hint spread before him in 
the hills and dales, the streams and oceans of the world, not less 
fruitful is the study of what takes place just 
beneath the surface of the earth where the Engineering 

roots of grain and shrub, reed and tree, take ^egrtation” 

life and form. Plant a kernel of wheat in the 
ground and note how its rootlets pierce the soil, extending always 
from the tip. They need no gardener or botanist to bid them 

Deciduous cypress, Taxodium distichum. 

lengthen and thicken where food chiefly abounds. In an arid 
plain of Arizona a vine, in ground parched and dry, goes down- 
ward so far, and spreads its fibrils so much abroad, as soon to 


show ten times as much growth below the drifting sands as above 
them. In fertile, well-watered soil the same vine descends less 

than half as far, and yet with 
more gain. A bald cypress 
in a swamp of Florida re- 
sponds to > different sur- 
roundings with equal profit. 
Finding its food near the 
surface its roots take hori- 
zontal lines, at no great 
depth in the soil. Every 
wind that stirs these roots 
but promotes their thrift and 
strengthens their anchorage. 
A wealth of sustenance 
floats in the swamp water. In seizing it and being thereby fed, 
the roots develop “knees” ; these brace the tree so firmly against 
tempests as to win admiration from the engineer. When tlie 
progeny of this cypress grow on well-drained land, the knees 
do liot api)ear, while the roots within- a narrowed area strike dee]). 
Thus simply in doing what its surroundings incite it to do, the 
tree acts as if it had intelligence, as if it consciously saw and 
chose what would do it most good. 

Lumbermen in the North observe much the same responsive- 
ness. In a grove of pines they see that the trees which stand close 
together are tall and cylindrical. When all the pines but one in a 
cluster arc cut down, that one will speedily thicken the lower part 
of its trunk by virtue of the increased action of the winds, just 
as a muscle thickens by exercise. 

So also is there responsiveness when we look upon the life of 
plants in the large. As the traits of a shrub or tree are lx)nK’ 
into its seed many a thousand impulses are 
Re![pL°fvL°ess. and mingled. Little wonder that their 

delicate accord and poise should be slightly 
difierent from those of the seeds from which the parents sprang. 
Let us suppose these parents to be cactuses, and that the offspring 
displays an unusually broad stem, of less surface comparatively 
than any other plant in its group. In a soil seldom refreshed by 

Deciduous cypress, hypothetical 



rain, this cactus has the best foothold and maintains it with most 
vigor. Sandstorms which kill brethren less sturdy, strike it in 
vain, so that its kind is multiplied. Wherever such a new char- 
acter as this gives a plant an advantage, it holds the field while its 
neighbors perish. Thus arises a high premium on every useful 
variation, be it in new stockiness of form, an acridity which repels 
vermin, or a strength which readily makes a way through sun- 
baked earth. Hence such new traits arc, as it were, seized upon 
and become points of departure for new varieties, and in the 
fullness of time, for new species. About a hundred years ago 
a gardener imagined a tuberous begonia, and then proceeded ste]) 
by step toward its creation by breeding from every flower that 
varied in the direction he desired. This man, and all liis kindred 
who have added to our riches in cultivated blooms, have no more 
than copied the modes of nature which, at the end of ages, liestows 
as free gifts every wildflower of the field and hedgerow. If the 
botanist of to-day is the master of a plastic art, so is the cattle- 
breeder who chalks on a barn-door the outline of a beeve he 
wishes to produce, and then straightway plans the matings which 
issue in the animal he has pictured. Artificial selection, such as 
this, is after all only imitation of that natural selection which has 
derived the horse from a progenitor little larger than a fox, in 
response, age after age, to changing food, climate, enemies, and 
the needs of his human master. 

Fields remote from those of the naturalist arc just as instruc- 
tive. The inventor sets before himself an end with conscious 

purpose, and then seeks means to reach that 
end, but at best his methods may be wasteful Imitation^ 
and imperfect. Nature, with unhasting tread, 
acting simply through the qualities inherent in her materials, 
through their singular powers of combination, of mutual adapt- 
ability, shows the discoverer results which to understand even in 
small measure tax his keenest wit, or displays to him structures 
at times beyond his skill to dissect, much less to imitate. Me- 
chanic art, indeed, is for the most part but a copy of nature, as 
when the builder repeats the mode in which rocks arc found 
in caves, in ridges at the verge of a cliff, or in the stratifications 
which underlie a county, all conducing to permanence of form, to 



resistance against abrading sand or dissolving waters/ What 
ensures the stability of a lighthouse but its repetition of a tree- 
trunk in its contour ? Engines and machines recall the animal 
body, grinding ore much as teeth grind nuts, lifting water as^the 
heart pumps blood through artery and vein, and repeating in 
mechanism of brass and steel the dexterity of fingers, the blows 
of fists. When an inventor builds an engine to drive a huge ship 
across the sea, he has created a motor vastly larger than his own 
frame, but much inferior in economy. At a temperature little 
higher tlian that (jf a summer breeze the human mechanism trans- 
mutes the energy of fuel into mechanical toil : for the same duty, 
less efficiently discharged, the steam engine demands a blaze al- 
most fierce enough to melt grate bars of iron. 

lieat is costly, so that its conservation is an art worth knowing. 
In the ashes strewn and piled on burning lava nature long ago 
told us how heat may be secured against dissipation. Other of 
her garments, as hair and fur, obstruct the escape of heat in a 
remarkable degree, and so does bark, especially when loosely 
coherent as in the cork tree. Feathers are also excellent retainers 

of heat, and have thereby so much profited their wearers, that 
Ernest Ingersoll holds that the development of feathers has had 
much to do with advancing birds far above their lowly cousins, 
the reptiles clad in a scaly vesture. 

As we look back upon the past from the vantage ground of 
modern insight we sec that men of the loftiest powers could be 

Strength of the 

blind to intimations now plain and clear. Many 
a time have designers and inventors paralleled, 
without knowing it, some structure of nature 

often seen but never really observed. All the variety and beauty 
of the Greek orders of architecture failed to include the arch; 

yet the contour of every architect’s own .skull was the while dis- 

playing an arched form which could lend to temple and palace 
new strength as well as grace. The skeleton of the foot reveals 

in the instep an arch of tarsal and metatarsal bones, with all the 

springiness which their posses.sor may confer upon a composite 
arch of wood or steel. Modern builders, whether wittingly or 
not, have taken a leaf from the book of nature in rearing their 
tallest structures with hollow cylinders of steel. What is this 


but borrowing- the form of the reed, the bamboo, a thousand 
varieties of stalk, one of the strongest shapes in which supporting 
material can be disposed? Pass a knife across a blade of pipe or 
moor grass and you will find a hollow cylinder stayed by but- 
tresses numbering nearly a score. More elaborate and even more 

Section of pipe or 
moor grass. 

Cross-section of bul- 
rush, Scirl^tis lacustris. 

gainful is the way in which tissue grows in the columns of dead- 
nettles and bulrushes. The bones in one’s arms and legs resemble 
the hollow cylinders of which these stalks show instructive 
variations, so that without going beyond his own frame the de- 
signer could long ago have learned a golden lesson, flow bone 
is joined to lx)nc is scarcely less remarkable, as in the braces of 
the thigh bone as it joins the trunk. As Ixmes move upon each 
other all shock is prevented by a highly elastic cushion : the 
sjirings of vehicles, the buffers of railroad trains, but repeat the 
cartilages in the joints of their inventors. 

In the theodolite and sextant, in the geometric lathe of the 
bank-note engraver, are ball-and-socket joints allowing motion in 
any plane. Equally free in their movements are the shoulder and 
bip joints, while their surfaces are lubricated by a delicate .syno- 
vial fluid supplied just as it is wanted. When pumi)s first re- 
ceived valves to direct their flow in one direction, their inventor 
was no doubt gratified at his skill. In the heart within his own 
breast, in his veins and arteries, were simple valves engaged in a 
similar task as they directed the currents of his blood. In pumps 
such as arc common in farm-yards, the action is jerk^^ the stream 
flowing and ebbing from moment to moment as the arm rises and 



falls. The tide of human blood would have the same uneven 
pulse were it not for the elasticity of its arterial walls. Their 

llunian liip joint in st'Ction. b'rom 
“'I'lio llnni.'in liody,” by II. N. AFarlin. 
Coinrij^lU, llcnry llolt tK: Co., New 
A'ork, 1S84. ReprodneecI b\ llieir per- 



Valves of veins. 

C, a capillary; TF, 
the heart end of the 
vessel. From “The 
1 Inman TJody/^ by 
F I. N. Martin. Copy- 
right, 1884, Henry 
Holt & Co., New 
York, and repro' 
dneed by their per- 

elasticity serves to equalize the flow, much as the air does in 
larj^e chambers on pumps for mines or waterworks. 

FCxamination of the heart brings out a principle in its structure 
closely paralleled in modern invention. Ciuns of old were cast 
or barged as ordinary columns or shafts are 

The Heart and todav, the strength of the metal being vir- 
the Built-up 1, r ,1 f t 

tually uniform throughout when the guns were 
at rest on their trunnions. As cxplosivi' 
charges more and more jxnverful were employed, these gnn^ 
gave way, the pressure of the exploding gases stretching th ‘ 
metal at the bore to rujiturc, before the outer metal could add it-^ 
resistance. A modern built-up gun is made up of a series of, let 



us say, four cylinders : the first, of comparatively small bore and 
thickness, is innermost. It is cooled to as low a temperature as 
jx)ssible, when a second cylinder is slipped over it red-hot to form 
a tight fit. Both masses of metal are now slowly cooled, wlien a 
third red-hot, closely fitting cylinder is passed over them. All 
three united masses are now cooled, when the fourth and widest 

Built-up gun. 

cylinder of all, red-hot, is passed over these three inner tubes, and 
the whole gun is allowed gradually to fall in tem]>erature. When 
this process is conijdeted the inner jxirts of the gun, by virtue of 
the shrinkage in the metal as it cooled, are under severe cotn- 
pression, while the outer ])arts are in as extreme a state of stretch 
or tension. When such a gun is fired its inner cylinders opj^osc 
much greater resistance to the outward ])ressiire of the cxph^ling 
gases than did the walls of the old-time guns. The strength of 
the old guns was uniform throughout when they were doing 
nothing, and very far from uniform at the instant of firing; a 
built-up gun, on the contrary, has uniform strength in its every 
]jart just when that uniformity is wanted, at the moment of ex- 
plosion. The built-up gun therefore uses projectiles vastlv heavier 
and swifter than those of former times. Its structure, made up 
of cylinders successively shrunk one n])on another, resembles 
that of the heart, whose two inner parts have their fibres woniifl 
somewhat like balls of twine, these in turn being tightly com- 
pressed by a covering of other fi])res. The heart has to resist no 
such explosive force as arises within a gun, but in its propulsioi; 
of blood through the arteries and veins it has to exert great pres- 
sure, with no rest throughout a lifetime. This pressure is uni- 
formly distributed throughout the muscular tissue by a structure 
which, as engineers would say, has its outer layers in tension and 
its inner layers in compression. During twenty- four hours the 


labor of an average human heart is equal to lifting two hundred 
and twenty tons one foot from the ground. 

What building-up does to strengthen the gun has been re- 
l)eate(l in the case of the circular saw : driven at a high speed it 
becomes so highly heated at its periphery that the resulting ex- 
pansion may crack the metal in pieces. In an improved method 
of manufacture the saw is hammered to a compression which 
gradually increases from rim to centre. In' this way the tendency 
of the periphery t© fly apart is withstood by the compressive forces 
at the central portion of the disc. 

This ingenious treatment of metal for guns and saws reminds 
us of a familiar resource in carpentry, illustrated on page 36. An 
ordinary lx)ok-shelf, if fairly long and not particularly stout, 
bends beneath its burden and may at last slip out from its mortices 
and fall with injury to its books. At the outset this is prevented 
by bending the shelf to convexity on its upper surface. Then a 
heavy load no more than brings the shelf to straightness, so that 
the books remain in their places with lx)th safety and sightliness. 
Flcre a principle is involved worth a moment’s pause. An in- 
ventor asks, What effect will a working load exert which it is 
desirable to lessen or withvStand? He gives his structure a form 
oi)])(^silc to that which will result from an imposed burden, se* 
that when at work his structure, a shelf, a cylinder, a saw, will 
assume its most effective shape. 

l"rom childhood we arc familiar with the triangular prisms of 
glass which break a sunl)eam into all the hues of the rainbow. A 
lens is a prism of circular form, and has. 
The Eye and the equally with an ordinary prism, the power to 
Dollond Lenses, show rays of all colors. This was for a long 
time a source of error and annoyance in tele- 
sco])ic images. Sir Isaac Newton from some rough and ready 
experiments concluded that the trouble was beyond remedy, yet 
'all the while his own eyeballs were transmitting images with little 
or no vexatious fringe of color. Let us note how Dollond set 
about a task which Newton deemed impossible. He knew, what 
Newton did not know, that crown glass disperses or scatters light 
only half as much as docs flint glass, so he united a lens of tin- 
one to a lens of the other, and obtained a refracted or bent beam 



of light almost unchanged in its whiteness. Of course, in this 
combination there was an increased thickness of glass, but its 
doubled absorption and waste of light was a small drawback com- 
pared with the advantage of almost wholly excluding the tinted 
fringe which had so long vexed astronomers. In the eyeball arc 
first a crystalline lens, next an aqueous humor, third a vitreous 
humor; these three so vary in their qualities of refraction and 
dispersion as to render images quite free from color fringes. 
Compound lenses on the Dollond principle, repeating the struc- 

A is flint glass, 
B is crown glass. 
They unite to 
form an achro- 
matic lens. 

B, C, F, prism crown glass. 
C, 1), 1% prism flint glass, 
more dispersive than crown 
glass. The beam S emerges 
as E, but little decomposed. 
Were A, B, F a prism of 
one kind of glass, E would be 
much decomposed. 

ture of an eyeball, are used in all good telescopes, microscopes, 
and cameras, and are now executed in varieties of Jena glass 
which bring perturbing hues to the vanishing point. In their 
achromatic, or color-free, lenses and their cameras, or dark cham- 
bers, our photographic instruments much resemble the eye. In- 
deed, it may be that when we see an object the impression is due 
to a succession of fleeting photographs, following each other so 
rapidly on the retina as to seem a permanent picture. The eye, 
furthermore, is stereoscopic; by uniting two images seen from 
slightly differing points of view, it enables us to judge of size, 
solidity, and distance. 



Long before there was a philosopher to classify levers into 
distinct kinds, the foot of man was affording examples of levers 
of the first and second orders, and his fore- 
Limbs and Lungs ^ ^^ver of the third order. Ages before 

as Prototypes. the crudest bagpipe was put together, the 
lungs by which they were to be blown, and the 
larynx j(;ined to those lungs, were displaying a wind instrument 
of perfect model. Lhe wrists, ankles, and vertebrae of Hooke 

might well have served him in de- 
signing his universal joint. Indeed 
weapons, tools, instruments, ma- 
chines, and engines are, after all, but 
extensions and modified copies of 
the bodily organs of the inventor 

Canals have called forth the in- 
genuit}^ of an army of engineers ; 
ever since the first heart-throb, the 
circulation of the human blood was 
exemi)lifying a system in vvdiich the 
canal liquid and the canal boats move 
together, making a complete circuit 
twice in a minute, distributing sup- 
plies wherever reejuired, and taking 
up without stop])iiTg return loads 
wherever they are found ready. The 
heart, with its arteries and veins, 
forms a distributing apparatus which 
carries heat from places at which it 
generated, or in excess, to places 
where it is deficient, tending to establish a uniform, healthful tem- 
perature. To copy all this, with the ven- 
tilating appliances prefigured in the 
lungs, is a task which in our huge 
modern buildings demands the utmost 
skill of the architect and engineer. 

In a great city each branch post office 
is connected solely with headquarters, to 

of fhp. f''^^ Order. 



Lever of tfw 3'"-^ Order. 

P, power. J', fulcrum. 
W, weight. 



Postal and Tele- 
phonic Service. 

which it sends its letters, papers, and parcels, receiving in return 
its batches for local distribution. I'or each branch office to com- 
municate with every other would be so costly 
and cumbrous a plan as to be quite imprac- 
ticable. Our postal method is adopted in 
every telephonic service ; Z communicating with D or j\I only 
after he has had his line joined to the central switchboard which 
connects with every telephone in the whole system. All this was 
prophesied in the remote ancestry of both postmasters and elec- 
tricians as their nerves took the paths of what is in effect a com- 
plete telegraphic circuit, with separate up and down lines and a 
central exchange in the brain,— that prototype of all other means 
of co-ordination. 

Pianos, organs, and other musical instruments yield their notes 
by the vibration of strings, pipes, or reeds of definite size and 
form. Across the larynx, the box-like organ 
of the throat, the vocal cords vibrate in an Fibrils of the 

identical way. When we sing a note into an Ear and Eye. 

open piano, the string capable of giving out 
that note at once resjionds. 1 lelmholtz believed that in the ear the 
delicate, graduated structures, known as the rods of Corti, vibrate 
in the same way when sound-waves reach them, giving rise to 
auditory inqiressions. Analogous in operation arc the tibrils of 
the eye which respond to light-waves of various length and in- 
tensities. The human eye has muscles which modify its globu- 
lar ity, rendering its lenses more or less convex. A ca^ has a 
higher degree of this kind of ability, so that it can dilate its pupil 
so much as to sec clearly in a feeble light. A man who remains in 
a darkened room so rests his nerves of vision that in four or five 
hours he can readily discern what would be unseen were he newly 
brought into the darkness. 

Not only in the frame of man, but in the bodies of the lower 
animals, are suggestions which ingenuity might well have acted 
upon in the past, or worthily pursue in the 
future. The science of electricity was born The Electric Eel. 
only with the nineteenth century because the 
gymnotus, or electric cel, had not been undcrstandingly dissected. 
Its tissues disclose the very arrangement adopted by Volta in his 



A Beaver Tooth 
and the Self- 
Sharpening Plow 

first crude batter}', namely, layers of susceptible material sur- 
rounded by slij4^btly acid moisture. The characteristics of this eel 
have their hoinolno-ies in the human body; in the muscles which 
Ijcnd the fore-arm, for example, are nearly a million delicate 
fibrils C()mi)aral)le in structure with the columnar organs of the 
gvninotiis. I'liesc fibrils arc so easily excited by electricity as to 
denote an essential similarity of build. Toth the columnar layers 
of the eel and the fibrils of human muscle are affected in the same 
way by strychnine and by an allied substance, curare. 

The frames of other animals furnish forth a goodly round of 
analogies with recent products of mechanical ingenuity. A 
beaver tooth might well have been the model 
for a self-shar|)ening plowshare, widely used 
throughout the world. This tooth has a thin 
outer layer of hard enamel, within which, 
dentine, less hard, makes u{) the rest of the structure. Gnawing 
wears the dentine mucli more than the enamel, so that the tooth 

takes on a bevel resembling that of the 
chisel which pays frequent visits to a 
carpenter’s oil-stone. The scale of 
enamel gives keenness, the dentine en- 
sures- strength, so that the tooth 
sharpens itself by use, instead of 
growing dull. Much the same struc- 
ture is repeated in a plowshare by 
chilling the underskin of the steel to 
extreme hardness, while the upper face of the share is left com- 
paratively soft. .As it goes through the ground the upper face 
wears away so as to yield a constantly sharpened edge of the thin 
chilled under metal. Thus tlie heavy draft of a dull share is 
avoided without constant recourse to the blacksmith for re- 

In another field of ingenuity a great inventor scored a success, 
simply by delil)crately taking a lesson from nature. James Watt. 

to whom the modern steam engine is most in- 
Shaping a Tube, debted for its excellence, was once consulted by 
the proprietors of the Glasgow Water Works, 
as to a difficulty that had occurred in laying pipes across the river 



Clyde to the Company s engines : the bed of the river was covered 
with mud and shifting sand, was full of inequalities, and subject 
to a current at times of considerable force. With the structure of 
a lobster’s tail in his mind. 

Watt drew a ])lan for an 
articulated suction-pipe, so 
jointed as to accommodate 
itself to the shifting curves 
of the river-bed. This 
crustacean tube, two feet in 
diameter, and one thousand 
feet in length, succeeded 
perfectly in its o])eration. 

To-day powerful hydraulic 
dredges discharge through 
piping with dexible joints 
such as Watt devised ; in 
one instance this jHping is 
5700 feet in length. 

In many another case art 
has used a gift of nature 
simply as received, and then 
improved upon it. In mak- 
ing their harpoons the Es- 
kimo used the s])iral teeth 
of the narwhal ; linding their shape advantageous, they copied it 
for arrowheads. This is undouhtedly one of the origins of the 
screw form, of inestimahle value to the mechanic and engineer. 

Savages turn birds and beasts to account as food, clothing, and 
materials for weapons, and tools; they also observe with ]n*()ht the 
instincts of these creatures. Le Vaillant, the Lessons from 
famous explorer, tells us that in y\frica the Lower Animals : 
negroes eat any strange food they sec the mon- A Tool-Using • 
keys devour, well assured that it will prove Wasp, 

wholesome. When the surveyors of the first transcontinental 
railroad of America began their labors, they gave diligent heed 
to the trails of buffaloes in the Rocky Mountains, believing that 
these sagacious brutes in centuries of quest had discovered the 

Narwhal with a twisted tusk. 
Reproduced from the Scicntilic 
American, New York, by permis- 



easiest passes. In constructive powers bees, ants ana wasps far 
outrank quadrupeds. Indeed one of the supreme feats of human 
architecture, the dome, forms part of the nest of the warrior white 
ant, Termes bclHcosus, 

It is deemed a mark of unusual intelligence when an ape, of 
kin to man himself, uses a stone as a hammer wherewith to break 

open a nut, and yet the like in- 
telligence is displayed by Am- 
morphila urnaria, as described 
by Dr. and Mrs. George W. 
i’cekham in their charming 
book, ‘‘Wasps Solitary and 

“Just here must be told the 
story of one little wasp whose 
individuality stands out in our 
minds more distinctly than 
that of any of the others. We 
remember her as the most 
fastidious and perfect little 
worker of the whole season, 
so nice was she in her adaptation of means to ends, so busy and 
contented in her labor of love, and so pretty in her pride over the 
completed work. In filling up her nest she put her head down 

* Published by Houghton Mifflin & Co., Boston. 

Wasp using a pebble as a hammer. 
I'rom “Wasps Solitary and Social,” 
Copyright, 1005, by (ieorge W. Peck- 
ham and Klizaheth Ci. Pcckham. Re- 
produced by their permission. 



into it and bit away the loose earth from the sides, letting it fall 
to the bottom of her burrow, and then, after a quantity had ac- 
cumulated, jammed it down with her head. Earth was then 
l)rought from the outside and pressed in, and then more was bit- 
ten from the sides. When at last the filling was level wdth the 
ground, she brought a quantity of fine grains of dirt to the spot, 
and picking up a small pebble in her mandil)les, used it as a 
hammer in pounding them down with rapid strokes, thus making 
this spot as hard and firm as the surrounding surface." 

It was a wasp, too, wdiich suggested to Reaumur, as he exam- 
ined its nest, that wood might well serve as the raw material for 
paper, and serve it does to the amount of millions of tons a year. 
To-day we have as a new fabric for garments, glanz-stoff, an 
artificial silk produced from cellulose; its German manufacturers 
have imitated as nearly as they could the silk-worm's thread, just 
as for some years the filaments for incandescent lamps have been 
made from liquid cellulose forced through minute holes. At first 
bamboo fibres were used for this purpose ; to-day art furnishes 
a thread of more uniform and lasting (juality. This achievement 
is of a piece with many another. 'Fo-day when an inventor seeks 
to imitate a natural t)roduct he docs so with a ]:)ower of analysis, 
a wealth of new materials, such as his forerunners could not have 
imagined. It is in laboratories stocked more diversely than ever 
before, with their resources better understood than at any earlier 
time, that the triumphs of modern ingenuity proceed. 

In all likelihood one of the feats of nature soon to be paralleled 
by art, in an economical way, will be one phase of the breathing 
process ; every time we inflate our lungs their 
tissues perform a feat which has thus far Separating 

baffled imitation except in a roundabout and 
wasteful manner. Air is a mixture of oxygen 
and nitrogen ; the work of life is subserved by the oxygen only, 
which is separated from air by the lungs and passed into the 
current of the blood. Oxygen and nitrogen, like any other two 
gases, tend forcibly to diffuse into each other, as we may see in 
the distension of a thin rubber sheet dividing a container into 
two parts, one filled with oxygen, the other with nitrogen. To 
overcome the force of diffusion which keeps together the oxygen 


and nitrogen forming a cubic foot of air, of ordinary tempera- 
ture, w(nild rcquire such an effort as would lift twenty-one pounds 
one foot from the ground. This task the lungs accomplish hy 
means which elude observation or analysis. It would mean much 
to llie arts if this j^arting power could he imitated simply and 
chcai)ly. In common combustion each volume of oxygen which 
unites with the fuel, carries with it four volumes of nitrogen 
which have to ])e heated, not only reducing the temperature of the 
llame, hut removing in sheer waste much of the heat. A supply 
of oxygen free from admixture would double the value of fuel 
for many i)ur])oses, creating a temperature so high that it would 
l3e diihcult to find building materials refractory enough for the 
furnaces. Cdieap oxygen would greatly increase the light de- 
rivable from oil and gas, as proved in the brilliancy of an oxy- 
hydrogen jet. In bleaching and in scores of other processes, 
o.xygen is so valuable that, notwithstanding its present cost, the 
demand for it steadily increases. Cannot the lungs, chemically or 
mechanically, be copied so as to yield this gas at a low price for ti 
Ihousand new services? 

Jn addition to se])arating oxygen from air our vital organs are 
every moment performing chemical tasks just as elusive. The 
liver, for instance, is a sugar-maker. The elaboration of living 
tissue is of transcendent interest to the physiologist ; it is fraught 
with tile same attraction to the chemist who would build com- 
pounds from their elements, to the engineer who would transform 
heat or chemical energy into motive jx^wer with less than the 
enormous, loss of our present methods. 

In 18S7 the late I’rofessor S. P. Langley of Washington began 
exiieriments in mechanical flight. He found that one horse- 
jiower will support in calm air and propel at 
Flight. forty-five miles an hour a wing-plane weighing 

209 pounds. Dr. A. V. Zahm, of the Catholic 
University of America, at Washington, has recently ascertained 
that a thin foot-square gliding plane weighing one pound soars 
with the least expenditure of power at about 40 miles an hour, 
while at 80 miles the power required is more than twice as much. 
As engines have been made weighing less than ten pounds per 
horse-power, capable of yielding a horse-power for five hours 



with four pounds of oil, wc are plainly approaching the mastery 
of the air, — so freely exercised by the sparrow and -the midge. 
x\mong the students eager in this advance arc the men who 
examine with the camera how wings of diverse types behave in 
flight, and then endeavor to imitate the strongest and swiftest of 
these wings. 

Professor Langley conducted another inquiry of fascinating 
interest, this time respecting those natural liglU-producers, the 
fireflies, especially the large and brilliant 
species indigenous to Cuba, Pyropliorus nocti- Light. 

Incus. As the result of refined measurements 
with the spectroscope and the bolometer, the most delicate heat 
detector known to the laboratory, he said: "‘The. insect spectrum 
is lacking in rays of red 
luminosity and presumably in 
the infra-red rays, usually of 
relatively great heat, so that it 
seems probable that wc have here 
light without heat.” Wlien we 
remember that ordinary artificial 
light is usually accompanied by 
fifty to a hundred times as much 
energy in the form of wasteful and injurious heat, wc see the 
importance of this research. Tf light can be produced without 
heat by nature, why not also bv art? 

Another notable case of cfiiciency in nature has already been 
remarked, namely, the conversion by the animal frame of fuel- 
values into mechanical work, ^khis is of a 
Converting Heat picce with the chief task of the engineer as he 
Into Work. puts his engines in motion by burning coal or 
wood, oil or gas. Tt is a remarkably good 
steam engine which yields as much as one tenth as a working div- 
idend. Gas engines have sprung into wide popularity because 
they yield larger results, in extremely favorable cases reaching 
thirty per cent. A heat engine, of any type, has its effectiveness 
measured by comparing in absolute units the heat which enters it 
with the heat which remains after its work is done. The zero of 
the absolute scale is 460° below the zero of Fahrenheit. So 

Cul)aii firefly, life size. 



that if an engine begins work at 920"^ Fahr. (1380° absolute), and 
the working sul)stancc is lowered in temperature by its action in 
the machine until it falls to 460° Fahrenheit (920° absolute), the 
engine has a gross efficiency of one third. Economy depends 
upon employing a working substance at the highest feasible tem- 
])erature in such a mode that it leaves the engine at the lowest 
temperature possible. Hence we see engineers devising super- 
heaters for their steam, and producing metal surfaces which 
either need no lubrication at all, or employ such a lubricant as 
graphite, which bears high temperatures without injury. 

Now let us glance at the mechanism of our own frames, which, 
according to Professor W. C). /Vtwater, converts about twenty per 
cent, of the energy value of our food into mechanical work. This 
is a remarkable performance, especially when we remember that 
in health the lK)dily warmth does not rise alxjve 98° Fahrenheit. 
What explains this amazing effectiveness at a temperature so far 
below that of either a steam engine or a gas engine? A simple 
experiment may be illuminating. We take a plate of zinc and a 
plate of cojiper; although they seem to be at rest we know them 
to be in active molecular motion, which motion is set free when 
they combine with oxygen or other elements. This combination 
may take place in two quite different ways, which we will now 
compare. In a glass jar, nearly filled with a solution of sulphuric 
acid and water, we immerse the plates of zinc and copper without 
their touching each other; lx)th rise in temperature as they cor- 
rode, as they unite with oxygen from the surrounding liquid. We 
may, if we wish, employ this he^it in driving an air engine; but 
we can do better than that, for an air engine wastes most of the 
heat supplied to it. We stoj) the heating process by joining the 
two plates with a wire through which now passes an electric cur- 
rent, our simple apparatus now forming a common voltaic cell. 
This current we apply to lift weights, propel a fan, or execute 
any other task we ]dease, all with scarcely any waste of energy 
whatever. The instructive point is that now chemical union i.^ 
taking ]dacc without heat, in a mode vastly more economical and 
easy to manage than if we allowed heat to be generated, and then 
applied it in an engine to perform work. The conclusion is ir- 
resistible : in the animal frame the conversion of molecular energy 



into muscular motion is by electrical means and no other. When 
the engineer learns in detail how the task is executed, and imi- 
tates it with success, he will escape the tax now iinj^OvSed on every 
engine which sets its fuel on fire as the first step in converting 
latent into actual motion. 

While inventors in the past might have taken many a hint from 
nature, as a matter of fact they seldom did so, hut went ahead, 
hit-or-miss, failing to observe that what they 
reached with much laborious fumbling, often Foresight instead 
they might have copied directly from nature. of Hindsight. 

In Colorado and California wc admire the dams which are convex 
upstream, withstanding in all the strength of an arch a tremen- 
dous pressure : this very plan is adopted by beavers when they 
build in a swift current, as one may see in many streams of the 
Adirondacks. In the rearing of irrigation dams, in tasks 'much* 
more difficult, human progress has gone forward by empirical 
attempts one after another, and science has followed, long after- 
ward, to give reasons for any success arrived at by rule-of- 
thumb. But this blundering hindsight is being replaced by a 
foresight which first spies out what may be hit, and then never 
wastes an arrow. Professor R. H. Thurston has said “Bleiich- 
ing and dyeing nourished before chemistry had a name; the in- 
ventor of gunpowder lived before Lavoisier; the mariner’s com- 
])ass ]:)ointcd the seaman to the pole before magnetism took form 
as a science. The steam engire was invented and set at work, 
substantially as we know it to-day, before the science of thermo- 
dynamics was dreamt of ; the telegraph and the telephone, the 
electric light and the railroad have made us’ familiar with marvels 
greater than those of fiction, and yet they have heen principally 
developed, in every instance, by men who had acquired less of 
scientific knowledge than we demand to-day of every college-bred 

To-day the leaders in applied science are of ([uite other stamp, 
riiey keenly observe what nature does, either in spontaneous 
chemical activities or iii the functions of a plant or an animal, 
then analyzing the process with more and more insight and ac- 
curacy, they ask. How may this with ccononiy and profit be 
imitated by art? A feat of Professor Henri Moissan is typical 


in this regard. In studying diamonds he became convinced that 
they have been produced in nature from ordinary carbon sub- 
jected to extreme temperatures and pressures. Imitating these 
heats and pressures as well as he could, he manufactured dia- 
monds from common graphite in an electrical furnace. These 
gems arc small, but they gleam with promise of what the fully 
armed physicist and chemist may achieve in duplicating the gifts 
of nature in the light of new knowledge, by dint of new resources. 


Knowledge as sought by disinterested inquirers ... A plenteous harvest 
with but few reapers . . . Germany leads in original research . • , The 
Carnegie Institution at Washington. 

W E have now taken a rapid survey of invention and discovery 
in the fields of Form, Size, Properties, Measurement, and 
the Teachini^s of Nature. We will here somewhat change our 
point of view and bestow a glance at the characteristics of in- 
ventors and discoverers, noting their powers of observation and 
experiment, their patience from first to last in learning from other 
thinkers and workers past and present. What any one man, how- 
ever able, can discover or invent, is the merest trifle in com- 
parison with the resources accumulated since the dawn of human 
vvit. And yet in adding a little to what he has learned, that little 
welds and vivifies his education as nothing else can. In setting 
out to add to known truth there must be a gmdly equipment in 
knowledge and skill. Knowledge, therefore, may serve as a start- 
ing point for the survey before us. 

Success in discovery and invention, as iii the case of a Newton 
or a Watt, dc]^euds not only iqxui rare natural faculty, but upon 
knowledge. Dr. Pye-Smith, of London, an 

eminent physician, says: — “Some would have Knowledge 
* " ^ • I^cccss&rv* 

us believe that erudition is a clog upon genius. 

This question has often been discussed, and it has even been 
maintained that he is most likely to search out the secrets of na- 
ture who comes fresh to the task with faculties unexhausted by 
prolonged reading, and his judgment uninfluenced by the dis- 
coveries of others. This, however, is surely a delusion. Harvey 




could not have discovered the circulation of the blood had he not 
been taught all that had been previously learned of anatomy. 
True, no procuress can be made by the mere assimilation of 
previous kiunvled^e. There must be an intelligent curiosity, an 
observant eye, and intellectual insight. I'ew things are more de- 
])l()ral)le than to see talent and industry eil^ployed in fruitless 
researches, partly retliscovering what is already fully known, or 
still )bornly toiling along a road which lias long ago been found 
to lead no whither. We must then instruct our students to the 
utmost of our power. Whether they will add to knowledge we 
cannot tell, but at least they shall not hinder its growth by their 
ignorance. The strong intellect will absorb and digest all that 
we put before it, and will be all the better fitted for independent 
research. The less powerful will at least be kept from false dis- 
coveries and will form, what genius itself requires, a competent 
and appreciative audience/' 

American inventors echo the dictum of the English physician. 
Says ]\lr. Octave Chamitc “It has taken many men to bring any 
great invention to jx'rfcction, the last successful man adding little 
to what was previously known. y\s a rule the basis of his success 
lies in a thorcnigh acituaintance with what has been done before 
him, and his setting alxmt his work in a thoroughly scientific way.” 
Professor W. A. Anthony observes: — ‘Tf the army of would-be 
inventors would enter the field with a full knowledge of what 
science has already done, the conquest of new territory would be 
rapidly accomplished.” To the same effect speaks Mr. Leicester 
Allen ‘‘While rarely there appears a man so highly endowed by 
nature with originating faculty that we call his talent genius, it 
will he found in the last analysis that his inventive power lies, 
not in some vague, mysterious intuition, but in a logical mind that 
can draw correct inferences from established premises ; in an 
analytical mind that enables him to reason from correct data, dis- 
cen'ering those winch are false ; in natural and cultivated per- 
ceptive faculties that enable him to determine the effect of a given 
set of conditions, and through exercise of which he is able to place 
clearly before his mental vision the exact statement or propositicni 
which defines the thing to be accomplished; in the ability to con- 
centrate his attention upon the problem in hand to the exclusioii 


of everything else, for the time being, and a perseverance that will 
not be denied — that failure cannot wear out.” 

^To many,” says Sir Michael booster. Professor of JMiysiology 
at Cambridge, '^scientific knowledge seems to be advancing by 
leaps and bounds; every day brings its fresh 
discovery, opening up strange views, turning Much is Still to 
old ideas upside down. Yet every thoughtful be Discovered, 
man of science who has looked round on what 
others beside himself are doing will tell you that nothing weighs 
more heavily on his mind than this: the multitude of ([uestions 
crying aloud to be answered, the fewness of those who have at 
once the ability, the means, and the opportunity of attempting to 
find the answers. Among the many wants of a needy age, few, if 
any, seem to him more ]:)ressing than that of the adecpiate en- 
couragement and support of scientific research.” With his own 
field of science in view he continues : “We want to know more 
about the causation and spread of disease and about the circum- 
stances affecting health before we can legislate with certainty of 
success. At home we want to know more about the spread of 
tubercle, of typhoid fever, and other infections diseases; we want 
to know more about the proper means to secure that the water wc 
drink, the food we cat, and the air we breathe, should not be 
channels of disease; we want to know more about the invisible 
elfic micro-organisms which swarm around us, to learn which arc 
our friends, and which our foes, how to nourish the one, how to 
defeat the other; we want to know the best way to shield man in 
th^ factory and the workshop against the works of man.” 

As to the fewness of those who have the highest capacity for 
original research, who have it in them to add to known truth in a 
notable way. Professor Simon Newcomb of Washington, the 
acknowledged dean of science in America, has said: — "It is im- 
pressive to think how few men wc should have to remove from 
the earth during the past three centuries to have stopped the ad- 
vance of our civilization. In the seventeenth century there would 
only have been Galileo, Newton and a few other contemporaries; 
in the eighteenth, they could almost have been counted on the 
fingers ; and they have not crowded the nineteenth. Even to-day, 
almost every great institution for scientific research owes its being 


to some one man, who, as its founder or regenerator, breathed into 
it the breath of life. If we think of the human personality as 
comprehending not merely mind and body, but all that the brain 
has set in motion, tlien may the Greenwich Observatory of to-day 
])C called Airy; that of Ihilkowa. Struve; the German Reichsan- 
stalt, ITelmholtz ; the Smithsonian Institution, Henry; the Har- 
vard Museum of Comparative Zoology, yXgassiz ; the Harvard 
Observatory, Pickering.’’ 

The late Professor Robert H. Thurston, of Cornell University, 
once said “Methods of planning scientific investigation involve, 
first, the precise definition of the problem to be 

Planning an solved ; secondly, they include the ascertain- 
Inquiry. jiient of ‘the State of the art,’ as the engineer 

would say, the revision of earlier work in the same and related 
fields, and the endeavor to bring all available knowdedge into re 
lation with the particular case in hand ; then the investigator seeks 
information which will ]X‘rmit him, if possible, to frame some 
theory or hypothesis regarding the .system into which he pro])oses 
to carry his exjieriment, his .studies, and his logical work, such as 
will serve him as a guide in directing his work most effectively. 

“The emjiirical, the imaginative, and even the guess work sys- 
tems, or perhai')s lack of system, have their ])lace in scientific re- 
search. 'file dim 'fitanic figure (T Copernicus seems to rear itself 
out of the dull tlats around it, pierces witli its head the mists that 
overshadow them and catches the first glim])se of the rising sun. 
Put first Copernicus made a .shrewd guess, and then followed witli 
mathematical work and confirmation. . . . Kepler, also, was 

strong almost beyond com])etition in s])eculative subtlety and 
innate mathematical ])erception. . . . J^\)r nineteen years lie 

gues.sed at the solution of a well-defined problem, finding hi.^’ 
speculation wrong every time, until at last a final trial of a last 
hyixithesis gave rise to deductions confirmed by observation. Hi^ 
first guess was that the orbits of the planets were circular, ne.xt 
that they were oval, and last that they were elliptical.” 

Pascal, great in what he knew, was great also in what he was. 
Walter Pater thus depicts his powers “Hidden under the ap- 
parent exactions of hi: favorite studies, imagination, even in them, 


played a large part. Physics, mathematics, were with him largely 
matters of intuition, anticipation, precocious discovery, short cuts, 
superb guessing. It was the inventive element in his work, and 
his way of painting things that surprised those most able to judge. 
He might have discovered the mathematical sciences for himself, 
it is alleged, had his father, as he once had a mind to do, withheld 
him from instruction in them.” 

No such gift of intuition as that displayed by Pascal fell to 
the lot of Buflfon, who tells us: — “Invention depends on patience. 
Contemplate your subject long. It will gradually unfold itself, 
till an electric spark convulses the brain for a moment.” 

As to the modes in which invention manifests itself, Mr. Wil- 
liam H. wSmyth says: — “P^xamine at random any one of half a 
dozen lines of mechanical invention, one characteristic common 
to them all will instantly arrest attention — they ])resent nothing 
more than a mere outgrowth of the manual jiroccsses and ma- 
chines of earlier times. Some operation, once performed by 
hand tools, is expedited by a device which enables the foot as well 
as the hand to be employed. Then power is applied; the hand or 
foot operation, or both, arc made automatic, and possibly, as a 
still further improvement, several of these automatic devices arc 
combined into one. All the while the fundamental basis is the 
old, original hand process ; hence, except in the extremely improb- 
able event that this was the best possible method, all the successive 
improvements arc simply in the direction, not of real novelty, but 
of mere modification and multiplication. The most important and 
radical departures from old methods, by which many of the in- 
dustries of the world have been completely revolutionized, arc 
nearly always originated by persons wholly ignorant of the ac- 
cepted practice in the particular industry concerned. The first 
and most im]X 3 rtant prerecpiisite to invention is an absolutely 
clear insight into, and a comprehensive grasp of, all the condi- 
tions involved in the problem. A scheme for the cultivation of 
invention should in part include: — (i) Accurate and methodical 
observation. (2) Cultivation of memory and the faculty of asso- 
ciation. (3) Cultivation of clear visualization. (4) Logical 
reasoning from actual observation. The course should include 



exercises in drawing from simple objects, and the solution of a 
simple problem, such as that of a can-soldering machine/’ 

Investigators arc never so useful as when thoroughly dis- 
interested ; let them find what they may, it will cither have worth 
in itself or lead to vSomething which has. Dr. 

The Debt to 
Research in 

Pyc-Smith says : — 

“Facts have been found at every step of 
science which were valueless at their dis- 

covery, but wliich, little by little, fell into line and led to appli- 
cations of the highest importance— the observation of the tarnish- 
ing of silver, the twitching of the frog’s leg, were the origin of 
])hotography and telcgra])hv ; the abstract problem of spontaneous 
generation gave rise to the antisc]:)tics of surgery. . . .* In 

medicine, as in every other ])ractical art, progress depends upon 
knowledge, and knowledge must be pursued for its own sake 
without continually looking about for its practical applications. 
Harvey’s great discovery of the circulation of the blood was a 
strictly physiological discovery, and had little influence u|K)n the 
hcjding art until the itivention of auscultation. So, also, Dubois 
Feymond’s investigation of the electrical properties of muscle 
and nerve was purely scientific, but we use the results thus ob- 
tained every day in the diagnosis of disease, in its successful 
treatment, and in the scarcely less important demonstration of 
the falsehoods by which the name of electricity is used for pur- 
poses of gain, 'riie experiments on blcxxl pressure, begun by 
Hales, and carried to a successful issue in our own time by Lud- 
wig, have already led to knowledge which we use every day 
by the bedside, and which only needs the discovery of a better 
method of measuring blood pressure during life to become one oi 
our foremost and most practical aids in treatment. Again, we 
can iiKxst of us remember using very imperfect physiological 
knowledge to fix, more or less vsucccssfully, the locality of an 
(Organic lesion of the brain. I also remember such attempts being 
described as a mere scientific game, which could only be won after 
the pi aver was beaten, since when the accuracy of diagnosis was 
established, its object was already lost: but who would say this 
now% when purely ])hysiological research and purely diagnostic 
success have led to one of the most brilliant achievements of 


practical medicine, the operative treatment of organic diseases of 
the brain 

The prevention of disease, as important as its cure, owes an 
incalculable debt to Louis Pasteur. De Varigny says in “Ex- 
perimental Evolution’^ : — 

“Pasteur, about 1850, spent a long time in seemingly very 
speculative and very idle studies of dissymmetry and symmetry 
in various crystals, especially those of tartaric acid ; the jiractical 
value of such investigations seemed to lie naught, and at all events 
it had no interest save for the elucidation of some ]x)ints in C 4 'ys- 
tallography. Put this investigation led logically to the study of 
fermentation, and the final outcome of Pasteur’s work has been 
—leaving out the ste])ping stones — the discovery of the real cause 
of a large number of diseiases, the cure of one of thetn, and the 
expectation, based on facts, that all these diseases can be dc-feated 
by appropriate methods.” 

What is true in medicine is equally true in physics. C’oncerning 
the debt of the inventor to the man of ph\’sieal research, Mr. 
Addison Prownc has this to say : - 

“A few weeks ago 1 was talking with an 

Research in 

electrician who has made several very interest- Physics and 

ing and imixirtant inventions. I asked him of Chemistry, 

how much importance he conceived that the scientific men of the 
closet, the original investigators, so-called, had been in working 
out the great inventions of electricity during the last fifty years 
— telegra]ihs, cables, telephones, electric lighting, electric motors; 
and whether these achievements were not in reality due mainly 
to practical men, the inventors who knew .vvdiat they were after, 
rather than to the men of science who rarely aiqilied their work 
to practical use. He said, ‘The scientific men are of the utmost 
importance ; everything that has been done has jiroceeded upon 
the basis of what they have previously discovered, and upon the 
principles and laws which they have laid down. Nowadays we 
never work at random — f go to my lalxiratory, study the apiilica- 
tion of the principles, facts and laws which the great scientists 
like Faraday, Thomson and Maxwell have worked oiU, and en- 
deavor to find such devices as shall secure my aim.' As Tyndall 
said, ‘Behind all our practical applications there is a region of in- 


tellectiial action to which practical men have rarely contributed, liut 
from which they draw all their supplies. Cut them off from that 
region and they become eventually helpless.’ ” 

Research is golden only when brought to fruit by co-operation. 
To f|iu)te Professor Tyndall: — 

"‘To keep science in healthy play three classes of workers arc 
necessary : ( i ) The investigators of natural truth, whose voca- 
tion it is to pursue that truth, and extent the field of discovery for 
its own sake, without reference to practical ends. (2) The 
teachers who diffuse this knowledge. (3) The appliers of these 
principles and truths to make them available to the needs, the 
comforts, or the luxuries, of life. These three classes ought to co- 
exist and interact.” 

Concerning the larger problems of engineering research, Pro- 
fessor Osborne Reynolds, of Owens College, Manchester, says 

“Every one who has paid attention to the history of mechanical 
progress must have been impressed by the smallness in number 
of recorded attempts to decide the broader questions in engineering 
by systematic experiments, as well as by the great results which, 
in the long run, have a])parcntly followed as the effect of these 
few researches. I say ‘apparently,’ because it is certain that there 
have been other researches which probably, on account of failure 
to attain some immediate object, have not been recorded, although 
they may have yielded valuable experience which, though not put 
on record, has, befc^re it was forgotten, led to other attempts. P)Ut 
even discounting such lOvSt researches it is very evident that 
mechanical science was in the past very much hampered by the 
want of sufficient inducement to the undertaking of experiments 
to settle questions of the utmost importance to scientific advance, 
but which have not promised pecuniary results, scientific questions 
which involved a greater sacrifice of time and money than the 
individuals could afford. The mechanical engineers recently in- 
duced Mr. Ceauchamp Towers to carry out his celebrated re- 
searches on the friction of lubricated journals, the results of 
which research certainly claim notice as one of the most important 
steps in mechanical science.” 

Lord Rayleigh has said : — 

“The present development of electricity on a large scale de- 



pends as much upon the incandescent lamp as the dynamo. The 
•success of. these lamps demands a very perfect vacuum— not more 
than one millionth of the normal quantity of air should remain. 
It is interesting to recall that in 1865 such vacua were rare even 
in the laboratory of the physicist. It is pretty safe to say that 
these wonderful results would never have been accomplished had 
practical applications alone been in view. The way was pre- 
pared by an army of men whose main object was the advancement 
of knowledge, and who could scarcely have imagined that the 
processes which they had elaborated would soon be in use on a 
commercial scale and entrusted to the hands of ordinary work- 
men.'’ He adds: — “The requirements of practice react in the 
most healthy manner upon scientific electricity. Just as in former 
(lays the science received a stimulus from the application to 
telegraph}^ under which everything relating to measurement on a 
small scale acejuired an importance and development for which 
we might (Otherwise have had l(3ng to wait, so now the require- 
ments of electric lighting are giving rise to a new development of 
the art of measurement on a large scale, which cannot fail to 
prove of scientific as well as ])ractical imi)ortance.'’ 

Regarding the territory likely to yield most fruit to the re- 
vSearcher, he observes : — “The neglected 1 x)rdcr land between two 
branches of knowledge is often that which best re])ays cultiva- 
tion ; or, to use a metaphor of iMaxwcll’s, the greatest benefits 
may be derived from a cross-fertilization of the sciences." 

Why (lermany leads the world in science becomes clear when 
we olyserve her co-ordination of industry with the higher educa- 
tion and with original research. Professor Wil- 
helm Ostwald has said : — “When the student in 'phe Example 
(lermany has finished his univensity course he is of Germany, 
still entirely free to choose between a scientific 
and a technical career. . . . The occupation of a technical 

chemist in works is very often almost as scientific in its character 
as in a university laboratory. . . . The organization of the 

power of invention in manufactures on a large scale in Germany 
is, as far as I know, unique in the world's history, and is the very 
marrow of our splendid triumphs. Each large works has the 
greater part of its scientific staff— and there arc often more than 



a hundred doctors of philosophy in a single manufactory —oc- 
cupied not in tlie management of the manufacture, but in making 
inventions. 'L'he research laboratory in such works is only dif- 
ferent from one in a university from its being more splendidly 
and sumptuously fitted. I have heard from the business managers 
of such works that they have not infrequently men who have 
worked for four years without practical success; but if they have 
known them to possess nihility they keep them notwithstanding, 
and in most cases with ultimate success sufficient to pay all ex- 

In 1902 Mr. Andrew Carnegie, with a gift of ten million dol- 
lars, founded in Washington the Carnegie Institution for Original 
Research. Its president is Dr. R. S. W(X)(l- 
Mr Carnegie’s ^vard, formerly of Columbia University, New 
Aid to Original York. One of its first enterprises was to estab- 
Research. lish at Cold Spring Harbor, New York, a 
station for experimental evolution directed by 
1 )r. Charles ]]. Davenport. Here will be extended the remarkable 
experiments of Dr. Hugo dc Vries, of Amsterdam, vC^ho dis- 
covered that the large-tlowered evening primrose suddenly gives 
rise to new species. Other experiments arc in progress with 
regard to the variability of .insects, the hybridization of plants 
and animals. A marine biological laboratory has been established 
at I'ortugas, b'lorida; and a desert botanical laboratory at Tucson, 
Arizona. In its grants for widely varied purposes the policy oi 
the 1 institution is clear: only those inquiries arc aided which give 
promise of fruit, and in every case the grantee requires to be 
a man of proved ability, care being taken not to duplicate work 
already in hand elsewhere, or to essay tasks of an industrial 
character. J^xperience has already shown it better to confine 
research to a f(‘w large projects rather than to aid many minor 
investigations with grants comparatively small. 

(Ine branch of the work reminds us of Mr. Carnegie’s method 
in establishing public libraries — the supplementing of local public 
spirit by a generous gift. In many cases a university or an ob- 
servatory launches an inquiry which soon broadens out b.eyond 
the range (U' its own small funds; then it is that aid from the Car- 
negie Institution brings to port a ship that otherwise might re- 

Dk. r. s. woodward, 

President, Carnegie InshiutioxN, Washington, D. C. 


main at sea indefinitely. Let a few typical examples of this kind 
he mentioned Dudley Observatory,' Albany, New York, and 
Idck Observatory, California, have received aitl toward their ob- 
servations and computations ; Yerkes Observatory, Wisconsin, has 
been helped in measuring the distances of the fixed stars. Among 
other investigations promoted have been the study of the rare 
earths and the heat-treatment of some high-carlxin steels. The 
adjacent field of engineering has not been neglected : funds have 
been granted for experiments on ship resistance and propulsion, 
for determining the value of high pressure steam in locomotive 
service. In geology an investigation of fundamental principles 
has been furthered, as also the specific problem of the flow of 
rocks under severe pressure. In his remarkable iiujuiry into the 
economy of foods. Professor W. O. Atwater, of Wesleyan Uni- 
versity, Middletown, Connecticut, has had liberal help. In- the 
allied science of preventive medicine a grant is advancing the 
study of snake venoms and defeating inoculations. 

At a later day the Institution may jxissibly adopt plans reepm- 
inendcd by eminent advisers of the rank of lh*ofessor Simon 
Newcomb, who points out that analysis and generalization are 
to-day much more needed than further observations of a routine 
kind. He has also had a weighty word to say regarding the de- 
sirability of bringing together for mutual attrition and discussion 
men in contiguous fields of work, who take the liearings of a 
great problem from different points of view. 

Speaking of the study of human life and society, Professor 
Karl Pearson is clear that both thorough training as well as sound 
theories are needed if research is to be fruitful. In the course of 
a letter to the Carnegie Institution, he says: — “Biological and 
sociological observations in to) many cases arc of the lowest grade 
of value. Even where the observers have begun to realize that 
exact science is creeping into the biological and sociological fields 
they have not undcrsto)d that a thorough training in the new 
methods is an essential preliminary for effective work, even for 
the collection of material. They have rushed to measure or count 
every living form they could hit on, without having planned at 
the start the conceptions and ideas that their observations were 
intended to illustrate. I doubt whether even a small proportion 


of llic biometric data being accumulated in Europe and America 
could by any amount of ingenuity be made to provide valuable 
results, and the man capable of making it yield them would be 
better employed in collecting and reducing his own material.” 

Pnjfessor Edward C. Pickering, Director of the Harvard Ob- 
servatory, has suggested that astronomers the world over resolve 
themselves into a committee of the whole for the attack of great 
questions, the work to be duly parcelled out among the observa- 
tories best placed and equipped for specific tasks, to the end that 
rc])ctition be avoided and a single, comprehensive plan be pur- 
sued. Not only in astronomy but in every field of science such 
concerted attack would have great value. In engineering, inv 
example, there are ({uestions as to the durability of steels and other 
building materials, which when investigated would yield rich 
harvests to every practicing engineer on the globe. It may be ex- 
pected that in effecting co-ordinations of this kind the Carnegie 
Institution will play a notable part in the science of the twentieth 



What to look for . . . Wc may not see what we do not expect to see . . . 
Lenses reveal worlds great and small otherwise unseen . . . Observers 
of the heavens and of seashore life . . . Collections aid discovery . . . 
Happy accidents turned to profit . . . Value of a fresh eye . . . Popular 
beliefs may be based on truth . . . An engineer taught by a bank swal- 

A bility to observe is an unfailing mark of an inventor or 
. discoverer : it is quite as much a matter of the mind as of 
the eye. A botanist, keenly alive to varieties of hue, of form in 
leaves, tendrils, and petals may not give a second glance to 
stratifications which rivet the gaze of a geologist for hours to- 
gether. Each sees what he knows about, what he is interested in, 
what he brings the power and desire to see. When Faraday was 
asked to witness an experiment he always said : “What is it that 
I am to look for?’’ He knew the importance of concentrating his 
4 attention on the very bull’s eye of a target. 

How much goes to sound observing is thus stated by John 
Stuart Mill, — “The observer is not he who merely sees the thing 
which is 1x3 fore his eyes, but he who sees what parts the thing is 
composed of. One person, from inattention, or attending only in 
the wrong place, overlooks half of what he secs ; another sets 
down much more than he sees, confounding it with what he 
imagines, or with what he infers; another takes note of the kind 
of all the circumstances, but being inexpert in estimating their 
degree, leaves the quantity of each vague and uncertain ; another 
sees indeed the whole, but makes such an awkward division of it 
into parts, throwing into one mass things which require to be 
separated, and separating others which might more conveniently 



he considered as one, that the result is much the same, sometimes 
even worse than if no analysis had been attempted at all/’ 

How an explorer of ability may witness a new fact without 
rcalizinjj^ that it points to a great industry, is shown in the case 
of Lord Dundonald. In 1782, or thereabout, near Culross Ahl)e\ 
in Scotland, he built a tar-kiln. Noticing the inflammable na- 
ture of a va])or arising during the distillation of tar, the Earl, hv 
way of ex])eriment, fitted a gun-barrel to the eduction pipe lead- 
ing from the condenser. On applying fire to the muzzle, a vivid 
light blazed forth across the waters of the Frith, distinctly visible 
on the op])osile shore. Soon afterward the inventor visited Janies 
Watt at Handsworth, near nirmingham, and told him about the 
gas-lighting at the kiln, but his host paid no attention to the 
matter. 1 1 is assistant, William Alurdock, however, was impressed 
by the story, and some years later applied gas to the illumination 
of the Soho works where Watt’s engines were built. This was 
the beginning of gas-lighting as a practical business. 

Professor Adam Sedgwick, of Cambridge University, famous 

as a geologist, and Charles Darwin once took an excursion in 
\\ ales amid markings of extraordinary interest which neither of 
them noticed. Darwin tells us: “I had a striking instance of how 
easy it is to overlook jihenomena, however conspicuous, before thev 
have been observed by any one. We sjient many hours at Cwni 
Idwal, extimining the rocks with extreme care, as Sedgwick was 
anxious to lind fossils in them, but neither of us saw a trace of 
the wondeiful glacial ])henomena all around us; we did not notice i 
the plainly scored rocks, the perched boulders, the lateral and 
teiminal moraines, yet these phenomena are so conspicuous that, 
as I declared in a ])aper published many ycai's afterward, a house 
blunt down by fire could not tell its story more plainlv than did 
this vallev. If it had been filled with a glacier, the phenomena 
would liave lieen less distinct than they now are.” At a later dav 
vvdun Dai wins jiowers of observation had become acute in tlie 
highest degree, he noticed a bird’s feet covered with dirt. Ralher 
«i eianmon i:,ict, not worth dwelling on, earlier observers had snp- 
p(^scd. Not so thought Darwin, lie carefullv washed the binU 
eet, and planting the removed solids he was rewarded with sev- 
eral stiange plants brought from afar by his winged visitor. 



A cousin to Charles Darwin, Francis Galton, is an investigator 
of eminence. Tn a study of visual memory, a faculty in which 
observation bears its best fruits, he says : — 

“It is a mistake to sup])ose that sharp sight is accompanied by 
clear visual memory. I have not a few instances in which the in- 
dependence ot the two faculties is emphatically commented upon; 
and r have at least one clear case where great interest in outlines 
and accurate apprehension of straightness, s([uareness, and the 
like, is unaccompanied by the power of visualizing.” 

A new instrument, machine or engine is imagined by its creator 
long before it takes actual form ; everything he sees that will he of 
help he builds at once into his design, everything else, however 
interesting in itself, he passes with a heedless eye. 

“If we think birds, we shall see birds wherever we go,’’ says 
John Burroughs. An observer faithful and accurate in noticing 
birds and beasts, rocks and leaves, may come at 
last utx)n a (lower which opens a sphere of Think Birds 
knowledge wholly new, as when the round- and You Shall 
leaved sun-dew was first observed to entrap See Birds, 
and feed ui)on insects. Much, also, depends 
u])on comparisons such as occur only to a mind -at once broad and 
alert. One may iicMce in spring and early summer a few leaves 
growing directly from the trunk of a tree, sometimes near .the 
ground. In nia])les these leaves arc decidedly narrower than those 
growing from branches in the usual way, and they often have a 
* reddish tinge. Comparing a variety of such leaves with fossil 
impressions of allied species, Professor Robert T. Jackson of 
llostoii came upon an interesting discovery. He found that these 
sporadic leaves closely resemble those borne by the remote an- 
cestors of our present trees: they arc the lingering reminders of a 
far distant day. 

An observation equally keen saved the orange groves of Cali- 
fornia from destruction by the fluted .scale insect. In 1890, or 
thereabout, the orange growers in their extremity sought the ad- 
vice of Professor C. V. Riley, entomologist to the Department of 
Agriculture at Washington. He asked: “Where did the pest 
come from ?” “Australia,” was the answer. “Is it much of a 
nuisance there?” “Not particularly.” “Then what keeps it 


down, wliat preys upon it?” “Nothing specially,” was the re- 
sponse. Dissatisfied with this answer, Professor Riley sent to 
Australia a trained entomologist and acute observer, Mr. Albert 
K(X‘bele, who gathered various insects noticed as preying upon 
the fluted scale. Distributing these upon his arrival in California 
he was fortunate enough to find that one of his assisted emi- 
grants, a lady bird, Vedalia cardinalis, fed so ravenously u]>on 
the fluted scale as to restrict its ravages to quite moderate 

It was an eciually disciplined eye which in the laboratory first 
noticed that air is non-conducting until traversed by an X-ray, 
when it becomes conducting in a noteworthy degree. The field 
of radio-activity, at which we have glanced in this book, owes its 
cultivation to observers keen to note phenomena utterly unlike 
those before dwelt upon by the human eye. C.)ftcn close ob- 
servers learn what would never be imagined as possible : in rifle- 
making the tendency of the drills, which revolve nearly a tlicni- 
sand times a minute, to follow the axial line in a revolving bar 
is a fact which may be accounted for after observation, but whicb 
no one would i)re(lict. 

One day (')n the (Glasgow and Ardrossan Canal a spirited horse 
took fright; it was then observed, with astonishment, that a boat, 
the “Railh,” to which it was attached, for all its increased speed, 
went through the water with less rcvsistance than before. The 
vessel rode on tlie summit of a wave of its own creation with this 
extraordinary effect. The “Raith,” said Mr. Scott Russell, 
“weighed 10,239 pounds, requiring a force of tt2 ^xmiids to drag 
it at 4.72 miles an hour; 275 pounds at 6.19 miles an liour, and 
hut 2()Syj jxninds at 10.48 miles per hour.” Thus paradoxically 
was reversed the rule that the resistance of a vessel increases 
rapidly as she is moved through the water. Afr. Russell added: 
— "Some time since a large canal in bmgland was closed against 
general trade by want of water, drought having reduced the 
depth from 12 to 5 feet. It was then found that the motion of 
the light boats was more than before ; the cause was obvious. 
1 ho velocity of the wave was so much reduced by the diminished 
depth, that, instead of remaining behind the wave, the vessels 
rode on its summit.” 



The Mississippi 
Jetties of James 
B. Eads. 

One of the most difficult problems ever solved by an American 
engineer was the making navigation safe for vessels of fairly 
deep draft in the lower branches of the Mis- 
sissippi. The difficulties were overcome by 
James Ik luads, of St. I-X)uis, hi his system of 
jetties. J:te remarked, says his biographer, 

Mr. Louis How, that other things being equal, the amount of 
sediment which a river can carry is in direct proportion to its 
velocity. When, for any reason, the current becomes slower at 
any sjiecial jdace, it drops j)art of its burden of sediment at that 
l)lace, and when it becomes faster again it picks up more. Now, 
one thing that makes a river slower is an increase of its width, 
])ecausc then there is more frictional surface; and contrariwise, 
one of the things that makes it faster is a decrease of its wMth. 
Narrow the Mississi]ipi then, at its mouth, said Eads, and it will 
])ec()me swifter there, and consequently will remove its soft bot- 
tom by picking up the sediment (of which it will then hold much 
more), and by carrying it out to the gulf, to be lost in deep water 
and swept away by currents, you will have your deep channel. 
In other words, if you give the river some assistance by keeping 
its current tc'jgether, it will do all the necessary lalxir and scour 
o\it its own bottom. This sound reasoning, based upon observa- 
tion as sound, was duly embodied in a scries of jetties which have 
I)roved successful. 

Such a river as tlie Mississippi taking its source through an 
alluvial ])lain, has bends which go on increasing by the wearing 
away of the outer banks, and the deiiosilion of 
mud, sand and gravel on the inner bank. In 
oSyf) at the Ldasgow meeting of the British 
Association for the Advancement of Science, 

Professor James Thomson showed a model which made the 
phenomena of the case perfectly clear. A stream eight inches 
wide and less than two inches deep, flowed round a bend. As it 
lurned this bend the water exerted centrifugal force, while a thin 
layer of the water at the bottom, representing a similar layer close 
lo a river-bed, was retarded by its friction with the remainder of 
die stream, exerting less centrifugal force than like portions of 
die larger body of water flowing over it farther away from the 

Suggests an 



Aids to 

boltom. CVjiiscv|iicntly the bottom layer flowed in obliquely 
across tile channel toward the inner hank ; rising up in its retarded 
motion betwixt the fast flowing water it tirotccted the inner bank 
from scour. y\t the same time this retarded current brought with 
it sand and other detritus from tlfe bottom, duly deposited along 
the inner hank of the stream. 

d'lie powers of the eye, acute as tlicy are, have narrow limits: 
inestimable therefore is the value f)f the microscoiio, the tclcscoiie 
and the camera which bring to view uncounted 
Instrumental images otherwise unseen. Let us remark how 
in the early days of instrumental aids a great 
observer just missed noting a phenomenon of 
utmost im])ortancc,— the black lines of the solar spectrum, uj)on 
which b'raiinhofer, an optician of Munich, based his spectroscope. 
In sending a solar beam through a lens and a prism Sir Isaac 
Newton admitted the rays through an oblong slit at times as 
narrow as one twentieth of an inch. lie saw the familiar colors, 
from red to violet, and nothing more. Even with a crown lens, 
such as he ])robahly used, four lines distinctly apiiear ; that is, they 
appear to-day, to an observer who is looking for them. In 1802 
tlu'se lines were observed, as far as we know, for the first time 
on record, by Dr. W'ollaston, who drew six of them in a diagram 
accomiianying a pajier in the rhiloso])hical Transactions. Four 
of these lines he regarded as boundaries of the colors of the 
spectniin : ot the other two lines he attempted no explanation, 
lie used iirisms of various materials but found no alteration in 
the lines while he studied a sunbeam. When he cm])loyed candles 
or an electric light he' found the appearances difTerent, why, he 
could not undertake to explain. In 1814, Fraunhofer observed 
these lines in detail, majiiied them, and proved that they identiiicd 
elements long known to chemists. As he built his spectroscoiie lu* 
gave the chemist, the physicist and the astronomer an instrument 
of research worthy a place beside cither the microscope or the 

Dr. Wollaston, in 1802, as we have seen stood upon the 
threshold of spectroscopy without knowing it. During the same 
year he ])orformed an experiment which took him into the field 
of photography without his recognizing the possibilities of th:it 


wonderful art. He took paper which had J^cen dipped in muriate 
of silver and caught on its surface impressions of the ultra-violet 
light in a solar spectrum. These rays, as rings, were reflected 
from a thin plate of air, as in the case of the colors of thin plates, 
at distances corresponding to their proper places in the siu'ctrum.. 
Thus was established the close" analogy between rays visible and 
invisible, and by a method destined to give mankind a universal 
limner in light of all kinds, and in much radiance which is not 
luminous at all. 

Edward Emerson Larnard, of the Yerkes Observatory, Wil- 
liams Bay, Wisconsin, is in the first rank of living astronomers. 
Among his many discoveries the most remark- 
able is that of the fifth satellite of Jupiter at Two Observers 
the Lick Observatory. Ifis early work at the of the Skies. 
V’anderbilt Observatory, Nashville, gave full 
promise of his later achievements. One evening in November, 

I <883, he was observing an occnltation of the well-known star 
Beta Capvicorni by the moon. He had patiently waited for his. 
opportunity ; such an occultati(ui is best seen when the moon is 
a small crescent, the star disappearing at the dark curve of the 
moon where its hcains do not overpower the feeble stellar ray. 
When the moon passes between the eye and a fixed star, the dis- 
appearance of the star is instantaneous. At the distance from 
which we look at it the star is a point only, and as the moon has 
no atmos])hcre, the instant the edge of the lunar surface touches 
the line joining the eye of the observer with the star, it vanishes 
from sight. When the moon passed in front of Beta Capricorni 
Mr. Ijarnard noticed that instead of disaj)])earing at once, there 
was a sudden partial diminution of the light of the star, then a 
total extinction of the remaining point. The interval between 
the diminution and complete extinction of the light occupied only 
a few tenths of a second, hut it was long enough to put his keen 
mind upon inquiry. j\Ir. Barnard in an astronomical journal 
called attention to the phenomenon and sugg(\sted that instead of 
there being only one star, as formerly supposed, there were really 
two stars so close together that in an ordinary six-inch telesco])e, 
such as he had used, they appeared to be one. He inferred also 
that one of the pair must be a good deal brighter than the other, 


because at the beginning- the change in brightness was less than 
at the end. This surmise was soon afterward fully verified by 
Mr. S. W. Burnham with the eighteen and one half inch equa- 
torial of the Dearborn Observatory at Chicago, revealing a close 
and unequal double star which would have remained unresolved 
had he used a less powerful instrument. 

This Sherburne Wesley Burnham is the most successful dis- 
coverer of double stars who has ever lived. “The extreme acute- 
ness of vision,’’ says Professor John Fraser, “which enables one 
to prosecute such research with the highest success is a very rare 
gift; and the discovery of close doubles, as in his case, is its 
severest test. To measure a star — that is, to ascertain by means 
of the micrometer the distance and position angle of the com- 
panion witli reference to the principal star— is one thing, and to 
find new ami close doubles is a very different thing. Baron 
Dembowski, the most noted measurer of double stars, had no suc- 
cess as a discoverer, and confessed his inability to find new 
doubles. When, however, a new double had been found by an- 
other observer, and the distance and position angle of the com- 
panion approximately estimated, he could readily find and ac- 
curately measure it. When Mr. Asaph Hall, in 1877, had found 
the two satellites of Mars and described their positions, it was not 
difficult for any astronomer who had access to a large Clark tele- 
scope to find them and sec all that IMr. Hall had seen. The whole 
difficulty was in seeing them for the first time. Besides the 
ability to see a difficult object, there is required an intelligence 
and experimental knewvledge of the subject, which are as rare as 
the visual faculty itself. Some of the lower animals have more 
acute vision than human beings; but they do not know all they 
see, or understand relations to other f^icts. They have plentv ot 
sight, but they lack insight. Mr. Burnham’s powers in Ix^th thesi' 
respects is extraordinary.” 

^ At the Cape of Good Hope Obscrvaitory remarkable observa- 
tions of double stars have been recorded. Sir David (nil, tlie 
director, says: “At the Cape Observatory, as has always been 
the case elsewhere, the subject of double star measurement on 
any great scale waited for the proper man to undertake it. Thcri' 
is no instance, so far as I know, of a long and valuable scries ot 


double star discovery and observation made by a mere as:istant 
acting under orders. It is a special faculty, an inborn capacity, 
a delight in the exercise of exceptional .acuteness of eyesight 
and natural dexterity, coupled with the gift of imagination as to 
the true meaning of what he observes, that imparts to the ob- 
server the requisite enthusiasm for double star observing. No 
amount of training or direction could have created the Struves, 
a Dawes or a Dembowski. The great double star observer is 
born, not made, and I believe that no extensive series of double 
star discovery and measurement will ever emanate from a regular . 
oliservatory through successive directorates unless men are 
specially selected who have previously distinguished themselves 
in that field of work, and who were originally driven to it from 
sheer compulsion of inliorn taste.’’ 

It is sometimes said that the faculty of observation is a spepial 
gift with limitations, that the naturalist secs bones, feathers, 
shells because he is looking for them, while 
the armorer or the engineer but seldom gives Eye of a 

a second glance to anything but guns, girders. Naturalist, 

or machinery. 

To this rule we find striking exceptions. Edward S. Morse, 
of Salem, Massachusetts, is the foremost American expert in 
Japanese pottery. As a youth he was a railroad draughtsman in 
Portland, Maine, where his ambidexterity with the pencil and his 
discoveries in natural history lirought him to the notice of Louis 
Agassiz. As a boy he was greatly interested in the shells of his 
native State; before he left .school he had discovered and de- 
scribed a new species of land snail. Helix astcriscus, which the 
older naturalists had regarded as the young state of another and 
well-known species. At the same lime he determined the distinct 
character of a most minute species. Helix minutissimUy which 
had been descri]3ed as such thirty years before, but which the 
later authorities had believed to be the young of another species. 
This faculty for discrimination led him to demonstrate a new 
bone in the ankle of birds which Huxley, and others, had sup- 
posed to be a process and not a separate bone. This discovery 
added another to the many reptilian characters which have been 
disclosed in the anatomy of birds. He also established beyond 



question that the hrachiopods, always believed to be mollusks, arc 
nr)t mollusks at all, but are related to the worms. In Mr. Morse’s 
case we have either a man with a universal power of observation, 
or enjovinj^- distinct faculties of perception, each usually appear- 
in<^^ alone in an observer. Noticini:^^ a Japanese shooting a bow and 
arnnv one day he took up the study of the attitude of the hand 
in pulling the bow. His memoir on this subject, with illustra- 
tions, has attracted world-wide interest. Pursuing this theme 
he examined an ancient object of bronze having three prongs, 
labeled as a bow-])uller in luiropcan museums, showing that it 
had no relation whatever with the bow. Keenly susceptible to 
the beauty and variety of roofing tiles in Europe and the ICast, 
he has for the first time given them classification, and .shown 
their ethnological significance. While teaching natural history 
at the I'uiversity of 'f(d<io he brought together the Japanese pot- 
tery now exhibited at the Museum of Fine Arts in P»oston, unsur- 
passed as a collection in the world. His eye was as sharp in 
reading a jiotter’s mark, however worn and blurred, as when as 
a hoy in Maine he defined minute species of land shells. 

Altogether commendable is the spirit which leads a boy or girl 
to collect and arrange shells, common wildflowers, seaweeds, and 
the diverse minerals brought to light in a rail- 
road cutting. What is thus gathered, com- 
pared, and studied will leave a much dceiier 
imiiressiou on the memory than what is seen for a moment in a 
museum or a ])ublic garden. y\iid yet, to the profound student 
the museum is indispensable: he gives weeks or months to the 
contents of its cases, su])plementing what he has learned in the 
field, by the seashore, in the woods. Take, for example, pro- 
tective resemblances, one of the most fascin^lting provinces of 
natural histeny. Here is a hornet clcar-wing moth. What has 
made it look like a wasp? P>oth share the same field of life, and 
while the wasp does not prey on the moth or in any perceptildc 
way compete with it, the two insects have a vital bond. In its 
sting the wasp has so formidable and thoroughly advertised a 
wea]xm that by closely resembling the wasp the moth, though 
stiiigless, is able to live on its neighbor’s reputation, and escape 

The Value of 


attack from the birds and insects which would devour it if they 
did not fear that it is a stin^in^i^ wasp. So far is the resemblance 
carried that when the moth is caught in the hand it curves its 
body with an attitude so wasplike as vseriously to strain the nerves 
of its ca])lor. 

How came about so elaborate a mascjuerade? At first, aj^^es 
ago, there was a faint likeness between the moth and the wasp; 
any moth in which that likeness was unusually decided had there- 
in an advantage and teiuled to be in some measure left alone by 
enemies. In thus escaping it could transmit in an ever-increasing 
degree, its peculiarities of form and hue to its iirogeny, until in 
the rapid succession of insect generations, amid the ecpially rapid 
destruction of comparatively unprotected moths, the present 
striking similarity arose, fustances of this kind alioimd, form- 
ing some of the most attractive exhibits in the American IMuseum 
of Natural History of New York, and other great museums. 
Mr. W. H. Dates,. who first explained these resemlilaiices, did so 
as the result of comjiaring many various examples preserved in 
his cabinets at home, although, of course, his memory of habits 
observed in the field was indis])ensable. llis ample collections 
enabled him to bring into view at once many ca])tures separated 
1)y wide intervals of time and space. It was the o]i])ortunity thus 
afforded of taking a comprehensive survey of rest'mblances as a 
whole that led him to think out the underlying reason. 

Accident has played a noteworthy part in both discovery and 

invention. Nathaniel Ilayward long ago remarked that sul])hur 

deprives rubber of stickiness, (diaries (lood- 

vear one day comliined some rubber and sul- Accidental 
' , - ' . . . , . , ’ Observation. 

l)hur by way o1 experiment ; (|Uite by accident 

he overturned ])art of the mixture upon a hot stove. He saw in 

a moment that heat is essential to make rubber insensible to both 

heat and cold : he had indeed discovered vulcanization, h.xam- 

ples of this kind abound in- the history of every art. As far 

afield as the war on insect jiests in France a priceless discovery 

was hit upon unsought a few years ago. One autumn the vines 

were still suffering from phylloxera when a mildew caused by a 

fungus began to do serious damage to crops. Through the spray- 


of vines with blue-stone to prevent pilfering of fruit, it was 
noticed that the fungus was killed, leading to the most telling 
mode of attack on many of the pests which assail leaves, flowers 
and fruit. 

fames I largreaves once saw a spinning-wheel overturned, when 
])(4h the wheel and s])in(He continued to revolve on the floor. As 
Ik- ol)served the spindle thus changed from a horizontal to an 
upright ])osition it occurred to him that if a number of spindles 
were thus placed, side by side, several threads might be spun at 
once instead of a single thread. This was the origin of the spin- 
ning jenny; an invention which has parallels in the multiple 
drills, the gang-saws, and other machinery which take a task 
once (‘xecuted by a single drill, saw or punch, and simultaneously 
])erform it with ten, twtmty, or a hundred drills, saws, or punches. 

About thirty years before Josiah Wedgwood laid the founda- 
tion of his fitture eminence, a chance observation gave rise to 
improvenuMit in the earthenwares of StalTordshire. A potter 
from Uurslem, the centre of the ]X)tteries and the l)irthplace (T 
AW'dgwood, in travelitig to London on horseback was detained 
on the road by the inllatned eyes of his horse. vSeeing the hostler, 
th(‘ horse-doctor of those times, burn a piece of flint, and, having 
reduced it to a iitie powder, a])])ly it as a specific to the diseased 
e\es, it occurred to the ])otter that this Ix'autiful white powder, 
il combined with the clay used in his craft, might improve the 
strength and color of his ware. .An ex])eriment succeeded, and 
so began haiglish white ware, since manufactured on an immense 

.More important than this discovery of a new use for flint 
])owder was the discovery, also accidental, of electro-magnetism 
by Ih-otessor Oersted of Copenhagen. The incident is thus re- 
lated in a letter to Aliclaiel lAiradav from Professor Christian 
I lansteen ; 

“Pro lessor ( )ersted was a man of genius, but he was a very un- 
hai>py experimenter; he could not manipulate instruments, lb 
must always have an assistant, or one of his auditors who had 
easy hands, t(^ arrange the experiment; I have often in this way 
assisted him. Tn the eighteenth century there was a general 
thought that there was a great conformity, and perhaps identity, 


between the electrical and magnetical forces ; and it was a ques- 
tion how to demonstrate it by experiments. Oersted tried to place 
the wire of his galvanic battery perpendicular (at right angles) 
over the magnetic needle, but remarked no sensible motion. Once, 
after the end of his lecture, as he had used a strong galvanic 
battery to other experiments, he said, ‘Let us now once, as the 
l)attery is in activity, try to place the wire parallel with the 
needle as this was done he was (piite struck with perjilexity by 
seeing the needle making a great oscillation (almost at right 
angles with the magnetic meridian). Then he said, ‘Let us now 
invert the direction of the current and the needle deviated in 
the contrary direction. Thus the great detection was made; and 
it has been said, not without reason, that ‘he tumbled over it by 
accident.’ He had not before any more idea than any other jier- 
son that the force should be transversal.” 

Granting that many important discoveries thus come about in 
ways beyond human foresight, accident alone will not ])roduce 
an invention. As J.)r. Ernst Mach reminds us. in every such case 
the inquirer is obliged to take note of the new fact, to recognize 
its significance, to detect the ])art it plays, or can be made to play, 
in a new structure, or in a novel and sound generalization. What 
he secs before him, others also have seen, ])erhaps many times; 
he is the first to notice it as it deserves to be noticed, simply be- 
cause he has an eye earnestly desiring to behold just such a fact 
as this and use it to bridge a gap either in art or ex])lanation. 

Let us take a case where an accident, well observed, has meant 
a golden discovery. One day during a trip on the Thames in a 
steamer propelled by an Archimedean screw .devised by bb'ancis 
kettit Smith, the ]nT)pcller struck an obstacle in the water, so 
that about one half of the length of the screw was br{d\en off; it 
was noticed that the vessel immediately shot ahead at a much 
finickened ])acc. In conseciuence of this discovery, a new short 
screw was fitted to the vessel and with this new propeller the 
steamer went uniformly faster than before. 

In craft built ages before steamers were designed, fishermen 
have observed that sails torn in the middle, if the rents were not 
too big, were more effective than when new and whole. What 
thus began in sheer wear, or accidental damage, is now imitateci 



of set purpose. Under the equator one may often see small craft 
\vlu)se sails arc matting woven with large openings, as the sailors 
say ‘'to let out the wind.’* The mariners of 
Cartliegena, St. Thomas, and other islands f)f 
the West Indies, know that a ship goes 
better thus than if her sails were each one continuous breadtli 
of canvas. Japanese junks of clipper builds have sails made of 

Perforated Sails 
for Ships. 

Perforated sails. 

I, jil). ly slay-sail. 3, square sail. 4, top sail. 
5, sU)op with perforated sails. 

vertical breadths laced together so as to leave large apertures 
free to the air. Why is this breezincss of structure profitable? 
Ilecause against the concave surface of an ordinary sail the wind 
relxnuids so as to hinder its impulsive effect; through an a])er- 
ture the air rushes in a continuous current and no rebound take^ 
])lace. Tor a like reason, and with similar gain, Chinese rudders 
are made with separated boards or planks. The stream of water 
passing through such a rudder would exert an undesirable back 
pressure in a rudder of solid form. 

It would be interesting, and might prove gainful, to cxperimcnl 
with perforated sails in sail-boats, icc-lx)ats and wind-mills, b- 
large kites, sent to the upper air by meteorologists, it has been 
found helpful to give the fabric a few small perforations. 


It is not only neceSvSary to observe if one would learn, one must 
remember and compare observations. In a cycle of 223 lunations 
all the motions of the motni are re])eated ; it is 
astonishing that astronomers in Chaldea de- 
tected this pericxl, exceeding eij^hteen years as 
it docs. On the other hand, one of the most 

striking phenomena of a solar eclipse, its 

Must be Remem- 
bered and Com- 
pared : The Value 
of a New Eye. 

revelation of the solar corona, does not seem 

to have been noticerl until comparatively recent timesP The first 

known record of it is by Lobatchevsky, July 8, 1842. 

There is value in the teaching which teaches the eye what to 
observe; at times there is gain in a freshness of view nnwarped 
])y ideas as to what deserves to be inspected and what does not. 
J)r. Priestley, one of the founders of chemistry, says: — “[ do not 
at all think it degrading to the business of experimental pliilos- 
opby to compare it, as 1 often do, to the diversion of hunting, 
where it sometimes hai)pens that those who ])eat the ground the 
most, and are consequently best acquainted with it, weary them- 
selves without starting any game, when it may fall jn the way 
of a mere passenger; so that there is but little room for boasting 
in the most successful tehnination of the chase.” True, yet this 
discerning eye will always be found ])eside a brain of uncommon 
force and sweep. Mr. lulwin Reynolds, of Milwaukee, as re- 
lated in this book, never saw a mining stamp until the morning 
when he planned a bold and profitable simplification of it. Pro- 
fessor Alexander (Irabam Hell, who invented the telejihone, came 
to his triumph not as a disciplined electrician, but as a student, 
under his father, of articulate s]x*ech and its transmission. lie 
has told me that had he known the obstacles to be surmounted, 
he would never have begun his attack. 

Professor Ernst Abbe, of Jena, who more than any other in- 
vestigator is to be credited with tbe production of Jena glass, 
was at the outset of his labors quite ignorant of practical optics. 
Hut he had a thorough mastery of mathematical optics, and this 
in due season enabled him to revise the theory of the microscope, 
and to prescribe the conditions according to which the manu- 
facture of totally new kinds of glass should proceed. Every one 
of these men, every peer they have ever had among the volunteer 



forces of research, is far removed in native ability, in plasticity 
of mind, from Priestley’s “mere passenger.'^ If ignorance by 
itself were the chief qualification for discovery, science would 
long ago have entered upon its golden age. 

Micliael f'aradav, that consummate observer, held that at times 
the observations of comparatively untrained men are well worth 
attention. In one of his note-books he wrote*, 
Any Observation - "Whilst passing through manufactories and 
May Have Value, (‘ngaged in the observance of the various 
ojierations of civilized life, we are constantly 
hearing obsf'rvations made by those who find employment in these 
t)laces, and are accustomed to a minute observation of what passes 
before them which are new or fre(|uently discordant with re- 
ceived opinions. 1'hese are frequently the result of facts, and 
though some are founded in error, some on prejudice, yet many 
are true and of high importance to the practical man. Such of 
them as come in my way T shall set down here, without waiting 
for the princii)le on which they depend; and though three fourths 
of them ultimately ju'ove to be erroneous, yet if Init one new fact 
is gathered in a nudtitude, it will be sufficient to justify this mode 
of occupying time.” 

Often a conviction widely held by the plain people of a country- 
side is based on many and sound observations, long before a 
scientific theory accounts for the facts. For 
Folk Observation generations there was a saying among 

Foreruns Science. ( lernian peasants that when a storm is ap- 
])r()aching a fire should be made in the stove, 
with as much smoke as possible. IVofesstn* Schuster has shown 
that this saying and the custom founded upon it arc rational, as 
the products of combustion and the j.mokc act as an effective con- 
ducted' to discharge the atmosphere slowly but surely. lie quotes 
statistics showing that out of each looo cases of lightning stroke, 
6.3 churches and 8.5 mills were struck, and but 0.3 factory chim- 
neys. Only the factories had fires burning. 

yV mighty wcwk has been wrought by glaciers on the surface of 
our globe. Long before this fact was discovered by professional 
geologists it was clear to many of the plainer people. Jean de 
Charpenficr, one of the first propounders of the theory of glacial 

FOLK obsj:rvation 


action now funclanieiital in geological science, relates: — ‘When 
in the year 1815, I reUirnecl from the magniiicent glaciers of the 
valley of the Rhone, I spent the night in the hamlet of Lourtier, 
in the cottage of Perraiulin, a chamois-hunter, (^ur conversation 
turned on the peculiarities of the country, and especially of the 
glaciers which he had repeatedly explored and knew most in- 
timately. ‘Our glaciers,’ said rerraudin, ‘had formerly a much 
larger extent than now. Our whole valley was occuj)ied by a 
glacier extending as far as IMartigny, as is proved hy the boulders 
in the vicinity of this town, and which are far to(^ large for the 
water to have carried them thither.’ ” Char])entier adds that he 
afterward met with similar explanations on the part of moun- 
taineers in other sections of Switzerland. 

Cowpox was long observed by English country folk to be a 
preventive of smallpox. It was in hearing a servant woman say 
so that Dr. Jenner was drawn to the study which ended in his 
successful vaccinations, in all the triuni])hs since won in this de- 
partment of medical science. Eor two thousand years the peasants 
of Italy have suspected mosquitoes and other insects to be con- 
cerned in the spread of malarial and other fevers. It remained 
for Dr. Ronald Ross in our day to prove that the sus])icion was 
founded in truth. In “The Naturalist in La Plata,” one of the 
best books on natural history ever written, Mr. W. Tl. Hudson 
says: — “The country people in South America believe that the 
milky secretion exuded by the toad possesses wonderful curative 
properties; it is their invariable specific for shingles — a painful, 
dangerous malady common amongst them, and to cure it living 
toads are ai)i)lied to the inllamed part. T dare say learned phy- 
sicians would laugh at this cure, but then, if J mistake not, the 
learned have in past times laughed at other si^ccifics used by the 
vulgar, but which now have honorable ])laces in the ])harniaco- 
pceia — pe]osine, for cxami)lc. Afore than two centuries ago, very 
ancient times for South America, the gauchos were accustomed 
to take the lining of the rhea’s (a large ostrich’s) stomach, dried 
and powdered, for ailments caused by impaired digestion ; and the 
remedy is popular still. Science has gone over to them, and the 
ostrich-hunter now makes a double profit, one from the feathers, 
and the other from the dried stomachs which he supplies to the 


chcniisls of liucnos Ayres. Yet he was formerly told that to take 
the stomach Of llie ostrich to improve his digestion was as wild 
an idea as it would he to swallow birds’ feathers in order to. fly.” 

vSnake poison has kuig been used by the Hottentots as an anti- 
dote to snake poison. Wdth aid from the C'arnegie [iistitution (d* 
Washington, Dr. Ilideyo Xognchi, of the University of Pennsyl- 
vania, has succeeded in producing antivenins, to use the medical 
term, for the venoms of the water-moccasin and Crotaliis ad(iinaii- 
/cns snakes, using the venoms themselves in preparing his anti- 
dotes. 1I(‘ is continuing his researches in this remarkable field 
of the lu'aling art. 

Kelp, as it drifts and sways in the Atlantic, attracts from the sea 
both the iodine and the bromine dissolved in minute (jiiantities in 
the sea- water, ddiis trait of fastening ui)on a ])articnlar and ran' 
ek'menl is dis])layed by ])lants on hind as well as by sea-weeds, 
fn the 1 lorn silver mine of Ptah, the zinc mingled with the silver 
is betokened hv the ahundance of a zinc vu^let, I'ioln calauiinaria, 
a delicate cousin of the ])ansy. In (iermany this little flower was 
believc'd to point to zinc de])osits long beh^re zinc was discovered 
in its juicc's. 'The late Mr. W^illiam Dorn, of South Carolina, had 
faith in a bush of unrecorded name, as declaring that gold veins 
stood iKiieath it: that his faith was not baseless is ])roved by the 
large fortune he won as a gold miner in the Pine Ridge country — 
his guide the hush aforesaid. Air. Rossiter WA Raymond, a 
famous milling engineer of New Ak)rk, has given some attention 
to “indicative jilants” of this kind. ITe is of oinnion that their 
unwritten lore among ])ractical miners, prospectors, hunters, and 
Tndi ans is well w<u'th sifting. 

1 fe says “judging from the general laws of the distribution 
of jdants, and from the analogy furnished by Viola calauiinaria, 
we may expect that an indicative i)lant will be, not a distinct 
species, but a variety of some widely distributed st>ecies, the range 
of the sjiecics as a whole being determined by general conditions 
of climate, altitude and soil, while the characteristics of the variety 
are altected by causes peculiar to the mineral deposit. Tempera- 
ture and moisture, as Agricola long ago pointed out, are among 
these causes, and color is one of the most sensitive of their 'effects. 
It is (luite reas(niable to believe the soil may affect the color of the 


plant absorbing it. On the other band, it is not certain, even if a 
plant is proved to indicate by color or other peculiarities tlic 
presence of silver, that silver is the substance actually entering 
into and altering the plant. The effect may be due to some other 
mineral sul)stances associated with the silver-ores ; and our silver- 
plant may be indicative of silver in a silver region only.” 

]\[r. Ra\'mond remarks that a general relation between the flora 
and the geological formation of any given district is a fact 
familiar to field-geologists. Many plants, too, indicate the neigh- 
borhood of water. A Ix^tanist knowing the root-length, water- 
requirements and habits of different species can often determine 
from the surface vegetation, he tells us, the nature, amount and 
distance of the underground water-supply.^ 

How observation may lead to a bold and successful experiment 
is told by Mr. H. If. Chittenden, Register of the Treasury mnder 
President Lincoln, in his J^ersonal Reminis- 
cences . ^ ^ Lesson from 

Between the Winooski Valley and Lake a Bank-Swallow 
Chanijdain, north of the city of ILirlington, lies 
a broad sand plain high above the lake level, through which the 
Central Vermont Railroad was to be carried in a tunnel. But the 
sand was destitute of moisture or cohesiveuess, and the engineers, 
after expending a large sum of money, decided that the tunnel 
could not be constructed because there were no means of sustain- 
ing the material during the building of the masonry. 1'hc removal 
of so large a quantity of material from a cut of such dimensions 
also involved an expense that was prohibitory. The route was 
consequently given up and the road built, in a crooked ravine 
through the centre of the city, involving ascending and descending 
grades of more than 130 feet to the mile. When the railroad was 
op^'ned these grades were £ound to involve a cost which ])ractically 
drove the through freights to a competing railroad. 

There was at the time a young man in the engineers’ office of the 

^ In his paper on Indicative Plants,” published in the "I'ransactions of 
the American Institute of Mining Engineers, 1886, Mr. R. W. Raymond 
illustrated in natural size P^iola calamiuaria, /ImorfyJia crcscens, and llriao- 
nium ovalifolhim. His paper is followed by the interesting discussion it 
called forth. 


railroad who said that he could tunnel the sand bank at a ver}’ 
small cost. He was summoned before the managers and ques- 
tioned. ‘‘Yes/’ he said, “1 can build the tunnel for so many dol- 
lars per running foot, but I cannot expect you to act upon mv 
opinion when so many American and European engineers have 
declared the project impracticable.” The managers knew that the 
first fifty feet of the tunnel involved all the difficulties. They of- 
fered him, and he accepted, a contract to build fifty feet of the 

His j)lan was simplicity itself. On a vertical face of the bank 
he marked the line of an arch larger than the tunnel. On this 
line he drove into the bank sharpened timbers, twelve feet long, 
three l)y four inches square. Then he removed six feet of the 
material and drove in another arch, just inside the first one, of 
twelve-foot timbers, took out six feet more of sand, and repeated 
this process until he had space enough to commence the masonry. 
As fast as tliis was completed the space above it was filled, leaving 
the timbers in place. 

Thus he progressed, keeping the masonry well up to the excava- 
tion, until he had pierced the bank with the cheapest tunnel ever 
constructed, which has carried the traffic of a great railroad for 
thirty years, and now stands as. firm as on its completion. 

.The engineer was asked if there was any suggestion of the 
structure adopted by him in the books on engineering. “No,” he 
said, “it came to me in this way. I was driving by the place where 
the first attempts were made, of which a colony of bank-swallows 
had taken tiossession. It occurred to me that these little engineers 
had disproved the assertion that this material had no cohesion. 
They have their homes in it, where they raise two families every 
summer. Every home is a tunnel, self-sustaining without 
masonry. A larger tunnel can be constructed by simply extending 
the principle, and adopting masonry. This is the whole story. 
The bank-swallow is the inventor of this form of tunnel ‘construc- 
tion. I am simply a copyist — his imitator.” 



Newton, Watt, Ericsson, Rowland, as boys were constructive . . . The 
passion for making new things . . . Aid from imagination and trained 
dexterity . . . Edison tells how he invented the phonograph . . . Tele- 
phonic messages record themselves on a steel wire . . . Handwriting 
transmitted by electricity . . . How machines imitate hands . . . Orig- 
inality in attack. 

A N inventor is a man of unusual powers. To begin with be is 
i \. cast in a larger mold than ordinary men ; he has keener eyes, 
more skilful hands, a better knitting quality of brain. In his 
heart he believes every engine, machine, and process to be im- 
prova])le without limit. He is thoroughly dis- 
Early Talent in satisfied with things as they are and alert to 
Construction. detect where an old method can be bettered, or 
a gift wholly new be conferred on mankind, as 
in the telephone or the phonograph. His uncommon faculty of 
observation we have had occasion to remark. Another talent as 
much in evidence, and quite irre])rcssible even in early life, impels 
him to make, weave, and build. Invariably the man who has added 
to the resources of architecture, engineering, machine design, has 
begun as a boy in repeating the rabbit-hutches, windmills, and 
whittled sailing craft of bigger boys. This means that he soon 
acquires a mastery of chisel, plane, and drill, that the lathe be- 
coi]jes as obedient to him as his own hand. Watt, Maudslay, 
Stephenson, and every peer they ever had, could go to the bench 
and make a valve, a mitre-wheel, a link-motion just as imaged in 
their mind’s eye. Lacking this dexterity other men, occasional!}^ 
fertile in good ideas, never bring them to the birth. 

While inventors owe their talents to nature, these talents need 
sound training, if at a master's hands, so much the better. Just 
as the best place to learn how to paint, is the studio of a great 


artist, so the best school for ingenuity is the workshop of a great 
inventor. Maudslay, who devised the slide-rest for lathes, and 
Cdcment, who designed the first rotary planer, were trained h\ 
Jlraniah, who invented the famous hydraulic press, and locks of 
radically new and excellent pattern. Whitworth, who created 
lathes of new refinement, whg established new and exact stand- 
ards of measurement in manufacturing, was trained by JMaudslay ; 
so was Nasmyth, who devised the steam hammer. ]\lr. Edison 
in his laboratory and worksho]:) has called forth the ingenuity of 
many an assistant who has since won fame and fortune by inde- 
])endent work. 

lUit as a rule inventors, like the vast brotherhood of other men, 
must toil by themselves, and get what good they can out of un- 
aided diligence*. Cobbett used to say that he thought with tlir 
point of his ])en : the very act of writing lifted into cansciousne>^ 
many an idea which otherwise had died stillborn. Beethoven, 
like all other great tone-])oets, would play a few bars as they canu* 
to his imagination, and while he touched the keys the music, as if 
vyith pinions of its own, took such heavenly flights as those (»f 
the I'ifth S\ inphony. In just this mode while an inventor is shap- 
ing a new model he feels how he can better its lines, give it a 
simpler design than he first intended. Ilis hands and eyes think 
as well as his brain ; while lever, link, and cam unite together tlicv 
suggest how they may be more compactly built, more effectively 
joined. Ilis partner, the discoverer, is under the same spell witli 
regard to some long-standing puzzle of rock, f)r plant, or star. De- 
cause in his soul he believes nature to be intelligible to her ven 
core, he is sure that this ])articular puzzle can be fathomed, aial 
he keeps thinking day bv day of possible solutions. At olla i' 
times, and even during sleep, his brain is subconsciously at 
U{)on his ])robleni, bringing to view j)romising i)oints for attack. 
With new light he is bold enough to say, this problem can I'c 
sol veil by me. .\t last dawns the happy morning when he veri fu- 
a shrewd guess, or when a crucial ex])eriment stam]:)s a the(n*y a- 
proven truth, indispensable aid having arisen as one attemp'- 
through battling failure, suggested the next. All boys and giik 
are the better, happier, more useful when they are early '• 
thoroughly trained to use their eyes, ears, and hands; to the ui- 


ventor and discoverer this training opens a career which other- 
wise is denied. 

Among the greatest of the sons of men who have united the 
faculties of invention and discovery stands Sir Isaac Newton. As 
with his compeers we lind tliat his art as an inventor was but the 
llower of his handicraft as a mechanic. 

Sir Isaac Newton almost from the cradle was a builder. His 
])iographer, Sir David ]h*ewster, says : — 

“He had not been long at school before he 
exhibited a taste for mechanical inventions. 

With the aid of little saws, hammers, hatchets, 
and tools of all sorts, he was constantly occu- 
pied during his play hours in the construction of models of known 
machines, and amusing contrivances. The most ini])ortant i)icces 
of mechanism which he thus constructed, were a windmill, a 
water-clock, and a carriage to be moved by the ])erson who sat in 
it. ^^1len a windmill was in course of being m'ected near (irant- 
ham, Sir Isaac frecpiently watched the operations of the workmen, 
and ac(juired such a thorough knowledge of its mechanism, that 
he completed a working model of it, which Dr. Stukely says was 
as clean and curious a ])iece of workmanslii]) as the original. This 
model was freciuently ])laced on the to]) of the house in which he 
lived at (Irantham, and was put in motion by the action of the 
wind upon its sails. In calm weather, however, another mechan- 
ical agent was recpiired, and for this ])urj)ose a mouse was put 
in re(juisition, which went by the name of miller. 

“The water-clock constructed by Sir T.saac was a more useful 
piece of meclrmism than his windmill. It was made out of a box 
which he begged from Mrs. Clark’s brother, and, according to 
Dr. Stukely, to whom it was described by those who had seen it, 
it r'esembled i)retty much our common clocks and clock-cases, but 
was less in size, being about four feet in height, and of a pro- 
portional breadth. There was a dial-])latc at top with figures of 
the hours. The index was turned by a i)iecc of wood, which cither 
fell or rose by water dro]:)ping. 

“The mechanical carriage which Sir Isaac is said to have in- 
vented, was a four-wheeled vehicle, and was moved with a handle 
or winch wrought by the person who sat in it. We can find no 

Newton as a 
Boy— A Tireless 


distinct information respectmg its construction or use, but it 
must have resembled a Merlin’s chair, 'which is fitted to move 
only on the smooth surface of a floor, and not overcome the in- 
ecjualities of a common road. 

“FTc introduced the flying of paper kites, and is said to have in- 
vestigated their best forms and proportions, as well as the number 
and position of the points to which the string should be attached. 
1 le constructed also lanterns of crimplcd paper, in which he placed 
a candle to light him to school in the dark winter mornings ; and 
in the dark nights he tied them to the tails of his kites, in order to 
terrify the country people, who took them for comets. 

“In the yard of the house where he lived, he was frequently 
observed to watch the motion of the sun. He drove wooden pegs 
into the walls and roofs of the buildings, as gnomons to mark 
by their shadows the hours and half-hours of the day. It docs 
not appear that he knew how to adjust these lines to the latitude 
of (irantham; hut he is said to have succeeded, after some years’ 
observation, in making them so exact that anybodv could tell what 
o’clock it was by Isaac’s dial, as it was called. 

“Sir Isaac himself told Mr. Conduit that one of the earliest 
scientific experiments which he made was in 1658, on the day of 
the great storm when Oomwell died, and when he himself had 
just entered into his sixteenth year. In order to determine the 
force of the gale he jumped first in the direction in which the 
wind blew, and then in opposition to the wind; and after meas- 
uring the length of the leap in both directions, and comparing it 
with the length to which he could jump on a perfectly calm day, 
he was cnahlcd to compute the force of the storm. Sir Isaac 
added, that when his companions seemed surprised at his saying 
that any particular wind was a foot stronger than any he had 
known before, he carried them to the place where he had made the 
exi^erinicnt, and showed them the measure and marks of hi^ 
several leaps. 

“W hen a young man he made a* telescope with his own hand>. 

James W^att, who became the chief improver of the steam en- 
gine, when a hoy received from his father a set of small carpentry 
tools. The little fellow would take, his toys to pieces, rebuild them 
and invent playthings wholly new. A cousin of his, Mrs. Camp- 



bell, has recorded that Watt as a lad was often blamed for idle- 
ness; she adds 

“His active mind was employed in investigating the properties 
of steam; he was then fifteen, and once in con- 
versation he informed me that he had read Watt as an 
twice, with great attention, S’Gravesande’s Inquiring Boy. 
‘Elements of Natural Philosophy/ adding that 
it was the first book ujx)!! that subject put into his hands, and that 
he still thought it one of the best. While under his father’s roof, 
he went on with various chemical experiments, repeating them 
again and again until satisfied of their accuracy from his own ob- 
servations. He had made for himself a small electrical machine, 
and sometimes startled his young friends by giving them sudden 
shocks from it.” 

John Ericsson as a child was the wonder of the neighborhood, 
says his biographer, Mr. William C. Conant. From the first he 
exhibited the qualities distinguishing him in 
later life. His industry was ceaseless; he was prlcodt^*<^ 
busy from morning to niglit drawing, planning Ericsson, 
and constructing. The machinery at the mines 
near his home was to him an endless source of wonder and delight. 
In the early morning he hastened to the works, carrying with 
him a drawing pencil, bits of paper, pieces of wood, and a few 
rude tools. There he would remain the day through, seeking to 
discover the principles of motion in the machines, and striving to 
copy their forms. In his tenth year this boy undertook to design 
a pump for draining the mines of water. The motor was to be a 
windmill. Such a contrivance the young , inventor had never 
seen, yet he succeeded in drawing designs for his mill after the 
most approved fashion of skilled engineers by following a verbal 
description given by his father of a mill he had just visited. 

Henry A. Rowland became at Johns Hopkins University in 
Baltimore one of the great physical investigators and inventors 
of the nineteenth century. As a boy he de- 
lighted in chemical experiments, glass-blow- Rowland's Early 
ing, and similar occupations. The family were Experiments, 
often summoned by the young enthusiast to 
listen to lectures which were fully illustrated by experiments, not 


always free from prospective danger. His first five-dollar bill 
fjought him, to his delight, a galvanic battery. The sheets of the 
New York “Observer’’ he converted into a hot-air balloon, which 
made a brilliant ascent and flight, setting fire, at last, to the roof 
of a neighboring house. One day he saw a pump at work in the 
hold of a steamer, sending out a stream which fell from a height 
of five or six feet to the river. “Why,” he exclaimed, “don’t you 
put that i)ipc down into the river and save power ?” As a student 
at the Troy Polytechnical Institute he invented a method of 
winding naked strips of wire on cloth so as virtually to effect its 
insulation. This was afterward profitably patented by some one 

In “The Senses and the Intellect” Professor Alexander Bain 
considers the inventing and discovering mind : — 

“Not one of the leading mental peculiarities 
The Passion for c^ipplicablc to scientific constriictivencss can be 

Experiment. dispensed with in the constructions of i)rac- 
tice:— the intellectual store of ideas applicable 
to the special dei)artment; the powerful action of the associating 
forces; a very clear perception of the end, in other words, sound 
judgment; and, lastly, that patient thought, which is pro])crly 
an entranced devotion of the energies to the subject in hand, 
rendering application to it spontaneous and easy. 

“With reference to originality in all departments, whether 
science, practice, or fine art, there is a point of character that de- 
serves notice, as being more obviously of value in practical in- 
ventions and in the conduct of binsiness and affairs — I mean an 
active turn, or a profuseness of energy, put forth in trials of all 
kinds on the chance of making lucky hits. In science, meditation 
and speculation can do much, but in practice, a disposition to try 
experiments is of the utmost service. Nothing less than a fanati- 
cism of experimentation could have given birth to some of our 
grandest practical combinations. The great discovery of Da- 
guerre, for example, could not have been regularly worked out 
by any .systematic and orderly research; there was no way but to 
stumble upon it, so unlikely and remote were the actions brought 
together in one consecutive process. The discovery is unaccount- 
aUe, until we learn that the author had been devoting himself 



to experiments for improving the diorama, and thereby got 
deeply involved in trials and operations far removed from the 
beaten paths of inquiry. The energy that prompts to endless 
attempts was found in a surprising degree in Kepler. A similar 
untiring energy — the union of an active temperament with intense 
fascination for his subject — appears in the character of Sir Wil- 
liam lierschcl. When these two attributes are conjoined; when 
profuse active vigor operates on a field that has an unceasing 
charm for the mind, we then see human nature surpassing itself. 

“The invention of photography by Daguerre illustrates the 
probable method whereby some of the most ancient inventions 
were arrived at. The inventions of the scarlet dye, of glass, of 
soap, of gunpowder, could have come only by accident; but the 
accident, in most pf them, would probably fall into the hands of 
men engaged in numerous trials upon the materials involved. In- 
tense application — ‘days of watching, nights of waking’ — went 
with ancient discoveries, as well as with modern. In the historical 
instances, we know as much. The mental absorption of Archi- 
medes is a proverb. 

“The wonderful part of Daguerre’s discovery consists in the 
succession of processes that had to concur in one operation be- 
fore any effect could arise. Having taken a silver plate, iodine 
is first used to coat the surface; the surface is then exposed to 
the light, but the effect produced is not apparent till the plate 
has been immersed in the vapor of mercury. To fall upon such 
a combination, without any clue derived from previous knowl- 
edge, an innumerable series of fruitless trials must have been 
gone through. 

“A remark may be made here, applicable alike to science and 
to practice. Originality in either takes two forms— observation 
or experiment on the one hand, and the identifying pnKesses of 
abstraction, induction, and deduction on the other. In the first, 
the bodily activities and the senses are requisite; the last are the 
purely intellectual forces. It is not by high intellectual force that 
3 man discovers new countries, new plants, new properties of ob- 
jects; it is by putting forth an unusual force of activity, adven- 
ture, inquisitorial and persevering search. All this is necessary 
in order to obtain the observations and facts in the first instance ; 



when these are collected in sufficient number, a different aptitude 
is broujj^ht to bear. By identifying and assimilating the scattered 
materials, general properties and general truths are obtained, and 
these may be pushed deductively into new applications; in all 
which a powerful reach of similarity is the first requisite; and 
this may be owned by men totally destitute of the active qualities 
necessary for observation and experiment.’' 

In “The Hazard of New Fortunes” Mr. W. D. Howells depicts 
a man of force who, without education, becomes rich. He has 
little patience with poor men, who, he says, 
The Chief ‘‘don't get what they want because they don’t 

Impulse in want it bad enough.” The rough old 

Westerner, Dryfoos, was sound in his view. 
Success in discovery as in money-making is as^ much a matter of 
passion as of intelligence, says Mr. O. F. Cook: — 

“The first and most essential preliminary for a successful in- 
vestigaHon is an interest in the ciucstion, and any method which 
tends to diminish or relax interest is false and futile. Diligence 
in learning the facts of a science is a distinctly unfavorable sym])- 
tom in a would-be investigator when unaccompanied by a vital 
constructive interest. That a student hoards facts does not mean 

that he will build anything with them. Intellectual misers are 
common, and are quite as unprofitable as the monetary variety. 
A scientific specialist may have vast knowledge and life-long ex- 
perience, and yet may never entertain an original idea or make 
a new rift in the wall of the unknown which baffled his predeces- 
sors. Indeed, such men commonly resent a readjustment of the 
bounds of knowledge as an interference with their vested capital 
of erudition. 

“Investigation is a sentiment, an instinct, a habit of mind; it 
is man’s effort at knowing and enjoying the universe. The pro- 
ductive investigator desires knowledge, for a purpose; he may not 
be eager for knowledge in general, nor for new knowledge iit 
particular. He values details for their bearing on the problem 
he hopes to solve. He can gather and sift them to advantage onl> 
in the light of a radiant interest, and his ability to utilize them 
for correct information depends on the delicacy of his perception 
and the strength of his mental grasp. The investigator, like the 



athlete, must first be born ; he can not be made to order, but his 
training determines the degree of excellence to which he can 
attain. No- amount of training can remove organic defects, but 
bad training may be worse than none in lessening the attainment 
of the most capable. That education is false and injurious which 
puts the matter first and retards or prevents the development of 
constructive mental ability, a power not peculiar to the investiga- 
tor, but in him reaching the greatest scope and freedom of 

A picturing faculty such as comes to the flower in an inventor 
may often be observed in a skilful workman. In a shoe factory 
a veteran will lift a hide, utterly irregular in 
form, and cut soles and heels from it, so that 
the remaining s(;raps are a mere trifle, while Picturing Power, 
flaws have been avoided. 

Hugh Miller, in '‘My Schools and Schoolmasters,” thus speaks 
of a fellow stone-mason: — '‘John I'^raser’s strength had never 
been aljovc the average of that of Scotchmen, and it was now 
considerably reduced ; nor did his mallet deal more or heavier 
blows than that of the common workman. He had, however, an 
extraordinary power of conceiving of the finished piece of work, 
as lying within the rude stone from which it was his business to 
disinter it ; and while ordinary stone-cutters had to repeat and re- 
repeat their lines and draughts, and had in this way virtually to 
give their work several surfaces in detail ere they reached the 
true one, old John cut u])on the true figure at once, and made one 
surface serve for all. In building, too, he exercised a similar 
power; he hammer-dressed his stones with fewer strokes than 
other workmen, and in fitting the intersjiaces between the stones 
already laid, always ])icked from out the heap at his feet the stone 
that exactly filled the ])lace ; while other operatives busied them- 
selves in picking up stones that were too small or too large; or, 
if they set themselves to reduce the too large ones, reduced them 
too little or too much, and had to fit and fit again. Whether build- 
ing or hewing, John never seemed in a hurry. He has been seen, 
when far advanced in life, working very leisurely, as became his 
years, on one side of a wall, and two stout young fellows building 
against him on the other side— toiling, apparently, twice harder 


than he, but tlie old man always contriving to keep a little ahead 
of them both.” 

Henry Maudslay, famous as an inventor, had the same ex- 
(juisite sense of form. When he executed a piece of work he 
was greatly indebted to the dexterity he had accjuired as a black- 
smith in early life. He used to say that to be a good smith you 
must he able to see in an iron bar the object you mean to get out 
of it with hammer and chisel, just as the sculptor secs the statue 
he intends in carve from a block of marble. 

Inventors and artists have in common a keen perception of 
form, an ability to confer form with skill and accuracy. Often 
the same man is at once inventor and artist. 
Eyes and Hands ^ class Leonardo da Vinci is the most 

Inform the Brain, illustrious example. y\lexander Nasmyth, of 
I'.dinhurgh, who invented the bow-string 
bridge, was an eminent painter of portraits and landscapes. His 
son, James Nasmyth, who devised the steam hammer and the 
steam pile-driver, tells us in his autobiogra])hy : — 

“My father taught me to sketch with exactness every object, 
whether natural or artificial, so as to enable the hand accurately 
to reproduce what the eye had seen. In order to acquire this al- 
most invaluable art, he was careful to educate my eye, so that 1 
might ])erceive the relative proportions of objects placed befon' 
me. He would throw down at random a number of bricks, or 
pieces of wood representing them, and set me to copy their forms, 
proporti(ms, lights and shadows. I have often heard him say that 
any one who could make a correct drawing' in regard to outline, 
and also indicate by a few' effective touches the variation of lights 
and shadows of such a grouj) of model objects, might not despair 
of making a good and correct sketch of Yrtrk Minster. ]\ly 
father was an enthusiast in praise of this Q;raphic hini^iiai^c, and 
T have followed his example. In fact it formed a principal i)art 
of my own cducatkm. It gave me the power of recording obser- 
vations with a fe\v graphic stndvcs of the pencil, and far sur- 
])assing in expression any number of mere words. This graphic 
eloquence is one of the highest gifts in conveying clear and cor- 
rect ideas as to the forms of objects — whether they be those of 
a simple and familiar kind, or of some form of mechanical con- 


struction, or of the details oi a fine building, or the characteristic 
features of a widc-strctching landscape. This acconiplishnicnt 
of accurate drawing, which I achieved for the most part in my 
father’s workroom, served me many a good turn in future years 
with reference to the engineering work which became the husi- 
ness of my life.” 

Ilis mastery of the pencil had undoubtedly a great deal to do in 
cultivating his powers of inventive imagination. He says: — “Tt 
is one of the most delightful results of the possession of the con- 
structive faculty, that one can build up in the mind mechanical 
structures and set them to work in imagination, and observe be- 
forehand the various details performing their respective func- 
tions, as if they were in absolute form and action. LTnless this 
happy faculty exists in the brain of the mechanical engineer, he 
will have a hard and disappointing life before him. It js the 
early cultivation of the imagination which gives the right flexibil- 
ity to the thinking faculty.” 

Drawing is one of the courses in every manual training school 
in America. The first of these schools was organized in 1879 
St. Louis, under the direction of Professor C. 

M. Woodward. Within the past thirty years, Manual Training, 
from the kindergarten to the university, Amer- 
ican education has addressed itself as never before to bringing 
out all the talents of pu])ils and students. In earlier days there 
was little appeal to sense perception, to dexterity, to the faculties 
of eye and hand which all too soon pass out of ])lasticity, to leave 
the young man or woman for life destitute of powers which, 
had they been duly elicited, would have broadened their careers 
by widening their horizons. To-day, ha])pily, our schools are more 
and more supplementing literary and mathematical courses with 
instruction in the use of tools, in modeling, design, and pattern- 
making. Every jirocess is thoroughly explained. All the studies 
are linked into series ; these unite practice and its reasons with a 
thoroughness impossible in the outworn schemes of a])]irentice- 

All this is a distinct aid to inventiveness. As Professor Wood- 
ward says in “Alanual Training in h'ducation” “Manual train- 
ing cultivates a capacity for executive work, a certain power of 



creation. Every manual exercise involves the execution of a 
clearly defined plan. Familiar steps and processes arc to be com- 
bined with new ones in a rational order and for a definite purpose. 
As a rule these exercises arc carefully chosen by the instructor. 
At proper times and in reasonable degree, pupils arc set to form- 
ing and executing their own plans. Here is developed not a single 
faculty, but a combination of many faculties. Memory, com- 
parison, imagination, and a train of reasoning, all are necessary 
in creating something new out of the old.” 

Every inventor of mark is a man of native dexterity whose 
skill has been thoroughly cultivated. Let us observe such a man 
as he came to an extraordinary triumph. One 
How the Qf great inventions of all time is the 
Phonogr^^ph was piiQuog-faph, giving us as it does accurate re- 
cords of sound which may be re])eated as often 
as we please. The ideas which issued in the perfected instrument 
were for years germinating in Mr. lulison’s mind; they took their 
rise in his recording telegraph. One afternoon Mr. Edison told 
the story to the late Mr. George Parsons Lathrop, who published 
it in' Harpers’ Magazine for I'ebruary, 1890:—“! worked a circuit 
in the daytime at Indianapolis, and got a small salary for doing 
it. Put at night with another operator named Parmley, T used 
to receive newspaper reports just for the practice. The regular 
operator, who was given to copious libations, was glad enough to 
sleep off the effects while we did his work for him as well as \vc 
could. I would sit down for ten minutes, and take as much as I 
could from the instrument, carrying the rest in my memory. 
Then, while I wrote out, Parmley would serve his turn at taking; 
and so on. This worked well until they put a new man on at the 
Cincinnati ciul. He was one of the (iuickest despatchers in the 
business, and we soon found it was hopeless for us to try to keep 
up with him. Then it was that I worked out my first invention, 
and necessity was certainly the mother of it. 

“I got two old IMorsc registers, and arranged them in such a 
way that by running a strip of paper through them, the dots and 
dashes were recorded on it by the first instrument as fast as they 
were delivered from the Cincinnati end, and were transmitted to 
us through the other instrument at any desired rate of speed or 


slowness. They would come in on one instrument at the rate of 
forty words a minute, and we would grind them out of the other 
at the rate of twenty-five. Then were n’t we proud ! Our copy 
used to be so clean and beautiful that we hung it up on exhibition ; 
and our manager used to come and gaze at it silently, with a 
puzzled expression. Then he would depart, shaking his head in a 
troubled sort of way. He could not understand it ; neither could 
any of the other operators ; for we used to drag off my impromptu 
automatic recorder and hidcTt when our toil was over. But the 
crash came when there was a big night’s work —a presidential 
vote, I think it was — and copy kept tx)uring in at the top rate 
of speed, until we fell an hour and a half or two hours licliind. 
The newspapers sent in frantic complaints, an investigation was 
made, and our little scheme was discovered. We could n’t use 
it any more. 

'It was that same rude automatic recorder,'' Edison explained, 
“that indirectly — yet not by accident, but by logical deduction — 
led me long afterward to invent the phonograph. I ’ll tell you 
how this came about. After thinking over the matter a great 
deal, I came to the point where, in 1<S77, 1 had worked out satis- 
factorily an instrument which would not only record telegrams 
by indenting a strip of paper with dots and dashes of the Morse 
code, but would also repeat a message any numl)er of times at 
any rate of speed required. 1 was then experimenting with the 
telephone also, and my mind was filled with theories of sound 
vibrations and their transmission by diaphragms. Naturally 
enough, the idea occurred to me : If the indentations on paper 
could be made to give forth again the click of the instrument, why 
could not the vibrations of a diaphragm be recorded and similarly 
reproduced? I rigged up an instrument hastily, and pulled a strip 
of paper through it, at the same time shouting, ‘Hallo!’ Then the 
paper was pulled through again, my friend Batchelor and 1 listen- 
ing breathlessly. We heard a distinct sound, which a strong 
imagination might have translated into the original ‘Hallo!’ That 
was enough to lead me to a further experiment. But Batchelor 
was sceptical, and bet me a barrel of apples that I could n't make 
the thing go. I made a drawing of a model, and took it to Mr. 
Kruesi, at th^.t time engaged on piece-work for me. I marked it 



$4, and told him it was a talking machine. He grinned, thinking 
it a joke; but set to work, and soon had the model ready. I ar- 
ranged some tin-foil on it, and sjXDke into the machine. Kriicsi 
looked on, and was still grinning. But when I arranged the 
machine for transmission, and we both heard a distinct sound 
from it, he nearly fell down in his fright; I was a little scared 
myself, I must admit. I w'on that barrel of apples from Batchelor, 
though, and was mighty glad to get it.” 

In October, 1905, I paid Mr. Edison a visit at his laboratory, 
when he showed me the phonograph as now perfected. Chief 
among his improvements is a composition for 
records which is much harder than the wax 
formerly employed, and may therefore revolve 
more swiftly with no fear of blurring. His reproducer is to-day 
a built-up diaphragm of mica, highly sensitive. In the reproducer 

The Latest 

Edison phonograph. 

A, speaking tube. B, D, scale. C, receiving 
cylinder. E, repeat lever. F, swivel plate. G, 
connecting key. 11, foot trip. I, plug attach- 
ment. J, ear-tubes. K, switch. 

arm is placed the highly polished, button-shaped sapphire which 
tracks with fidelity the grooves which sound has recorded on the 
cylinder. These features, combined in a mechanism of the ut- 
most accuracy in make and adjustment, have opened for the 



phonograph a vast field in the business world. Some of the great 
firms and companies of New York and other cities now use 
phonographs instead of stenographers ; a letter or a contract is 
dictated to a revolving cylinder with all the swiftness of ordinary 
speech. Afterward a secretary listens to the reproducer and 
writes the letter or contract at any speed desired. On occasion ■ 
a cylinder bearing a message may be sent to a correspondent who 
listens to its words as sent forth from his own phonograph, no 
intermediate writing being required. Such instruments arc ex- 
tensively used in teaching foreign languages, learners being free 
to have a difficult pronunciation repeated until it is mastered. 
Mr. Edison has much improved the musical records familiar 
throughout the world; these are now produced in molds of gold 
with a delicacy that refines away the scratchiness of tone so un- 
pleasant in earlier cylinders. 

As the fruit of rare experimental ability Mr. Valdcmar Poul- 
sen, an electrical engineer of Copenhagen, has invented the 
telegraphonc. This instrument proceeds upon 
the fact that the electrical pulses of the tel- Telephone Mes- 
ephone, minute and delicate though they are, sages Recorded 
can register themselves magnetically upon a 
moving steel wire but one-hundredth of an Telegraphonc. 
inch in diameter. The message is repeated as 
often as the wire is borne between the poles of an electro-magnet 
ill circuit with a telephonic receiver. The accompanying figure 
shows the transmitter, the traveling wire, and the receiver as it 
repeats a message. The instrument in its latest form is illustrated 
opposite page 314. In supplementing , the telephone most 
usefully, this apparatus brings a fresh competition to bear upon 
the telegraph. In many cases a man of business has preferred 
to telegraph rather than to telephone a message, because a 
telegram as a written record affords proof in case of error or dis- 
pute. Now suppose that through a telegraphonc a broker offers 
six per cent, interest for a loan ; his voice impressed on the wire, • 
duly preserved for reference, identifies him as securely as would 
his signature on a written offer. Take a different case : a patient 
rings up a physician only to find him not at home; a message 
committed to a few yards of wire is listened to by the physician 


the moment he returns to his office. Take an example of yet an- 
other service: a letter may be dictated at Newark and recorded 
on a wire in Brooklyn, and there, at leisure, be put upon paper 




record it only is necessary to pass the steel between the poles of 
a strong magnet. 

A telephone transmits a familiar voice so that its tones are at 
once recognized. By electrical means a telautograph reproduces 
writing at a distance so precisely that it may 
be as readily identified. To understand how 
this feat is accomplished let us begin with the Telautograph, 
transmission of vertical marks varying in length. 


Si ! i 

A, sending a vertical line S M by electricity. 
B, sending a horizontal line S M by electricity. 

This task, as above illustrated, we perform by sending to a 
receiving pencil a current varying in strength between limits 
which correspond to the variations in length of our transmitted 
Hues. The strength of this current, say 0.429 volt, decides where 
a mark will begin ; the strength of that current in rising to say 27.5 
volts, decides where that mark will end. To vary the strength 



of the current as desired we employ a square rod of aluminiuni, 
tightly covered with a thin copper wire insulated by silk wrapping. 
We place this rod beside our tablet, and scrape from its inner- 
most surface the silk covering so as to leave the wire bare, while 
between its strands the silk remains intact as an effective insula- 
tion. Our rod is now a rheostat, whose use we shall presently 
discover. We are wont to think of co])])cr as a good conductor, 
and so it is. Used in stout bars or thick wires it exerts but littk' 
resistance to an electric current/ but when we employ a wire of 
])ut 1/200 of an inch in diameter, about the thickness of the paper 
on which this is printed, the narrowness of path reduces the 
pressure of a current so much tliat in the course of 375 feet it 
falls to one eighth. Tn like manner a glass tube of minute di- 
ameter might receive at one end water under extreme pressure, 
and at a yard distance send out a mere dribble. The co])per wire 
of our scptarc rod, or rheostat, is so thin that when connected at 
K with a source of no-volt electricity, at V this voltage, or 
pressure, has sunk to but one twentieth of a volt. 

Let us suppose our rheostat at V connected with a circuit ex- 
tended to the receiving station. A wire, kept in this circuit, and 
moving up and down with our pencil, in a line always parallel 
with the side of our tablet, sends to the receiving station a cur- 
rent constantly varying in its pressure. As the wire passes from 
S to ]\r the transmitted current rises from 0.429 to 27.5 volts. 

At the receiving station we provide means whereby the current 
arriving at a voltage of 0.429 and rising to 27.5 will mark a 
vertical line the length of S M. A simple device for this purpo'^e 
consists in a hollow coil of copper wire, or a solenoid, as elec- 
tricians call it, through which circulates the arriving current, the 
coil being free to be drawn as a shell over a cylindrical electro- 
magnet. The degree to which such a coil, duly attached to a re- 
tractile spring, is drawn over a suitable electro-magnet, depends 
upon the strength of the current circulating in the coil. In the 
simple instrument we arc using let us assume that when a current 
of no volts comes in, the coil moves to K, the end of its path: 
that when a current of 6.875 volts arrives, the coil moves to O : 
the receiving coil and the sending rheostat being marked with 
the same divisions. Our receiving coil actuates a pencil which 


accordingly marks a line of the same length and direction as that 
set down on the tablet of the sending instrument. 

Let us next transmit between these two stations a series of 
liorizontal lines. To do this we duplicate our first apparatus. We 
place a second rheostat along the foot of our sending tablet, not 
along its side, and slide a second wire along its bared surface 
with motions always parallel to those of the marking pencil. Thus 
a second current, going by a wire of its own to the receiving 
station there repeats through a second coil, or solenoid, the hori- 
zontal marks of our sending pencil. 

We have now two sets of apparatus, alike in all respects, one 
sending rheostat at right angles to the other ; one receiving 
solenoid at right angles to its mate. In the actual telautograph 
the rheostats are curved, as shown in the picture facing page 318, 
and they are so joined by levers that the up-and-down and side- 
wise motions of writing are accurately represented, from moment 
to moment, in the two varying currents sent afar. As these cur- 
rents arrive they actuate a pencil, similarly furnished with levers, 
so that it moves in a path which exactly corresponds with that of 
the sending pencil. The ap])aratus has an ingenious ink supply, 
and a device to shift the paper as filled line after line. In its basic 
features the telautograph was invented by the late Professor 
IClisha Clray of Chicago. Its ])resent form is largely due to the 
modifications and additions of Mr. (ieorge S. Tiffany of New 
York. The instrument is giving satisfactory service in thou- 
sands of banks, factories, hotels, business offices, and households. 
Its records at both ends of a line make it of inestimable value in 
many cases, as aboard a warship where orders of the utmost im- 
portance may be committed to its taldets. ICxterior and interior 
views of the instrument are given facing page 318. 

Only a few machines deal with writing or its duplication, most 
machines perform quite other tasks at first wrought by the 
hands. Inventors have 'always gone astray 
when they have sought to imitate a hand pro- Machines Cannot 
cess with anything like precision. On this I^irectly Imitate 
point Sir John Pletcher Moulton, of London, 
says : — ‘^Doubtless you have often had to send k coded.” 
a message by telegraph to some distant country 



to which the rate charged per word is high. You write your mes> 
sage as tersely as may be, but even thus its length is formidable. 
You resort to your telegraphic code. It tells you that if you will 
change the j)hraseology of your message you can by a single 
code- word rej^resent a whole phrase. You thereupon set to work 
to recast your message so as to make it capable of being expressed 
in code-words. When you have done so, you have not improved 
it as a message. It is less terse and less naturally expressed. If 
you were writing and not telegraphing, you would prefer to use 
it in its original form. But as now expressed, each of the phrases 
of which it is composed can be sent over the wires in the form 
and at the price of a single word, and the cost of the whole is but 
a fraction of what would have been the cost of the message as 
originally framed. It has been cast in a form suitable for cheap 
telegra])hing. Just so with the inventor. He has to find a series 
of operations which, in their totality, arc C(iui valent to the series 
of the hand worker. But each of these operations in itself nck'd 
not be such as would in hand lalx>r be suitable or even practicable. 

“Jt is necessary and sufficient for him that they arc suited to 
the new conditions, so that they can be well and easily done by 
mechanism, and that, taken as a whole, they produce the same 
result as the scries which he is paralleling. He is re-writing the 
series in terms suited to mechanism just as the message was re- 
written in terms suited for telegraphing. The meaning of 
the message must remain the same, but the terms used to express 
it are no longer those most naturally used in writing or speaking, 
but arc those which can be telegraphed at least cost. 

“To make my meaning clear, let me revert to the familiar 
operation of sewing. The hand process is plainly unsuited for 
mechanical reproduction. How is it to be 
Sewing Coded translated into an equivalent cycle suitable for 
in a lilachine. mechanism? In other words, how is it to be 
k:odcd’? This case is interesting, inasmuch as 
we have two independent solutions worked out at different dates 
and widely different in nature. The earlier invention imitated the 
hand cycle very closely. The thumb and finger of the right hand 
in the human being were replaced by pairs of pincers capable of 
|aking hold of the needle and letting it free again, but to avoi(’ 


1 ELAU lOGRAini, 1X1 liKIOR, 



having to follow the intricate movements of the human fingers 
in the operation two pairs of pincers were used, one on each side 
of the work, which passed the needle backw/irds and forwards 
through the fabric one to the other. Following out this idea the 
needle was pointed at both ends with an eye in the middle^ and, 
as in hand sewing, it carried a moderate length of thread. The 
pair of pincers which held the threaded needle advanced to the 
fabric and passed through it to the other pair which took it and 
retreated so as to draw the thread tight and form the completed 
stitch. To form the next stitch the work was moved through the 
proper distance and the same process was gone through, the line 
of movement of the needle always remaining the same. 

‘There is not much ‘coding’ here. Tlie new cycle imitates the 
hand-worker so faithfully that it benefits little by the advantages 
of mechanical action. As in hand work it can only sew, with 
moderate lengths of thread, and must therefore have the needles 
re-threaded at intervals. Its superiority over hand labor is there- 
fore so slight that it is doubtful whether such a sewing machine 
could ever have competed with, much less replaced, hand work. 
But if has one great merit. The needle mechanism is capable of 
being re-duplicated almost without limit, and the movement of the 
work which is necessary to direct the stitches for one needle will 
serve equally well for any number of needles working parallel to 
it. Hence the machine that would have failed as a sewing ma- 
chine has survived and proved useful as an embroidery machine. 
The work is stretched between two rows of pincers and moved 
by the workman according to the stitches of the pattern. Each 
stitch is repeated by each of the parallel needles which work side 
by side at convenient distances, and thus as many copies of the pat- 
tern are simultaneously produced as there are needles. Each is a 
perfect facsimile of all the others, and as each copies faithfully 
the errors of the workman, this machine is entitled to the proud 
boast that it^ productions possess all the defects of hand work— 
an essential we are told of artistic beauty. 

“What is the cause of the comparative failure of this attempt 
at a sewing-machine ? It is evident that it is due to the retention 
of the feature of the hand operation by which the needle is passed 
fr<)m one holding mechanism to the other. The inventors of the 



modern sewing-machine on the one hand decided to work with a 
needle fixed in its holder and never leaving it throughout the 
operation. It at once followed that the needle and thread must, 
on the back stroke, return through the same hole through which 
they had entered the fabric, so that no stitch could be formed un- 
less some obstacle were interposed to the return of the thread. 
Here the two famous and successful forms of the machine parted 
company. Both placed the eye at the point of the needle that the 
stroke might not be needlessly long, but while the lock stitch 
machine used a second thread to provide the necessary obstacle, 
the chain stitch machine availed itself of a loop of the original 
thread for that purpose. Thus in the lock stitch machine the sub- 
stituted cycle became as follows : — 

(1) The work is moved under the needle for the new stroke. 

(2) The needle (which has an eye at its point through which 
the thread passes) pierces the fabric carrying with it the thread. 

(3) A second thread is passed between the thread and the 
needle (by means of a shuttle or its equivalent) when the needle 
is at its lowest position. 

(4) The needle returns while a take-up retracts the thread so 
as to tighten the stitch. 

^Tliis cycle would, for hand work, be immeasurably more com ■ 
plicated and difficult than ordinary sewing, but it consists of 
operations mechanically easy of performance in swift and accu- 
rately timed sequence, and as the whole of the thread in use has 
no longer to be passed from one side of the fabric to the other as 
each stitch is made, it has brought with it the all-important ad- 
vantage of our being able to work with a continuous thread. 
Here, then, is a magnificent example of ‘coding.' It is not to be 
wondered at that the machines which it has given to the world 
are in well-nigh universal use, and have profoundly modified 
both our social and industrial economy.*' 

* One of the supreme inventions of all time is the mower of Obed 
Hussey, of Maryland, devised in 1833, and afterward adapted to 
reaping. In the primitive reaping of tall grain 

Obed Hussey one hand keeps the stalks upright, while the 
and His Mower, other hand cuts these stalks with a scythe. 

Hussey, in a masterpiece of ‘‘coding," arrayed 



metal fingers which keep the grain from bending, while vibrating 
knives sever the stalks. To this day his invention remains the 
core of millions of mowers as well as reapers ; it has economized 
labor to an extent beyond estimate, 
and by shortening the time required 
in harvesting has saved many million 
bushels of grain which otherwise 
would have been destroyed by bad 

Not a few inventors of the first 
mark are found among the men of 
great ability who unite training in two 
distinct fields of science, whose al- 
liances they thoughtfully cultivate. 

TT 1 1 li. ^ 1 • • Obed Hussey’s mower 

1 bus Helmholtz, at once a physician 

... ^ or reaper. 

and a physicist, devised the ophthalmo- 
scope, that simple instrument for observing the interior of the 
eye. On a plane less lofty an inventor’s success may turn on his 
width of outlook, his intimacy with fields 
remote from the home acre, so that he may New Modes 
gainfully ally two arts or processes that, to 
a casual glance, seem utterly unrelated or unrclatable. When 
a pneumatic tube between a post-office and a railroad station 
is obstructed, there would seem to be no promise of aid in a 
fire-arm. But snapping off its blank cartridge at the open end of 
the tube gives back an echo through the air within the tube; in 
measuring the interval between touching the trigger and hearing 
the echo, there is news as to where the tube is choked, the velocity 
of sound in air being known. From the labors of a postmaster 
let us turn to those of an apothecary, who pounds and grinds his 
drugs in a mortar which has descended from the day when it 
reduced grain to flour. The grindstones which succeeded the 
mortar were only in recent years ousted by Hungarian rollers of 
steel which separate the constituents of grain with a new per- 
fection. Their excellence consists in imitating the crushing of 
the mortar, not in attempting the grinding of the familiar burrs. 

The miller’s practice in one particular has given the postmaster 
a hint of value. In a flour-mill a cheap and suflicient motor is 



simple gravity as the products pass from one machine to the next. 
At the very outset the wheat is taken by conveyors to the top 
floor, whence its products descend, stage by stage, impelled l)\ 
gravity alone, until the finished and barreled flour rolls into ship- 
ping rooms beside the railroad tracks. This principle has been 
adopted at the Chicago Post-office, where the mails as received 
arc borne to the top floor, thence, by gravity, they take their wav 
as sorted and re-sorted, to the ground floor where they arc finally 
disposed of. 

In a field somewhat parallel is the modern art of designing the 
layout of a great manufacturing plant so that the material shall 
travel as little as possible between its entrance and its exit. In a 
well planned ship-yard the machines arc so placed that the steel 
plates, bars and girders, the planks and boards, move continuousl\ 
from one machine to its neighbor, ending at last by reaching the 
building berth. 

Shears for metal, cutting scissors-fashion, have long been 
familiar; the Pittsburg, Fort Wayne and Chicago Railroad em- 
ploys the Murphy machine, on the same principle, to cut up old 
ties and bridge timbers intended for fuel. The upper movin.e: 
blade is set about an inch out of line from the lower fixed blade, 
so as to allow spikes or bolts to pass through without injurini^: 
the machine. In dividing cord wood for stoves and furnaces a 
machine of this kind might be used instead of a saw. 

It is by perfect means of subdivision that new and chcaj) 
materials for writing and ])rinting are now produced. The leaves 
offered by the papyrus to scribes were used for centuries, so that 
the plant has given its name to paper now made from fibres (d 
cotton, linen, or wood, finely divided, thoroughly mixed, and 
squeezed between rollers much as if paste. Paper from its 
smoothness, its absence of grain and its low price, is far pref- 
erable to papyrus leaves or vellum. Its manufacture has been 
copied in diverse new industries. Wood ground to powder, 
worked into pulp, molded into pails, tubs and the like, is satn 
rated with oil to produce wares of indurated fibre. A pail tbu'^ 
manufactured will not split apart in dry weather when empty, 
absorb liquids, and it is as easily kept clean as glass. 

While wood has thus found a rival in pulp, stone has a new 



competitor much more formidable. Pavements and piers are 
idlen needed in long stretches, without joints for the admission 
of rain or frost. The demand is met by cements and concretes 
easily laid in unjointed miles. These materials when strengthened 
with skeletons of steel find many uses; a brief survey of them is 
given in this book. A sister product, terra cotta, baked at high 
temperatures, is now molded in beautiful designs not only for 
tiles, but as walls, cornices, finials, vases, hearths, and statuary. 

Clay as tablets was one of the first mediums of the printer’s 
art, an art of late years exposed to many a surprise from unex- 
])ected invaders. Composition is now performed 
by machines of various models, one of them Linotype and 
being Mcrgentlialcr's linotype, as employed for Wedges 
Ibis lx)ok. Tn effect this machine is a caster 
rather than a compositor, and recalls the chief tasks of the -type- 
foundry. As an operator touches its keys he releases a succession 
of matrices, from which is cast a line as a unit. In its latest form 

Alcrgeiitlialcr linotype, showing five double wedges for justification. 

this machine enables the operator to change instantly from one 
tout to another, introducing roman, italic, and black face type in 






Sur/jres A and B are \ 
]raUel with each other, j 

J. W. Scliuckcrs’ dc)nl)le- 
wcdgc jiistilicr. 


J i 

the same line at will. Intricate book, tabular and pamphlet mat- 
ter, with chajiter headings, titles, or marginal notes may in this 
new model be set up at a speed four to six times quicker than 
hand composition. 

An illustration shows the two-letter matrices of a special Mer- 
gcnthaler machine. The upper is usually a body character and 
the lower an italic, a small capital or a black face. These lower 
matrices are lifted a little by a key so as to come in line with upi)er 
matrices. In this way the comiiositor has at command two 
distinct fonts. (Iroove IL receives the cars of the matrices. In a 
normal position 1) receives the ears of the matrices elevated to 
produce the secondary characters. In this way the matrices art' 
held in position as casting jiroceeds. Five double-wedge justifiers 
will be observed between the matrices. These devices, invented 

by J. W. Schuckers, hirm an essential 
part of the machine. Justification, 
let the reader be reminded, is 
spacing the contents of a line that it 
shall neatly end with a word or syl- 
lalile. In typewritten manuscript the 
lack of justification leaves the ends 
of lines jagged and unsightly. Mr. 
►Schuckers at the end of every word 
places a pair of wedges. When the 
ojierator is close to the end of a 
line he pushes in the whole row of 
wedges in that line ; the outer 
sides of each pair remain always parallel, and as jnishcd in these 
outer sides arc just sufficiently forced apart to space out the line 
with exactitude. To lift a table or a desk, and at the same time 
keep it always level, we may use pairs of wedges in the same 
manner; they must, of course, be much larger and thicker than 
those used in linot\'py. Sec next page for an illustration. 

To-day a book may be reproduced without any recourse what- 
ever to the type long indispensable. A photographer takes the 
volume, and repeats it in pages of any size we wish, dispensing 
not only with the type-setter or the type-caster, but even with 


ilie proofreader, since a camera furnishes an exact facsimile of 
the original work. Tf the ])ook is illustrated, a further economy 
is enjoyed ; its pictures are copied as faithfully and cheaply as the 



A, two wedges partly in contact. 

B, two wedges fully in contact, outer sides parallel. 

Ingenuity in 
Copying and 

A feat which is a mere trifle as compared with reproducing a 
book by photography, turns upon a loan from an old resource. 
Confectioners from time immemorial have 
squeezed paste out of bags through apertures 
into ornaments for wedding cakes and the 
like. With similar bags decorators force a 
thin stream of plaster into a semblance of flowers, fruits, and 
arabesques on their ceilings and cornices. On the same plan, 
with pressure more severe, soap is forced from a tank through a 
square opening to form bars for the laundress. Increasing the 
pressure once again, clay for bricks is urged forth, to be divided 
into lengths suitable for the kiln. Lead pipe is manufactured on 
the same principle, recalling the production of macaroni. A 
further step was taken by Alexander Dick, the inventor of Delta 



Frost as a 

metal ; by employing hydraulic pressure on metals at red heat he 
poured out wires and bars of varied cross-sections, superseding 
the method of drawing through dies. 

Cold as well as heat may be employed in a novel manner. The 
flesh of birds, beasts, and insects is now frozen hard, so as to be 
sliced into extremely thin sections clearly show- 
ing the details of structure. How a freezing 
process may aid the miner was shown first in 
Germany in 1880, when Hermann Poetsch, a mining engineer, 
had to sink a shaft near Asherslebcn, to a vein of coal, where, 
after excavating 100 feet, a stratum of sand eighteen feet thick, 
overlying the coal, was encountered. It occurred to Poetsch that 
the great difficulty occasioned by the influx of water through the 
sand could be overcome by solidifying the entire mass by freezing. 
To do this, he penetrated the sand to be excavated with large pipes 
eight inches in diameter, sunk entirely through it and a foot or 
two into the underlying coal. These were placed in a circle at 
intervals of a metre, and close to the periphery of the shaft. They 
were closed at the lower end. Inside each of these and open at its 
lower end was a pipe an inch in diameter. This system of ])ipcs 
was so connected that a closed circulation could be produced 
down through the small pipes and up through the large ones. A’l 
ice-machine, such as brewers use, was set up near by and kept at 
a tempdfaturc below zero Fahrenheit. A tank filled with a solu- 
tion of chloride of magnesium, which freezes at —40° Fahr., had 
its contents circulated through the ground pipes described. 
Thermometers placed in pipes sunk in the mass of sand showed 
51.8° Fahr. at the beginning of the process. The circulation was 
kept up and on the third day the whole mass was frozen. Within 
the continuous frozen wall the material was excavated without 
damage from caving in or inflow of water. The freezing entered 
the coal three feet, and to a distance six feet outside the pipes. 
The circulation was kept up until the excavation and walling were 
complete. On a somewhat similar plan tunnels have been bored 
through difficult ground. Of late years at Detroit, and elsewhere, 
serious breaks in water-mains have been repaired after a freezing 
process has solidified the stream. 


Light, as well as heat and cold, is to-day bidden to perform 
new duties. It was long ago observed that polarized light as it 
takes its way through transparent crystal or glass clearly reveals 
in areas of variegation, any strains to which the crystal or glass 
may be subjected. Of late this fact has been applied with new 
skill to investigating strains in engineering structures. A model 
ill glass, carefully annealed, is placed in the path of a beam of 
j)olarized light. By shifting the points of appli- * 
cation and of support, by loading the structure Polarized Light 
more or less, and here or there, the distribution and X-Rays, 
of .stresses and strains is directly shown to the 
eye. In this way curved shapes of various kinds have been in- 
vestigated, as well as bodies in which Hooke’s law of the strict 
proportionality of strain to stress does not apply. Photographs 
taken by this method show 
the distribution of stresses 
in rings subjected to ex- 
ternal compression, crank 
shafts, and car-coupler 
luxiks. It would be interest- 
ing thtis to compare stand- 
ard types of girders, trusses, 
and bridges, as well as 
arches of various forms, Polarized light showing strains in glass, 
both regular and skew. 

Polarized light, which when first discovered seemed nothing 
more than a singular and quite sterile phenomenon, has other uses 
of great imixirtance. It tells the chemist ho\v much sugar a given 
solution contains ; it displays the inner architecture of rocks when 
these are sawn into thin sections. 

Even more valuable than polarized light are the X-rays dis- 
covered by Professor Rontgen. One of their latest uses is to 
reveal impurities and air bubbles in electric cables, affording a 
procedure much simpler and easier than to employ electrical in- 
struments. In the production of X-rays and similar rays a tube 
Jis nearly vacuous as possible is employed. As an aid in removing 
air Professor James Dewar, of Cambridge University, has recently 



adopted cocoanut charcoal with remarkable success. He subjects 
it to the intense cold of liquid air, then establishing coinmunica 
tion between a receptacle filled with this charcoal and a bulb ex 
hausted to one fourth of the ordinary atmospheric pressure, Ik. 
has air so tenuous that an electric spark passes through it witl. 
difficulty. So much for developing the long known affinity of 
charcoal for gases, a property which increases in degree as tem- 
peratures fall. 



Self-acting devices abridge lalior . . . Trigger cfTects in the laboratory, 
the studio, and the workshop . . . Automatic telephones . . . Equi- 
librium of the atmosphere may be easily upset. 

A t this place wc may for a little while consider a few funda- 
, mental principles of construction whereby inventors have 
economized material, labor and cnerg^y by making; their xlevices 
self-acting, and by so poising a contrivance that a mere touch at 
the right time and place sets it going. 

Humphrey l^otter was a boy whose duty obliged him to open 
and shut the valves of a Newcomen steam-engine as it slowly 
w^nt its rounds. He was a human sort of boy, 
who liked play better than his irksome task, so Steam Engines, 
he found a way to rid himself of the drudgery 
of constantly moving his valve-handles to and fro. He tied a rod 
to the walking beam in such wise that it opened the valve at the 
proper moment, and, at another point in its circuit, when neces- 
sary, closed it. Then and only then did the steam-engine become 
self-acting. In the best modern types of engine this automaticity 
goes far indeed. Not only does the mechanism pum]) water as 
required into both the boiler and the condenser, it shuts off steam 
instantly when the engine moves too swiftly, and, when the engine 
speed is sluggish the port betwixt boiler and cylinders is opened 
to the full. And further: automatic stokers bear coal into the 
furnace at a rate which varies with the demand, should the steam 
pressure fall through an undue call for power, then an extra 
quantity of coal is borne upon the grate-bars. When oil is the fuel 
automatic stoking is, of course, at its best, there being neither 
cinders nor ashes to be removed— a duty, by the way, which in 
large central stations requires extensive machinery, all automatic. 




The essence of autoinaticity is that meclianism at a certain, pre- 
determined point in an operation shall perform a required act. 

Thus, to take the common example of a striking- 

Self-winding clock : at the end of each hour a detent is pulled 

SO as to release a hammer which hits a gong tlu- 
proper number of times. Let us suppose the clock to be driven 1)\ 
a weight or a s])ring in the ordinary way ; every day or every week 
the weight or spring will recjuire to l.)e wound up. In time-pieccN 
of a new variety the period during which no attention whatever is 
needed is lengthened to a year. The Self-wdnding Clock Com- 
pany, of IJrooklyn, New York, makes a clock which is driven In 
a fine spring, much like a common clock ; that s])ring every hour 
is automatically wound u]) by a tiny electric motor connected with 
a small battery in the clock case. An attachment is provided b\ 
which, through the wires of the Western Ldiion Telegraph Com- 
pany, the clock is every hour regulated to the standard time of llu‘ 
National ( )bscrvatory at Washington. The charge for this service 
is one dollar a month. 

d'o-day a designer ahvays seeks to make a 'machine self-acting, 
to limit the operator’s task to starting, directing, and stop])ing,- all 

Looms and 

with the utmost facility and the least possible 
exertion. So far has success geme in this direc- 
tion that a single tender in a cotton-mill may 

have charge of sixteen Northrop looms, and go to dinner leaving 

all at work. In case that a thread breaks in any of them, the loom 




will stop of itself and no barm will be done, the only loss consist- 
iiig- in the time during which the wheels and levers have lain idle. 
V stop-motion at its simplest is a fork through which the thread 
travels; as the thread moves forward, the fork is bent downward 
e xtending a light coiled siiring ; should the thread break, the spring 
instantly lifts the fork, which in rising stops the machine. 

Among the most noteworthy automatic machines are the presses 
which take a continuous roll of paper, print both sides, cut it into 
leaves, fold these, paste them at the back, and, if desired, sew them 
together and attach a cover. Such a press stands for the union of 
several operations once distinct ; it argues great ingenuity, careful 
planning, with ])a])er exactly adapted to the stresses it must en- 
counter, while the ink is of a <|uick-drving variety. 

liinding o])erati()ns and a good deal of printing have to deal 
with separate sheets of pa])er or card. To feed these to presses, 
folders or binders was for many years a task 
for the hand, d'o-dav the Dexter P'older Dom- The Dexter 

l)any, of New ^"ork, in a diversity of machines 
su])crsedes tliis toil l)y an ingenious imitation of 



manual movements. The ui)permost sheet of i)a])er in a i)ile is for 

a moment held down at A by a rubber finger, during that moment 

a small rubber roller Ji slightly buckles the sheet; at the same time 



Appliances in 

is the funclioi 

an airblast lifts the sheet from its pile ; that done, all in a twinklin^t::, 
finger A rises and the sheet passes either into a press or a folding 
machine. So nicely limited is the pathway for the paper that no 
more than one sheet can pass at a time; if two or more sheets 
preseiU themselves, the feeding mechanism stops, bringing the 
])ress or folder to a standstill. As each sheet passes from nnder 
the rubber fingers, the table bearing the pile of paper is lifted by 
just one thickness of paper. 

J\Tr. James Douglas, president of the Copper Queen Company, 
New York, thus describes automatic devices in metallurgy: “The’ 
gold mill, with its scries of automatic opera- 
tions, is the offspring of Californian ingenuity. 
Tn it manual labor is almost entirely replaced by 
ocular labor, for superintendence and not work 
of the mill-hands. The ore, dumped into the 
breakers, falls into large pockets, whence it slides into automatic 
feeders, which su])ply the stam]:)s with regulated quantities. The 
free gold is ])artly extracted by lujuid mercury in the mortars, and 
by coi)per ])lates attached to their sides, and partly on an apron of 
amalgamated copper ])lates, over which crushed pulp flows as it 
issues from the battery screen. Automatic vanners receive the 
tailings, separate the sulphurets, and discharge the waste. When 
the power is water, the stream is divided to IVlton wheels, coupled 
* to the separate groups or even pieces of machinery. The absence 
of intermediate running gear increases not only the sense, but the 
reality of automaticity, and makes a skilfully arranged and thor- 
oughly equipped Californian mill one of the triumphs of modern 
mechanical metallurgy.’' 

An interesting field of ingenuity concerns itself with giving 
work the right start and a simple path. A tear in a sheet of paper 
accurately follows the line of a directive crease. 
Directive Paths. Postage stamps, small as they arc, we readily 
detach from one another because perforation'^ 
give direction to the tearing strain. So the quarryman takes cao 
to cut a V-shaped groove in the rock he is to break, along whicli 
groove the break takes its way. A bolt when over-strained will 
break in the thread, whether this be the smallest section or not, 



because the thread is a starting point for a parting. A rod of 
glass is divided with a slight jar, provided that a groove has been 
filed in its surface. In all this there is shown the importance of 
avoiding in a casting, or forging, such ininute cracks as under 
severe strain may lead to rupture. 

Within the past ten years automatic musical instruments have 
been much improved and are now well established in public favor. 
Not a few teachers of mark use them in their 
schools as a means of familiarizing their pupils The Pianola, 
with the best music. All these instruments af- 
ford an opportunity for expression on a performer’s part ; the ef- 
fects producible by a practiced performer arc remarkable, and give 
color to the prediction that automatic music may have a parallel 
history \vith that of the photograph, which has at last attained a 
truth and beauty which bring it to a rivalry with the art- of the 

From the educational series issued by the /lu)lian Company, 
New York, a few notes from Schumann’s “Traumerei” are here 
given, together with these notes as they ai)])ear on a music roll for 
the Pianola. 

A Pianola is operated by suction, through the exhaustion of air 
from a bellows normally distended l)y springs as .shown in 5 in the 
accompanying illustration. The exhauster is o])erated by the 
pedal 1 ; the board 3, with its .small bellows, exhausts the air from 
5 in the chest 7 by a series of valves not .shown in detail. When 
the air is pumped from 5 by tbe motion of exliauster 3, this bel- 
lows collapses notwitlistanding the retractile spring 6. The ex- 
haust condition may now operate upon any chamber of the whole 
mechanism through trunk 7 and pii)c 8. When a ])erf oration in a 
music sheet 16 passes over its corre.sponding duct in tracker 15, 
air is admitted through tube 14, which relieves the diaphragm in 
chamber 9, made of a very thin piece of leather, upon which rc.sts 
the stem of valve ii. Owing to the suction in chamber 9 this 
diaphragm instantly raises and shuts the outer j)ort 23 by means 
of valve IT, giving a free communication from pipe 8 through 
chambers 9 and 12, to the striking pneumatic 13 which collapses, 
and through pitman 19 and finger 20 strikes the key. As soon as 



the iiiipcrforated part of the music sheet has passed over the hole 
15 in the trackerboard, the flow of air throuj^h pipe 14 is cut olT 

and tlie ])ressure on the small diaphra.t^m in chamber 9 has ceased 
to be operative, and valve i 1 immediately drops and allows air to 

fjke off pedal. 

(b) ry Lme. 

(c) /y.yr. 

(d) A/’w.'.w; Afj.'As 
( e) A < ■ / / I ’ft'e.'af.'cna. 

1 , i orphraac’nL'mbc.y correspond, to numbers nn music. 

First notes of the “Traumcrei” on a Pianola roll. 


pass into striking* pneumatic 13, through port 23, so that pneumatic 
1 3 and the key levers come back to their normal positions. 

Much self-acting machinery employs electricity. By virtue of 
this wonderful agent the Automatic bdectric Company of Chicago 
instals telephonic systems which enable a sub- 
scriber to connect himself directly with any 
other subscriber, without the intervention of an 
operator at the central station. As exemplified in large exchanges 
such as those of Dayton, Ohio, and Grand Rapids, Michigan, the 
apparatus is complex in its detail. If we take a small exchange. 



To Cal ling Phone To Calling Phone td Calling Phone 

Before calling. Calling the fifties. Calling 58 from among the fifties. 

Automatic telephone. Automatic Electric Co., Chicago. 

Automatic Hi.kcikic Co., Chicago. 



such as that of a village with loo instruments, wc may readily 
understand the main principles of the method. Let us suppose 
that No. I of our instruments is at the Post Office, where the 
I ’ostmaster^wishes to call 58. With a finger he moves hole 5 in the 
dial plate of his calling instrument (see the page opix)site 336 ) 
until it touches a protruding stud. Then he lets go, when the dial 
returns to its original position. In returning it sends five impulses 
to the central office where a vertical rod is lifted five notches (see 
illustration, page 336. He next moves hole 8 to the stud and lets 
go. This time the rod turns through a considerable part of its 
semicircle of motion. The instant its journey is at an end a tiny 
metallic arm Hies out and connection is completed with a wire run- 
ning to 58, ringing his hell. In case he is busy, a buzzing noise 
will be heard in telephone No. 1. The switch mechanism which 
comes into play in all this is .simple. There arc ten rows of 
switches, ten in each row ; the lowest row runs from i to 10, the 
next from 11 to 20, and so on. The upward motion of the vertical 
rod in our example brought it to the fifties; the turning motion 
decided that out of these fifties switch 58 should be connected 
with No, I. When a conversation ends, hanging u]) the receiver 
sends a current over lx)th wires of the circuit so as to release the 

selector rod, which returns to its original position. 

Tf instead of a village wc have a fairly large town, with an ex- 
change of 1000 subscribers, a call for let us say 829 will involve 
taking to the stud first hole 8, then hole 2, and lastly hole 9. And 
so on for exchanges still larger. The pioneer inventor in auto- 
matic telephony was the late Mr. Almon B. Strowger. 

From triggers electrical we now pass to. triggers chemical. A 

gun may be charged with powder and remain for years perfectly 

at rest until a touch on the trigger explodes the 

powder with tremendous effect. The example Chemical 


is typical : nature and art abound with cases 
where a little energy, rightly directed, controls energy vastly, per- 
Iiaps infinitely, greater in quantity. Often in a chemical comixHind 
the poise of attraction is so delicate that it may be disturbed by a 
breath, or by a note from a fiddle, as when either of these induces 
iodide of nitrogen to explode. A beam of light works the same 
result with a mixture of chlorine and hydrogen. One of the most 



familiar facts of chemistry is that a fuel, such as coal, may remain 
intact in air for ages. Once let a fragment of it be brought i > 
naming heat and all the rest of the mass will take fire too. Inm 
has a strong affinity for oxygen, but for union there* must be ,1; 
the beginning some moisture with the gas; the same is true ot 
carbon. A burning jet of carbon monoxide may be cxtinguisli( <l 
by plunging it into a jar of dried oxygen. Gases from the thro.n 
of a blast furnace, at a tem])erature of 250° to 300” Centigrade 
are not inilammable in the atmosphere until the air is moistened In 
steam or otherwise. Then in a Hash combustion begins in earnest. 

In ])hotogra]diy we meet with similar facts: violet rays ma\ 
begin an im])ression which yellow light can finish and finish onl\. 
Vulcanite is trans])arent to red ami infra-red rays which, althoiigli 
without action uj)on an utiexi)osed plate, are capable of continuing 
the action of actinic rays upon a plate wliich has been exposed for 
a very short time. 

h'rom t)liotograi)hv let us pass to a glance at the atmospheric 
conditions which greatly affect its work. The weather from day to 
(lay de])ends upon factors so variable and 1111- 
Why Weather stable that prediction beyond twenty-four honr^ 
is Uncertain. is unsafe. ‘‘Suppose a stratum of air,” sa\- 
Professor Ikdfour Stewart, “to be very nearl\ 
saturated with aciueous vapor; that is to say, to be just a little 
ab('>ve the dew-])oint ; while at the .same time it is losing heat but 
slowly, so that if left to itself it would be a long time before 
moisture were de])()sited. Now such a stratum is in a verv delicate 
state (’jf molecular eciuilibrium, and the dropping into it of a small 
crystal of snow would at (nice cause a remarkable change, ddu 
snow would cool the air around it, and thus moisture would b- 
deposited around the snowflake in the form of fine mist or dew. 
Xow, this deposited mist or dew, being a licpud, and giving out all 
the rays of heat possible to its temperature, would send its lu'.i’ 
into emi)ty space much more rapidly than the saturated air ; there 
fore it would become colder than the air around it. Thus more .lii 
would l)e cended, and more mist or dew de])(3sited ; and so < ” 
until a com]dete change of condition should be brought about, b 
this imaginary case the tiniest possible flake of smnv has pulK-' 
the trigger, as it were, and made the gun go off,— has altered con 



plctely tlic whole cTrrani^^cincnt that iiii^ht have gone on for some 
time longer as it was, had it not been for the advent of the snow- 
llake. We thus j^ee how in our atmos|iliere the presence of a con- 
densable liquid adds an element of violence, and also of abruptness, 
amounting to incalculability, to the motions which take place, 
riiis means that our knowledge of metecuological jihenomena can 
never be mathematically com])lete, like our knowledge of planetary 
motions, inasmuch as there exists an element of instability, and 
therefore of incaleulability, in virtue of which a very considerable 
change may result from a very small cause.’’ 

Tn view of the inherent difficulties it is certainly creditable that 
the predictions of the Idiited States W\\Tther lUireau should prove 
true six times in seven, greatly inuring to the safety of mariners, 
of passengers by lake and sea, and to the saving of crops under 
threat of destruction bv storms. 



Simplicity always desirable, except when it costs too much . . . Taking 
direct instead of roundabout paths. Omissions may be gainful . . . 
Classilication and signaling simpler than ever before. 

I ^OR a simple task the inventor's means shoukl be as simple as 
possible. Mr. J. J. Thomas in his '‘Farm Implements*’ 
says : — 

"After a trial of a multitude of implements and machines, we 
fall hack on those of the most simple form, other things being 
e(|ual. The crow-bar has been employed from 
tinic immemorial, and it will not likely go oiit simplicity of 
of use in our day. F'or sim])licity nothing ex- Build Desirable, 
ceeds it. wSpadcs, hoes, forks are of similar 
character. The plow, though made up of parts, becomes a single 
tiling when all are bolted and screwed together. For this reason, 
with its moderate weight, it moves through the soil with little diffi- 
culty-turning aside for obstructions, on account of its wedge 
form, when it cannot remove them. The harrow, although com- 
posed of many jiicces, becomes a fixed, solid frame, moving on 
through the soil as a single piece. So with simpler cultivators. 
Contrast these with Pratt’s ditching machine considerably used 
some years ago, hut ending in failure. It was ingeniously con- 
structed and well made, and when new and every part uninjured, 
worked admirably in some soils. But it was made up of many 
parts and weighed nearly half a ton. These two facts fixed its 
doom. A complex machine of this weight moving three to five 
feet per second, could not strike a large stone without a formidable 
jar, and continued repetitions* of such blows bent and deranged 
the working parts. After using a while, these bent portions re- 
tarded its working; it must be frequently stopped, the horses bc- 




coming badly fatigued, and all the machines were finally thrown 
aside. This is a single example of what must always occur with 
the use of heavy complex machinery working in the soil. Mowing 
and reaping machines may seem to be exceptions. lUit they do 
not work in the soil, or among stones ; but operate on the soft, 
slightly resisting stems of plants. ICvery farmer knows what be- 
comes of them when they arc rejieatedly driven against obstruc- 
tions by careless teamsters.” 

In discussing form we saw that simple shapes, such as those of 
sticks cut. from a cylindrical tree, are not so strong as the less 
simple forms of hollow cylinders.- We found 
that a joist, of plain rectangular section, is not Simplification 
so good a burdenbearer as a girder whose sec- Has Limits, 
tion resembles the letter 1. 1 f a slide for a 

timber is to be built on a mountain side, a novice would suppose 
that a straight inclined i)lane would alYord the speediest path for 
the descending wood. Not so. More speedy is a slide contoured 
as a cycloid, the curve traced by a pencil fastened to the rim of a 
wheel as the wheel rolls along a floor beside a wall against which 
the pencil presses. 

Not all tasks arc simple, so that it is often best to build and use 
a machine as complicated as a turret-lathe or a Jaccpiard loom. 
Whatever the inventor seeks first, last and all the time is Itcon- 
omy; to that end he adojits whatever means will serve him best, 
whether simple or not. Professor A. 1*. W. Kennedy, famous as 
a teacher of machine design, says: — 

“Simplicity docs not mean fewness of parts. Reuleaux showed 
long ago that with machines there was in^ every case a ])ractical 
minimum number of parts, any reduction below which was accom- 
panied by serious practical drawbacks. Nor is real simplicity in- 
compatible with considerable apparent com])lexity. d'he purposes 
of machines being continually more com]dex, simidicity must not 
be looked upon as absolute,' but only in its relation to a particular 
purpose. There are many very complex-looking pieces of ap- 
paratus which work so directly along each of their main branch 
lines that they are in reality simple. It is usual that the first 
attempt to carry out a new purpose results in a very complicated 
machine. It is only by the closest examination of the problem, the 



at its very essence, that tlie machine can be simplified. 
If a problem is only soluble by extremely complicated ai)paratu>, 
it becomes a cjucstion whether it is worth having. Closely allied 
t(j simplicity is IJirectness. Certain transformations are unavoid- 
able, but the fewer the better. In some cases they may be as in- 
dispensable as the abused middleman in matters economic. In the 
first machine to do something mechanically hitherto done 1)\ 
hand, the error is often made of trying to imitate hand-work 
rigorf)usly. 1'he first sewdng-machine was, [ believe, made in 
stitch in the same way as a seamstress. It was not until a form 
of stitch suitable for a machine, although unsuitable for the hand, 
was devised, that the sewing-machine w’as successful. The fir<i 
railroad carriages were ])ractically stage-coaches put on truck'^. 
from which tlu* ])resent carriages have only very slowly been 

A few years ago it was usual to attach pumps, dynamos, and 
other machinery to their actuating engines by pulleys an I belts. 

'To-day in most cases the connection is direct : 

Directness. all the energy which would be absorbed by iiUei ' 
vening wheels and leather is saved, fn steam 
turbines one and the same shaft carries the steam-vanes and the 
armature of an electrical generator. In saw^-mills (^f modern de- 
sign a very long steam cylinder is provided with a ])iston direcll\ 
attached to the saw carriage. The same principle gives high 
economy to the steam hammer and t)ile-driver of Nasmyth, flani- 
incrs, drills, cutters and other tools driven by comj)ressed air are 
directly attached to the rod which holds the ])iston. In like man- 
ner Saunders’ channeling machine, actuated by steam, has its cut- 
ters attached to its ])iston, so that a blow' is dealt with no inter- 
vening crank-shaft, lever or spring. 

Direct, too, is the binding machine for magazines and cheai 
books, w'hich sim])ly stitches with wire the w'hole together at the 
hack, as if so many thicknesses of cloth. With the same imnie 
diacy w'e have w'all-])aj)ers printed directly fnun the oak or mapk 
they are to represent. Indeed, veneers are now' so cheap and goo<l 
as to be used instead of paper as w’all coverings. In the province' 
of art Air. Hubert Herkomer has accomplished a notable feat it! 
the way of directness, dispensing wdth the. camera, or any of the 



oicher's prcliiiiinaries of biting* or rocking. I To paints in mono- 
chronic on a copper plate as be would on a jianel cn* canvas, covers 
his painting with fine bronze powder to harden the surface, from 
w hich he then takes an electrotype. 

A supreme feat of directness was the invention of a machine 
which relates itself to art, seience and business, the phonograjih. 
i'orty years ago Faber constructed a talking machine of bellows 
lo imitate the lungs, with an artificial thn^at, 1aryn\, and lips 
affording a weird and faiiUy imitation of the voice, h'dison, bid- 
ding sound-waves inijiress tliemselves directly on a tilastic cyl- 
inder, reproduces human tones and other sounds with vastly belter 
thTect. Faber sought to copy the method of voice production, 
h'dison set himself the task of taking tones as ])rodnced and 
making them impress a surface from which they can be reiieated 
at will. 

A lamj) commonly used by camjiing jiarlies, and wtdl worthy 
of wader emploMiient, is <at once a source of beat and light; while 
it b(.)ils a kettle it sheds an ample beam n])on 

one’s table or book, just this union of two 
services may be found in the crude lamp of 
the Eskimo. 

Which Pay a 
Double Debt. 

Many jirocesses of manufacture once sejiarate are now united 
with economy of time and ])o\ver. Steam cylinders for mangling, 
ironing and surfacing paper, effect smoothing and drying at out) 
operation. (Ireen lumber for making furniture is bent and st'a- 
soned at the same time. Wire is teinjiered as drawn. A{ first 
rellectors wa're distinct from laiujis ; in an exeelkait form of in- 
candescent bulb the u])per part of the container is silvered, in- 
creasing the efficiency of reflection in decided measure, as shown 

on page 75. 

Sometimes an indirect path is better than a direct course; or, 
as the sailors say: “d'he longest way round is the shortest way 

there.’’ We can readily measure the contents 
of solids wdiich are regular or fairly regular of 
outline. It is easy to com])ute or estimate the 

Solid Contents. 

contents of a stone as hewm by a mason to form part of a wall, but 

to find the volume of a rough boulder by direct measurement is too 

difficult a task to be w'ortb while. Let us have recourse, then, to 



an indirect plan which goes back to Archimedes : it will remind us 
of how the casting process evades the toil of chipping or ham- 
mering a mass of metal into a desired form. We take a vessel 
of regular shape, preferably a cylinder, duly graduated, ami 
partly fill it with water. Any solid, however irregular, immersed 
therein, will at once have its contents declared by the height i<. 
whic\^ the water rises in its container, the water-levels before and 
after the immersion being compared. Incidentally we here liavr 
a means of ascertaining specific gravities. Weigh this body be- 
fore and during immersion ; comparison of the two quantities will 
tell the specific gravity of the body, that is its density as compared 
with that of water. For example a mass of iron which in air 
weighs 7.75 pounds will in water weigh 6.75 pounds, so that tlie 
specific gravity of iron is 7.75, the difference between the two 
weights being unity. 

Sometimes we wish to know the solid contents of a body which 
will not bear immersion in water; a mass of gum, for instance. 
In such a case we immerse the body in a graduated vessel filK'd 
with fine dry sand, carefully sifted free of' hollow spaces. Fotli 
before and after immersion the sand is brought to a level which 
is carefully noted. The difference bct\vcen these levels, measured 
in. the graduations of the container, gives the solid contents of 
the immersed body. 

The degree in which a crystal, or a particular kind of glas‘^, 
bends a beam of light is usually measured by giving the cry.stal or 
glass the form of a ])rism, through which ray^ 
arc sent. Sometimes a crystal is so small and 
irregular that this method is not feasible. Tliei; 
the iiKpiirer resorts to an indirect plan. He immerses the crystal 
in liquids which he mixes until the crystal disappears through 
ceasing to bend light differently from the surrounding bath. H<^‘ 
then fills a hollow glass prism with this liquid, and in noting 
refraction he learns that of the immersed crystal. 

A fresh eye, wdth a keen brain behind it, often detects wasted 
work in a process long sanctioned by tradition. At the Tamarac 
Copper "Mine, in Northern Michigan, some new ore-crushers were 
needed in 1891. Among the engineers who sought to furni'^h 
these machines w^as Mr. Edwdn Reynolds, of Mihvaukee, wdio^e 





iniprovcnicnts of the Corliss have made him famous. That 

he mii^ht see ore-enisliers at work for the hrst time in his life, he 

visited the Tamarac mine, lie observed that 

the stamps were built on an immense bed of Omission of 

c'^ostly timbers and rubber sheets, sujiposed to Elements 

lie indispensable to efficiency. Ilis eye, unwarjK'd 

l)v harmful familiarity, utterly condemned this elastic foundation. 

Ite at once proposed to discard both timbers and rubber, and rear 

I ilcnkinsop's lormnotivo, i«Sii. 
Alicldk’ton Colliery, near Leeds, hjii4land. 

new crushers directly on a vast block of soli<l iron. This heresy 
<[uite shocked the directors of the Tamarac C'ompany; they stood 
out ai^ainst Mr. Reynolds’ ])lan for two years. Then, with pro- 
found mis^iviiii^s, they allowed him to erect a slam]) of the 
cheap and simple pattern he had sugg;ested, so laying the iron bed 



that, in case of its expected failure, work would be delayed not 
more than two days. Up went the Reynolds’ stamp, and out 
poured sixty per cent, more crushed ore than from a preceding 
machine using the same power. Instant by instant its energy was 
wholly exerted in crushing rock, not largely in the useless conl- 
pression of an enormous elastic bed. 

Long before there was any Tamarac Mine, inventors had both- 
ered themselves providing for difficulties as imaginary as tliose 
v/hich, at vast outlay, were met by the timber underpinning of 
old-time bre stamps. In 1825 the builders of locomotives at 
Easton, in England, provided their engine-wheels with teeth which 
worked into racks with corresponding projections. They were 
afraid that a smooth wheel on a smooth track would slip without 
onward motion. Their unnecessary gear was discarded when it 
was found that under a heavy engine a smooth wheel has adequate 
adhesion on a rail as smooth as itself. Toothed wheels and racks 
are now only at work on the railroads of Mount Washington and 
other steep acclivities. As James Watt used to say to William 
Murdock, his trusted lieutenant, — ‘‘It is a great thing to know 
what to do without. We must have a book of things to 

be scratched out.” 

Daily newspapers in part owe their cheapness to an omission 
that at first seemed bold enough. l"or many years ])rinting paper, 
made in continuous rolls each of a mile or 
Printers Abandon more, used to be cut into sheets, fed one by one 
Useless Work. to the press. It was a long stride in economy 
when the printer left the roll alone, and let an 
automatic press feed itself from tlie unwinding paper, cutting olT 
a sheet only after the printing. 

A parallel example is recorded in the twin art of telegraphy. 
At first it was believed that two wires were indispensable for a 
circuit. Steinheil showed that a single wire 
Electricity Used suffices if its terminals arc soldered into plate< 

as Produced. buried in the ground. Thus, at a stroke, b\ 

impressing the earth into the service of elec- 
trical communication, he reduced the cost of telegraphic lines hy 
one half. In anotlier field the electrician has given himself a 
good deal of trouble in vain. As it originally streamed from 


voltaic batteries, the electric current bad always a single direction; 
il was, to use a familiar phrase, a direct current. I>ut when Far- 
i;lay invented the first dynamo, and produced electricity from 
! Mechanical motion instead of fn^n more costly chemical energy, 
ilie current was not direct but alternating; that is, its pulses came 
at one iiivStant from the ])ositive pole, the next instant from the 
negative. Inventors took great ])ains in devising apparatus to 
ronvert these alternating pulses into a direct current such as that 
\iclded by a voltaic batterv. To-dav the alternating current for 
many important ])urposes, including trans|)ortation, is employed 
just as it leaves the dynamo. Such a current usually has com- 
paratively high tension, at which transmission is much more 
economical than at low tension, small conductors serving instead 
of large ones. 'Phis advantage in many cases more than offsets 
the loss entailed by reversal of the magnetic field at each alterna- 
tion ; a loss but small wlten iron for the electro-magnets is well 

Roc’ may be so hard as to withstand a drill of the hardest 
steel; then the engineer ])ours an acid of the necessary dissolving 
power. A water pijte may freeze at a j)oint 
difficult of access; it is thawed by the warmth Short Cuts in 

created by an electric current. A surveyor has Engineering, 

to reduce to sejuare feet the irregular area of a 
factory site or a garden plot; around the edge of his diagram he 
runs a ])laninieter, it tells him automatically what surface it has 
surrounded in its excursion. If he has no planimeter, a delicate 
balance will serve just as well, him take a i)iecc of paper, 
uniform in thickness, and cut it into the shape of the area in 
([uestion. In weighing the diagram with care he learns its super- 
ficies because he knows the weight of each scpiare inch or foot of 
the paper. Pum])s for ages have exercise<l the wit of inventors 
who have devised wheels, screws, pisUms, and scoo])s of every 
imaginable form. AT. (iiffard boldly discarded all moving parts 
whatever and in his injector, actuated directly by a blast of steam, 
provided a capital means of sending water int(j a bcnler. 

A generation ago engineers of eminence were attempting the 
transmission of energy in a variety of ways. Ko])es and wire 
cables were installed for considerable distances in Germany and 



Switzerland ; in France there was an extensive piping of coni 
pressed air, still in evidence at the capital ; and water under high 
pressure is to some extent to-day employed in London. All thesr 
schemes, together with the old methods within a shop itself of 
taking motion from motor to machine by belt (U* chain, have been 
wiped off the slate by the electrical engineer. W ith a tax of tlK* 
lightest he carries for many miles in a slender wire a current 
whose energy takes any form we ])lease, • not finly mechanical 
motion, hut chemical action, light or heat, f'an simplitication go 
farther than this, or the future hold for us another gift as golden? 

Ilinrlers, reapers, and mowers have irregular surfaces which it 
would t? costly to paint by hand. Even to use the painting ma- 
chine which works by comjiresscd air would 
Printing by he somewhat expensive. In the painting sho]> 

Immersion. of ^ factory both brushes and nozzles are ban- 

ished. The large floor is fitted up with a scries 
of tanks: overhead are the lines of a suspension railway. The 
tanks are filled with ])aint, the articles to l.)e treated are run in on 
the rails, lowered automatically for their hath, and then carried 
off to drip and to dry. In this way a large and complicated agri- 
cultural machine can he ])ainted in a few seconds. WT're deep 
tanks em])loyed, this method would s(|ueeze oil, varnish, or ])aint 
into the ])ores of wood very thoroughly. 

Astronomers suffer much from the inaccuracy of the images 
viewed in their telesco])es in conseciuence of the disturbances in 
the atmosphere, common even in clear weather. 
Churning the Air j observatories have, of late years, been 

^ established at ,\re(juipa, Peru, and at other sta- 

tions where the atmosphere is calm and little 
disturl)cd by currents. On investigation Professor S. P. Lang- 
ley, of Washington, discovered that a good deal of the perturba- 
tion of telescopic images arises from currents within the tele- 
scojuc tube itself. As a remedy he adopted the heroic, yet simjde. 
measure of thoroughly stirring uj) the air in the tube by a bknver 
or other suitable means. Its air, thus brought to uniformity oi 
condition, yielded images much clearer than those equally ob- 
tained. Especially convincing in this regard are capital photo- 
graphs of artificial double stars wh.ose beams were entirclv con- 



fined within a horizontal tube in which they traveled to and fro 
through no less than 140 feet of churned air. These pictures 
showed that the disturl^ance within the tube itself ap])eared to be 
wholly eliminatcci by the device of vigorously stirring the air 

This recalls a method of shipping pianos in refrigerator cars. ' 
rhe instruments are carefully brought to the tem])eralurc of the 
car, which is maintained at about zen^ CTntigrade. When the 
pianos arrive at their destination they are slowly warmed to the 
temperature of common air. Xo matter how long they have been 
cold, they suffer no hurt : for it is not cold, or moderate elevation 
of temperature, that does harm so much as uneasy i1uctuati(^ns 
from one to the other. 

When one visits a public library, the title of a particular book 
is foiuul in the catalogue in a moment, livery Ix^ok as ac(juired 
has its title written on a card, and thousands of 
such cards are ])laced in ali)habetical order, just Replace B^*oks 
like the words in a dictionary. thousand 
cards or so l)egin witli “A,” and are ])lac('d in a drawer marked 
“A,” which stands first in the case, and so with the rest, 'fhere 
is always room to spare in each drawer, so that when a card for 
a new book comes in there is sjiace for it. It was a happy thought 
of a Dutch inventor when he thus made an index which can al- 
ways bv. alphabetical, easily added to or snl)tracted from, sinijily 
because its leaves are mere cards with the liinding of a common 
index omitted. In libraries the catalogue-cards are of 

standard sizes, so also are the drawers in which thesi‘ arc' dis- 
posed. In fact library-furniture of all kinds is to-day thoroughly 
standardized in its styles and dimensions, making it easy to fit 
up or to extend a library whether ])ublic or private. 

The use of cards, or slips for like purposes, has jiasst'd from 
the library to the business office, the study, the housekeeper’s ‘ 
desk. Merchants keep their customers’ names on this plan, so as 
to send them ])nce lists fnan time to time. Depositors in banks, 
policy-holders in assurance companies, tenants of real estate in 
cities, members of clulis, are all recorded in this sim])le and 
accessible fashion. Some great manufacturing houses re- 
ceive a million letters in a twelvemonth ; an adaptation of the 



card-index makes any single letter accessible in half a minute at 
most. To an extent which steadily grows, the same plan is ousthig 
the old-fashioned ledgers from our offices ; in their stead we are 
now using series of movable leaves which are removed when 
filled, giving place to new leaves in an unbroken round. 

A good many readers make notes as they go. If these arc 
written in books they soon become so numerous, so various of 

topic, as to demand laborious indexing. It is better to lake the 
notes in a form which will index itself. Slips of good paper can 
be bought at low cost, and, as in the accom])anying illustration, 
“Astronomy,” “Cdass,” “Photography,” or other headings may 1 h' 
adopted. All the slips under a given head are nnnibered con- 
secutively. Kept on edge in a shallow box, or tray, they are scll- 
indexing, and a new slip takes its proper ])lace at once. From its 
compactness this kind of note-kee])ing puts a premium on tin* 
abbreviations which suggest themselves in a special study. 

A card system employed as a catalogue, or for account keeping, 
is made up of simple units which may be added to or dednctc<i 
from with utmost ease. They may be manip- 
Unit Systems. nlated as readily as the bricks, all alike, with 
which a child builds a house, a box, or a steeple. 
This principle a few years ago was extended to book-cases, each. 



about a foot high and about thirty-three inches long; while each 
formed a unit by itself it could be combined with other such units 
to furnish forth a library. 

This plan had been adopted 
for office furniture of all 
kinds, — cabinets in which 
papers may be filed away, or 
which arc divided into 
pigeon-holes for blanks and 
the like. In some handsome 
designs a unit unfolds as a 
small writing desk, while 
adjacent units contain draw- 
ers of various si/x's. F.ach 
unit is so moderate in di- 
mensions as to be readily 
portable; a dozen, a score, a 
liundred may be joined to- 
gether to equip a sitting- 
room or tlic cashier’s office 
in a bank. 

When an American visits 

London for the first time, he Sectional l.o..k-case, desk, 

may fall into an error which and drawers, 

will much ]irovoke him. Sup- 
pose that he has to call at 457 Strand. He begins at number i 
in that thorough fare, and proceeds a goodly distance when, to his 
dismay he observes that the numbers he is 
passing on his right are .strictlv consecutive,-— Numbering as a 
100, loi, 102 and so on. A weary trudge 
brings him to 457, opposite number T, whence he started. That 
odd numbers should be on one side of the street, and even num- 
befs on the other, did not occur to the .city fathers of Lx)ndon 
centuries ago. In this regard a forward step was taken in Pliila- 
dclphia, where the streets parallel with the Delaware River arc 
First, Second, and so on, while each house on the streets crossing 
them from the river westward is so numbered as to tell between 
what streets it stands. Thus, when we walk up Chestnut Street, 



the first door above Ninth Street, on the right, is 901, althougli 
the house next below it, across Ninth Street, is 839; and so (jn 
witli all parallel streets. If the thoroughfares in Philadelpliia, 
running at right angles to the Delaware River, were labeled ave- 
nues, and consecutively numbered, the system would be a troubk- 
saver indeed. 

In New York the cross streets as they run east or west of 
h'ifth Avenue are named east or west. In crossing each aveiuu' 
eastward or westward the numbers jump to the next wbok- 
hundred, as in Jdiiladelphia. The building at the southwestern 
corner of Third Avenue and bkist 23rd Street is 162; that on [hr 
eastward corner, opposite, is 200. Thus in cross streets the nniii 
her of a house tells ns between which avenues it will be found. 

In hotels and office-buildings, tbronghont America, the nnni- 
bering greatly aids an in([tiirer. Room 512, for example, will be 
found on the fifth door; immediately beneath is 412 on the fourth 
lloor ; directly above is 612 on the sixth iloor, the first figure al- 
ways denoting the lloor. 

A ca])ital use of mimerals to convey information is that devised 
by Melvil Dewey, formerly State Librarian of New York at 
Albany. I le divides literature into ten great 
Classifying Books, departments, giving each of^them one of tlu‘ 
ten numerals. History, in this scheme, is rep- 
resented by 9 as the first figure in the number of a book; the sc'c- 
ond figure refers to the geograjihical division to which the work 
belongs, thus 7 means North America ; the third figure standing 
for the jxditical division treated by the book, i representing [hr 
British Empire. A work on Canadian history, therefore, will bear 
as its number, 971. 

Everybody knows what a money-saver is the familiar code of the 

ocean cables, by which “behygged” stands for “Will the property 
be advertised for sale?” reducing the toll b\ 

An Advance in 

the cost of six words. ]\lost of the terms in a 
code are not dictionary words, but such colloca- 
tions of letters as “carthurien” and “brank- 

strop.” A new code devised by .Mr. Charles G. Burke, of New 
York, proceeds upon the use of four numerals, i, 2, 3, 4, wbiick 
he transmits in the fewest signals possible to a cable, i is a dot ; 2 

HUHlvE CODE 353 

a dash, 3 a dash-dot ; 4 a dot-dash. This is how they look when 
received on ]:)aper in comparison with ordinary messai;*es 

o 00 0000 00 00 0000 O 00 I 

000 o* o a 00 oool 

Ach uchado 

Present code. Automatic transniitliiiij: strip. 

Achuch ado 

Signals received from above strip. 

I 3 2 I I 4 3 2 

Burke code, d'ransmdtint; strip. 

I 3 2 I I 4 3 2 

Signals received from al)ove strip. 

12 3 4 

TIu' Iiiirke mimerals 

forming the permutations. 

4 2 2 13 3 2 

A Burke comljination of 8. 



It is the separate signal with the time consumed in its trans- 
mission which is the real unit of cost. The codes now in use em- 
ploy words whose letters, as signaled, demand more than twicr 
the time required by the Burke system. Thus 4221332, as trans- 
mitted by Mr. Ikirke, means “Advise creditor to prove claim and 
accept dividend,” for which but ten signals suffice. In the co(k^ 
now in the hands of the public, an average word of seven letters 
would C(3ntain twenty -three signals. How wide is the variety of 
sentences possible in the new method? If the numerals are em- 
ployed in permutations of seven figures, as 1342423, a Burke code 
will contain 16384 sentences; in permutations of eight figures, 
four-fold, and in permutations of nine figures, sixteen-fold as 
many, or 262,144 sentences, a variety much more ample than that 
of any other system. Atr. lUirke finds that an average code mes- 
vSage has 8 letters to a word, each word requiring about 25 elec- 
trical impulses in transmission ; an average permutation on his 
system does not demand more than 10 impulses. 

Air. Burke has also devised a capital mode of simplifying tel- 
egraphic signals of all kinds. A messagcMii the usual Alorsc code 
has dots, dashes and spaces, each produced by depressing a key 
for a short, a long, or a longer ])eriod. Air. Burke interrupts a 
current with a key solely with dot-intervals ; the periods during 
which the current is unbroken are, according to their length, dot- 
signals, (lash-signals, or spaces : — 

BurkeAl 1 

D otMo rse 

Continental Alorse Code. 



luliicatcd guessing . . . Weaving power . . . hnagination indispensable 
, . . The proving process . . . Theory' gainfully directs both observation 
and experiment . . . Professor 'Fyndairs views . . . Discursiveness illus- 
trated in Thomas Young. 

\ S far back as the first man with brains in his head, there was 
X V an ache to know why the sim shone, the stars twinkletl, the 
winds blew, why harvests here were plentiful and there vSeant. 
The whole burden of witchcraft, of fetichisin, of beliefs in voo- 
doo, is a pathetic proof gf this human loiyi^in.^' 
to explain. What, after all, are suporstiti('>ns Theories as 
but premature ex])lanations that overstay their Finder Thoughts, 
time? When men of thought get a glimpse of 
an interpretation really true, they are eager to prolong that 
glimpse until it becomes a survey whose due tests confirm and 
buttress a well grounded anticipation. This ex])loring process 
reminds us of what took ])lace long ago when an architect of un- 
exampled boldness first imagined a dome for a temjile, and 
brought his dream to fulfilment. 1 le began by rearing a single 
arch, fairly strong;, yet hardly strong enough; a second arch arose 
to meet the first at their comnuu! crest ; now, in mutual su])j)ort 
both had a stability neither could display alone; at last when the 
wall had gone full circle it had a strength vastly greater than 
lliat of any ])art by itself, d'he long-admired arch had indeed 
become no more than an clement to be joined with other arches to 
ereate a unit of an cualer distinctly higher. 

b'or ages the men who studied nature looked u])on it as little 
changed since it left its Maker’s hand. Of infinite stimulus was 
the perception that it is a drama, not a tableau, which spreads it- 
self before the eye. Speedily and with incomparable instruction 




it was traced how every actor in that drama had been molded 
by the part it had played in maintaining itself upon the stage (jf 
life. Every rival, parasite or foe, every stress of climate, w;,s 
studied in its influence on food or frame, while the ever-threat- 
ened doom for irresponsiveness was the extinction which befell 
countless forms once masters of the earth. No hue of scale or 
feather, no barb or tusk, no curve of beak or note of song Init 
served a i)urpose in the plot or advanced the action in soynic con- 
flict to the death. When Darwin was confronted in plant or bea^t 
by an organ or a habit which puzzled him, he \\^is wont to ask, 
What use can this have y\nd seldom was the question asked 
in vain, lie laid great stress on the directive worth of a well- 
considered theory. I le tells us, “I am a firm believer that without 
s[)eculation there is no good and original d)scrvation.’’ In a letter 
he remarks, “Jt is an old and firm conviction of mine that the 
naturalists who accumulate facts and make many partial general- 
izations are the veal benefactors of science. Those who merel\ 
accumulate facts I cannot very much respect.’’ 

In rising from facts to explanations a weighty debt is due to 
'modern aids to eyes and hands. To men who knew only what 
direct vision coidd tell them in a single life-time, it was but na- 
tural to repeat : — “'fhe thing that hath been, is that which- shall he: 
and that which is done, is that which shall he done; and there is 
no new thing under the sun.” lUit we of to-day arc in diffcreni 
case, d'he astronomer, joining camera to telescoi)e, lengthens the 
diameter of the known universe a thousand-fold; he discovers 
system after system in st^iges of life such as our sun and’ its at- 
tendant orbs have passed through in ages so remote as to refuse 
computation. And many types of nebulae and stars are innv 
studied which were never so much as imagined, until they re- 
^'ealed themselves uiH)n the idiotogra])hic ])late. Meanwhile the 
geologist, examining the closely welded ribs of our globe, coin- 
paring the birds, beasts and men of to-day with their earliest 
known ancestry, believes that the earth has been a vSccne of life for 
a million centuries or more. As we restore one act after another 
in this great cosmical drama, we arc able to forecast those which 
may next appear. i>ecause the whole scheme of things from 
centre to rim pulses in one ethereal ocean, every actor has inter- 



play with every other, so that the sweep of events discloses a unity 
all the more intimate the more closely it is studied. At this hour 
phvsicists and chemists, with electricity their new servant at com- 
iiiand, are i^atherinor pn^of that what have lonj^ been called “ele- 
ments,” arc ])rohahly one suhst'anee, variously assembled, inovini;’ 
at speeds and in paths infinitely diverse, repeatini;- in little the 
mic^hty swinj^s af suns and planets. ThrouLfhout these researches 
a constant sjiur is the thoui^ht that here may he traced such pro- 
cesses of development as have been laid hare in every other pro- 
vince of nature. From circumference to centre, evolution, is the 
master key of each keen (|uestioner. 

( )r<^anic nature to the modern interpreter is thus alive throui^h 
and through. In his view ah^m and. mdecule are also alive in a 
subordinate, elemental degree. Indeed, he 
thinks, it is their life borne in air, water and ’'Modern Views 
food which in plant or animal rises to new 
jilaiies of dignity. He looks afresh at the hrokeii aliun crystal 
which repairs itself in a solution, and sees there the removal off the 
imaginary fence which long divided organic nature frojn in- 
organic. (See illustration, ])age 194.) It was a shrewd guess of 
Sir Isaac Newton that the diani/md is combustible; he did not 
suspect it to be carbon, but he knew it to be higbly refrangible as 
are many combustible bodies. Ilis ccnijecture shows him taking 
the first step toward the current view that jirojierties, the modes 
of belKivior of matter, are* not jiassive (jualitics, but are due to 
real activities; that what a substance is depends upon how its 
ultimate parts iiKxve. Clausius and Maxwell in a theory which 
marks a new era explained the elasticity of,gas(‘s as m.'uii Tested in 
the ceaseless motion of tlieir molecules, declaring that an ounce of 
:iir within a fragile jar is able to sustain- the pressure of the atnios- 
l)here around it, because the air, though only an ounce in weight, 
dashes against its container with a;n im])act forcible enough to 
balance the external pressure-. I’roof where(rf a])pears in measur- 
ing the velocity of air as it rushes into a vacuum. 1 1 ere a 
significant point is that in leaving the realm of mass-mechanics, 
where the tax of friction is inexorable, we enter a sphere where 
the swiftest motion may go on forever without paying friction 
the smallest levy. 



Elasticity o.f solids is explained on the siiine principle. If \\r 
swiftly turn a ^yroscppic wheel we can only change its plane ( i 
rotation by an effort, which effort is repai<l 
Elasticity when the n\etal is allowed to resume its original 
Explained. plane of motion. It is imagined that in lik(' 
manner the particles in an elastic spring move rapidly in a definiii- 
plane ; if deflected therefrom- they oppose resistance and are read\ 
to do work in returning thereto. Of kindred to the kinetic theory 
of elasticity is the explanation of heat a distinct and ceaseless 
molecnlar motion (jn which the dimensions of masses depend. It 
has long seeiued- to me that every case of ‘'potential” energy, a> 
that of a' si)ring hent or coiled, may in like manner embody actual 
though impalpable and invisible nrotion. I presented this view in 
tin; L'opular Science Monthly, December, 1876. 

'Flic ve.ry constiliilion of matter is now referred to the motion^, 
highly diversified, of tlie simplest substance ])ossibIe. Ilehn- 
holtz, T.ord Kelvin, and Professrir Clerk Maxwell have imagined 
the molecules of lead, iron, or other element as vortices horn of 
the ether in which without resistance they forever \,vhirl. As we 
see in the case of a ([uickly rotated chain, substantial rigidity is 
conferred by motion sufficiently swift. Nor are molecules with- 
out somewhat of individuality. W'e are wont to think of masses 
of solid iron as jirecisely similar in (piality, but experience show^ 
us that one bar of iron may vary from another by all that has 
differenced the history of the two. A careful workman uses 
a steel d-ie for only a short service before he returns it to the an- 
iK'alcr, well assured that the metal, destiite its seeming wholeness, 
has suffered severe internal strain at every blow, which, were no 
caution exercised, would soon reveal itself in fracture of the die. 
or ruined work, bracts of this kiiuk which every day confront 
the mechanic and engineer, convey a ])ro|f.iecy of the sensibility 
and menuu'v which dawn with life. 

A theory helpful to the observer or the cxi)crimenter comes at, in many cases, from much guesi>ing. ddie theorist fills lii^ 
mind with facts, bnxxls over them, emleavcH*'^ 
to explain them, but whether his theory is true 
or false must be decided solely by proof. Thi^ 
point was clearly stated by Dr. Pve-Smith, of London, in his 

Guesses and 



[hirvcian oration, 1893:— “As Paley jiustly puts it, he only clis- 
( tA'crs who proves. To hit upon a true conjecture here and there, 
amid a crowd of untrue, and leave it again without appreciation 
,)f its importance, is a sign, not of intelligence, but of frivolity. 
W'e are told that of the seven wise men of (Jreece, one (I believe 
it was Thales) taught that the sun did not go around the earth, 
but the earth around the sun. Hence it has been said that 
Thales anticipated Copernicus — a flagrant example (^f the fallacy 
in question. A crowd of idle philosophers who sat through the 
long summer days and nights of Attica discussing all things in 
heaven and earth must sometimes have hit upon a true o])inion, 
if only by accident, but Thales, or whoever broached the helio- 
centric dogma, had no reason for his belief and showed himself 
not more, but less, reasonable than his companions. The crude 
theories and gross absurdities of ])hrenoI()gy are not in the least 
justified or even excused by the present knowledge of cerebral 
localization; nor do the baseless speculations of Lamarck and 
lu'asmus Darwin entitle them to be regarded as the forerunners 
of Charles Darwin. Lp to 1859 impartial and competent men 
were bound to disbelieve in evolution. After that date, .or at 
least, so soon as the facts and arguments of Darwin and Wallace 
had been published, they were e(jually lx)und to believe in it. I le 
discovers who proves, and by this test Harvey is the sole and 
absolute discoverer of the movements of the heart and of the 

Discovery is the reward of diligence, such as that of Harvey, 
but not of diligence alone. Professor William James, in his 
P.sychology remarks: — “The inquirer s, tarts 
with a fact of which he secs the reason, or a 
theory of which he secs the proof. In either 
case he keeps turning the matter incessantly in his mind, until 
by the arousal of associate iqx)!! associate, some habitual, some 
similar, one arises which lie recognizes to suit his need. This, 
however, may take years. No rules can be given by which the 
inv^estigator can proceed straight to his result ; but both here and 
in the case of reminiscence the accumulation of helps in the way 
of associations may advance more rapidly by the use of certain 
methods. In striving to recall a thought, for example, we may 



The Detection 
of Likeness 

of set purpose run through the successive classes of circiiuh 
stances with which it may possilily have been connected, trusting; 
that when the rijj^ht member of the class has turned up it will 
help the thought’s revival. ... In scientific research this ae- 
cumulation of associates has been methodizx'd by Mill as ‘foiir 
methods of experimental inquiry.’ By the method of A^rcc 
meiit, of Difference, of Residues, and of Concomitant Variation.^, 
we make certain lists of cases, and by ruminating- these lists in 
our minds the cause we seek will be more likely to emerge. Ihit 
the final stroke of discovery is only prepared, riot eifected In 
them. Idle brain tracts must, of their own accord, shoot the 
right way at last, or we shall still grope in darkness.” 

Among the talents of the discoverer, perhaps the chief is to 
detect similarity in phenomena which, to casual observation, are 
unlike. Of this the capital example is Frank- 
lin's proof that lightning and common fric- 
tional electricity are one and the same. Jh'o- 
fessor Alexander l>ain, in “The Senses and 

the Intellect,” thus describes this talent: 

^‘When it first occurred to a retlecting mind that moving water 
had a projierty identical with human or brute force, namely, the 
property of setting other masses in motion, overcoming re- 
sistance and inertia — when the sight of the stream suggested 
through this point (.)f likeness the ])ower of the animal — a new 
addition was made to the class of prime movers, and when cir- 
cumstances permitted, this j)ower could be made a substitute for 
the others. It may seem to the modern understanding, familiar 
with water-wheels and drifting rafts, that the similarity here 
was an extremely obvious one. But if we put ourselves back 
into an early state of mind, when running water affected the 
mind by its brilliancy, its roar, and irregular devastation, we may 
easily suppose that to identify this with animal muscular energy 
was by no means an obvious effect. Doubtless when a mind arose, 
insensible by natural constitution to the superficial aspects ol 
things, and having withal a great stretch of identifying intellect, 
such a comparison would then be possible. We may pursue the 
same example one stage further, and come to the discovery of 
steam-power, or the identification of expanding vapor with the 



previously known sources of mechanical force. To the common 
eye, for ages, vapor presented itself as clouds in the sky; or, as 
a hissing noise at the sjxuit of a kettle, witli the formation of a 
foggy, curling cloud at a few inches* distance. The forcing up 
of the lid of a kettle may also have been occasionally observed. 
But how long was it ere any one was struck with parallelism 
of this appearance with a blast of wind, a rush of water, or an 
exertion of animal muscle? The discordance was too great to 
be broken through by such a faint and limited amount of like- 
nCvSS. In one mind, however, the identification did take place, 
and was followed out into its consequences. The likeness had 
occurred to other minds previously, but not with the .same re- 
sults. Such minds must have been in some way or other distin- 
guished above the millions of mankind, and we are endeavoring 
to give an exjdanation of their superiority. The intellectual 
character of Watt contained all the elements prei)aratofy to a 
great stroke of similarity in such a case — a high susceptibility, 
both by nature and education, to the mechanical properties of 
bodies; ample previous knowledge, or familiarity; and indilYcr- 
ence to the superficial and sensational effects of things. It is 
not only possible, however, but exceedingly probable, that many 
men possessed all these accomplishments ; they arc of a kind not 
transcending common abilities. They would in some degree at- 
tach to a mechanical education, as a matter of course. That the 
discovery was not sooner made supposes that something farther, 
and not of common occurrence was necessary ; and this additional 
endowment appears to be the identifying jiower of similarity in 
general ; the tendency to detect likeness in the midst of disparity 
and disguise. This su])position accounts for the fact, and is con- 
sistent with the known intellectual character of the inventor of 
the steam engine.’^ 

A discoverer needs for success much more than identifying 
power. Professor John Tyndall, one of the chief expositors of 
science in the nineteenth century, speaks thus 
of the part played by an investigator’s iniagina- The Part Played 
tion : — by Imagination. 

“How arc the hidden things of nature to be 
revealed ? How, for example, are we to lay hold of the physical 



basis of light, since, like that of life itself, it lies entirely outside 
the domain of the senses? Now philosophers may be right in 
affirming that we cannot transcend experience. But we can, at all 
events, carry it a long way from its origin. We can also magnify, 
diminish, cpialify, and combine experiences, so as to render them 
fit for purposes entirely new. We are gifted with the power of 
' Imaginaticm, and by this power wc can lighten the darkness 
which surrounds the world of the senses. There are tories even in 
science who regard imagination as a .faculty to be feared and 
avoided rather than employed. They had observed its action in 
weak vessels and were unduly im])ressed by its disasters. Ihn 
they might with equal justice point to exploded boilers as an 
argument against the use of steam. Bounded and conditioned In 
co-operative reason, imagination becomes the mightiest instrument 
of the physical discoverer. Newton’s passage from a falling apple 
to a falling moon was, at the outset, a leap of the imagination. 
When William 'riiomson tries to i)lace the ultimate particles of 
matter, between his comi)ass points, and to apply to them a scale of 
millimeters, he is ])ower fully aided by this faculty. And in much 
that has recently been said about i)r()toplasm and life, we have 
the outgoings of the imagination guided and controlled by the 
known analogies of science. Tn fact, without this power, our 
knowledge of nature would be a mere tabulation of co-existences 
and sequences. ^^T‘ should still believe in the succession of dav 
and night, of summer and winter; but the soul of Force would 1 h 
dislodged from our universe; causal relations would disapj)ear, 
and with them that science which is now^ binding the parts of na- 
ture int('> an (U'ganic whole.” 

ih'ofes.sor 'ryiidall also tells us how sound theories are divided 
from unsound : — 


“From a starting-point furnished from his own researches or 
those of others, tlie investigator proceeds by combining intuition 
and verification. He ponders the knowledge he 
Theories Must possesses and tries to push it further, he guess^ - 
be Verified. and checks his guess, he conjectures and con- 
firms or explodes his conjecture. The>e 
guesses and ct^njectures are by no means leaps in the dark; for 
knowledge once gained casts a faint light beyond its own im- 



mediate boundaries. There is no discovery so limited as not to 
illuminate something beyond itself. The force of intellectual 
])cnctration into this penumbral region which surrounds actual 
knowledge is not, as some seem to think, dependent ujx^n method, 
but upon the genius of the investigator. There is, however, no 
genius so gifted as not to need control and verification. The pro- 
foundest minds know best that Nature’s ways are not at all times 
their ways, and that the brightest Hashes in the world of thought 
are incomplete until they have been proved to have their counter- 
parts in the world of fact. Thus the vocation of the true experi- 
mentalist may be defined as the continued exercise of spiritual in- 
sight, and its incessant correction and realization. Ilis experi- 
ments constitute a body, of which his purified intuitions arc, as it 
were, the soul.” 

Theories, however helpful, should be held with a loose hand. 
He declares : — 

“In our conceptions and reasonings regarding the forces of 
nature, we i)erpetually make use of symbols which, whenever 
they possess a high representative value we dignify with the name 
of theories, dduis, i)rompted by certain analogies, we ascribe elec- 
trical phenomena to the action of a ])eculiar Iluid, sometimes flow- 
ing, sometimes at rest. Such conce])tions liave their advantages 
and their disadvantages; they afford ])eaceriil lodging to the in- 
tellect for a time, but they also circumscribe it, and by-and-by, 
when the mind has grown too large for its lodging, it often finds 
difficulty in breaking down the walls of what has become its 
prison instead of its home.” 

In the same vein was the remark of Michael b'araday “I can- 
not but doubt that he who as a mere t)hilosoj)her has most power 
of penetrating the secrets of nature, and guessing by hyix)thcsis 
at her mode of working, will also be most careful for his own safe 
l)rogrcss and that of others, to distinguish the knowledge which 
consists of assumption, by which I mean theory and hyixjthesis, 
from that which is the knowledge of facts and laws.” 

He once wrote a letter on ray- vibrations to Mr. Richard Phil- 
lips ; at its close he said ‘T think it likely that I have made many 
mistakes in the preceding pages, for even to myself my ideas on 
this point appear only as the shadow of a speculation, or as one of 



tliosc impressions on tlie mind which arc allowable for a time as 
{guides to tlKiUj^ht and research. He who labors in experimental 
iiKiiiiries, knows how nnmeroiis these are, and how often their 
apparent fitness and beauty vanish before the proj^rcss and de 
velopmeiil of real natural truth.” 

“.Summint^ u]), then,” says Professor William Stanley Jevons. 
in “Principles of Science,” “it would seem as if the mind of tiu- 
^reat discoverer must combine almost contradictory attributes. I Ir 
must be fertile in theories and hvjjotheses, and yet full of facts 
and precise results of exjierience. He must entertain the feeblest 
analoj^'ies, and the merest j^^uesses at truth, and yet he must hold 
them worthless until they are verified in experiment. W hen there 
are any iLi^rounds of jirobability he must hold tenaciously to an old 
opinion, and yet lie must be prejiared at any m(')ment to reliiujuisli 
it when a sinji^le clear contradictory fact is encountered, ‘ddu 
])hiloso])her,’ says k'araday, ‘should be a man willini^ to listen ti* 
every sui;‘|L;estion, but determined to judj;'o for himself. He should 
not be biassed by appearances; have no favorite hvjxitheses ; be 
of no school; and in doctrine have' no master. Tfe should not Ix' 
a resiiecter of jiersons, but of thini^'s. d'ruth should be his ])rimar\ 
object. If to these (|ualities be addc'd industry, he may indeed 
hope to walk within the veil of the temi)le of Ciature.’ ” 

C haracter, no less than mind of the hii^hest order, ever distin- 
i;'uishes the <»reat researcher. Says Professor "ryndall : — “Those 
who are unac(|uainted with the details of scientific investit^'atiou. 
have no idea of the amount of Irdior expended on the determitUi 
tion of those numbers on which important calculations or in- 
ferences depend. They have ik^ idea of the patience shown by a 
Perzelius in deterniiniiiiL;* atomic weights; bv a Pei^nault in di 
terminiiim' co-efficients of ex])ansion; or of a Jouleun determiniue 
the mechanical eciuivalent of heat. There is a morality broui^bt t 
bear u])on such matters, which, in jioint lof severitv, is j^ndial 1 
witlK^ut a jiarallel in any other domain of intellectual action.” 

Surely there was a union of the hi'^liest character and of con 
suinmate ability in Stas, the Pel^ian chemist, who eliminated fror 
his chemicals every trace of that pervasive element, sodium. ^ 
thoroughly, that even its spectroscopic detection was impossible. 



The greatest man of science that luiglaiul has given to the 
world was Sir Isaac Xewton, second only to him was Dr. Thomas 
Voimg, who established tlie wave-theory of 
light, who deciphered Egyptian hieroglyphics a Word for 
with marvelous skill, and was withal an accom- Discursiveness, 
plished ])hysician. In i8oi he was appennted 
to the professorship of natural philosophy in the Royal Institu- 
tion, London, founded in oSoo l)y Ilenjamin rh(un])son, Ccnuit 
Rumford, a native of \\'ol)urn, Massachusetts. W hen Dr. Young 
(lied, Davies (iilhert, i^resident of the Royal Society, delivered a 
commemorative address in the course of which he declared that 
in ^'(jung’s opinion it is ])rol)ahly most advantageous to mankind 
that the researches. of some in(|uirers slunild he concentrated with- 
in a given coni])ass, hut that others should i)ass more rapidly 
through a wider range. 1 le helieved that the faculties of the mind 
were more exercised, and ])rohal)ly rendered stronger, hy^ g'<>itke^ 
i)eyond the rudiments, and overcoming the great elementary difti- 
culties, of a variety of studies, th:in hy employing the same nuniher 
of hours in any one ])tirstiit that the doctrine of the division of 
lah'or, however api)licahle to niat(‘rial ])roduct, was not so to in- 
tellect, and that it went to reduce the dignity of man in the scale 
of rational existences. lie thought it impossible to foresee the 
capabilities of im])rovement in any science, .so much of accident 
having led to the most im])ortant discoveries, that no man could 
say what might he the com])arative advantage of any one study 
rather than of anotlu'r; though he would have scarcely recom- 
mended the j)lan of his own course as a model to others, he still 
was satisfied in the method which he had pursued. 



Analogies have value . . . Many principles may be reversed with profit 
. . . 1'he contrary of an old method may be gainful . . . Judgnjent gives 
place to measurement, and then passes to new iiclds. 

A CONVICT JON that has over and over a^ain served the dis- 
coverer assures him that like causes underlie effects which 
seem diverse. When Thomas Young- observed the recurrent bands 
of darkness due to interferences of light, he at once detected a 
parallel to the beats by which interferences of 
Gufde^^ ^ sound produce silence. He was therefore per- 
suaded that light moves in waves as does sound, 
that it is not, as Newton supposed, a material emission. A chapter 
might be fdled with examples of the same kind : let one suffice. 

If an ordinaty clothes-line, say twenty feet long, receives a 
wave-impulse from the hand at one end, the motion will proceed 
to the other end as a series of waves. If a rope twice as heavv 
is used, a larger part of the original im|)ulse will be received at 
the remote end than in the first experiment. Of course, there 
conies a limit to the thickness of the rope which may be thus em- 
ployed ; we must not choose a ship’s cable for instance, but the 
rope most effective in results is much heavier than one would su])- 
posc before trial. Lord Rayleigh, in his treatise on the theor> 
of sound, has shown that according to Lagrange it is unnecessary 
to thicken a cord when we wish to add to its weight ; as an alter- 
native we may fasten weights u])on it at due intervals, the wlioU* 
having less mass than if wc used a heavy rope of e([ual effective 
ness. Just what intervals arc best will depend upon the thickness 
and rigidity of the cord, upon its length, the amount and kind ot 
wave committed to it, as shown by Professor ATichael I. Pupin of 
Colum'bia University, New York, who extended the mathematical 
problem dealth with by Lagrange and Lord Rayleigh. In the sin- 




gular efficiency of transmission tints studied he saw a principle 
which, by analogy, he believed to hold true in the electrical field 
as in mechanics. This principle he has illustrated in his paper 
published in the Proceedings of the xVmcrican Jnstitutc of hdcc- 
trical Engineers, 1900, page 215. Tn A of the acec^mpanying fig- 
ure, derived from that paper, is a tuning fork, C, with its handle 

Prof. Pupiii’s diagram explaining his system of long 
distance telephony. 

rigidly fixed. To one of its ])rongs is attaclicd a flexible incx- 
tensible cord, bd. Let the fork vibrate steadily by any suitable 
means. The motion of the cord will be wave motion, as in Ik 
The attenuation of the wave as it dies down is represented in C. 
Experiments show that, other things being equal, increased density 
of the string will diminish attenuation, because a^larger mass re- 
quires a smaller velocity in order to store u]) a given ([uantity of 
kinetic energy, and smaller velocity brings with it a smaller fric- 
tional loss. Moreover, as the string is increased in density, its 
wave-length is shortened. 

Suppose now that we attach a weight, say a ball of beeswax, at 
the middle point of the string, so as to increase the vibrating mass. 
This weight will become a source of rellcctions and less wave 



energy will reach the farther end of the string than before. Sub- 
divide the beeswax into three equal parts and place them at thrci. 
equi-distant paints along the cord. The efficiency of transmission 
will be better now than when all the wax was concentrated at a 
single i)oint. JJy subdividing still further the efficiency will br 
yet more improved ; but a point is soon reached when further sub- 
divisions produce very slight improvement. This ]X)int is reached 
when the loaded cord vibrates nearly like a uniform cord of the 
same mass, tension, and frictional resistance ; such a cord, bearing 
12 small weights of beeswax, is represented as L) when at rest, as 
K when in motion. . . . It is im])ossible so to load a cord 

as to make it suitable for waves of all lengths; but if the dis- 
tributif)!! of the loads satistk‘s the recjuirements of a given \vave- 
length, it will also satisfy them for all longer wave-lengths. 

vV cord of this kind has mechanical analogy with an electrical 
wave conductor. In a wire transmitting electricity inductanci* 
coils may he so placed as to have just the effect of the bits of wav 
attacluvl to the cord in our illustration; in both cases the wave> 
are transmitted more fully and with less blurring than in an un- 
loaded line, 'riie mathematical law of both cases is the same. 
It was in ascertaining that law so as to kianv where to ])lace hi> 
inductance coils that Idrofessor I’upin arrived at success. Pre- 
ceding inventors, missing this law, came only to failure. He con- 
structed an artificial cable of 250 sections, each consisting of a 
sheet of paraffined ])aper on both sides of which was a stri]) of 
tin-foil, the whole fairly representing a cable 250 miles in length. 
.\t each of the 250 joints in the course of this artificial circuit he 
inserted a twin inductance coil wound on one six)ol 125 milli- 
metres broad and high, and se])arated by cardboard 1/64 incli 
thick. I^ach coil had 580 turns of Xo. 20 P>rown & Sharpe wire. 
Just as with the weighted ro])e this circuit transmitted its current 
much more efiiciently than if the inductance coils had been absent. 

This artificial cable, when without coils, through a distance 
ecpial to fifty miles of ordinary line worked well, up to seventy - 
five miles it served fairly well, but proved impracticable at 100 
miles, and impossible at distances exceeding 112 miles: all thi'^ 
in exaer correspondence with an actual line of the same length. 
Over a uniform telephone line an increase of distance interfere.^ 



with the transmission of speech, not only by tliininisliing* the 
volume of sound, hut also from the rapid loss of articulaticm. At 
lirst this manifests itself as an apparent Unverinj^* of vocal pitch. 
In Professor Thi])in\s experiments an assistant’s vcnce at the end 
of 75 miles of uniform cable sounded like a strong baritone; at 
lOO miles it became dnimmy so that it was uiulerstood with diffi- 
culty, although the s]ieaker had his mouth close to the trans- 
mitter, and spoke as loudly as if he were addressing a large 
audience. At more than lu miles nothing but the lowest notes 
of his voice could be heard, the articulation was entirely gone. 
As soon as the coils were inserted the drumminess ceased, and 
conversation could be carried on as rajiidly as one chose llirougli 
the whole circuit of- i u miles. Dnimminess is due to the oblitera- 
tion of the overtones, long distance transmission weakening these 
overtones much more than it does the low fnndanuMital tones. 
The addition of coils makes the rate of weakening tlie same for 
all vibrations, hence the transmitted sound has the same character 
at the end of the line as at the beginning. 

In practice Professor Ptt])in’s method has ])roved a remarkable 
success. In ordinal*}' circuits it reduces materially the ((uantity 
of wire necessary, ^^dlere a circuit is imusnally long it assures 
clearness of tones or of signals at distances ])reviously out of 
the (itiestion. It makes t)ossible telephony across the Atlantic: a. 
cable for this service would cost only one fourth more than an 
ordinary telegrai)hic cable as now laid and tiscal. A decided ad- 
vantage is reai)ed by its tise in underground cabU‘s, liable as they 
are to a serious blurring of currents at distances com])aratively 
short. The intervals at which inductance, taals should be placed 
depend upon the circumstances of each case. These* are dis- 
cussed by Professor Pu])in in the j)ai)er here mentioned. 

Analogy in many a path such as that of Professor Pupin has 
served as a guide to the discoverer and inventor. ICepially gain- 
ful has been the conviction that many rules 
work both ways, so that ingenuity has only to Rules that Work 
execute the converse or the reverse of a fa- Both Ways, 
miliar task in order to abriflge toil, or reach a 
prize wholly new. 

A crow wishes to get at a clam which it has dug out of the sand. 



To break the stout shell is beyond the strength of its bill, so the 
knowing bird flies aloft, lets the clam fall on a rocky beach or a 
stone and forthwith enjoys a meal. It makes no difference 
whether a hammer falls on the shell, or the shell falls on a ham- 
mer : the crow takes the one method within its power. So with 
the wood-cliopper whose axe becomes imbedded in a stick of 
birch or maple : he lifts wood and axe together as high as he can, 
then lets the axe fall on its back, when the shock instantly tears 
the stick apart. Drilling in a lathe is usually executed by the 
screw of the poppet advancing during the i)roccss. In boring 
long holes, the object to be bored is rotated and moved in a 
straight line, while the tool advances without revolving. In an 
emergency William I'airbairn, the famous engineer, had in hand 
a large task of riveting. He took a ])unching machine, reversed 
its action, and had a riveting machine which turned out work 
twelve times as fast as a skilful workman. 

As in the machine shop so in transportation. One of the notions 
of the pioneer railway engineers in England was that their rails 
must be Hanged, for how else could wheels remain on the track? 
l>ut somebody vvdth breadth of view-point asked, Why not leave 
the rail Hat, or nearly so, and put the flange on the wheel, an 
easier thing to do? Accordingly to the wheel the flange went 
and there it stays, to remind the traveler of the Eastern maxim : 

“To him who is well shod 
it is as if the whole world 
were covered with leather.’' 

In many tasks we have a 
like choice of methods. We 
wish to measure the velocity 
of a stream; if we immerse 
a bent glass tube so that its 
horizontal part is up- 
stream, the height to which 
the water rises in the up- 
right half of the tube will tell us what we wish to know; if wc 
reverse the tube, a sinking instead of a rising in the upright glass 
will measure the speed of our current. 

For many years turbines have proved themselves better than 

Water heightened Water lowered 
in tube. in tube. 


other water-wheels, so that wherever an old-fashioned breast- 
wheel still goes its creaking round, there the 
sketcher seizes the picturesque outlines of a ^urbine^ 
motor whose remaining da}s are few. A tur- 
bine in carefully curved vanes gets from falling water all the 
power it holds; when the task is to lift water, then this very 
turbine, reversed in direction, is the \\'orthington jiunqi, the most 
efficient water-lifter known. 'The rules for construction are the 
same whether we start with falling water and derive jiowcr from 
it, or begin with power and raise water thereby. Ouite as ])ic- 
torial as a breast-wheel is a wind-mill, the older the better, thinks 
the artist as he views its weather-beaten frame. Much later than 
the wind-mill as a -device is its counterpart, the fan-blower; the 
lines most effective for the one are also best for the other. Much 
more effective than the old-time mills of but four arms are new 
mills .whose whole circle is covered by blades. J^'an-blowers with 
a like multijilicity of vanes, yield most duty. 

For ages one of the observations of every day has been that 

a column of water exerts pressure in proportion to its height. 

Usually this pressure is thought of as l)eing 

exerted downward, but if a pipe, filled with Hydraulic 

Pressure as a 

water at pfreat i)ressure, he curved U])\var(l at Counterbalance, 
its base, then the contained li({uid presses up- 
ward. Mark the gain of thus varying a little fnan the oialinary 
view point of a case. In 0^83 Mr. J. h\ Holloway, of C.'alifornia, 
set up a turbine with its stream admitted from below and moving 
ujiward through the vanes of the machine, fie thus obliged the 
water pressure to aid in su])])orting the wheyl, materially diminish- 
ing its friction through thus counterbalancing its weight, d'his 
lilan has been adopted at Xiagara h'alls for the gigantic turbines 
there erected, among the most ])owerfuI in the world. 

That simple ap])Iiance, a garden squirt, exemj)Iifies two im- 
portant kinds of apparatus", one the converse of the other. Infill 
the cylinder with water, force the ])iston along 
its course, and you have a puni]). Admit water Engine and Pump, 
under pressure, as from a city faued. and it 
drives the piston of a motor; in princi])le such is the mechanism 
of thousands of motors in London, using water under a pressure 



of 500 ])0111k1s, or so, to i1k* sriuarc inch. An apparatus, essential!' 
tlie same, when sni)])]ie(l with steam or j^as ])ecomes the familiar 
eiiiL^ine at work in iinct.iinted factories and mills. It was a f^reai 
advance in stc'am en![;ane desii^n when the sinj^le cylinder of W'an 
was replaced hy two or more cylinders, nsin<^ steam at hii^h in 
stead of low jiressiire. 'rims ap])ortioned in a .series of cylinder^ 
the steam is not nearl\' as much cooled, with loss of w’orkiiie 
power, as when hut one cylinder is used. So likewise, it is best u> 
divide the compressini;* of air into two or more sta^i^es, so that at 
each statue the air may he cooled, and thus more easily ccanpresseil 
than if a.siip^le operation completed the business. 'I'lie best air 
com])ressor is virtually the converse of a steam eni^ine. 

( )f late vears reci])rocatine: machinery, of one kind and an- 
other, has had to i^ive place to rotary designs. In these, as in 
their ])redecessors, are strikini^ cases of rules that work both 
ways. I f steam at hi^h ])ressure is fully to yield its energy in a 
1 *arsons-\\'eslin!L;house turbine, for caxample, the vanes must he 
rijLi^htly curved, and there must he a succession of them in circles 
jL^radtially widened so that the steam may part with its enerj;-y, a 
step at a time. In miniipif, in metalhir^'v, in many another ,i(reat 
industry, compressed air is refiuired in hu.t;e volumes. For its 
])roduction Mr. l‘arsons has invented an a])paratus virtually the 
twin of his steam ttirhine, only that it runs in a reversed direction; 
it may he directly yoked to a steam turbine. 

C'urrents of air much less forceful than those of steam in a 
turbine are <;'enerated by the electric fans of our sho])S and offices. 

W hen their vanes move as the hands of a clock. 
Fans. a breeze comes toward you; reverse their 

motion and the stream blows away from yt>ii. 
Flace such a fan in the side of a box otherwise closed; driven 
in one direction the vanes force air into the box; driven the op- 
tiosite way the vanes remove air from the box. Powerful currents 
of this kind, such as stream from a Sturtevant blower, arc used 
for blast furnaces and the larti^est steam installations. The en- 
i^ineer ch(X)ses between two methods ; he can seal up the hre-rooin 
and force in air which will find its way through the grate-bars t») 
the fuel, or he places a fan in the smoke-stack to induce a cur rent 


by cxliaiistioii. In New York and lAindon iiiuIcr^Tound pneu- 
matic tubes carry letters to and from the post-offices. When the 
central eni^ine works its fans exhaustively, water may he drawn 
into the tubes from the streets so as to do much harm. W'hen the 
n-round is thoroiyq;hly dry it is best to exhaust the air at one end 
of the line and compress it at the other. This union (T a push 
and a pull resembles Lord Kelvin's plan in (u*ean tele<;ra])hy, by 
which a cable is first connected with the negative ])(>le of a battery 
and then, for a signal, made to touch the positive j)ole. With its 
])ath thus clearetl, a message pulses along at a redoubled jxice. 

Electrical art teems with rules that work both ways. ( )ersted 

observed that a current traversing a wire deilects a nearby com- 

])ass needle, h'araday, with the guiding law of 

recii^rocitv ever in mind, forcibly deilected a Electrical 
* . ' ' Reciprocity, 

magnetic needle so as to create a current in a 

neighboring wire by the motion of his hand. J fe thus dis- 
covered magneto-electricity, in 'ryndall’s opinion the greatest re- 
sult ever obtained by an experiment. On the simple principle then 
discovered by Imraday are built tlie huge generators that revolve 
at Niagara, at jiower-houses large and small throughout the 
world, for the ])roduction of electricity by nurhanical motion. A 
compass needle has a field, or breadth of inlluence, surrounding its 
surface, which is small and weak. .\ monster magnet in a gen- 
erator has a field at once large and strong. W hen an electrical 
conductor, such as a coil of co])])(‘r wire, is forcibly rotated in 
that field, powerful currents of electricity arise in the wire, 
equivalent as energy to the mechanical effort of rotation. Take 
another case: a current decoin])oses w*'itc*r.; the resulting gases as 
they comhine yield just such a current as that which parted them. 
Join a strip of bismuth to a strip of antimony, and let a current 
traverse the ])air; the junction will become heated. At another 
time, using no current, touch that joint with the hand for a 
moment; the communicated warmth, though trilling in anunmt, 
creates a current ])lainly revealed by a galvanometer, affording 
a delicate means of detecting minute changes of tem])(‘rature. In 
1874 W. Gramme showed four of liis dynamos at the Vienna Ex- 
hibition. IM. Eontainc, an electrician, saw a pair of loose wires 



near one of the machines and attached them to its terminals ; the 
other ends of the wires happened to be connected with a dynamo 
in swift rotation. Immediately the newly attached machine be- 
gan to revolve in a reverse direction as a motor. Thus by an acci- 
dent, wisely followed up, did electricity add itself to motive 
powers, establishing an industry now of commanding importance. 

In the chemical effects of a current we have parallel facts. Ex- 
pose a nickel-iron plate to the alkaline bath of an Edison storage 
cell ; at once the metal begins to dissolve, yielding a current. Now 
send a slightly stronger current into that plate; forthwith the 
plate picks out iron-nickel from its compounds in the liquid, grow- 
ing fast to its original bulk. So many of this kind occur 
that chemists believe that synthesis and electrolysis are always 
counterparts. lie that as it may, we must remember that often 
chemical action is much more intricate than it seems to be at first 
sight. Thus in dry air, or even in dry oxygen, iron is unat- 
tacked ; but bring in a little moisture and at once oxidation pro- 
ceeds with rapid i)acc. So with the combustible gases emerging 
from the throat of a blast furnace; they refuse to burn until they 
meet a whiff of steam, when they instantly burst into flame. 
Chemical energy usually moves in a labyrinth which thei chemist 
may be able to thread only in one direction. A retracing of his 
steps is for the day when he will know much more than he does 

rroj)erties purely physical, and therefore much simpler than 
those studied by the, oft'er us noteworthy instances of 
rules that work both ways, l^'or years the walls 
Ovens and Safes, and doors of safes and bank vaults have been 
filled with gyjxsum as a substance all but im- 
pervious to heat. To-day Norwegian cooking che.sts, on much 
the same principle, are attracting public attention by their econ- 
omy. A pot is filled with, let us say, the materials for soup, it 
brought to a boil, and then ])laced in a chest thickly clad with a 
non-conducting coat of felt or even of hay, as illustrated on page 
189. In an hour or so a capital soup is found to have cooked it- 
self simply by its own retained heat. A resource long familiar 
to the builder of safes and strong-boxes is thus taken into house- 
hold service with much profit. It is plain that whatever obstructs 

Coi)yri«ltt, r.'Kh Uro'., Ni-w V<.rk. 

()uan(;k, N'ew Jehsey. 



the passing of heat may be employed either to keep it in or keep it 
I tilt. For years inventors busied themselves in finding non-con- 
ductors wherewith to cover steam-pipes and steam-boilers. To- 
day, in cold storage plants, these non-conductors are just as use- 
ful in covering pipes filled with circulating li(|uids of freezing 
temperatures. Take a parallel case in the field of physical re- 
search. In 1873 Dulong and IVtit in their measiireinent of heat 
avoided losses of heat with a new approach to perfection by using 
glass vessels one inside another, with exhausted spaces in be- 
tween. In 1892 Professor Dewar aptdied this device to keeping 
liquefied gases, of extremely low temperatures, from being 
warmed by surrounding bodies, an aim just the converse of that 
of Dulong and Petit, Often, as in these cases, the applications of 
a quality may come in pairs ; one invention may suggest its twin. 

This convertibility of principle may be observed as cleai’\' in the 
phenomena of nature as in the creations of ingenuity. Water 
expands as it freezes; when this expansion takes place freely, 
the freezing temperature is 0° C., but when exiiansion is resisted, 
as when the water is confined in a strong gun-barrel, the freezing 
temperature is lowered, for now the ice has to do work in the act 
of crystallization. So with the boiling ]K)inls of liipiids ; they rise 
as atmospheric pressure increases, they fall as atmospheric 
pressure is reduced. A pr(')spector on Pike’s Peak cannot boil 
an egg in his kettle. Next day he descends a mine in the valley, 
to find the boiling point higher than when he built his fire beside 
the mouth of the mine. 

Take another example of inversion, this time in the field of 
mensuration. Every schoolboy knows that cubes res])ectively 
one, two, three, and four inches in diameter 
have contents respectively of one, eight, ^^sily 

twenty-seven, and sixty-four cubic inches; 
that is, the contents vary as the culies of the diameters of these 
solids.^ This is true of all solids alike in form. Cones, therefore, 
which have an angle of let us say fifteen degrees at the apex, 
vary in contents as the cube of their heights. Cones usually are 
looked at as they rest on their bases ; it is worth while to consider 
them reversed, pointing downward. An inverted cone, duly su])- 
ported on a frame allowing motion upward and downward, ancl 



into a cylinder partly filled with water, is a simple mean- 
of extracting cube root within say one and ten as limits. TIk 

Cu1)c-root extractor. 

riic cone displaces water as the cube of its depth of immersion, in thi^ 
case within i and 3 as limits. 

C(nie should be marked off into tenths, and the cylinder, betwee: 
high and low-water, into thonsandths. On a similar plan 
tapering wedge acts as a stpiare-root extractor, displacing watu 
as the square of its depth of immersion. 


From Effect to 

A mechanic, no less than a geometer, may sliovv sagacity in 
taking up a cpicstion in reverse, and reasoning from effect to 
cause. An expert printer examines a spoiled 
sheet as it leaves the press, observing that it is 
sineared and crumjded with a decided skew. 

At once he sto]:)s the macliinery and puts his finger (')n a lever that 
has become crooked, or on the wheel that has been strained out 
of true. AFr. Joseph V. 

Woodworth says of milling 
cutters : —“When a cutter is 
broken by being wrongly 
run backwards c^n to the 
work, the breakage is char- 
acteristic. Although the man 
who broke it will be ab- 
solutely sure that it ran in 
the right direction, the 
cracks down the face of the 
teeth lell a different story.” 

In his manual on steel, 

Mr. William Metcalf reads 
a record ecjually legible to a 
trained eye:— “Ff an axe, 
after tempering, is found 
cracked near the corners of 
its edge, these corners have 

been hotter than the middle of the blade. If a crack a])i)ears at 
the middle of the edge, there the heat was greater than at the 
corners; snipping and comparing the grains will tell the story. 
If a somewhat straight crack is noticed, near the edge and parallel 
thereto, the chances are that the crack indicates a seam.” 

At this point let us for a few moments leave the field of 
mechanics, and notice how inferring cause from (‘ffect may aid 
students of rocks, of the heavens, of the human frame. A geolo- 
gist, observing a dense limestone, learns how severe the pressure 
which brought loose sediment to this compactness. In the glass- 
like texture of quartz he finds an equally i)lain record of intense 
heat. The scorings on rock-surfaces, in lines froni northward 

S( jiia re - rc x > t e x t rac t( ) r. 
Wetlge displaces water as the srpiare 
of its dei>tli of iiiiniersioii. 



to southward, disclose to him the paths in which ages ago the 
glaciers moved from their birth-places in the polar zones. In 
astronomy a feat of inference incomparably more difficult wa.s 
accomplished by John Couch Adams and Urbain Leverrier, each 
independently of the other. The orbit of LJranus displayed cer- 
tain minute irregularities which they referred to a planet, at that 
time iKjt as yet observed, whose place they indicated. Their re- 
markable inference was verified by the discovery of Neptune on 
September 23, 1846. 

fn a ])alh remote indeed from that of the observer of planet and 
star, the surgeon in much the same way reasons from result to 
cause. In 1870 Fritsch and Bitzig, two German investigators, 
observed that in ajiplying an electric shock to a well defined area 
of the brain of a chloroformed dog, its limbs moved. One part 
of the brain thus excited would cause the fore-leg to twitch, an- 
other ])art would lead the hind-h‘g to move. When a specific area 
of the animal’s brain was taken away, a corres])onding part of its 
body-- the eyes, ears, or limbs, were ])ermanently paralyzed. From 
studies thus begun it has been clearly ])roved that in the brain 
of’ animals lherc‘ is a division of labor, each activity being as 
much localized within the skull as it is externally in the nose, 
ears, or feel. The examination of human victims of disease and 
injury has confirmed all this. A ])atient may have suffered k)ss 
of pow'cr to writ(\ to s])eak, to stand firmly on his feet, for w’ceks 
or months before the end. The cause in many cases is found to 
be a tumor, sometinu's no larger than a i)ea, wdiich has pressed 
down up(3n a ])articular area of the brain and so given rise to the 
tnnible. .\ depressed fragment of bone in fracture of the skull 
has a similar effect. \\ ith these facts in mind, wdien a surgeon is 
called in to treat a patient who is suffering* from loss of ])ow*cr tc3 
write, speak or stand, he lifts the sufferer's skull for a small s])ace 
over the speciallv indicated area, relieving the depressed frac- 
ture, or exposing the small tumor, w hich he removes, usually w*ith 
restoration to health. 

A generation agci much was said about functional diseases, it 
being* supposed that apart from the mechanism of bone, muscle or 
nerve, the bodily functions might go astray of themselves. Im- 
provements in the microscope have shown that many of these dc- 



rangcnicnts arc due to diseases of structure; and beyond the 
raiycfc of the microscope a careful study of symptoms enables the 
physician to infer that physical structures are affected in modes 
which, (uie of these days, he may be able to see and picture. 

An eminent oculist, Or. Casey A. Wood of Chicago, tells me 
lliat certain diseases of the brain and kidneys derange the sight 
iu a way clearly revealed by an opthalmosco])e, a small instru- 
ment by which tlie interior of the eye may be explored through 
the pupil, 'riius a jiatient complaining of imperfect vision may 
be really suffering from an ailment involving much more than 
the eyes. 

A noteworthy group of physicians devote themselves to the 
care of the insane, that is, of ])atients whose brains are diseased. 
As a general rule when insanity declares itself, manners depart 
first, then morals, and finally the physical ])owers of the eye, the 
ear, the hand. All in reverse telling the story of how mankind 
became human ; first in developing the faculties shared with bird 
and beast, then in rearing character, and at last, in adding the 
graces of behavior. 

From this digression into matters of astronomy and of the 
human body and mind, let us return to the workshoj) and the 
engine-room, 'fliere is gain, as we have seen, 
when an inventor takes a familiar jirocess. Profit in 

like planing, and reverses it, so that instead of 
the ])lane moving across a board, the board is moved beneath a 
planer. \"ot seldom, too, ])rofit has followed u])on adopting a 
])lan just the contrary of a time-honored jiractice, as when a 
I'renchman jiierced a needle with an (we near its point instead of 
away from its jioint, taking a stej) that did much to make the sew- 
ing-machine a jiossibility. (jiiiis were loaded at the muzzle for 
ages, until one day a man of daring loaded them at the breech, to 
find that method iireferable in every way. \ bullet or ball might 
then be larger and closer in fit than before, have greater velocity 
and jienetration, while truer in flight, estiecially if s])ed from a 
rifled gun. Anything left in the gun was in front of the new 
charge instead of behind it. In manufacture, the perishable ])arts 
of the gun, its vent and the adjacent steel, are now in a movable 
breech-piece where they may be replaced with little cost and 



ln)ul)lc. Loading; and firinp^ may be much more rapid than with 
muzzle-loaders, while less space is required and the gunners are 
much less •cx])osed than formerly. And ages before there wa^ 
such a thing as a firearm, a vast stride in tilling the ground was 
taken simply by reversing an ancient i)ractice. At first the soil 
was scratched by a stick drawn along its stirfacc ; when some 
])rimcval TCdiscm gave the stick a forward instead f)f a backward 
thrust he created the plow, and tillage began in earnest. 

In feeding coal to a fire, as in the case of a common grate, the 
one ])lan for centuries was to add the fuel from above. As 
gradually hc'ated by the glowing mass beneath it, this fresh fuel 
sent forth comjiaratively cool gases winch, to a considerable ex- 
tent, jiassed into tlie chimney without being burnt. A mechanical 
stoker of the underfeed type forces fresh coal beneath the fuel 
already aglow ; the result is that all the gases from the fresh coal 
])ass through an incandescent bed which heats them highly, so 
that on emergence into the air-current they are thoroughly con- 

Link Bi’lt Machinery Co.’s Shop, Chicaj^o, 
showing Sturtevant ventilating and lieating apparatus. 

' In large machine shops a heating system is finding favor which 
equally departs from traditional, methods. In a small workshop 
piping filled with steam or hot water serves well enough : in a 



lofty machine shop it serves badly, sending as it does warm cur- 
rents of air toward the roof where warmth does only harm. The 
union of a fan with a system of steam coils iulroduces a vast im- 
provement. Air warmed to any desired temperature is carried in 
ducts throughout the building, with outlets at the points most in 
need of heat. Instead of being allowed to take its way to the 
roof, the warmed air is forcibly directed to the lloor which other- 
wise would be unduly cool. 1 because the air is in rapid motion 
the heating coils may not be more than one fourth as extensive 
as for a system of direct railiation. This plan has the further ad- 
vantage of utilizing exhaust steam without producing undue back 
pressure on the pumiis or engines, and yields results almost ecjual 
to those from live* steam. See accompanying illustration. 

Lighting as well as heating may share the gain of changing 
an old method for its contrary. Many forms of rellectors, both in 
glass and metal, have been designed to scatter the beams of lamps, 
usually in a downward direction. An excellent i)lan directs the 
positive carbon of an arc-lamp to the ceiling instead of to the 
door; from the ceiling, duly whitened, the rays descend more 
thoroughly and agreeably diffused than if reilected from mirrors 
or refracted by ])risms, however ingeniously shai)ed and disposed. 
Sec illustration on ])age 75. 

In the days of small tilings in engineering, which ended only 
with Watt and his steam engine, when a k(‘ttle was to be heated 
the pro]K‘r ])lace for its fire was thought to be outside. I hit when 
big boilers came in, with urgent necal that thi‘ir coiitcmts be heated 
with all des])atch, it was found gainful to i)ut the tire inside. 
Stephenson owed no small ])art of the si\ccess of his locomotive, 
the “Rocket,” to its boiler being outside its (lame, ddie most 
efficient modern boilers fulh' develop this princij)le. 

Tn an ordinary furnace the draft moves ui)ward, ob(*ying the 
impulse due to liie lightness of its lieated gases, d'his direction 
is reversed in down-draft 'furnaces which were originallv devised 
by Lord Dundonald more than a century ago. Tn their modern 
types a fan blast forces the draft downward through the fuel, 
with the effect that the irases are so intens(‘lv heatfal as to be 
thoroughlv burned. The gratc-l)rirs are of watcT-tulie, connected 
to the boiler as part and parcel of its heating surface. In the 



Loomis gas-producer a like method is adopted : the fuel is charged 
through an open door in the top of the generator and the gas is 
exhausted from the bottom of the fire. Thus all tarry ami 
volatile matter in bituminous coal or wood is converted into a 
fixed gas. 

Thirty years ago one would have supposed the wheels of ordi- 
nary carts and carriages to be safe from change, to be among the 

heirlooms secure of transmission to 
posterity. Not so. Observe the wheel 
of a bicycle and note that instead of 
stout sp(dvcs upholding the hub, then 
arc thin steel wires from which the 
hub is suspended. Thus strength i 
gained while the wheel is lightenet 
and material economized. Wheels of 
like model arc now used in manv 
other vehicles wdiere lightness 
particularly desired. This plan of 
using s|xikcs in tension instead of in 
compression is credited to Leonardo 
da Vinci who flourished four centuries 

Bicycle wheel sus- 
pended from axle 
hy wires. 


Judgment in 
Theorizing : 
Rules Have 

While the men who add to known truth, whether in the realm 
of matter or of mind, must build on ac(|uired knowledge, they do 
so with common sense, by exercise of the 
supreme faculty of judgment. To begin with, 
they perceive that every force acts within lim- 
its-, acts concurrently with other fj)rces whicli 
modify its etfects. Speaking of gravity Jh'o- 
fe.ssor William James says: — “A pendulum may be deflected by 
a single blow and swing back. Will it swing back the more often, 
the more we multiply the blows? No. Vov if they rain upon the 
pendulum too fast it will not swing at all, but remain deflected in 
a .sensibly stationary state. Increasing the cause numerically 
need not increase numerically the effect. Blow through a tube ; 
you get a certain musical note ; and increasing the blowing in- 
creases for a certain time the loudness of the note. Will this be 
true indefinitely ? No ; for when a certain force is reached, the 



note, instead of g^rowing louder, suddenly disappears and is re- 
placed by its higher octave. Turn on the gas slightly and light 
it; you get a tiny flame. Turn on more gas and the flame in- 
creases. Will this relation increase indefinitely? No, again: for 
at a certain moment up shoots the flame into a ragged streamer 
and begins to hiss.’^ 

In a spirit as judicial Sir William Anderson has said .-—“There 
is a tendency among the young and inexperienced to put blind 
faith in formula?, forgetting that most of them are based upon 
premises which are not accurately re])rodnced in practice, and 
which in many cases arc unable to take into account collateral dis- 
lurbances, which only experience can foresee, and common sense 
guard against.” 

That, with regard to a new machine, all the facts of construc- 
tive and working cost should be in view, and after tests in prac- 
tice, is the conviction of Ih'ofessor A. Ik W. 

Kennedy :—”i\lachines cannot be finally crili- Do Not Pay 
cized, pronounced good or bad, simply from ^cent^for^a° 

results measurable in a laboratory. ( )ne wishes Dollar, 

to use a steam plant, for example, by which as 
little coal shall bo burnt as possible. I hit clearly it would be 
worth while to waste a certain amount of coal if a less economical 
machine would allow a larger saving in the cost of repairs or of 
interest. Or, it might be worth while to use a machine in which 
a certain amount of extra power was obviously emiiloyed, if only 
by means of such a machine the cost of attendance could be meas- 
urably reduced. The Svorth-whilcuess' of economies comes out 
only in practical exjicricncc. A careful training in comiiaratively 
simple parts fits a man more than anything else in gauge accu- 
rately the importance of such parts as those named. No doubt 
there are many men in whom the critical faculty is insufficiently 
developed to allow them ever to be of use in these matters, but to 
those who are intellectually capable of Hhe higher criticism’ it is 
of inestimable value to have had a systematic training in the 

To the same effect arc remarks by Professor J. ITo])kinson 

“Doubling the thickness of a cylinder by no means doui)les its 
strength. Conversely, doubling the strength of the material will 



permit the thickness to be diminished to much less than one half. 
Until 1869 hydraulic presses were mostly made of cast iron. 
There was much astonishment at the great reduction in thickness 
and weight which hecame possible when steel was substituted for 
the weaker material. In the case of guns it is well-known that 
greater strength can be obtained if the outer hoops are shrunken 
on the inner (jiies. Mathematical theory tells us what amount oi 
shrinkage should give the best results. A gun may have a shrink- 
age so great as to weaken it.’’ 

lie continues: — “Mathematical treatment of any problem is al- 
ways analytical — attenti(jn is concentrated upon certain facts, and 
for the moment other facts arc neglected. I’or example, in deal- 
ing with the thermodynamics (T the steam engine, one dismisses 
from consideration very vital points essential to the successful 
working of the engine — (|ucstions of strength of parts, lubrica- 
tion, convenience for re])airs. Ihit if an engineer is to succeed be 
must not fail to consider every element necessary to success; be 
must have a ])ractical instinct which will tell him whether the 
engine as a whole will succeed. 1 1 is mind must not be only 
analytical, or he will be in danger of solving bits of the problems 
which his work presents, and of falling into fatal mistakes on 
points which he has omitted to consider, and which the plainest, 
intelligent, practical man would avoid almost without knowing it. 
Again, the ])()wers of the strongest mathematician being limited, 
there is a constant teint)tation to fit the facts to suit the mathe- 
matics, aiul to assume that the conclusions will have greater accu- 
racy than the ])remises from which they are deduced. This is a 
trouble one meets with in other a])])lications of mathematics to 
ex]>erimental science. In order to make the, subject amenable to 
treatment, (^ne finds, for example, in the science of magnetism, 
that it is boldly assumed that the magnetization of magnetizable 
material is proiiortionate to the magnetizing force, and the ratio 
has a name given to it, and conclusions arc drawn from the as- 
sumption ; but the fact is, lu) such projiortionality exists, and all 
conclusions resulting from the assumption are so far invalid. 
Whenever possible the mathematical deductions should be fre- 
quently verified by reference to observation and experiment, for 
the very simple reason that they arc only deductions, and the 



premises from which the deductions are drawn may be inaccurate 
or incomplete. We must always remember that we cannot i^et 
more out of the mathematical mill than we put into it, though we 
may get it in a form infinitely more useful for our purpose.” 

IVofessor Alexander Ilain in his “Senses and the Intellect'’ 
concludes :~“A sound judgment, meaning a clear and precise 
perception of what is really efTecte<l by the contrivances employed, 
is to be looked upon as the first re([uisite of the practical man. 
He may lie meagre in intellectual resources, he may be slow in 
getting forward and putting together tlie appropriate devices, but 
if his perception of the end is unfaltering and strong, he will do 
no mischief and practice no (piackery. lie may have to wait long 
in order to bring together the a]iposite machinery, but when he 
has done so to the satisfaction of his own thorough judgment, the 
success will he above dispute. Judgment is in general more im- 
portant than fertility; because a man by consulting others and 
studying what has lieen already done, may usually obtain sug- 
gestions enough, hut if his judgment of the end is loose, the 
highest exuberance of intellect is only a snare.” 

As applied science rises to higher and higher plaiu’s, a good 
many questions which were once matters of judgment become 
subjects of estimate, often precise. A century , 

ago the forms of shijis were decided by sheer judi^ment Moves 
sagacity; to-day, as we have seen in this lionk, to New Fields, 
such forms are of definite aiijiroved ty’pes, each 
adapted to specific needs, and never de])arted from by a jirudent 
designer except in slight and carefully noted variations. Such 
examples may he drawn from many another field where .science 
and industry join hands, es])ecially in every branch of modern 
engineering. A new ])ower-i)lant, in every detail of its installa- 
tion, is so .standardized that a competent cor])s of erectors, from 
any part of the civilized world, can readily put it togetiier. Its 
designers from first to last have .sought to make operation, 
and every working part '‘fool-pn)of.” In of accident any 
item of the structure broken or deranged can be supplied by the 
builders at once. 

All this does not mean that .science in its onward march is 
eliminating the need for judgment, but simply that judgment is 



constantly passin.e^ into territory wholly new. In devising gas- 
engines of novel jjrinciple, in combining chemicals for new 
economies of illumination, the faculty of judgment enters province ^ 
vastly broader than those from which it has retired as its a]) 
])roximations have given place to exact measurements. Manna’; 
skill has of late undergone a similar change of sco])e. Many a 
modern machine ])er forms hammering, punching, riveting na;'.a 
effectively and swiftly than human hands, so that here an (')peratt'r 
of little skill re])laces a mechanic (M much skill. lUit in aiiollur 
and higher field, deftness was never more in re([uest than to-dav, 
111 the final adjustments of a voltmeter, of a refractometer, in tlu 
last ])olish given to an observatory lens, a delicacy of touch i- 
demanded com])are(l with which the dexterity of an old-tinie 
planisher or tile-grinder is mere clumsiness. 



Newton, tile snprenio s^cner.'ili/er . . . l*'ara(lay, llie master of experiment 
. . . Rell, the inventor of the telephone, transmits speech hy a heaiii 
of lii'ht. 

H AX'TXG now lakcii a rajiid t^vnoral view of (Jn^crvalion and 
experiment, of llie faeiilty of sound llieorizint;', let ns enter 
the iirescnce of two i;reat masters of research and inventio^n, 1)C- 
j^innint;' with a man who united the loftiest powers as a mathema- 
tician, a physicist, and a ,t;enerali/er. 

I low Sir Isaac Xewton discovered the law of .efravitation is 
thus told in his Life liy Sir I)avi<l llrewstcr: — “ft was eitlier in 
16(15 or ififif) that Xewtoids mind was first 
directed to the snhjt'ct of gravity. Tfe apjiears How Newton 
to liave Ic'ft ( anihrid^e s<tmc‘ tiiiK* liehn'e Discovered the 

AnjL;nst S, 1605, when tlie collej^e was dis- Gravitation, 
missed on account of the pla..L;'ne, and it was, 
therefore, in tlu* anlnmn of tliat year, and not in that of 166)6, that 
the ajiplc is said to have fallen from the tree at W’oolsthoriie, and^ested to Xewton tin* idea of i^'ravity. When silting;- alone in 
the J4'ard(‘n, and ■'pecnIatiniLi’ f)n the jiower’of tp'avily, it occurred 
to him that, a.s the ^anie p(Aver by which the apph* fell to the 
?.t‘ronnd was not scaisibly diminish.ed e.t the ei'reatest distance fron: 
the centre of the earth io which we (\in rc*a('h, iu‘ilh(‘r at the snm- 
mits of the 1 )fliest spires, nor on tlu* tojis of tlu‘ hii^lu'st moiin- 
ta.ins, it ini<X‘’t c-xteial to the iiKjon and retain lua* in lier orbit, in 
the same in-inner as it bends into a curve the path of a stone' or 
a caniK'.n ball, when projected in a straic;ht line from the surface 
of the earth. If the' moe>n was thus kejit in her orhit by L^ravita- 
tiein, or, in ollic'r words, its attraction, it wais eqnrdly prohahle*, he' 
thought, that the planets were kept in their orbits hy gravitating 



towards tlie sun. Kepler had discovered the great law of tlie 
planetary motions, that the squares of their periodic times were 
as the cubes of their distances from the sun, and hence Newton 
drew -die im])ortant conclusion that the force of gravity, or attrac- 
tion, by which the planets were retained in their orbits, varicf] 
as the s{iuarc of their distances from the sun. Knowing the forct' 
of gravity at the earth’s surface, he was, therefore, led to com- 
pare it with the force exhibited in the actual motion of £lie moon, 
in a circular orbit; but having assumed that the distance of the 
moon from the earth was e(iual to sixty of the earth’s semi-di- 
ameters, he found that the force by wbicli the moon was drawn 
from its rectilinear path in a second of time was only 13.9 feet, 
whereas at the surface of the earth ii was i6.t in a second. This 
great discrepaftcy between his theory and what he then considered 
to be the fact, induced him to abandon tlie subject, and pursue 
other studies with which he had been occupied. 

*‘tt does not distinctly appear at what time Newton became 
acquainted with the more accurate measurement o^ the eartli. 
executed by Picard in 1670, and was thus led to resume his in- 
vestigations. 1 beard’s method of measuring his degree, and the 
precise result which he obtained, were communicated to the Royal 
Society, January 1 1, 1672, and the results of his observations and 
calculations were tnihlished in the Philosophical Transactions for 
1675. Put whatever was the time when Newti^n became ac- 
quainted with I^icard’s measurement, it seems to he quite certain 
that he did not resume his former tiioughts concerning the moon 
until 1684. Pemberton tells us, that ‘some years after he laid 
aside’ his former thoughts, a letter from Dr. TFooke put him on 
inquiring what was the real figure in which a body, let fall from 
any high jilace, descends, taking the motion of the earth round its 
axis into consideration, and that this gave occasion to his resuming 
his former thoughts concerning the moon, and determining, from 
Picard’s recent measures, that ‘the moon appeared to he kept in 
her orbit purely by the ])ower of gravity.’ Put though Hooke’- 
letter of 1679 was the occasion of Newton’s resuming his inquirio. 
it does not fix the time when he employed the measures of 
Picaril. Tn a letter from Newton to Halley, in 1686, he tells him 
that Hooke’s letters in 1679 were the cause of his ‘finding the 


inctliod of cloterminingf the figures, which, when I had tried in 
llic ellipsis, I tl'.rew the calculations by, bcini^ upon other studies ; 
and so it rested for about five years, till, upon your re(|uest, I 
sought for the paj)crs/ Hence Mr. Rii^aud considers it clear, that 
the figures here alluded to were the paths of l)(Mlies acted u])on 
])y a central force, and that the same occasion induced him to 
resume Jiis former thoughts concerning the moon, and to avail 
himself of I’icard’s measures to correct his calculations. It was, 
therefore, in 1684, that Newton discovered that the moon’s de- 
ilection in a minute was sixteen feet, the same as that of hodit'S 
at the earth’s surface. As his calculations drew to a close, he is 
said to have been so agitated that he was (d)liged to desire a 
friend to finish them.” 

With no mathematics beyond simple arithmetic, Michael Far- 
aday displayed powers (M experiment and generalization so ex- 
traordinary that in these respects he stands at 
the same height as Newton himself. In the Michael 

life of ]\lichael haradav, by Hr. J. H. (Had- ^r 

Stone, we arc given his accoutit of the great Working, 
physicist’s method of wen-king - 

“The habit of Faraday was to think out carefully beforehand, 
the subject on which he was working, and to ])lan his mode of 
attack, 'riien, if he saw that some new ])iece of ap])aratus was 
needed, he would describe it fully to the instrument maker with a 
drawing, and it rarely ha])])ened that tluo'e was any need of 
alteration in executing the order. If, however, the means (^f ex- 
periment existed already, he would give Anderson, his assistant, 
a written list of the things lie would, at least a day before 
— for Anderson was not to be hurried. When all was ready, he 
would descend into the lalioratory, give' a (juick glance round to 
see that all was right, take an apron from the drawer, and rub 
his hands together as he looked at the jireparations made for his 
work. There must be no to^d on the table but such as he re- 

quired. As he began his face would be exceedingly grave, and 
during the progress of an experiment all must be exceedingly 
quiet; but if it was proceeding according to his wish, he would, 
commence to hum a tune, and sometimes to rock himself side- 
ways, balancing alternately on cither foot. Then, too, he would 



often talk to his assistant about the result he was expecting. lU' 
would put away each tool in its own place as soon as done with, 
or at any rate as soon as the day's work was over, and he would 
no,t unnecessarily take a thing away from its place. No bottle 
was allowed to remain withmit its proper stopper; no open glas> 
might stand for a night without a paper cover; no rubbish was lo 
])e left on the floor; ])ad smells were to be avoided if possible; and 
machinery in motion was not to be t)crmitted to grate. In work- 
ing, also, he was very careful not to employ more force than was 
wanted to pn)duce the effect. When his experiments were fin- 
ished and put away, he would leave the laboratory, and think 
further about them upstairs. 

“It was through this lifelong series of experiments that Far- 
aday won his knowledge and mastered the forces of nature. The 
rare ingenuity of his mind was ably seconded by his manipula- 
tive skill, while the (juickness of his ])erceptions was ecpialled In 
the calm ra])idity of his movements, lie had indeed a passion for 
experimenting. This pee])s out in the j)reface to the second edi- 
tion of his ‘Chemical Manipulation,’ where he writes, ‘Ileing in- 
tended especially as a book of instruction, no attempts were made 
to render it pleasing, otherwise than by rendering it effectual ; for 
I concluded that, if the work taught clearly what it was intended 
to inculcate, the high interest always belonging to a well-made or 
successful ex])eriment would be sufiicient to give it all the re- 
cpiisite charms, and more than enough to make it valuable in the 
eyes of tliose for whom it was designed.’ 

“He could scarcely pass a gold leaf electrometer without 
causing the leaves to diverge hy a sudden flick from his silk hand- 
kerchief. 1 recollect, too, liis meeting me at the entrance to the 
lecture theatre at Jermyn Street, when Lyon Playfair was giving 
the first, or one of the first lectures ever delivered in the building. 
‘Let us go up here,’ said he, leading me far away from the central 
table. I asked him why he chose such an out-of-the-way place. 
‘Oh,’ he replied, ‘we shall be able here to find out what are the 
acoustic qualities of the room.’ 

“The simplicity of the means with whicli he made his experi- 
ments was often astonishing, and was indeed one of the mani- 
festations of his genius, A good instance is thus narrated by Sir 


Frederick Arrow : — ‘When the electric lig^ht was first pcrnianently 
exhibited at Diingeness, on 6th June, 1862, a committee of the 
Elder Brethren, of which I was one, accompanied Faraday to 
observe it. Before we left Dover, Faraday showed me a little 
common paper box and said, “1 must take care of this ; it \s my 
special photometer,"— -and then, openiiii^* it, jiroduced a lady’s or- 
dinary black shawl pin (jet, or imitation, perhaps) — and then 
liolding it a little way olY the candle, showed me the image very 
[listinct ; and then, putting it a little further off, placed another 
candle near it, and the relative distance was shown by the size of 
the image.’ 

“In lecturing to the young he delighted to show how easily 
apparatus might bo . extemjiorized. "riius, in order to construct 
an electrical machine, he once inverted a four- cd stool to 
^erve for the stand, and took a wliite glass bottle for the cylinder. 
A cork was fastened into the mouth of this bottle, and a bung was 
fastened with sealing wax to the other end : into the cork was in- 
serted a handle for rotating the bottle, and in the centre of the 
bung was a wooden pivcjt on which it turned : while with some 
stout wire he made crutches on two of the legs of the stool for 
the axles of this glass cylinder to work upon. The silk rubber 
he held in his hand. A japanned tea cannister resting on a glass 
tumbler formed the conductor, and the collector was the head of 
1 toasting fork. With this a])])arently rough a])i)aratus he ex- 
hibited all the rudimentary experiments in electricity to a large 

Faraday, in addition to the rarest ability in ex])eriment, had an 
f)rderliness of mind which gave the utmost effectiveness to his 
work in every department. 1 fis successor, 

Professor John Tyndall, says: — Faraday's 

Faradays sense of order ran like a lu- imagination, 
uinous beam through all the transactions of his 
life. The most entangled and comi)licatcd matters fell into har- 
mony in his hands. Flis mode of keeping accounts excited the 
idmiration of the managing board of the Royal Institution. And 
bis science was similarly ordered. In his ICxpcrimental Re- 
“^earches he numbered every paragra])h, and welded their various 
parts together by incessant reference. His private notes of the 



Experimental Researches which arc happily preserved, ar<. 
similarly numbered; their last paragraph bears the number 16,041. 
His working qualities, moreover, showed the tenacity of liiv 
Teuton. His nature was impulsive, hut there was a force bchiii.l 
the impulse which did not permit it to retreat. If in his warm 
moments he formed a resolution, in his cool ones he made tliai 
resolution good. Thus his fire was that of a solid combuslihlt . 
not that of a gas, which blazes suddenly, and dies as suddenly 

Faraday had exalted powers of imagination and as he gazed at 
the curves in which iron-filings disposed themselves when tapj)etl 
on a card held above a magnet, he saw similar “lines of force" 
surrounding every attracting mass of whatever kind. Other ol) 
servers had confined their attention to what takes place, or \< 
sup])oscd to take place, in a conductor; he closely scanned wliat 
took ])lace around a conductor. He was thus addressed in a letter 
from that remarkable physicist, Professor James Clerk Maxwell 
of Cambridge 

“As far as I know you are the first ])erson in wl^m the idea I'f 
bodies acting at a distance by throwing the surrounding medium 
into a state of constraint has arisen, as a principle to be actualh 
believed in. We have hatl streams of hooks and eyes (lying 
around magnets, and even pictures of them so lK‘sct ; hut nothing 
is clearer than your description of all sources of force keeping u|) 
a state of energy in all that surrounds them, which state b\' its in- 
crease or diminution measures the work done bv any change in 
the system. You seem to see the lines of force curving round «'1>- 
stacles and driving jilump at conductors, and swerving towar'! 
certain directions in ervstids, and carruug with them everywhere* 
the same amount of attractive ])ower, spread wider or denser a- 
the lines widen or contract. You have seen that the great mystery 
is, not how like bodies repel and unlike attract, but how like bodies 
attract by gravitation. Rut if you can get over that difficuliy 
either by making gravity the residual of the two electricities "r 
by simply admitting it, then your lines of force can 'weave a web 
across the sky,’ and lead the stars in their courses without any 
necessarily immediate connection with the objects of their at- 
traction. ...” 


IMichacl I'araday, as we have seen, hv rest-arehes nf eonsiiin- 
matc ability laid the foundation of modern electrical science and 
art. In that held there is to-day no inventor 
more illustrious than lh*ofessor Alexander How Light 

( Jraliain I’.oll, the creator of the telephone, that BeafeTofTpeLh. 
simplest and mdst imjiortant of electrical de- 
vices.’ Xot content with ohlii;'ini>* a wire to carry speech in elec- 
tric waves, Professor Pell has impressed beams of lii^lit into the 
same service. 'Jdie successive steps by which he arrived at the 
])hotophone are of extraordinary interest, llis story as i;'iven in 
the proceed in t^s of the .American Association for the .Advance- 
ment of Science, 1880, is here .somewhat condensed : - 

“In hrin^inj;- before ycni .some disccnA'ries by Mr. Sumner 
d'aiiiter and myself, which have resulted in the production and 
reproduction of sound by means of lii^ht, let me sketch the state 
of knowledi^c which formed the starting' point of our experi- 
ments. 1 shall first describe selenium, aud the uses of it devised 
by previous expeiimenters ; our researches have so widenecl the 
class of si^tances sensitive, like selenium, to li^ht-vibrations 
that this seWiliveness seems to be a ])roperty of all matter. We 
have found this i)roj)erty in p)l<k silver, platinum, iron, steel, 
brass, co})])er, zinc, lead, antimony, <^erman-silvi‘r, ivor\’, celluloid, 
jH'utta ])ercha, hard and soft rubber, paper, ])archnient, wood, mica, 
and silvered f’iass. At first carbon and nucrosco])e i^iass secMued 
insensitive: later exjierinients ])roved them to be no excejitions to 
the rule. 

“We find that when a vibratory beam of li^hl falls upon these 
substances they emit sounds, the ])itch of whi(di de])ends upon 
the fre(|uency of tlu' vibratory chan<;e in the lii^lit. We also find 
that when we contn)l the form or character of the li,e;ht-vihrations, 
we control the (juality of the sound, and obtain all varieties of 

’ Profe.ssor PcH’s narrative, of liovv lie invented tlie trlejihone i^ giva ii in 
“Invention and ])i<;coverv,” one of the six volnnies of “Kittle MastcTpieees 
of Scienee,” Donhhalay, I’age ^ Co., New N'ork. In “Idanie. Ideetrieity 
and the Camera” by the present writer, published by the sanu* firm, is a 
chapter describini^ the teleiihfine in its later deveh)pmt‘nls. This chaptcT 
was revised by the late Professor Alexander Melville liell, father of the 


articulate speech. W'c can thus speak from station to stati< n 
wherever we can project a beam of li^ht. Selenium, indispensahli 
in the apparatus, was discovered by r>cr::clius in 1817. It is a 
metalloid resembling tellurium ; they differ, however, in electric al 
properties ; tellurium is a good conductor, selenium in its usual 
forms is a non-conductor. Knox, in 1837, discovered that seleniuia 
is a conductor when fused; in 1851, Hittorf showed that it con 
ducts when in one of its allotropic forms. Wdie-n selenium i'. 
raj)idly cooled from a fused condition it is a non-conductor. In 
this vitreous form it is dark brown, almost black by reflected light, 
having an exceedingly brilliant surface; in thin films it is trans- 
parent, and appears of a beautiful ruby red by transmitted light. 
When selenium is cooled from fusion with extreme slowness, it 
presents an entirely different appearance, being of a dull lea<l 
color, and liaving throughout a granular or crystalline structure 
and looking like a metal. It is now o])a(|ue even in very thin 
films. It was this kind of selenium that Hittorf found to be a 

conductor of electricity at ordinary temperatures. He also noticed 
that its resistance to the passage of electricity diminished con- 
tinuously by heating up to the point of fusion ; and that the resist- 
ance suddenly increased as the solid passed to liquidity. It was 
early discovered that ex])osure to sunlight hastens the change of 
selenium from one allotropic form to another; an observation of 
significance in the light of recent discoveries. 

“Air. Willoughby Smith, an engineer engaged in the laying of 
submarine cables, had devised a system of testing and signalling 
during their submersion. Imr this system, in 

The Cardinal 1872, it occurred to him that he might cnii)l(n' 

crystalline selenium, on account of its high re- 
sistance, at the shore end of a cable. On experiment the selenium 
was found to have all the resistance reepnred ; some of the bar^ 
displayed a resistance of 1400 megohms, as much as would be 
offered by a telegraph wire long enough to reach from the earth 
to the sun. Hut this resistance was found to be extremely vari- 
able; the reason was disclosed when Air. Alay, an assistant, ob- 
served that the resistance of selenium is less in light than in 
darkness. This discovery created widespread interest througli- 
out the world. Among the investigators who at once turned their 


attention to the subject was Professor W. G. 5 \dams of King’s 
College, London, who proved that the action on selenium is 
chiefly due to the luminous rays of the spectrum, the ultra-red 
and ultra-violet rays having little or no effect. Dr. Werner 
Siemens, the eminent German physicist, produced a variety of 
selenium fifteen times more conductive in sunlight than in dark- 
ness. This extraordinary sensitiveness was brought about by 
heating for some hours at a temperature of 210° C., followed by 
extremely slow cooling. 

“( )bservations concerning the effect of light upon the con- 
ductivity of selenium had employed the galvanometer solely; it 
occurred to me that the telephone, from its 
extreme sensitiveness, might be substituted ^he Telephone 
with advantage. On consideration T saw that Brought in. 
the experiments could not be conducted in the 
ordinary way with continuous light, for a good reason: the law 
of audibility of the teleplione is precisely analogous to the law of 
electrical induction. No effect is i)roduced during the passage of 
a continuous and steady current. It is only at the moment of 

Telephones receiving sounds through a beam of light. 

change from a stronger to a weaker state, or, rice versa, that any 
audible effect is produced ; this effect is exactly proportional to 
the amount of variation in the current. It was, therefore, evident 
that the telephone could only respond to the effect produced in 


selenium at tlie moment (jf chang^e from light towards darkness, 
or vice versa, and that it would be advisable to intcimit the light 
with great rapidity so as to produce a succession of changes m 
the conductivity of the selenium corresponding in frequency in 
musical vibrations within the limits of the sense of hearing. Ihir 
I had often noticed that currents of electricity, so feeble as hardly 
to produce any audible effects from a telephone when the circuit 
was sim])ly opened and closed, caused very perceptible musical 
sounds when the circuit was rapidly interrupted ; and that the 
higher the pitch of the sound the more audible was its effect. 1 
was mucli struck by the idea of producing sound in this way by 
the actifin of light. Accordingly I ])roposed to pass a briglu 
light through one of the orifices in a perforated screen consistint; 
of a circular disk with holes near its circumference. Upon rapidl) 
rotating the disk an intermittent beam of light would fall on llic 
selenium, and from a connected telephone a musical tone would 
be [iroduced, its pitch deiiending upon the rapidity with which 
the disk stiun round. 

“U])on further consideration I saw that the effect could not 
only be tiroduced at the extreme distance at which selenium would 
normally respond to the action of a luminous 

Variations of body, but that this distance could be indefinitely 
Light Necessary, increased by using a parallel beam of light, so 
that we might telephone from one place to an- 
other with no conducting wire l)etwcen the transmitter and the 
receiver, "fo reduce this idea to ])ractice it was necessary to devise 
an apparatus to be operated by the voice of a speaker, by which 
variations could be ])roduced in a parallel beam of light, corre- 
sponding to variations in the air produced by the voice. I jne- 
posed, therefore, to pass light through two jdates perforated h'. 
many small orifices. One of these plates was to be fixed, th- 
other was to be attached to the centre of a diaphragm actuated 
by the voice. In its vibrations the diaphragm would cause tin 
movable plate to slide to and fro over the surface of the fiN< '1 
])late, by turns enlarging and contracting the free orifices for ll e 
j^assage of light. The parallel beam emerging from this ap- 
paratus could be received at some distant place on a lens focussiu;^' 


it upon a sensitive piece of selenium placed in a local circuit, with 
a telephone and a galvanic battery. The variations in the light 
])roduced by a speaker's voice should cause corresponding varia- 
tions in the electrical resistance of the selenium at the distant 
place, and the telephone in circuit with the selenium should 
reproduce audibly the tones and articulations of the sj^eaker’s 
voice. It is greatly due to the genius and perseverance of inv 
friend, ]\[r. Sumner 'rainter, that the problem thus entered upon 
has been successfully solved. 

“The first point to which wc devoted our attention was reducing 
the resistance of crystalline selenium within manageable limits. 
The resistance of selenium cells, emi)l(n'ed by 
former experimenters, was counted in millions 
of ohms; there is no record of a cell measuring 
less than 250,000 ohms in the dark. We have 
succeeded in producing cells measuring only 300 olnus in the 
tlark and 150 in the light. Our predecessors all seemed to luivc 
used platinum for the conducting part of their cells, excepting 
Werner Siemens, who found that iron and copper would do. Wc 
have discovered that brass, although chemically acted upon by 
selenium, forms an excellent material ; indeed, we are inclined to 
believe that the chemical action between brass and selenium has 
contributed to the lowness in resistance of our cells, an intimate 
union taking place between the two substances, fn brass we 
have constructed many cells of diverse forms. One of them 
(two are described by Ih'ofessor Hell), is cylindrical so that it 
may he used with a concave rellector instead of with a lens. Tt is 
com[)osed of many metallic disks separated by mica disks slightly 
smaller in diameter. The spaces between the brass disks over 
the mica are filled with selenium, and the alternate brass disks are 
metallically connected. Tlic selenium is applied to the cell duly 
heated : next comes annealing. To effect this an fjven is inserted 
in a pot of linseed oil standing upon glass sup]M)rts in another 
similar pot of linseed oW. The whole is then heated to about 
214° C., and kept there for twxmtV'four hours, then allowed to 
cool down during forty to sixty hours until the temperature of 
'ordinary air is reached. 

Treatment of 
the Selenium. 


“We have devised more than fifty forms of photophonic trans- 
mitters. In one of them (several others arc described by Vn, 
lessor Bell), a beam of light passes throu!L;!i 
A Perfected a lens of variable focus formed of two slicei> 

Transmitter. of thin glass or mica containing between lluin 

a trans])arent li(inid or gas. When vocal vi])ra- 
tions are communicated to this gas or liquid, they cause a vibra- 
tory change in the convexity of the glass surfaces with a cona* 
sponding change in the intensity of the light as it falls upon tlu 
selenium. We have found the simplest a])paratus to consist in a 

plane mirror of flexible material, 
such as silvered mica or microscopr 
glass, against the back of which tlie 
speaker’s voice is directed. 

“A large number of trials of this 
apparatus have been made with tlu' 
transmitting and receiving instru- 
ments so far apart that sounds could 
not be heard directly through the air. 
In a recent ex])eriment j^lr. Tainter 
o])erated tlie transmitting instru- 
ment, placed on the top of the 
h'ranklin School House in W'ashing- 
lon, 1). C. ; the receiver being ar- 
ranged in a window of inv labora- 
tory, at a distance of 213 metres. Upon placing the telephone to 
my car, I heard distinctly from the illinninated receiver: ‘Mr. 
Bell, if you hear what 1 say, come to the win(k)w and wave your 

“We have found that articulate speech can l)c reproduced h> 
the oxyhvdrog^ji light, and even by a beam fnan a kerosene laiu]>. 
The loudest cfTects follow upon interrupting the light by mean- 
of a perforated disk swiftly rotated. Because this apparatus 
noiseless it allows a close approach of the receiver while U' l 
interfering with its message. 

“We have endeavored to ascertain the nature of the rays whiea 
affect selenium, placing in the path of an intermittent bean, 
various absorbing substances. *In these experiments Profc'-^ ’ 

Selenium cylinder with 



Cross has rendered us aid. When a solution of alum, or bisul- 
phide of carbon, is einploved, there is but slight reduction in 
loudness, but a solution of iodine in bisulphide of carbon cuts 
olT most of the audible eiYect. Even an opaque sheet of hard 
rubber is less obstructive. 

‘It is a well known fact that the molecular disturbance pro- • 
diKed in a mass of iia^i by the magnetizing inlluence of an inter- 
mittent electrical current can be observed as 
sound by ])lacing the ear in close contact with Experiments 

the iron. It occurred to us that the molecular * 


disturbance produced in crystalline selenium by 
the action of an intermittent beam of light should be audible in a 
similar manner with no telephone or battery. Alany experiments 
were made to verify this theory; at first without definite results, 
fhe behavior of the hard rubber just mentioned suggesteil listen- 
ing to it also, "fliis was tried with an extraordinary result. I 
held the sheet in close contact with my ear while a beam of inter- 
mittent light was focussed upon it through a lens. A distinct 
musical note was immediately heard. Other substances, as enu- 
merated iitj^the outset of my address, were now successively tried 
in the form of* thin disk.S, in every case vvitli success. On the 
whole, we feel warranted in announcing as our conclusion that 
sounds can be produced by the action of a varialde light from sub- 
stances of all kinds in the form of thin diaphragms. The reason 
why thin diaphragms are more effective than masses appears to 

A perforated disc rotated yields a succession of sounds from light. 

be that the molecular disturbance produced by light is chiefly a 
surface action, and that the vibration has to be transmitted 
through the mass of the substaftcc in order to affect the car. Wc 


have led air, directly in contact with an illuminated surface, to 
the car by throwing the luminous beam upon the interior of a 
tube. We have thus heard from interrupted sunlight very per- 
ceptible musical tones through tubes of ordinary vulcanized rulj- 
ber, of brass, and of wood. These were all the materials at hand 
in tubular form, and we have had no opportunity since of extend- 
ing the observations to other substances. A musical tone can be 
heard by throwing the intermittent beam of light into the ear it- 
self. This experiment was at first unsuccessful on account of the 
position in which the car was held.” 



Bessemer a man of golden ignorances ... Ills boldness and versatility 
. . . The story of his steel process told hy himself . . . Nohel’s heroic 
courage in failure and adversity ... llis triumph at last . . . d'urns an 
accidental hint to- great protit . . . Inventors to-day organized for at- 
tacks of new hreadth and audacit}'. 

I N 1855 Henry Jlcsscmcr hc^an to change the face of the civil- 
ized world as he perfected his ])r()cess for steel-making. The 
story of his struggles, defeats and eventual triumph is told in his 
autobiography published in London by l^'rom that 

hook the ])uhlishers have i)ermitted the follow- 
ing pages to be drawn. As a boy I lenry Pesse- BessemePs 
mer had a strong mechanical turn, amusing . 
himself with a lathe at an age when lads usually 
prefer marbles or tag. In his youth there was a clear ])romise 
of inventive faculty, plainly inherited from his father, Anthony 
Pessemer, and naturally jmrsuing the lines of paternal interests. 
Mr. Pcssemcr, senior, manufactured tv])e of ])articular dura- 
bility; this (juality his s(Pi discovered due to additions of a little 
tin and coi)per to the ordinary alloy. It was in this held of alloy- 
ing that young Pessemer took his next stej) as an inventor, fore- 
shadowing the tremendous feat he was in due time to acconi])lish. 
He busied himself as an engraver of rollers for.embossing ])aper ; 
in cutting their deeply incised lines there was a tendency in curves 
to drag or blur the surface of the metal. After several unsuccess- 
ful attem])ts he produced an alloy of tin and hismuth free from 
this fault. 

Soon afterward Bessemer's attention was directed to the hronze 

‘“Sir Henry Bessemer: an Aulohiography.” Offices Engineering, ^ 
Bedford St., Strand, London, 1905. 16 shillings. 



powders sold at high prices to printers and decorators. These 
powders were produced by hand in Germany by processes so 
laborious as to make the cost enormous. Examining the material 
with a powerful microscope Bessemer was convinced that lie 
could dispense with hand labor, and turn out a powder of equal 
quality at nominal expense. His machinery for this purpose 
proved a success and laid the foundation of his fortune; un- 
patented and worked in secret for thirty-five years, it yielded him 
a huge profit indispensable for the costly experiments he had ever 
in hand. Naturally enough his fame as a man of ingenuity was 
promptly noised, abroad, and his talents were next invoked for 
a much-needed improvement of sugar-cane milling. The momcMil 
that I’essemcr saw a cane-mill at work he placed his finger on 
the chief cause of its wastefulness. He noticed that the cane was 
squeezed between two rollers for only a second, a period so short 
that the cane at once rc-expanded and re-absorbed much juice. 
He forthwith designed a press, on much the same principle as a 
hydraulic press, which subjected the cane to severe pressure for 
two and a half minutes, until every drop of juice had left the 
fibres, .almost doubling the output of the old machinery. For 
success in this task Bessemer declares himself indebted to a golden 
ignorance. He says: ‘T had an immense advantage over many 
others dealing with the problem under consideration, inasmuch 
as 1 had no fixed ideas derived from long-established practice 
to ccmtrol and bias my mind, and did not suffer from the too- 
general belief that whatever is, is right. Hence I could, without 
check or restraint, look the question steadily in the face, weigh 
without prejudice or preconceived notions, all the. pros and cons, 
and strike out fearlessly in an absolutely new direction if thought 

But in his case ignorance in one field was joined to knowledge 
in many another field, and there he found weapons wherewith 
to surmount an old difficulty at a quarter never assaulted before. 
He continues : “The first bundle of canes I ever saw had not 
arrived from Madeira a week before T had settled in my own 
mind certain fundamental principles, which I believed must gov- 
ern all attempts to get practically the whole juice from the cane ; 
but, of course, there were many circumstances that rendered it 

Copyrijjhl, l.oiiclmi Co, 


OF LoNlKiN. 


necessary to modify first principles, having reference to cost of 
construction, lightness for easy transit across country, freedom 
from necessity for repairs, and the like/' 

In the supreme effort of his life Bessemer once more held him- 
self a debtor to his ignorance, to the fact that Ins mind was un- 
worn by routine and ruttiness. Referring to 

his attempt to make a cheap metal stronger Bessemer s Steel 
^ Process. 

than cast iron for guns, he says: “My knowl- 
edge of iron metallurgy was at that time very limited, and con- 
sisted only of such facts as an engineer must necessarily observe 
in the foundry or smith’s shoj) ; but this was in nne sense an ad- 
vantage to me, for I had nothing to unlearn. Al y mind was open 
and free to receive any new impressions, without having to 
struggle against the bias which a life-long practice of routine 
cannot fail more or less to create.” 

Now appears the genius of the man, showing that if his brain 
was unoccuj)ied by rules-()f-thumb it was full to overllowing with 
original and sound ideas. He goes on t(j say: “A little rellec- 
tion, assisted by a good deal of practical knowledge of copper 
and its alloys, made me reject all these frnm the first, and look 
to iron of some of its C(;nibinations, as the only tnaterial suitable 
for heavy ordnance.” Of fascinating interest is the great in'® 
ventor’s story of how ste]) by step he arrived at his final success. 
After reciting his preliminary experiments, in an endeavor to 
remove carbon from pig iron so as to make malleable iron and 
steel, he says : 

^'On my return from the Ruelle gun- foundry I resumed my 
experiments with the open-hearth furnace, when some pieces of 
pig iron on one side of the bath attracted my attention by re- 
maining unmelted in the great heat of the furnace, and 1 turned 
on a little more air through the fire-bridge with the intention of 
increasing the combustion. On again opening the furnace do(jr, 
after an interval of half an hour, these two pieces of ])ig still 
remained un fused. I then took an iron bar, with the intention 
of pushing them into the bath, when I disc(wered that they were 
merely shells of decarbnrized iron, showing that atmos[)Iieric air 
alone was capable of wholly decarburizing grey ])ig iron, and cf)n- 
verting it into malleable iron without puddling or any other 



niani])iilati(jn. Thus a new direction was ^iven to my thoup;hts, 
and after due delil)eration I l)ecaine convinced that if air ccnild 
he l)roii^lit into contact with a sufficiently extensive surface of 
molten crude irf)n, it would rapidly convert it into malleable iron. 
W ithout loss of lime I had some fire-clay crucibles made with 
dome-shaped perforated covers, and also with some fire-clav 
blow-pij)es, which I joined on to a three-foot length of one-inch 
,£^as pijie, the opjiosite end of which was attached by a i)iece of 
rubber tnbini:!^ to a fixed blast pi^ie. This elastic connection ])ci - 
milted of the blow ])ipe beine: easily intn^xluced into and with- 
drawn from the crucible which, in effect, formed a converter. 
About ten jKninds of molten |.^rev pijc^ iron half filled the crucibli', 
and thirty minutes’ blowini;' was found to convert this metal into 
soft malleable iron. 1 lere at least one "reat fact was demon- 
strated, namely, the ab.solute decarburization of molten crude iron 
without any manipulation, but not without fuel, for had not a 
very hii^h temperature been kept up in the air furnace all the time 
this (|uiet blowiii!:>‘ for thirty minutes was m'oiiye^ on, it would 
have resulted in the solidification of the metal in the crucible loni;' 
before complete carburization had been effected. Hence arose the 
all-im])ortant (luestion : C'an sufficient internal heat be produced 
f)y the introduction of atmospheric air to retain the lluidity of the 
metal until it is wholly carburized in a vessel not externally 
heated? This I determined to try without delay, and I fitted up a 
lai’i^er blast -cylinder in connection with a 20 horse-iiower engine 
which I had daily at work. I erected an ordinary founder's 
cupola, capable of melting* half a ton of pij^ iron. Then came the 
question of the best form and size for the experimental con- 
verter. I had very few data to guide me in this, as the crucible 
converter was hidden from view in the furnace during the blow. 
I found, however, that slag was produced during the process, 
and e.scaped through holes in the lid. Owing to this, I constructed 
a ver\' sinijile form of cylindrical converter, about four feet ir 
interior height, sufficiently tall and capacious, T believed, to ])revent 
anything but a few sparks and heated gases from escaping 
through a central hole made hi the flat top of the vessel for that 
purpose. This converter had six horizontal tuyeres arranged 
around the lower part of it; these were connected by six adjust- 


rJ)lc branch pipes, deriving their supply of air from an annular 
rectangular chamber, extending around the converter. 

“All being thus arranged, and a blast of lo or 15 ])()unds’ pres- 
sure turned on, about seven hundred-weight of molten j)ig iron 
was run into the ho])])er provided on one side of the converter 
for that purpose. All went on (luielly for about ten minute, s ; 
sparks such as are commonly seen when tap])ing a cupola, accom- 
panied by hot gases, ascended through an opening on the to]) of 
the converter, just as 1 had sui)posed wouUl be the case. Ihit 
soon after a rajiid change took ])lace : in fad, the silicon had heen 
quietly consumed, and the oxygen, next uniting with the carbon, 
sent up an ever-increasing stream of s])arks and a voluminous 
white llame. ."riien followed a succession of mild explosions, 
throwing molten slags and sjilashes of metal high up into the air, 
the a])paratus becoming a veritable volcano in a state of active 
erujition. Xo one could ap])roach the converter to turn off the 
blast, and some low, Hat, zinc-covered roofs, close at hand, were 
in danger of being set on fire by the shower of red-hot matter 
falling on them. .All this was a revelation to me, as I had in no 
way anticipated such violent results. Ilowc’ver, in ten minutes 
more the erui)ti()n had ceased, the llame died down, and the ])ro- 
ce s was comjilete. On ta])])ing the converter into a shallow |)an 
or ladle, and forming the metal into an ingot, it was found to be 
wholly decarburized malk'able iron. Such wi're the conditions 
under which the first charge of ])ig iron was converted in a 
vi'ssel neither internally nor externally heati'd by firi'.” 

The narrative continues with details of fmilier masterly ex- 
’ eriments until the new ])roeess was turning out stecHs of (.‘xcel- 
lent (juality, containing any desired fraction of ('arbon, at a cost 
of but six to seven pounds sterling jier ton as against fifty to 
ixty ])Ounds by the methods which Ilessemer laid uiion the shelf. 
Ilis ])redecessors had made forty to fifty ])ounds of steel at a 
time in small crucibles,^ he made five tons in twent\ minutes, fn 
his magnificent simplification Ilessemer at a stroke dismissed a 
1 mg series of troublesome ])rocesses long believed to be as un- 
avoidable as winter’s cold. He did away with the smelting of 
pig iron, the rolling, shearing and piling of bars, and the heating 
furnace. From the beginning of the Jjessemer manufacture to 


Bessemer did not at once enter upon success in the practical 
application of his process, llrilish pii;* iron, with which he dealt, 
abounded in phosphorus, an element which he could not drive out, 
and which made his steels faulty. Tt was only when, at leni;th, 
he obtained pure pig iron from Sweden that he was able to sup- 
])ly the .market with pure, soft malleable iron, aud with steels of 
various degrees of hardness. In a secjiiel, full of interest, he 
sketches the shrewd means by which he secured a handsome 
fortune from his great invention, for Hessemer had remarkable 
business ability as well as inventive genius. 11 is labors in steel- 
making obliged him to neglect his devices in the plate-glass manu- 
facture which, /lesjiite their nierit, were also lu'glected by the 
producers of plate-glass. I le remarks : “'I'he simple fact is that 
an invention must be nursed and tended as a mother nurses her 
baby, or it inevitably ])crishes.” 

So far from finding it gainful to concentrate his mind (in a 
single problem, ignoring every other, llessemer delighted in 
pursuing a wide variety of exjieriments, esjie- 
cially before his engrossing responsibilities in Bessemer’s 

the manufacture of steel. In glass-making he Versatility, 

introduced some notable improvements, lie tells us: “In going 
over a glass-works T had noticed what I, at the moment, thought 
was a great oversight in the mod(‘ of proceeding. 1'he materials 
employed, namely, sand, lime and soda in ascertained (piantities, 
were laid in heaps upon the paved iloor of the glasshouse, and 
a laborer proceeded to shovel them into one larg(‘ hea]), turning 
over the jiowdered materials, and mixing* them together; a cer- 
tain ([uantity of oxide of manganese was added during the gc-neral 
mixing ojieration, for the jmrpose of neutralizing the green color 
given to glass by the small amount of oxide of iron contained 
in the sand. The materials were then thrown into the largo glass 
pots, which were already red-hot inside the furnace. What ap- 
peared to me to be wanting in this rough-and-ready operation 
was a far more intimate blending of these dry materials. A grain 
of sand lying by itself is infusible at the highest tem])erature 
attainable in a glass pot, and the same may be said of a small 
lump of lime; but both are soluble in alkali, if it be within their 
reach. These dry powders do not make excursifjiis in a glass t)ot 



and look about for each other, and if they lie separated the tinu 
reciiiired for the whole to pass into a state of solution will j:^reail\ 
depend on their mutual amtact. In such matters I always reason 
hy analogy, and look for confirmation of my views to other manu- 
factures or processes with which I may ha])pcn to have bccoim 
more or less acquainted. I may here remark that I have alwa\^ 
adopted a different readinj:;* of the old pnwerh, little know! 
edi^e is a daiiLicrous thinj^' ; this may indeed he true, if your 
knowledj^e is e(|ually small on all subjects; hut 1 have found a 
little knowlcdjL^e on a j^reat many different thini^s of infinite servicr 
to me. f'rom my Cc'irly youth I had a stronj^* desire to know some 
thinir of any and all the varied manufactures to which I ha\e 
been able to i^ain access, and 1 have always felt a sort of annoy 
ance wheiievcM* any subject connected with manufacture was 
mooted of which I knew abscjlutely nothinj^. d'he result of tlii- 
fceliiif^, acting' for a .threat many years on a powerful memory 
has been that I have really come to know this dani^erous liiilr 
of a i^'reat many industrial ])r()cesses. 1 have been led to say tlii-- 
so as to illustrate my observations on the extreme slownc'ss of (be 
fusion of i^lass by an analogy in the manufacture of j;unj)()\\ der. 
1 have shown it impossible for tlie dry ])owdered materials em- 
ployed in the manufacture of .^lass to react chemically upon eac'li 
other when they are l\in|L:;* far a])art. Xow if 1 lake the thru 
substances, charcoal, nitre and sulphur, of which i:;-un])owdc‘r i- 
composed, and break them into small frai;inents, then shake theui 
lo(\sely toi^ether, and ])Ut a junnnl or two of this mixture on a 
stone lloor and apply a match, the nitre will fizzle briskly tla 
sul])hur will burn lit fully or out, and the charcoal will la ' 
several minutes before it is consumed. If, instead of this ernd^ 
:m(l inijK'rfect mixture, we take the trouble to i^rind these uv^v- 
duents under edj^e straies into a tine i)asle with waiter, and tli^ 
■ha- and granulate it, wa' have still the jirecise cluMuic'al elements i 
deal with which w e i, united on the st(^ne tlotw ; but they nmv exist e 
akh close and intimate contact as instantly to act upcni each oila 
‘ 1(1 a ton or two of these otherwise slow-burnino* materials \'. 

’ e converted into i^^as in the fraction of a second. The inferets 
w as sim; le enough, n-amely, to grind ti^gether the materials re 



qiiircd to form glass, and when the heat of the furnace arrives 
at the point where decomposition takes place, the whole will pass 
into the fluid stale much more quickly, and will yield a much more 
homogeneous glass than is obtained in the usual manner.” 

llessemer one day paid a visit to the works of his friends, 
Hayward and Company, London, manufacturers of paints and 
varnishes. He was struck with the wasteful- 
ness and imperfection of the time-honored Improves the 
r 1 • -1 • • ^ Drying of Oils. 

])rocess ot drying oils in an iron ])ot over an 

o])en fire; a crude method always attended with danger, and not 
seldom with a conqilete loss of the heated oil. As he walked 
through the works there occurred to him a much better plan 
which he at once embodied in a sketch. His ideas were jnit into 
practice by his friends, to their lasting ])rolit. Instead of a small 
charge of two or three gallons heated over an open lire, he sug- 
gested that fifty or sixty gallons should he run into a tank, in 
the bottom of which was a pi])e terminating in a large rose-head. 
Connected with this ])ipe was a coil that could he heated to any 
desired temperature, and air could he forced through this coil, 
escaping through the rose-head into the oil. The cwact degree of 
heat required could be thus maintained, and the jirocess com- 
pleted with certainty and .safety, without waste, and, above all, 
with no discoloration of the oil. 'This method, carried to a 
further degree of oxidation, is the foundation of the vast lino- 
leum industry throughout the world. 

It was in trying to make guns of a new strength that Sir I lenry 
Bessemer entered the ]xith which enabled him to make steel at 
little more cost than cast iron, ft was in pro- 
viding guns with explosives of new power that 
Alfred Nobel won both distinction and fortune. 

As in the case of Sir Henry Bessemer, his gifts 
have inured vastly more to the service of jieace than of war. 
It is estimated that during the Civil War, 1801-65, more explo- 
sives were used in the United States by civil, railroad, mining 
and quarrying engineers than in the field of battle. Chief of 
these explosives was gunpowder ; nitro-glycerine, though well 
known, had then little or no acceptance, for good reasons. How 

Alfred Nobel 
and His 


its defects were overcome is told by Mr. Henry de Mosenllial 
in an article on Alfred Nobel, in the Nineteenth Century Maga- 
zine, London, October, 1898. By the editor’s kind permission 
that article is here freely drawn upon. 

Nitro-glycerine, discovered by Sobrero in 1847, made 1)\ 
treating glycerine with a mixture of nitric and sulphuric aci(b; 
it is poisonous, very sensitive to a shock, and most dangerous to 
handle. Being liquid it runs into the fissures of rock wlieii 
poured into a bore-hole, and requires to be carefully confined 
that it may explode when ignited by means of a simple fuse. 
Nobel tried to overcome these deficiencies, first by mixing ilie 
liquid with gunpowder, and then by adding fluids which ren- 
dered it non-explosive, so that it could be safely transported, tin* 
added licpiid being removed .just before use; he also suggested 
confining it in a tube having the shape of a bore-hole, and firing 
it by means of a small gunpowder cartridge or primer. lUit all 
this did not avail, and accidents occurred so frequently that tin* 
use of the blasting oil was prohibited in Belgium, in Sweden, 
and later on in England. A vessel carrying some cases shii)])ed 
from Hamburg and bound for Chili was blown up, and the event 
caused such a sensation that it seemed as if the use of nitro- 
glycerine would be prohibited the world over. In the meantime, 
however, Nobel had solved the problem of its safe use, and at the 
end of i8()6 he had invented a com])()und, which he called dyna- 
mite, made by mixing the nitro-glycerine oil with porous ahsorh- 
ing material, thus converting it into a i^aste. Dynamite proved 
on experiment to be comparatively insensitive to a shock or a 
blow ; it burnt when ignited, and could be pr()])crly ex]doded 
only by means of a ])owerful detonator fixed to the end of the 
fuse and inserted into the plastic explosive. 

The invention of dynamite marks an epoch in the history of 
civilization. In judging of the degrees of culture of a ])e(4)le. 
we are guided to a great extent by the kind of roads and water- 
ways they have constructed, and by the facility with which the\ 
have obtained metals and applietl them to the arts. The Romaii'^ 
constructed excellent roads on the level, but in the mountains 
they could only make narrow and very steep paths. Canals and 



cuttings were made with great sacrilice and labor, and only where 
the soil was soft. Thus Suetonius states that in order to make 
a cutting about three miles long to drain the Lacus Fucinus, the 
I'huperor Claudius employed 30,000 men for eleven years. In 
the sixteenth century road making and mining were scarcely more 
advancetl. It took 150 years, ending with to mine five miles 

of gallery in the Ilartz mountains. Although blasting with 
gun])owder dates l)ack to the seventeenth century, it did not come 
into general luse until about the middle of the eighteenth century, 
at which time the total cubage mined in (Ireat llritain amounted 
to little more than of a large railway cutting at the present day. 
The use of gunpowder gave a great im])etus to mining and ])uhlic 
works, hut it was only the introduction of railways, and the neces- 
sity of laying the lines on easy gradients, which raised blasting 
to a science. The introduction of dynamite, thrice as powerful as 
gun]>owder and much more reliable, entirely revolutionized that 
science, and made it ])ossihle to execute the gigantic engineering 
works of our time, and brought about that prodigious develoj)- 
nient of the mining industry of the world which wc have wit- 
nessed since 1870. 

Dynamite is combined with twenty-live per cent, of inert mat- 
ter as an absorbent; for this large proportion of unexploding 
substance, Xohel sought an active substitute. 

This, he thought, might he a substance which Nobel Profits by 
would dissolve in nitro-glycerine so as to form an Accident, 
a homogenous paste. Xow for a sagacious ex- 
periment with a liijuid brought to his hand by accident. Whilst 
experimenting in search of such a material, he one day cut his 
finger and sent out for some collodion to form an artificial skin 
to protect the wound; having used a few drops for that purpose, 
it occurred to him to ]K)ur the remainder into some nitro-glycer- 
ine, and he thus discovered blasting glycerine, which he patented 
in December, 1875. Collodion is made by dissolving a gun-cotton 
in a volatile solvent, a mixture of ether and alcohol, and Nobel 
suggested that the viscous substance thus obtained should be 
mixed with the nitro-glycerine so as to form a jelly. On further 
experiment the jelly was dispen.sed with, and blasting gelatine 



was made, as it is now, ])y warming the nitro-<;lyccrine, and 
adding- a])oiit ci^^hl ])cr cent, of a j^un-cuttt)n wliicli was found 
to he solul)le in nitro-.e^lyecrine. The new explosive, half a- 
strong a,£4ain as dynamite, was too violent to he applicable to aii' 
hut the hardest rock. Xohel, however, discovered how to naxi 
crate its action, and .gelatine dynamite and j;eli^*nite were manu 
factnred hy the addition of saltpetre and wood-me'd to a hlastiii- 
.efelatine of less consistency than that eni])loyed without such ad 
mixture. lUastin^’ {gelatine was used in lari^e (juantities in tlir 
])i(‘rcint4- of the St. ( lothard tunnel, where the rock was so hard 
that no satisfactory work could he done without it. Since then 
tlu^ use of the j^elatine explosives has increased more and more, 
and in some countries they have entirely sui)erseded dynamite. 

Idle smokeless ])owder which Xohel orii^inated was based on 
his discv)verv that hv means of heated rollers he could incor- 

Nobel Invents 

.i»-e’laline altered 

porate with nitro-^lycerine a very hi.^h per- 
ceiitajL^e of that soluble nitro-cellulose, or 
cotton, which his factories were usinj^ in the 
manufacture of hlastinj:;' £>elatine. Illastin^ 
hy means of moderatin.i4' substances, had been 

tried in j^uns and had hurst them, .\ohel now found that if tlie 

nitrated cotton was increased from eijL^ht to about fifty ])cr cent, 
he obtained a ])owder suitable for firearms, d'he ])roe^ress in tlie 
construction of weapons, and especially the introduction of quick- 
firiiii;* i;ains, made it necessary to have smokeless ])owder, whik 
hij^lier velocities demandin<;* straij^hter jiaths for ])rojectiles couhl 
he attained with new arms resistiiii;* hii^h pressure, \\diilst in 
([uest (T .mch a ])owder, Xohel ])erfected several methods fer 
rci^ulatiiii;' the jiressure in i;uns, and modifying the recoil. Il 
was in the hci^inning- of iS 88 that he invented his well-known 
smokeless jiowder, or hallistite. Ilis discovery that the two most 
powerful shatterini;' explosives, nitro-i^lycerine and gun-cotton, 
when mixed in alxmt equal pro])orlions, would form a slow burn- 
ing ]K)wder, a propulsive agent with j)ressures which would excee<l 
the resistance of modern weapons, caused astonishment in tech- 
nical circles. Xohel submitted his powder to the British Ex 
plosive Committee, which fouml that instead of employing the 



variety of gun-cotton which is soluhlc in nitro-glvccrinc with the 
aid of heat, the insoluble kind could be used provided an assistant 
solvent could be added ; and that the manufacture could be carried 
on at lower temperatures than those necessary in producing- other 
explosives. The powder thus olitained was cordite, and this they 
recommended for adoption. 

Physically weak, of nervous, hij:;h struni;- and exeej)tionally 
sensitive disposition, Nobel was endowed with a stroni;* will, un- 
bounded enercfv, and wonderful iierseveranee : xt i. i 

\ Nobel, Bodily 

he feared no danger and never yielded to ad- Weak, was Strong 
versity. Many would have succuiiibed under in Mind and 
the misfortunes which befell hii'n, but the sue- Will, 

cession of almost iiisurmountable dilliculties, the exidosion of liis 
factory, causing a general scare and dread of the deadly compound 
he was making, the loss of his younger brother, to whom he was 
devotedly attached, the consecjuent paralysis of his father, and his 
mother's grief and anxiety, could not deter him from f)ursuing his 
aim. Ilis temerity frecfuently verged on foolhardiness, as when 
he was going to his father’s works one day at .St. lVtc‘rsl)urg, and 
finding Mio boat to take him across the river, he swam to the op- 
posite bank of the Neva. 11 ic co-existence of impulsive daring 
with sensitive timidity was a striking featiirt* in his character. He 
frequently (lemonstrated the value and .safety of his exjilosives with 
his own hands, although he was ])articidarly susce])til)le to head- 
aches caused by l)ringing nitro-glycerine in contact with the skin; 
these headaches affected him so violently that he was often obliged 
to lie down on the ground in the mine or (|uarry in which he was 
exjKU'imenting. On one occasion when .soUie dynamite could not 
he removed from a large cask he crejit into it and dug the ex- 
plosive out with a knife. i\lany other incidents could be related 
of the fearlessness he disidayed when the success of his invention 
depended entirely upon his demonstrations of its safety, which in 
those days had not yet been thoroughly ]n*()ve(l. 

Nobel died in 1896, at the age of 63 ; after ])roviding legacies to 
relatives and friends he left about $[2,000,000, its income to be 
annually divided into fifths, each fifth to be awarded for the most 
imjx)rtant discovery or improvement in chemistry, physics, physiol- 



ogy, or medicine, and for the ^york in literature highest in the 
ideal sense. In distributing these prizes no considerations ni 
nationality prevail. 

In these days of organization, the career of the inventor takes 
m a new' breadth. If his ideas are sound, poverty need be no ])ar 
to his success. To-day a man of proved ability 

Invention entertains an idea for a new machine, cmi- 


glue, or process may choose among the great 
firms or companies interested in the field he would enter. His 
* plans arc then canvassed by competent critics; if his suggestions 
harbor a fallacy it is pointed out; if his aims, though feasible, 
would be unprofitable, they are left severely alone. Perhaps m 
essence his schemes arc good,. but need modification; this is .duly 
supplied. Instead of working all alone in twilight or darkness, 
the inventor now takes up experiment with the aid of carefully 
chosen lussistanls, with amassed information as to what others have 
done in the same path, botli at liomc and abroad. 

When an inventor is an Edison, as remarkable in. executive 
ability as in creative power, it is be who organizes, as a gcnernl, 
the forces which test his ideas and perfect such of them as prove 
sound. Let lulison imagine a new storage battery ; forthwith ho 
enlists a cor])s ()f chemists and metallurgists, engineers and me- 
chanics, and keeps them busy attacking the difficulties of his quest 
mechanical, chemical, electrical. What if his mathematics go no 
further than arithmetic, are not masters of the calculus to be en- 
gaged on moderate terms in every nniv^ersity town? Ilis personal 
command of the iKucil fall.< far short of the facility of profes- 
sional draftsmen who, at reasonable salaries, will turn out plans 
and elevations (|uickly and accurately. Mis staff, lx)inid to him 
by affection and pride as with hooks of steel, are the fingers of his 
hands to win triumphs which neither he alone, nor his men hy 
themselves, could ever accomplish. 

It has been solely by organized ability, unfaltering faith* in 
ultimate success, and massed capital, that the steam turbine ha^ 
become the rival of tlie steam engine of Watt. A vast sum, ex- 
peuded during nine years, was Vc(|inrcd to perfect its delicate aii<! 
exacting mechanism. C^ne day a young engineer saw it wbirliiit; 
away at liiah speed ; with- the efficiency of the gas engine in miiul 


he asked, “Why not drive a turbine by gas instead of by steam ?’’ 
He took his idea to a leading manufacturing concern ; it was ap- 
proved, and now that young inventor is attacking the diffi- 
culties, neither few nor small, which stand in the way of building 
an effective gas turbine. 

In these latter days new doors are opened to ingenuity by the 
comprehensiveness of great industries, by the huge scale on which 
they conduct their business. A country black- Combina- 

smith is served well enough by a hand-blown bel- tions Create 
low5 ; at the Homestead Steel Works the blow- New Oppor- 
ing machinery has been designed by the best tumties. 
engineering talent in America. When the output of a trust, or 
even of a single company, rises to scores of millions of dollars 
every year, it is worth while to measure how far moisture in a 
blast may do harm, and adopt the elaborate plans of Mr. James 
Gaylcy for drying air before sending it into a furnace. Take an 
example of how the United States Steel Company has planned 
every detail betwixt mine and mill. Each lake carrier, of im- 
mense size, has its hold so curved that automatic clam-shells lift 
ten tons of ore at each descent, shovelcr and shovel being dis- 
missed. Vessels and docks dovetail into one another. The car- 
lengths, as a freight train .stajuls on its track, corresjiond to the 
distance between one steamer-hoist and the next. In like fashion 
every link in the chain is devised to save every possible foot- 
pound of •energy, every dispensable moment of time. Capital, al- 
ways cheaper than labor, is expended with both hands, and in no 
direction more liberally, than in setting at work the inventor of 
economical devices, and his twin brother, the, who deals 
with the whole industry as a single mechanism to be reduced to 
the lowest working cost and the highest ultimate efficiency. 

During 1904 the General Idcctric Company at Schenectady, 
New York, perfected for the New York Central & Hudson River 
Railroad an electric locomotive such as will be 
used for passenger service between New York Team-Work in 
and Croton. That locomotive, far outvying 
anything else that ever before moved on wheels, 
was created by a council of locomotive buUders, electricians, en- 
gineers, and mechanics. Some of the plans which they adopted 

Research and 



with success had failed in times past. Each motor was made part 
and parcel of the axle it turns, a directness of construction wliieli 
had never before proved to be feasible. Usually an electric 
motor has many magnetic ix>les ; the motors in this locomotiw 
have each only two poles. 

On much the same lines this Company is constantly experiment- 
ing with a view to cheapen and improve electric lighting. Ever\ 
fdament, every luminous rod or vapor, as newly devised, is tested 
and modified by as acute a band of investigators as exist in tlu- 
world, with all the benefit of daily conference and mutual aid. 

In such fields as those of the cheapening of light and motive 
jxnver, the utilization of electricity, the production of metals, it 
would seem that the day of the solitary re- 
Group Attack. searcher or inventor is drawing to a close. To- 
day the man of original ideas, of combining fa- 
culty, of uncommon deftness, of rare visual accuracy, is mated 
with his peers for a group attack on a many-sided problem when- 
each man’s resources will find their special play. In untiring labor 
at the bench and lathe, at the muffle and the test tube, one experi- 
ment follows another, all duly compared, judiciously varied and 
advanced as indication may Thus the fences which ex- 
treme siiecialization have set u]) are surmounted, each worker 
supplements the deficiencies of his fellows, and all join hands to 
take by assault a citadel that might forever defy single attack. 



An aid to the miner, qiiarryman and sculptor . . .An actuator for pumps 
. . . Engraves glass and cleans castings . . . J^ust ami dirt removed by 
air exhaustion . . . Westinghouse air-brakes and signals. 

S OAfE recent noteworthy advances of invention have been 
due to co-operation by many workers, not however on such 
lines of definite .^roiip attack as have just been remarked. 'Amonj^f 
these advances may be chosen feu' rapid survey the applications of 
compressed air, (jf plain and reinforced concrete, the economy 
of power-jiroduction and of fuel for whatever jnirposc cm])l()ycd. 
Let us liegin with C(un])ressed air. 

Hammers, drills, and i)icks, all workinj>’ by ])ercussion, are 
amoiijg the most effective tools. They may be attached to a steam 
piston, as are Xasmylh hammers and common 
quarry drills, yieldinj^ a much cheaper jiroduct 
than does hand labor. In many places where 
it is not feasible to use steam in this direct and 
most economical way, it is best to employ com- 
pressed air which works much as .steam does, 
so that a motor or a drill with no chang^e of build may be operated 
by one or other motive power at will. Comi)ressed air, unlike 
steam, may be taken long^ distances without condensation ; in tig^ht 
receivers it may be \<cpt without any loss as long^ as we like, and 
used in mines and tunnels where steam heat would be a nuisance, 
or where electricity would he unsafe. Electrical drills and cutters, 
moreover, are liable to have their insulation harmed by working^ 
.shocks, and by surrounding^ g^rit, sand or chips. In mines after a of gunpowder, a direct current from the main ])ipe quickly 
freshens the air; at all times the cool, pure breeze from the ex- 
haust pipe is a welcome aid to ventilation. Steam, one of the 

Compressed Air. 
In Effect Cold 
Steam for Driving 
Hammers, Drills, 
and Picks. 




chief servants of industry, must be kept and used hot. When its 
energy is used to compress air we have at command a substance 
with all the working quality of steam, without having to keep it 
warm. As it toils at common temperatures, we can imagine com- 
pressed air to be, in effect, cold steam. 

Of late years cutters driven by compressed air have been la|;gely 
adopted throughout the coal mines of the United States. A cutter 

New Inj^crsoll Coal Cutter. 

F, trunnion. B, C, piston rings. A, piston. E, wheel. 

weighing ten pounds, with air at seventy-five pounds behind it, 
strikes a blow i6o to 250 times a minute, beginning at the floor 

Drill stcfls. 

and making as little slack as a hand pick intelligently wielded. 
Other tools, in great diversity, actuated in the same way, ask only 
skill in guidance instead of muscular drudgery. Air drills are 
used in mines, wells, tunnels, and rock foundations; at will the 
mechanism impels a hammer instead of a drill. Air riveters buihl 
ships and bridges, as well as fasten together the comparatively 
small plates of boilers and fire-boxes. With a little variation in 
its form we have a tool which- caulks boilers, tanks, and ships. 
Air-hammers light and strong have revolutionized the art of cut- 
ting and carving stone, the force of a stroke being regulated by a 



touch. Pneumatic hammers are of two kinds : V'alveless liammcrs 
in which the piston is the hammer, opening and shutting.the inlet 
and exhaust parts; and valve hammers, in which there is a dis- 
tinct moving valve. Hammers without valves are always short of 

stroke, and are chiefly used in caulking and cliip])ing. Some of 
them yield as many as 250 strokes per minute. Valve hammers 
do not move at this high i)ace, rarely exceeding tliirty-iive strokes 
per minute, but each stroke is coivparatively long and forcible 
for riveting and the like severe work, in the Keller liamnier the 
valve moves longitudiiiall}- with the hammer barrel and in the 
same direction with the hammer piston, instead of in the op[)osite 
direction as is usually tlu* case. A blow, therefore, tends to seat 
the valve all the more firmly, instead c)f jarring it off its seat. An- 
other result is that the tool works efficiently even when the valve 
is loosened by much use. Phis liamnun* is manufactured by the 
Philadelphia Fhicumatic Tool (V)., Philadelphia. 

It is interesting to learn from Mr. \V. L. Saunders, of New 
York, how the air-tools just considered were introduced, lie 
says : — 

“Mr. McCoy is entitled to the credit of first applying pneumatic 
tools to heavy work, such as chipping metals, caulking boilers, 
cutting stone and so on. He was not, however, the originator of 
the broad idea, as long before he perfected the tool for heavy 
work it had been used as a dental plugger, a device working com- 



pressed air in a cylinder so that a piston struck the end of a tamp^ 
ing tool, used to insert gold into the cavities of teeth.’’ 

Rock drill used as blacksmith’s hammer. 
Ingersoll-Rand Co., New York. 

A rock drill, on occasion, may serve as a blacksmith s hammer. 
The drill, detached from its tripod, is fastened to a vertical sup- 
jxjrt. The ram, duly supplied with compressed air, is fixed in 

positiem over the anvil, uix^n 

Little Giant wood-boring machine. 
Chicago Pneumatic Tool Co. 

which it descends more fre- 
quently if less forcibly than 
a steam hammer. A rock- 
drill may also serve to drive 
drift bolts into the timbers 
of caissons. This task when 
effected by ordinary sledge 
hammers is slow and costly, 
while with compressed ali- 
as a servant capital work is 
done at much lower expense. 
The drill is ])rovided with 
handles so as io be readily 
managed by two men, who 
place the anvil, with its 
cupped end, on the head of 
the bolt to be driven. Pneu- 
madc energy does the rest. 

A\"ith dimensions much en- 

larged an air-driven piston becomes a rammer for foundry sand, 
for roads and pavements, for tamping the beds^ of railroads. In 
foundries a moulder is furnished with a small sand-sifter, 



vibrated by compressed air; he is now free lo use his shovel all 
ll;e time, so that he does live times as much work as before. 
I loists small and large are actuated by the same agency ; in every 
case the mechanism is so simple that 

rough usage is withstood and repairs, 
when needed, are easily effected. If a 
ratchet, a pawl, a bearing, wears out, a 
new one can be bought at small cost and 
at once fitted into place. Designers have 
])roduced rotary as well as reciprocating 
air tools ; of these a wood-borer is a 
capital example. 

Sometimes it is well worth while to em- 
ploy compressed air simply as a blast to 
keep a milling-cutter free from its chips; 
when the blast is cold, as it usually is, the 
cutter may turn all the (juicker. 

Compressed air can do much else than 
impel pistons of familiar type. In one re- 
markable device it has ])ut ])istons out of 
business altogether. 

Fill a tumbler to the brim with water, 
take a straw and dip it to the bottom of 
the glass, blowing as heartily as you can. 

WatiT lifted by 
compressed air. 

i\t once the water overflows because dis- 

placed by rising bubbles of air. Instead of a tumbler take a long 
upright pi])e filled with water, send to its base compressed air of 
aderpiate ])ressure, and you have the Poh-le air- 
lift, which carries water into the reservoirs of Air-Lifts. 
Fort Madisejn, Iowa, of Dixon, Illinois, of As- 
bur}' Fark, New Jersey, and many other towns and villages. On 
a smaller scale the air-lift brings up water from thousands of 
wells, rivers, and lakes. Aboard shij) it moves water ballast from 
one compartment to another, so as to give the vessel just the 
trim or inclination desired. In chemical works it raises licjuids 
so corrosive that no other lifter is feasible. It has no valves or 

other moving parts to be deranged or hurt in case its stream bears 
sand or dirt, so that it is a capital drainage pump; after serving 


thus it may bring sewage to farms and distribute it tborougbly. 
To be fairly efficient the air-lift requires that two thirds of the 
lengtii of its upright pipe be immersed below the surface of the 
lifjuid to be raised. 

Iu)r oil wells, which may be 2000 or more feet in depth, a 
lifter not so simple is employed. A pipe, comparatively large, is 
lowered to the oil. Its base forms a receiver 
Liquids Lifted which, at will, may be closed on its earthward 

by Ej^anding side, then through a small inner lube coin- 

])ressed air reaches the oil to force it bodily to 
the surface of the ground. The Harris pump lifts oil, water, or 
other licjuids with high efficiency: it allows the compressed ait- 

after use to act expansivcls ; 
this helps to drive the com- 
jtressor ; then this expanded 
air is once more highly com- 
pressed, and so recurrently. 

Compressed air readily 
moves litpiids as masses ; it 
as easily impels them as par- 
ticles. A lady’s toilet table 
usually disi)lays an atomizer. 
Its rubber bulb, sharply 
squeezed, emits a tiny 
stream of jterfnme as a 
quick air blast breaks a 
drop of li([uid into sj^ray. 
Magnify this apparatus and 
you have a painting machine 
for freight and passenger 
cars, fences, and out-build- 
ings. Driven as it is with 
projectile force the pigment 
penetrates further than if 
laid on by hand, reaching 
crannies and crevices which evade a brush. On the same prin- 
ciple Hook’s spraying machine sends Bordeaux mixture into the 



pressed air, showing switch. Pneu- 
matic h'nginecring Co., New York. 



foliage of an orchard, or delivers a solution of carbolic acid upon 
the floors, walls, and ceilings of a hospital or a sick-room. 
Strengthen such a blast and you can elevate, 
dry, and aerate grain, or lift the culm from a A Jack-of-AlI- 
coal heap to a furnace, and then discharge the 
ashes as they tumble from a grate. Where stretches of water 
arc sandy and muddy, conij^u'essed air dredges a channel by stir- 
ring up deposits at the bottom. 

An air compressor reversed in direction is an air exhauster, 
such as we find carrying money in department stores. The 
powerful in-draft of this apparatus, often 
Removing Dust ''nuving larKO pieces of paper or card into the 
and Dirt. ‘ pipes, has led to the invention of a means of 
reiiKn ing dust and dirt, admirable in thmanigh- 
ness. A receiver, shaped to suit its special task, is passed over 
pictures and their frames, upholstery, carpets or bare doors, and 

through the (le.xible pipe 
attached to its handle, dust 
and dirt are borne into a 
reservoir where they are 
caught by water for due 
removal. Ordinary sweep- 
ing witli a 1)1*00111, the usual 
wielding of a feather 
duster, or a blast of com- 
jin^^-sed air, but stir up dust 
and dirt for harmful redistribution. This “'^acuum” cleaning 
method takes dust and dirt wholly away, ami with wonderful 
celerity. See picture opposite page 164. It is astonishing to see a 
pound of fine flour removctl from a thick carjiet in twelve seconds, 
leaving behind not one visible jiarticle. This ])lan cleanses carpets 
without their being lifted from floors, or a billiard cloth just as it 
stands on a table. This service greatly promotes health ; the 
further the physician goes with his microscope the more con- 
vinced is he that dust is one of the chief carriers of disease. 

Not only dust but sand may be borne when a breeze rises to a 

Hardie nozzle for painting by com- 
pressed air. 



^Jn Lycll’s Bay, near Wellington, New Zealand, and in many 
other places throughout the world, flints have been found so 
beautifully and symmetrically polished that 
Sand-blast. they were at first believed to be products of 
art, yet nothing but wind-blown sand had 
given them form. Fifty years ago globes for gas jets were frosted 
by a handful of sand quickly thrown from side to side for a few 

minutes. Strange to 
say, gunnery was to 
supply the link to 
carry sand to labors 
of much greater 

(leneral B. C. 
Tilghman, of Bhila- 
del])hia, one day 
Vacuum renovators for carpets and upholstery, noticed the much 

worn touch-hole of an 

old bronze cannon, ffe felt sure that the wear had been due not 
so much to outflowing gases as to bits of unburnt powtler driven 
out at each discharge, identifying this al)rasion with the roughen- 
ing of glass in windows facing sandy shores of the sea. In 1870 
he began experiments by blowing sand jets with a fan, soon dis- 
covering that he had hit upon a cheap and easy means of frosting 
glass, carving stone, and scouring castings, lie was astonished 
to find that sand readily pierced materials harder than itself, as 
corundum and t(nighened steel. To-day the sand-blast executes 
many new tasks : it resurfaces stone buildings which have become 
discolored and grimy: it cleanses metallic surfaces for the welder, 
the electroplater, the enameler ; it renews files and ras])s ; it re- 
moves scale from boilers, ])aint and rust from steel bridges and 
other structures. The aiiparatus manufactured by Mr. C. Druck- 
lieb, of New York, designed much in the form of a steam injector, 
employs air at a pressure of about twenty pounds to the s(iuare 

Compressed air is at work oh so large a scale that its economical 
production and use arc matters of consequence Mechanism for 
30 th purposes, of the best design, involves a few simple prin- 



ciplcs. Suppose we have a cyliiulcr, fourteen inches lonj^, aiul 
that witli a piston wc force the a^ntained air within one inch of 
its base, so as to occupy 1/14 of its original 
volume. This act of compression, which we Air Compressors, 
will imagine to be all but instantaneous, will 
heat the air through 613° l^ahr., so that if at 60® when the opera- 
tion begins, the air will be 673° at the end. Suptxjse, further, that 
this air parts with no heat to sur- 
rounding metal, and that the piston 
moves without friction; the com- 
pressed air on being allowed to ex- 
pand will return all the work ex- 
pended in comi)ression, and resume 
its first temi)crature, If air 

would serve us in this ideal way, 
we would have an agent with all 
the good points of steam and none 
of its drawbacks. In actual ])rac- 
tice several items left out of our 
imaginary picture must be reckoned 
with. Air heated in compression 
([uickly warms surrounding masses 
and has to be cooled when sent off 
on distant errands, losing much 
working i)ower in the prf)cess. The 
very act of compression retards it- 
self : the air, because heated, has 
additional elasticity for the com- 
pressor to overcc 3 me. 

Plainly, the engineer should ])egin by sending into his com- 
pressor air as cool as j^ossible, during ccjmi)ressi(3n he should 
keep the tein])erature of the air as low as he can. .Moderate j^res- 
sures, to fifty pounds per square inch or so, may well be effected 
at a single stroke, the air as it issues from the com])ressing cyl- 
inder passing through pipes immersed in cold water, a similar 
chilling stream being sent around the cylinder walls themselves. 
This air at fifty pounds, duly cooled, may now, if wc wish, be 
brought to say 100 pounds pressure in a second cylinder ; its out- 

Iiijoctor s.iii(M)l;ist. 

C. Drucklirl), New York. 



put is in turn cooled as before by conveyance through pipes 
batbed in cold water. The more thorough the cooling, the less 
moisture will the air contain to give trouble afterward by con- 
densing in pipes or machinery. If a pressure higher than loo 

Vertical receiver, inter- and outer- 
cooler. I nKersoll-Rand Co., 
New York. 

pounds to the square inch is 
in request, a third compres- 
sor may be linked to the 
second. In some installa- 
tions, where extreme pres- 
sures are attained, four- fold 
apparatus is employed; its 
chief economy rests in cool- 
ing the air at four distinct 
stages, greatly diminishing 
the work which otherwise 
would have to be wastefully 

With the energy of steam 
economically converted into 
the energy of compressed 
air, the engineer sends his 
new servant as far as he 
pleases. Let us imagine that 
a mile off he wishes to drive 
a gang of saws. lie will 
soon notice that the exhaust 

pil)e is very c(d(l, and if the 
compressed air was not well dried as produced, its moisture will 
now be deposited not as water merely, but as frost to check the 
machinery. This is because air, like steam, falls in temperature 
as it expands at work ; that fall measuring the heat-ec[uivalcnt 
of the work performed. For the chill which the engineer ob- 
serves, he has a simi)le remedy: he surrounds the air pipe, as it 
enters its machinery, with a small heater, fed with coke, coal, or 
oil. At once all frost vanishes, and the air with added elasticity 
is vastly more effective than before. l>y no other means can so 
much work be won from fuel as through this device. In some 


cases a heater has yielded 1.25 horse power for an hour in re- 
turn for each pound of coal it has burned. 

In producing^ compressed air, inventors step by step have kept 
in view the best steam jiractice. It was long* ago observed that 
working steam when wholly expanded in one cylinder chills itself, 
imparting its chill to the cylinder walls so that they seriously cool 
the next charge of steam, hnvering its value for motive i)ower. 
In a multiple cx]xmsion engine of four successive cylinders, each 
in turn receives the steam, which with ihm'ongh jacketing is main- 
tained at the highest tem])eratnre possible. Keeping to converse 
lines the com])ress()r divides its task into stages, at I'ach of which 
a desired change of temperature can he easily elTected. With 
steam this change consists in adding heat: with compressed air it 
consists in abstracting heat. 

Thirty miles from ( 'leveland, at Xorth AmluM'st, ( )hi('), is the 
largest sandstone (juarry in the world. Its owners, the ('leveland 
Stone Company, in tlu'ir original plant tan- 
])loyed steam from no fewer than forty-nine ^ Centralized 
boilers, all machinery, including drills and Plant, 

channclers, being driven by steam. In Jannary, K^og, this was 
replaced by a centralized air plant which has rc\snlled in marked 
economy. In the ])()wer-h()nsc‘ four water-tnhe boilers, each of 257 
horsc-power rated capacity, drive coni])onnd compressors which 
deliver air at about loo pounds ])ressure. 1'his air, duly i)ii)ed, is 
distributed to drills, channek'rs, hoists, pumps, saws, grindstones, 
forge fires, and so on. hA'onoinies, familiar in electrical centraliza- 
tion, are here iiaralleled in an interesting way. In the working 
day not a moment is wasted. W hen the whistle blows the full 
working pressure is ready to begin work and maintain duty until 
night. There is no tluctnation of pressure due to careless boiler 
attendance; no wheeling coal or water barrels to keep ])ace witli 
advancing channclers. Some of the old boilers, discarded from 
steam service, are used as air receivers, these and other restTvoirs, 
together with the pipe line itself, unite their immense storage 
capacity so that throughout the day there is no peak load. In- 
cidentally the new ])lant renders the (juarry free from smoke-laden 
steam such as of old darkened its air and s(jiled its output. Fuel 



and labor under this system were reduced one half when a montli 
of the old service was compared with a month of the new. In 
one case steam is used for power outside of the main plant. Cl()>r 
to the power-house is a mill where eleven gang saws are driven 
by a steam engine of 175 horse-power. The nearness of this on 
ginc to the boilers ensures a somewhat higher economy than ii 
compressed air were employed. Here, as everywhere else, tlio 
engineer engages whatever servant will do good work at the 
lowest wages. 

By all odds the most important use of compressed air is that 
developed by Mr. George VVestinghouse, of Pittsburg, in his auto- 
matic brakes for railroads. For each loco- 
Westinghouse motive he provides an air compressor which 
fills in the engine itself, and beneath each car, a 
reservoir of compressed air. h.very reservoir 
aboard a long train in rapid motion may at the same instant, by a 
touch from the engine-runner, actuate the brakes so as to stop 
the train in the shortest possible time. This invention has accom- 
plished more for the safety of quick railroad travel than any other 
device; no wonder, then, that Westiughouse brakes are in all but 
universal use. They are now being adopted for trolley-cars which 
often require to be slopiicd in the briefest ])ossiblc period. The 
Westiughouse Com])any builds and installs elaborate signal sys- 
tems worked by compressed air and electricity. All these are de- 
scribed and jiictured in the ‘'Air I’rake Catechism,” by Robert U. 
Blackall, published by N. W. Henley & Co., New York. This 
book is constantly appearing in new editions, of which the reader 
should procure the latest. 



Pouring and ramming arc easier and cheaper than cutting and carving . . • 
Concrete for dwellings ensures comfort and safety from fire . . . 
Strengthened with steel it builds warehouses, factories and bridges of 
new excellence. 

S TONE and wood in the builder’s hands require skill and 
severe labor for their shaping; vastly simpler and easier is 
the task of molding a wall from wet clay, or other semi-plastic 
material. It was long ago discovered that certain mixtures of 
clay and sand, duly mingled and burned, became as hard as stone. 
To this discovery we owe, among other arts, that of brick-making. 
In joining brick to brick, or stone to stone, a mortar of uncommon 
strength was used by the Romans. All by itself, when laid a little 
at a time, it formed a strong and lasting structure. Then it oc- 
curred to some inventive builder. Why not save mortar by throw- 
ing ‘into it gravel and bits of broken stone? lie accordingly 
reared a wall of what we should now call rude concrete, whose 
lineal descendant to-day is a semi-plastic mass of Portland 
cement, sand, and gravel or broken stone, together with the neces- 
sary water. Its use allows the case and freedom of pouring, while 
affording structures with all the strength of stone or brick. 

For much of the early work lime and sand were mixed to make 
a mortar of the usual kind, in which stone or gravel was em- 
bedded. Afterward it was found that volcanic ashes, such as 
those of Puzzuoli near Naples, formed with .lime a compound 
which resisted water and was therefore suitable for structures 
exposed to damp or wet. In the middle ages concrete was em- 
ployed throughout Europe, after the Roman fashion, for both 




foundations and walls. Tn walls it was usually laid as a corr 
faced with stone masonry, large stones often being embedded in 
the mass. About T750, while building the third Eddystone Ligln- 
lK)Use, John Smeaton discovered that a limestone which con 
tained clay, when duly burnt, cooled, ground, and wetted, hard- 
ened under water, was indeed a natural cement, by which name it 
‘.s still known. Dc'posits suitable for the direct manufacture (U* 
natural cement were in 1818 discovered in Madison and ( 3 non 
daga Counties, New York, by Canvass White, an engineer who 
used this cement largely in building the Erie C'anal. Yatura’ 
cement has a jjowerful rival in Portland cement, due to Jose])li 
-Aspdin, of Leeds, who in 1824 uiixed slaked lime and clay, higlily 
calcined. The resulting clinker when ground, and only when 
ground, unites with water, the strength of the union increasint; 
with the fineness of the grinding. Pecausc this product look'^ 
like Portland st(U]e, much used in iMigland, it was given tiu* 
name of P(U*tland cement. The raw’ materials suitable for making 
it are widely distributed throughout North- America, much more 
w’idely than those from which natural cement may be had. 'Phis 
is the princi])al reason why P(Uiland cement is now' produced in 
the Ihiited States in about six- fold the ((uantity of natural cement. 

So rapidly has concrete grown in ])ublic favor with American 
builders that in H)05 they used seven-fold as much as in iSpo. 
It has been widely ado])ted for ])a\HMnents, as at P)ellefontaine, 
Ohio; f(U' breakwaters, as at (ialveston and C/hicago; for tnnneP. 
as in more than four miles of the New’ York Subway, d'lu- 
foundations beneath the ])ower-house of the Fnterboroiigh Rapi'l 
Transit C'om])any, Xew York, re(|iured 80,000 cubic yards: fm* 
the new’ station of the Pennsylvania Railroad Com])anv, New 
^^)rk, a much greater ({uantity is being employed; in tleir turn 
these figures will be far exceeded by the needs of the new Ch'otcn 
l^am for the water supply of Xew' York, and the Y^achuseii 
Dam for the w’ater supply of Poston. 

Camcrete has long been adopted for a variety of less ambition" 
purposes. At vSt. Denis, near Paris, it was many years ag" 
molded into a bridge of modest span. Tt lias formed thousantP 
of (hvcllings in factory and mining villages and towms, as w’cll a" 
many villas of handsome design. Tt is particularly w’cll adapted: 



for silos, as here illustrated.^ All this expansion of an old art 
has been stimulated by a steady reduction in the price of Port- 
land cement, and by constant improvement in its quality. As the 
manufacture has expanded, its standards have risen, its ma- 
chinery has become more economical and trustworthy in results. 
While the cost of concrete has thus been lowered by a fall in the 
price of cement, the wages of bricklayers and stone-masons have 

advanced, adding a new reason for building in concrete, since it 
requires in execution but little skilled labor. The gc^od points of 
concrete are manifold ; it forms a strong., fire-resisting, and damp- 
proof structure. For mills and factories another item of gain is 
that it forms a unit such as might be hewn out of a single huge 
rock, vibrating machinery therefore affects it much less than it 
docs an ordinary building. At the .same time its walls and floors 
obstruct sound, conducing to quiet. Concrete must be honestly 
made and used, otherwise, as in the case of rubbishy bricks, 

^The illustration of a silo and its foundation are taken l)y perinission 
from “Concrete Construction about the Ifome and f)n the T'ann,” copy- 
right T905 hy the Atlas Portland Cement Co., 30 l>road St,, New York. 
This book of 127 pages, fully illustrated, with instructions and specifica- 
tions, is sent gratis on request. 



ill laid, it may tumble down from its own weight. And further- 
more it is necessary to recognize how widely concretes of diverse 
composition vary in strength and durability. There should be a 

Concrete silo, Gedncy Farms, White Plains, N. Y. 

careful adaptation in each case of quality to requirement. Con- 
crete walls, as first produced, had a forbidding ugliness; this is 
being remedied by surfacings of pleasant neutral tones. A well 
designed residence executed. in concrete at Fort Thomas, Ken- 
tucky, is shown opposite this page. 

In Mr. Edison’s judgment a vast field awaits the concrete in- 
dustry in building small, cheap dwellings. He once said to me, 

I'kkkii-Coxstkuitmx Co.. Cixci.nxati. 



as he spoke of his cement mill,— “What I want to see is an archi- 
tect of the stamp of Mr. Stanford White of New York take up 
this material. Let him design half a dozen good dwellings for 
working people, all different. Each set of molds, executed in 
metal, would cost perhaps $20,000. Such dwellings could be 
poured in three hours, and be dry enough for (Kcupancy in ten 
days. A decent house of six rooms, as far as the shell would go, 
might cost only three hundred dollars or so. It would he stereo- 
typy over again and the expense for the models would disappear 
in the duplications r^eated all over the ccnmtrv.” 

Concrete is now supplied to builders in blocks, usually hollow 
and much larger than bricks. When cast in sand they look like 
stone. Of course, subjected as they arc to more than ordinary 
stresses, their production demands special care. Yhe methods, 
therefore, which arc adopted in manufacturing these blocks may 
be taken as the best practice in the industry broadly considered. 
Says Mr. H. II. Rice, of Denver “The sand em])loyed should 
be sharp, silicious and clean. The gravel used should contain a 
fair proportion of as large sizes as can be advantageously em- 
plo'ved in the particular machine used. Where gravel is not 
available, crushed stone takes its place. Care should he exercised 
to obtain stone as strong as the mortar. What proportions of 
sail 1, gravel and broken stone should he mixed together is a 
question determined by the extent of their voids : these may vary 
from one third to one half the whole volume. Assuming that 
we have to deal with the larger fraction, a mixture of i cement, 

2 sand, 4 gravel, should be enq^loycd ; this is classified as the 
lowest grade of fat mixture. y\t times a lean mixture, T cement, 

3 sand, 5 gravel, might be advantageously a(k)])te(l. Where 
gravel or broken stone is not used, the ])ro])orlion of cement to 
sand should he as i to 4. A fat mixture has greater tensile 
strength than a lean mixture, but resistance to com])rcssion de- 
pends upon a thorough filling of voids. A lean mixture thor- 
oughly worked, proves more satisfactory than a fat mixture with 
hasty and indifferent handling. With any mixture success is at- 
tained only by completely coating every grain of sand with 
cement, and every piece of stone or gravel with the sand-cement 
mortar. (Sec Mr. Umstcad’s results, page 240.) 



In producing concrete blocks there are three different 
methods, tamping, pressing, and pouring, each adapted to a par- 
ticular mixture for a special kind of work. Two-piece walls, de- 
vised in 1902, deserve a word of description. The pressed blocks 
of which they arc built show the new freedom conferred by con- 
crete as a building material. Each block has a long right-angle 
arm extcnditig inward from the middle, and a short arm extend- 
ing from each end. In laying the blocks in a wall no portion of a 

Wnll of two-piece concrete blocks. 
American Hydraulic Stone Co., Denver. 

block extends through the wall. By leaving the exterior vertical 
joints open to afford a free circulation of air, no part of a block 
on one side of the w\all touches any block from the opposite side ; 
this prevents the passage of moisture and produces in effect two 
walls, tied by the overlapping arms or webs in alternate courses^ 


and affording in its bond a great resistance, to lateral stresses. 
Illocks in other forms equally useful are steadily gaining 

Concrete, although widely available to the builder, is in many 
cases a material he cannot employ, h'or a store-house, thickness 
of wall, ensuring an equable temperature, is an advantage ; for 
an office-building, reared on costly ground, this thickness is out 
of the question, lleanis, too, cannot have much length in a 
material which is only one tenth as strong in tensile as in com- 
pressive resistance. ‘^Clearly the scojie for concrete by itself was 
to be limited unless it could find a partner able to confer strength 
while adding but slight bulk. An ex])erimcnt of the sinqilest was 
to be the turning point in a great industry. 

Concrete, as one of its minor uses, had often been molded into 
tubs for young trees and shrubs. In 1867, Joseph " Monier, a 
French garclener, in using tubs of this kind 
found them heavy and clumsy. \\y way of 
improvement he built others in which he em- 
bedded iron rods vertically in the concrete, 
securing thus a strong frame-work which per- 
mitted him to use but little concrete, and make 
tubs comparatively light and thin. MonicM* was not a man to rest 
satisfied with a single step in a path of so much promise. Before 
his day builders had joined concrete and metal, but without rec- 
ognizing the immense value of the alliance. Tie ])roc('eded to 
build tanks, ponds, and lloors of his united materials, at length 
rearing bridges of modest proportions. TTis work attracted at- 
tention in (iermany and Austria, as well as at home in P' ranee, 
so that soon reinforced concrete, as it was called, became a serious 
rival to brick and stone. ]"or two thousand years and more, co4i- 
crete had been a familiar re.source of the builder; to-day with a 
backbone of steel it fdls an imjx^rtant j)lact; between masonry and 
skeleton steel construction, boldly invading the territory of both. 

'Mr. If. 11. Rice’s first-prize paper on the manufacture of concrete 
blipcks and their use in Iniildin}:? construction appeared in the Cement Age, 
New York, October, Permission to use his paper and the illus- 

tration here presented, both copyrighted, has been courteously extended by 
the publishers. 

Concrete Rein- 
forced by a 
Backbone of 
Steel. Joseph 
Monier, the 



Reinforced concrete has been tlioroiij^hly studied with regard 
to its properties and the forms in which it may be best disposed. 

Since the strength of concrete is usually ten- 
Disposal of Steel greater in compression than in tension, 

in Reinforced designs should be compressive whenever pos- 
Concreie. sible, all tensile strains being carefully com- 

mitted to the steel. In arched bridges the 
strains are chiefly compressive, hence the success with which they 
arc executed in reinforced concrete. Afr. Edwin Thachcr of New 
York, eminent in this branch of engineering, secs no reason why 
spans of 500 feet should not be feasible and safe. Some remark- 
able discoveries have followed upon experiments with reinforce- 
ment diverse in form and variously placed within a mass. To 
increase the strength of a Sfiuare steel bar Air. E. L. Ransomc 
twists it into spiral form ; on scpiarc steel bars Air. A. L. Johnson 

Ran some bar. 

places ])rojections ; Air. hAlwin Thachcr rolls his steel into sec- 
tions alternately Hat and round. All these contours have large 

Cornigatod steel liar. St. Louis Expanded Metal Fire Proofing Co. 

surfaces at which metal and concrete adhere. Reinforcing bars 
desigtied by Air. Julius Kahn and by the Hennibifjue ('onstruc- 

Thaclicr bar. 


lion Company arc smooth, and slightly bent from straightness at 
intervals. In every ease the question is, Where will the tensile 

Kahn bar. 

strength of the steel do most good, because most needed? M. 
Considere has found that concrete hooped with steel wire has 


licnneliique armored concrete girder. 

more than twice the resistance of concrete in which an etpial 
amount of steel is centrally jdaced. In his floor constructions M. 

Matrai gives steel wires the 
^/STf^/suT/NG BARG curves tlicv woldd take under a 

1/ n ^ rj Kee])mg to its original 

^ ^ ’ lines the Abniier reinforcement of 

to-day consists in a rectangular 
netting of rods (;r wires. Some- 
what 'similar is the expanded 
metal backing invented by Mr. J. 
F. Colding ; it is sheet steel pierced 
with parallel rows of slits which 
are expanded until the metal as- 
sumes the form shown in an ac- 
companying illustration. A lock 
woven-wire fabric of galvanized 
steel wire is made by W. N. Wight & Company, New York, in 
any desired size of mesh, with an ultimate strength of 116,000 
pounds per square inch of metal. 



Monicr netting. 



For piling, reinforced concrete is extensively used. Its inde- 
pendence of moisture, its exemption from the ravages of the 
teredo, render it much preferable to timber for marine work. 

Expanded metal diamond lath. 

Reinforced concrete, like every other new building material, 
has called forth ingenuity in many ways. When, 
for instance, a factory is to be reared much in- 
ventive carpentry is required 
to plan and construct the Molds for Rein- 
forms, or molds, into which forced Concrete, 
the liciuid concrete is to be 
ix)ured around the steel skeletons. The foot- 
ings, outside and inside columns, walls, girders, 
beams, floor-plates, roofs, and stairs all require 
separate forms, intelligently devised with a view 
to economy. For the Ingalls lUiilding, Cincin- 
nati, the forms cost $5.85 per cubic yard of con- 
crete in place. White pine is the best wood for 
the puriK)se ; it is readily worked and keeps its 
expanded steel. shape when exposed to wind and weather. F(W 
common buildings a cheaper wood, spruce or fir, 
may be chosen; even hemlock will serve if a rough finish suffices. 

Built 1)1 concrete. Entrance. 



In most cases green lumber is preferable to dry as less affected by 
water in the concrete. In fine work the boards of which the 
molds arc made are oiled, and may 
be used over and over again. In all 
tasks a strict rule is that the re- 
inforcing metal be properly placed 
and remain undisturbed as work 

The Pugh Power r>uilding, 
erected for manufacturing purposes 
in Cincinnati, is a capital example of 
what can be done with reinforced 
concrete. It is 68 feet wide, 335 
long, and 159 high; its columns are 
spaced fourteen to seventeen feet 
longitudinally, twenty to twenty- 
three feet transversely ; the floors arc 

figured to bear a load of 230 iKiunds per square foot. In the same 
city is the Ingalls lUiilding, for offices, kx) by 50 feet, and 210 
feet high, designed by Air. E. L. Kansome of 
New York. Among other structures of his 
design, executed in the same material, is the 
St. Janies Episcojial Church, Hrooklvn, New 
York; buildings for the United Shoe Alachincry Conqiany, 
Beverly, Massachusetts, and jiiano factories for the h'oster-Arm- 
strong Company, Despatch, New York. The inspection sho])s of 
the Interborough Rajiid Transit C/onijKinv, W est 59th Street, 
New York, are also of reinforced concrete: no wood is used in 

Lock-woven wirc-f.ibric. 
W. N. WiRht & Co., 
Now N’ork. 

Buildings of 

wall or roof. 

Reinforced concrete forms nine bins in one of the grain 
elevators of the Canadian I’acific Railway at Port Arthur, On- 
tario, on the shore of Lake Superior. The walls arc nine inches 
thick, reinforced horizontally and vertically to a height of ninety 
feet and a diameter of thirty feet. There arc also four inter- 
mediate bins, the whole thirteen hohling 443,000 bushels. At 
South Chicago the Illinois Steel Cf)mpany has built four similar 
bins for the storage of cement, each twenty-five feet in diameter 
and fifty feet high, with walls five to seven inches thick. 



Many chimneys have been built of the new material; notably 
the chimney for the Pacific Coast Borax Company, Bayonne, 
^ New Jersey, 150 feet high, with an 

t O ■ ^ interior diameter of seven feet. These 

dimensions are exceeded at Los An- 
geles, California, where a chimney for 
the Pacific Electric Company rises 174 
feet alx)ve its foundations, with an in- 
side diameter of eleven feet. Both 
structures have hollow walls of the 
'Ransome type reinforced horizontally 
and vertically. 

'J'hat reinforced concrete serves to 
build chimneys and flues is proof of 
its fire-iTsisting quality. Concrete is 
a slow conductor of heat, and both it 
and steel have almost the same sliglit 
ex])ansibilitv as temperatures rise, so 
that they remain together in a fire. 
Terra cotta, wliicli expands much 
more than steel when heated, cracks 
off from the metal it was intended to 
])rotect, leaving it to bend or fuse in 
a blaze. Concrete, furthermore, be- 
haves well wlien its temperature is 
suddenly lowered, as when a fireman 
dashes a stream of water upon it at a 
fire. Ah’) wonder, then, that the re 
inforced concrete is more and more iii 
re((uest in cities as the material lor 
])uildings rising higher and standine 
more thickly on the ground than di 
buildings of old. . in the great fire 
San Francisco, April, 1906, reinforced concrete withstood ex 
trcnic tcinix'raturcs much better than any other material. It will 
he iart>cly n.scd in rebuilding the city. .. 

Frequently the question is asked. Is the steel in reinforced con- 

Coliiiiiii form, liii»al]s 
Building, Cincinnati. A, 
A, yokes. B, Ik spacing 
pieces. From “Rein- 
forced Concrete.” A. W. 
liuel and C. S. Hill. 
Copyright, loigineering 
Nows Puldishing Co., 
New York, 1904. 


24-, ^4 "rwsTED sr££L /eoos' 


crctc liable to corrosion, so that its walls arc likely to become weak 
and insecure after a few years? With careful jdannintj^ and faith- 
ful workmanship the results prove to he worthy of confidence. 
Professor Charles L. NovUm of IkKston has 
taken steel, clean and in all statics of cor- Resistance to 
rosion, and enilx'ddcd it in stone and cinder Rust, 

concrete, wet and dry mixtures, in carbon dioxide and sul- 
phurous g-ases ; other specimens were intermillently exixxsed 
to steam, hot water, and moist air 
for one to three montlis. Duly pnv 
tected by an inch or more of sound 
concrete the steel was absolutely 
unchanged while naked steel van- 
ished into streaks of rust. Mr. Ran- 
some says that in tearing- up a 
stretch of sidewalk in Powlinti^ 

Green Park, New York, in use 
twenty years, some embedded steel 
rods were found in ])erfect condition. 

The Turner Construction (/om])any, 
of New York, exposed coticrete 

blocks in whicli steel bars were embedded, and laid them on a 
b'Cacli at low tide where they were covered by salt water three 
or four hours every day; after nine months’ ex])osiire the blocks 
were broken disclosing- the bars free from rust. Professor 
Spencer I>. Newberry records that a water main at Grenoble, 
hTance, built on the Monier sy.stem, twelve inches in diameter, 
eip^hteen inches thick, containinjj^ a fntmework of i/iT) and 1/4 
inch steel rods, was found perfectly free from rust after fifteen 
years' service in damp <^round. Tfc also states that a retainini,^ 
wall of reinforced concrete in Herlin was examined after eleven 
years' use and the metal found uncorroded, except in some cases 
where the rods were only 0.3 or 0.4 inch from the surface. 

This waterproof ([uality of reinforced concrete recommends it 
as a material for tanks and reservoirs. In 1903 a water tower 
was built at Fort Revere, Massachusetts, for tlic United States 
Government, ninety-three feet in height, octagonal in section, en- 

Section of cliiniiu’y 
at Los An^rU‘s, Cal. 



cl()sin,c^ a tank twenty feet wide, fifty feet with walls six 

inches thick at the hottoni, three at the top, coated inside witli an 
inch of Portland cement. At Louisville, Kentucky, a reservoir 
has been built 394 by 460 feet, and about 
Tanks, twenty-five feet high. Its walls and columns 

Standpipes, concrete, its roof is in reinforced concrete 

Reservoirs. disposed as groined arches, each of nineteen 
feet clear span. A reservoir wholly of reinfcjrced concrete al 
Last Orange, New Jersey, is 139 by 240 feet, with a height of 

Coignet netting and hook. 

•22 1/3 feet. Tn the early days reinforced concrete was used for 
water-pipes: more than a hundred miles of such pipes arc now in 

Cross-section of conduit, Newark, N. J. Expanded metal reinforcement. 



service in Paris. \\'atcr-i)ii)cs nn the On^net system employ thin 
steel rods hooked at both ends and curved into encircliiiL:!^ hoops. 
Other rods laid lenc,nh\vise run thnnioh the hooks, so as to hold 
each part of the frame\v(u-k securely in place. At Newark, New 
Jersey, 4,000 feet of siiiii^le and i,5eH) leet of double bo-inch con- 
duits, reinforced with ^:5-ineh expanded steel, have ])een recently 

The material thus available for systems (^f water supply is also 
impressed into tasks c’)f sewerai;e. In I larrisburLf, Pennsylvania, 
a sewer of this kind three miles lou<;- 
interce])ts all other sewers, carrying' 
the wh(de stream below the city to an 
outfall in the Suscjiiehanna River. A 
water culvert, for somewhat similar 
duty, may on occasion be so heavily 
reinforced as to carry railroad tracks 
with safety, as in a culvert for a 
W'estern railroad shown in an ac- 
company i n i;- fi 541 ire. 

Part of the New ^'ork Subway is 
of reinforced concrete. Steel rods, 
about I ’4 inches S(|uare were laid at 

varying* distances aecordini;* to the different roof loads, from six 
to ten inches a])art. Ivods 1 Rs inches in diametc‘r tie the side 
walls, passing;* throui;h ani;le c<dumns in the 
walls and the bulb-an^le columns in the centre. 

T.a\ers of concrete were laid over the roof rods 
to a thickness of from eighteen to thirty inches, and carried two 

New York 

inches below' the rods, imbeddini;' tln'in. for the sides similar 
S(|uare rods and concrete were used and ani^le columns five feet 
a])art. The ccaicrete of the side walls is from fifteen to ei,i^htccn 
inches thick. 

At first, pro])crly enoui^h, reinforced concrete w'as ailoptcd 
w ith much caution in bridi::^e-buildin,!Li^. d o-day hundreds of 
bridp,*cs in this material are floin.LT service 
throujc^hout the w'orld. A e^nod exani])le of a Bridges, 

small liridq^e is that in I'oia'st Park, St. Louis, 
spanning;' the River des IV*res A notew’firthy desi.e^n on a large 
scale, by Professor William II. Purr, of Columbia University, 



New York, has been accepted for the Alemorial Bridge to cross 
the Potomac River at Washington. A centre-draw span of 159 

feet in steel is to be flanked on each side by three spans of re- 
inforced concrete, each of 192 feet. These spans are ribbed 

Memorial Bridge, Washington, D. C. 

arches, having a rise of twenty-nine feet, with their exteriors in 
granite masonry. In arguing for bridges in reinforced concrete, 
Mr. Edwin Thacher points out that under normal circumstances 



their steel is not strained to much more than one quarter of its 
elastic limit, so that a large reserved strength is available for 
emergencies, while the structure is more durable than a steel 
bridge and ultimately more economical, comparatively free from 
vibration and noise, proof against tornadoes and fire, and against 
floods also if the foundations are protected from scour. 



Improvements in ste.Tiii practice . . . Mechanical draft . . . Automatic 
stokers . . . Better boilers . . . Superheaters . . . Economical condens- 
ers . . . Steam turbines on land and sea. 

I N every industry a threshold question is how motive power may 
be had at the lowest cost. In this field within twenty years 
wholly new methods have been introduced, while old processes 

Francis vertical turbine wheel. Allis-Chalmers Co., Milwaukee. 



have been greatly aincnclcd. Thanks to economical water-wheels 
and generators, efficient transmission, and motors all but perfect, 
water-powers, as at Niagara Falls, now send electricity to thou- 
sands of distant workshops, to serve not only as an ideal means 
of actuation, but as a source of light, heat and chemical impulse. 
While electrical art has thus been marching forward, all the heat 
engines have been improved in every detail of construction. New 
valve-gears, economizers and superhealors, united with triple-ex- 
pansion cylinders of the boldest dimensions, worked at ])ressures 
and speeds greater than ever before, combine to make the best 
steam engines today vastly more elTcctive than those of a gen- 
eration ago. .And these engines are withal facing the aggressive 
rivalry of the steam turbines devised by l)e Laval, Parsons and 
Curtis, all much less heavy and bulky than engines, simpler to 
build and operate, while their motion is continuous instead of in- 
terrupted at every piston stroke. 

Competing with steam motors are the new gas engines, twice as 
efficient in converting heat into iiKHive j)ower. h'or this reason 
and because much im])rovement seems to ])e feasible in their de- 
signs, and in systems for sup])lying them with cheap gas, their 
adoption on a large scale in the near future ap])ears to be certain. 
Especially will this he the event should the turbine ])rinci|)lc be 
as successfully applied to gas as to steam motors. Already gases 
from coke ovens and blast furnaces, formerly thrown away or 
used only in ])art, arc being employed in gas engines with success. 

To-day the production of motive penver largely centres in 
stations so huge that they adopt with gain a])pHances too elaborate 
for use in small installations. At the; ])ower-housc of the Jntcr- 
lx)rough Rapid Transit 0)m])any, New York, for example, auto- 
matic machinery convews coal from barges to vast bunkers under 
the roof, an even distribution being elfected by self-reversing 
trippers. Twelve of the furnaces have automatic stokers. Ashes 
are removed by conveyors. Lubricating oil is ])umpcd to high 
rCvServoirs whence it descends to flush all the bearings ; it is then 
carried to filters from which it ])asses to another round of duty. 
It is plain that the huge scale of such a plant opens new doors to 
ingenuity, especially in the dovetailing of one service with an- 



In some central stations, as at Findlay, Ada, and Springfield, 
Ohio, the exhaust steam is utilized for district heating, so that 
the generation of motive power is merged into the larger field of 
fuel economy treated as a whole. Where there is a profitable 
market for exhaust steam it pays lo use a group of engines or 
turbines which arc either non-condensing, or only some of which 
are condensing, for the aim is not simply to use the motor which 
asks least fuel, but to install such motors and heaters as together 
will earn most for the capital invested. 

All experimental quadruple-expansion steam engine at Sibley 
College, Cornell University, has consumed but 9.27 pounds of 
steam of 500 pounds pressure per indicated 
Steam Engines. horse-power, with a mechanical efficiency of 
86.88 per cent. An Allis-Chalmers compound 
engine, tested December, 1905, at the Subway Power-house, New 
York, developed 7,300 horse-power from steam at 175 pounds 
pressure with a consumption of 11.96 ixninds of steam per in- 
dicated horse-power. The cylinders were not steam jacketed and 
no reheaters were used. This engine has two horizontal high 
pressure cylinders, 42 inches in diameter; and two vertical low 
pressure cylinders, 86 inches in diameter; all of 60 inch stroke. 
The four cylinders work on the same crank pin, with the effect of 
two cranks at right angles to each other in superseded designs. 
A similar engine, less powerful, is shown opposite this page. 

At this point let us put back the clock a little that we may un- 
derstand why tallness in chimneys is much less in vogue for steam 
plants than formerly, and why this change is 
found to be well worth while. A device at least 
two centuries old is the smoke-jack, of which a 
specimen lingers here and there in the museums and curiosity 
shops of England. The rotary motion of its vanes, due to the 
upward draft from a kitchen fire, was employed to turn a joint of 
meat as it roasted in front of the coals. To-day the successors of 
this primitive heat-mill are the cardboard or mica toys which, 
fastened to a stove-pipe, or close to a lamp chimney, set at work 
a carpenter with his saw, a laundress with her sad-iron, and so 
on. These playthings show us the simplest way in which heat can 
yield motive power; because simplest it prevails almost uni- 



St. Louis I^x position, 1004. 

Horizontal and vertical cylinders united to the same crank pin. 


versally, and yet it is wasteful in the extreme. Nobody for a 
moment would think of putting a wheel like that of a smoke-jack 
in a chimney so that the rising 
stream of hot gases might 
drive a sewing-machine or a 
churn, and yet for a task just 
as n'lechanical, namely, the 
pushing upward a chimney 
current itself, the heating that 
current to an extreme tem- 
perature is to-day the usual 
plan. Under good design the 
gases of combustion arc ob- 
liged to do all the work that 
can be Sfjueezed out of them; 
then and only then they are * 
sent into the chimney. What 
if their temperature be so low, 
comparatively, that their rise 
in the stack, if left to tlieiu- 
selves, is slow as compared with the rise in another stack of 
gases 300° hotter? One hundredth ])art, or even less, of the 
saved heat when applied through an engine to a fan will ensure 
as quick a breeze through the grate-bars as if the chimney gases 
were wastefully hot, and this while the chimney is but one eighth 
to one fourtji as tall as an old-fashioned structure. This Is the 
rea.son why mechanical draft is now adoi)ted far and wide in 
factories, mills and j)ower-bouses. The’ advantages which follow 
are manifold; the plant is rendered in(lei)endent of wind and 
weather, inferior fuels are thoroughly and ([uickly consumed, at 
times of uncommon demand a fire can be easily forced so as to 
increase the duty of the boilers. To-day in the best practice the 
feed water for the boilers is heated by the furnace gases just be- 
fore they enter the stack ; the l>iping for this ])urposc, formed into 
coils known as economizers, checks the chimney draft. This 
checking is readily overcome by mechanical draft, leaving the 
engineer a considerable net gain as fan and economizer are united. 
One incidental advantage in modern plants of sound design, and 





good management, is that they send forth but little smoke or none 
at all. With thorough combustion no smoke whatever leaves tlie 

The avoidance of smoke is promoted by the use of well de- 
signed mechanical stokers: two of the best are the Roney and 
the Jones models. The Jones apparatus force.s 
its fuel into the fire from beneath, so that its 
gases, passing upward through blazing coal, 
arc thoroughly consumed. 

In large plants the boilers arc usually of the water-tube variety, 
working at high pressures which may be increased at need. Mr. 

Walter 11. Snow says — “Until the recent past 
Boilers. the. steam generator or boiler and the manner 

of its operation received far less attention than 
they deserved. Although under the best conditions over 8o per 
cent, of the full calorific value of the fuel may l)e utilized in the 
production of steam, this high standard is seldom reached in 
ordinary practice. ]\lr. J. C. lloadley showed an efficiency of 
nearly 8<S per cent, in his tests of a warm-blast steam-boiler 
furnace witli air-heaters and mechanical draft, while Mr. W. II. 
Rrvan lias rejxirted eighty-six tests conducted under common 
conditions with ordinary fuel, u])on ])oilers of various tyt)es, whicli 
indicate an average efficiency of only 58 ])C'r cent., and have a 
range between a minimum of 34.6 per cent, obtained with a small 
vertical boiler, and a maximum of 81.32 per cent, with a water- 
tube boiler of impnn^ed setting, d'he possibilities of increased 
economy in ordinary boiler practice arc thus clearly evident.” 

iV cardinal iiuprcn’cment in steam engineering of late years has 
been in ])erfecting sujx’rheaters ; this advance owes much to the 
mineral oils now available for lubrication at 
Superheaters. temperatures which may be as high as 675'' 
I^'ahr. As steam expands to ])erform work it 
falls in temperature and much of it condenses as water, with 
marked loss of efficiency, with harm to its containers by severe 
hammering. A sui^erheater avoids this trouble by so raising tlx 
initial tem])erature of the steam that condensation cither cease 

' Tn his “Steam Boiler rractiee.” New York, John Wiley &; Sons, 1904 



altogether or is much lessened. The apparatus is usually a nest 
of tubes placed in the fire-box close to the boiler; or, the tubes 
may be heated by a fire of their own, away from the boiler. The 
Schmidt superheater has long, parallel bent tubes, connecting 
two parallel headers. It may be directly applied to locomotive 



Longitudinal section Cross-sec- sec- 

on a, b. tion on c, d. tic mi on e, f. 

Schmidt superlieater. 

boilers withonl csscntia.1 modification, and witbont clicckinpf the 
draft. ( )n the C anadian Pacific Railway about two bnndrcd 
.simple locomotives have been iirovided with superheaters, lower- 
ing the coal consumjition to S7, <S5, 8^^ and as lilth' as /ti ]x'r cemt. 
in com])arison with comjioiind engines having no sujierhcaters. 
At St. Louis in 1904 the IVnnsylvania Railroad conducted 
elaborate tests of diverse locomotives’, d'he m(»st economical 
compound engine each hour used 18.6 ])ounds of ordinary satu- 
rated steam ])er indicated horse-]R)wer. Aidecl Iw a superhc'aler 
this consumption was reduccfl to 16.6 pounds, a s.iving of HE75 
per cent. See i^ige 241. In (lermany ])orta 1 )le steam imgines of 
150 to 220 horse-])ower, su])erheating their steam to 170'" 

(Vntigrade above the temperature of saturation have, in comjiound 
types, reduced thicir demand for steam to 12.47 pounds jier horse- 
power hour and, in a triple-expansion moded, to 9.97 i)ounds. In 
all cases the steam pii)c takes the .shortest possible path between^ 
its superheater and its cylinder. 



By an knproved design Professor R. L. Weighton of Arm- 
strong College, Newcastlc-on-Tyne, has doubled the efficiency of 
the surface condenser, and reduced its con- 
improved sumption of water 44 per cent. In his ap- 
paratus the condensing water enters at the base, 
and leaves at the top, after several circuits instead of but two as 
in the ordinary condenser. This new apparatus is drained off in 
sections, instead of allowing the condensed steam to accumulate 
at the bottom, as in common practice. This sectional drainage is 
effected by dividing the interior into diaphragms somewhat in- 
clined to the horizontal, so that the water of condensation is re- 
moved as fast as formed and does not flow from the upper tubes 
over those beneath. The gain in this arrangement arises from 
the fact that the greater part of the condensation takes place in 
the upper part of a condenser, where the steam impinges first 
ujx)!! the tubes. 'Flic Weighton apparatus, in conjunction with 
dry air-pumps, shows a condensation of 36 pounds of steam per 
square foot of surface j)cr hour, with a reduction of pressure to 
one twentieth of barometric pressure (1J/2 inches as compared 
with 30) , using as condensing water 28 times as much as the feed 
water, at an inlet temperature of 50° Fahr. 

For a long time, and well into the nineteenth century, water was 
■lifted by pistons moving in cylindrical pumps. Meantime the 
turbine grew steadily in ^avor as a water- 
Steam Turbines. motor, arriving at last at high efficiency. This 
gave designers a hint to reverse the turbine 
and use it as a water lifter or pump : this machine, duly built, with 
a continuous instead of- an intermittent motion, showed much 
better results than the old-fashioned pump. The turbine-pump 
is accordingly adopted for many large waterworks, deep mines 
and similar installations. This advance from to-and-fro to rotary 
action extended irresistibly to steam as a motive power. It was 
clear that if steam could be employed in a turbine somewhat as 
water is, much of the complexity and loss inherent in reciprocating 
engines would be brushed aside. A pioneer inventor in this field 
was Gustave Patrick De Laval, of Stockholm, who constructed 
%is first steam turbine along the familiar lines of the Barker mill. 
Steam is so light that for its utmost utilization as a jet a velocity 



of about 2,000 feet a second is required, a rate which vo material 
is strong enough to allow. De Laval by using the most tenacious 
metals for his turbines is able to give their swiftest parts a speed 
of as much as 1400 feet a second. His apparatus is cheap, simple 
and efficient ; it is limited to alx^ut 300 horse-power. Its chief fea- 
ture is its divergent nozzde, which permits the outflowing steam to 

A, De Laval noi^zle and valve in section. B, Turbine buckets. 
C, Turbine wheel. 

expand fully with all the effect rcalizxd in a steam cylinder pro- 
vided with expansion valve gear. Another device of De Laval 
which makes his turbine a safe and desirable prime mover is the 
flexible shaft which has a little, self-righting play under the ex- 
treme pace of its rotation.’ 

Of direct action turbines the De Laval is the chief ; of com- 
pound turbines, in which the steam is expanded in successive 
stages, the first and most widely adopted was 
invented by the Hon. Charles A. Parsons of xhe Parsons 
Newcastlc-on-Tyne. From an address of his Steam Turbine* 

to the Institute of Electrical Engineers, early 
in 1905, the following narrative has been taken 


“In tlic 9arly clays of electric liglitin^ the speed of dynamos was 
far above that of the engines which drove them, and therefore 
belts and other forms of gearing had to be resorted to. To make 
a high-speed engine, tliercforc, was of considerable importance, 
and this led to the possibilities of the steam turbine being con- 
sidered. It was at once seen that the speed of any single turbine 
wheel driven by steam would be excessive without gearing, and 
in order to obtain direct driving it was necessary to adopt the 
coni]K)und form, in which there were a number of turbines in 
series, and thus, the steam being expanded by small increments, 
the velocity of rotation was reduced to moderate limits, h'ven 
then, for the small sizes of the dynamos at that time in use, the 
speed was high, and therefore a special dynamo had to be de- 
signed. Speaking generally, an increase of speed oPa dynaiuf) 
increases its outjiut, and therefore it was obvious that such a high- 
speed dynamo would be very economical of material. 

“These c:onsiderations led, in 1884, to the first compound steam 
turbine being constructed. It was of about to horse-power and 
ran .at 300 revolutions ])cr second, the diameter of tiie armature 
being about three inches. This machine, which worked satis- 
factorily for some years, is now in the South Kensington Museum, 
'rurbiues afterward constructed had two groups of 15 successive 
turliine wheels, or rows of blades, on one drum or shaft within a 
concentric case on the right and left of the steam inlet, the moving 
blades or vanes being in circumferential rows projecting out- 
wardly from the shaft and nearly touch-ing the case, and the fixed 
or guide blades being similarly formed and projecting inwardly 
from the case and nearly touching the shaft. A series of turbine 
wheels on one shaft were thus constituted, and each one complete 
in itself is like a parallel-flow water turbine, the steam, after per- 
forming its work in each turbine, passing on to the next, and 
jireserving its longitudinal velocity without shock, gradually fall- 
ing in pressure as it passes through each row of blades, and 
gradually expanding, h^ach successive row of blades was slightly 
larger in passage way than the preceding to allow for the in- 
creasing bulk of the elastic steain, and thus the velocity of flow 
was regulated so as to operate with the greatest degree of effi- 
ciency on each turbine of the series. ... It constituted an ideal 


rotary engine, but it had limitations. The c-oniparalivcly high 
speed of rotation necessary for so small an engine, made it difficult 
to avoid a whipping or springing of the shaft, so that considerable 
clearances were found obligatory, and leakage and loss of effi- 
ciency resulted. It was perceived that these defects would de- 
crease as the engine was enlarged, with a corresponding reduction 
of velocity. In 1888 therefore several turbo-alternators were built 
for electric lighting stations, all of the parallel-flow type and non- 
condensing. In 1894 the machines were much improved, the 
blade was bettered in its form, and throughout greater mechanical 
strength was attained. . . . Today (1905) under 140 pounds 
steam pressure, 100° Fahr. sii]>erheat, and a vacuum of 27 inches, 
the barometer being at 30 inches, the consumptions are in round 
numbers as follows: — A loo-kilowatt (134 horse-power) plant 
takes about 25 pounds of steam per kilowatt-hour at full load, a 
200-kilowatt (268 horse-power) takes 22 ])ounds, a 500-kilowatt 
(670 horse-power) takes 19 pounds, a 1,500-kilowatt (2,010 horse- 
power) 18 pounds, and a 3,000-kilowatt (4,020 horse-power) 16 
pounds (or 12 pounds per horse-power-hour). Without super- 
heat the consumptions arc about 10 per cent, more, and every 10° 
Fahr. of superheat up to about 150° lowers the consumption about 
I per cent. 

“A good vacuum is of great importance In a turbine, as the ex- 
pansion can be carried in the turbine right down to the vacuum 
of the condenser, a function which is ])ractically impossilde in the 
case of a reciprocating engine, on account of the excessive size 
of the low-pressure cylinder, ports, passages and valves which 
would be required. Every inch of vacuuih between 23 and 28 
inches lowers the consumption about 3 per cent, in a loo-kilowatt, 
4 per cent, in a 5 C) 0 -kilowatt, and 5 per cent, in a t, 500-kilowatt 
turbine, the effect being more at high vacua and less at low.’’ 

In 1894 Air. Parsons launched his “Turbinia,” the first steamer 
to be driven by a turbine. Her record was so gratifying that a 
succession of vessels, similarly equipped, were 
year by year built for excursion lines, for transit Marine Steam 
across the British Channel, for the British Turbines. 
Royal .Navy, and for mercantile marine service. 

The thirty-fifth of these ships, the “Victorian” of the Allan Line, 



was llic first to cross tlic Atlantic Ocean, arriving at Halifax, Nova 
Scotia, April i8, 1905. She was followed by the “Virginian’' of 
the same line which arrived at Quebec, May 8, 1905. Not long 
afterward the Cunard Company sent from Liverpool to New 
York the “Carmania’’ equipped with steam turbines, and in every 
other respect like the “Caronia” of the same owners, which is 
driven by reciprocating engines of the best model. Thus far the 
comparison between these two ships is in favor of the “Car- 
mania.” The new monster Cunarders, the “Lusitania” and the 
“Mauretania,” each of 70,000 horse-power, are to be propelled by 
steam turbines. The principal reasons for this preference are thus 
given by Professor Carl C. Thomas: — 

Decreased cost of operation as regards fuel, labor, oil, and 

Vibration due to machinery is avoided. 

Less weight of machinery and coal to be carried, resulting in 
greater s])eed. 

Greater simplicity of machinery in construction and operation, 
caUvsing less liability to accident and ])reakd()wn. 

Smaller and more deeply immersed propellers, decreasing the 
tendency of the machinery to race in rough weather. 

Lower centre of gravity of the machinery as a whole, and in- 
creased hcadr(X)m above the machinery. 

According to recent rei)orts, decreased first cost of machinery.^ 

'“Steam Turbines,” by Carl C. Thomas, professor of marine engineering, 
Cornell University, a comprehensive and authoritative work, fully illus- 
trated. New York, John Wiley & Sons, 1906. $3.50. 


Continued. IDEATING Sj‘:RVlCl-.S 

Producer . . . ^Moiul gas . . . P>last furnace gases . . . Gas engines 
, . . Steaiu and gas engines compared . . . J-)iesel oil engine best of 
all . . . Gasoline inotors . . . Alcohol engines . . . Steam and gas 
motors united . . . Heat and t)ovver profluction combined . . . District 
steam heating . . . Isolated plants . . . h'lectric traction and otlicr great 
services . . . Gas for a service of heat, light and power. 

S TEAM as motive power finds its most ‘formidable rival in 
cheap , leases, whose familiar varieties have l)een Inn^ used 
for illnmuiaticai. A simple experiment shows with what ease gas 
can be made, wliich, duly cooled, may be carried long* distiinces 
without the condensation which suluracts from 
the value of steam. Take a narrow tube of Gas-Power, 
metal f)r Jena glass, open at lx>th ends: put one 
end near the wick of a burning candle, at the otlicr end apply a 
lighted match, and at once a flame bursts forth. Here is a 
miniature gas-works ; close to tlic wick innanimahle gases arc gen- 
erated by the heat, before they have time to burn they are con- 
veyed through the tube to a point a foot distant where, on ignition, 
they yield a brilliant flame. Juilarge this operation so that instead 
of an ounce of wax ynw distill Ions of coal from hundreds of big 
retorts; set up a ga.s-liolder as huge as the dome (H the Capitol at 
Washington; instead of short tube lay miles of pipe through the 
avenues and streets of a city, and a trivial experiment widens into 
lighting a hundred thousand homes. So much for dividing coni- 
bustion in halves, by conducting gasification in one jdacc on a vast 
scale, and burning the produced gas whenever and wherever you 
please. One supreme advantage of llic process is that coal, wood 
and other sources of gas much cheaper than wax or oil can be 



employed. Alongside the retorts which gasify coal or wood are 
built scrubficrs which remove substances undcsired in the gas, — 
tar, sulphur, and so on,— all salable at good prices. It was in 1792 
that William Murdock,, an assistant to James Watt at the Soho 
Works near Birmingham, there originated gas-lighting. His 

enterprise was a seed-plot for 
a variety of industries which 
have reached commanding 
importance, and are to-day 
expanding faster than ever 
before. Illuminating gas 
from its first introduction has 
on occasion wrought dis- 
aster; when it leaks through 
a joint into a room it rapidly 
unites with air; instantly on 
the intrusion of a flame there 
is a violent explosion, that is, 
an abrui)t output of enormous 
energy set free under circum- 
stances which do only harm. 
Can the energy, as in tile case 
of blasting, be usefully di- 
rected ? 

Yes, as long ago as 1794, Robert Street designed a inmi]) driven 
by the explosion of turpentine vapor below the motor piston. He 
' was followed by inventors who used illuminating gas as their 
propelling agent; among these, in i860, was Lenoir of Baris, who 
built a double-acting engine with a jump-spark electric igniter 
such as to-day is in general use. His engine consumed 95 feet of 
gas per hour for each horse-power, which meant that commercially 
the engine was a failure. Lenoir^s design has been so much im- 
proved that now large gas engines yield in motive power one fifth 
of the wdiole value of their fuel, an efficiency twice that of the best 
steam engines or turbines, and five-fold better than that of 
Lenoir’s apparatus. 

How this remarkable result has been attained we shall consider 
a little further on, as wc briefly examine the construction of a 

Conihustiblc gas from- a candle is taken 
through a tube to a distance and 
there Inirnt. 



typical gas engine. At this point let us note how a c^as, suitable 
for an engine, is manufactured at least cost, the outlay being 
much less than in the case ot dliuninatiug gas which rejiresents 
but one third of the coal placed in the distilling retorts. Instead 
of this process (^f distillation, “producer” gas 
is due to a modified comhiistion which gasifies Producer Gas. 
all the fuel. In a jiroduccr of standard type, 
atmosjiheric oxygen comes into contact with tlv' glowing carbon of 
the coal or wood, forming carbon dioxide, C'O-. 'fhe heat gen- 
erated by this union is taken up by the carbon dioxide and the 
nitrogen of the supjilied air. ddiese gases as they rise through the 
fuel bring it to incandescence so that the carbon dioxide t d<cs up 
another atom of carbon, becoming carbon monoxide, C'( ). a bighly 
combustible gas. W ere there no im])urities in the fuel, were the 
entering air (piite free from moisture, the gases would be iir vol- 
ume 34.7 per cent, carbon monoxide and (>5.3 ]ier cent, nitrogen, 
with a heating value per cubic foot of about i iS llritish thermal 
units, a unit being the heal needed to raise a pound of water to 
40° I'ahr. from 3</\ where its density is at the maximum, (las- 
thus produced is intensely hot ; and as usually it contains suliihur, 
dust, dirt, and other admixtures, their removal by water in a 
scrubbeV would involve a waste of .about 30 jier cent, of the fuel 
heat, d'his loss is much diniinished by sending into the producer 
not only air but steam, to be decomposed into oxygen and hy- 
drogen; the oxygen combines with carbon to form more carbon 
monoxide, while the hydrogen is the most vahialde heating in- 
gredient in the emitted of gases. W'ere only air sent 
through llu‘ ])roducer, the outllowing gases would contain nitrogen 
to the extent of 63 jier cent. ; with a charge in ])art air and in part 
steam, this percentage falls to 52; as nitrogen is useless and waste- 
fully absorbs heat, this reduction of its (juantity is gainful. I>y a 
duly regulated admission of steam, a pn^ducer is kept at a tem- 
perature high enough to decom])ose steam, but not so high as to 
send forth gases unduly hot to the ])urifier. 

For water-gas the method is to bknv steam into the fuel until 
decomposition ceases ; the steam is then shut off, the fire allowed 
to recover intense heat, when mure steam is iiijected, and so on 



Producer gas is in more exten ;ivc use than water-gas. It is 
evolved in apparatus of many gc jd designs : let us glance at the 
Taylor gas producer built by R. D. Wood 
A Gas Producer. Company, Philadelphia. Its fuel enters in a 
steady stream, in controlled quantity, through 
a Bildt automatic feed which has a constantly rotating distributor 
with dellccting surfaces. The incandescent fuel is carried on a 

bed of ashes several feet thick, so 
that the coal gradually burns out 
and cools before its ashes arc dis- 
charged. Through a conduit an 
airblast is carried up through 
this layer of ashes to where the 
fuel is aglow ; united with this 
airblast is a pipe admitting steam : 
the united air and steam are 
emitted radially. In the ])roducer 
walls are sight or test holes so 
placed that the line dividing ashes 
from glowing fuel may at any 
time be observed. When this line 
becomes higher on one side tlian 
the other, scrapers, duly arranged, 
are used. At the bottom of the 
])roducer is a Taylor rotative 
table which grinds out the ashes 
as fast as they rise above the de- 
sired de])th, say every si.x to 
twenty- four hours, according to 
the rate of working. In large pro- 
R. D. Wood & Co., Philadelphia, ducers the ash bed is kept al)oiil 

three and a half feet deep, so that 
any coal that may the jx^int of air admission has amj)le tinn' 
to burn entirely out : in a producer with an ordinary grate such 
coal would fall waste fully into the ashpit. As the Taylor ash 
table turns it grinds the lower part of the fuel bed, closing an\ 
channels formed by the airblast, and restraining the formation of 
carbon dioxide, a useless product, to a minimum. A few impulses 


of the crank at frequent intervals maintain the fuel in*soli(l con- 
dition, reducing- the need of poking from above. 

Other American producers differ from tlie W'ood aj)paratus in 
details of design and operation; in principle all are much alike. 
Any good producer works well with cheap fuels, bituminous coals 
of inferior quality, culm, lignite, wood, peat, tanhark, and even 
straw fn)m the thresher. With each of these t’^-ere must he due 
modification of mechanism, together with means of forcing air 
and steam into the fire. A suction plant may he employed when 
superior fuels are ]:)urned, coke, anthracite, or charcoal: with cur- 
rents of air and steam automatically drawn into the producer, 
the surrounding room is not likely to he tilled with the harmful 
gases which may he occasionally ejected hy a pressure ])lant. 

England has gas-power installations much larger atuLinore 
elaborate than those of America. Of these the most extensive 
have been built by the Power-gas C\)rporation 
in London, under the ])atents of Mond, Duff Mond Gas. 
and Talbot. .\ Mond ])lant yields a gas having 
84 per cent, of the calorific value of tlu' coal consumed, which may 
be slack at six shillings, $i.4t), per ton. Where more than thirty 
tons of coal per day are used, it is worth while intercejiting the 
sulidiate of amiiKinia, amounting to <;o pounds ])er ton of coal, 
which in small ])roducers cannot readily be seized. Mond gas 
is free from tar, is cleansed of soot and dust, and holds less sul- 
phur than ordinary pro<lucer gas, ( )peration is sinqile enough : 
first of all the slack is brought into hoppers above the ])rodiicers. 
hTom these it is fed in charges, of from 309 to 1,000 ])ounds, into 
the producer bell, where the first heating takes ])lace : the products 
of distillation pass downward into the hot zone of fuel before 
joining the bulk of gas leaving the producer. 'Vh\s converts the 
tar into a fixed gas, and pre])ares the slack for descent into the 
body of the producer, where it is acted upon by an airblast satu- 
rated with steam at 185° Fahr., and siqierheated before coming 
into contact with the fuel. The stream of hot gases from the 
producer now traverses a washer, a rectangular iron chamber with 
side lutes, where a water spray thrown by revolving dashers brings 
down the temperature of the gases to about 194° I'ahr. In plants 
which recover the ammonia sulphate, the gas takes its way through 



a lead-Hntcl tower, filled with tiles of large surface, where it meets 
a downward flow of acid liquor, circulated by pumps, containing 
ammonia sulphate with about 4 per cent, excess of free sulphuric 
acid. Combination of the ammonia with this free acid ensues, 
yielding still more ammonia sulphate. The gases, freed from 
their ammonia, are conducted into a cooling tower, where they 
meet a descending shower of cold water effecting a further 
cleansing before the gases enter the main pipe for delivery to con- 
sumers. Jn its general ])lan, a Mond plant resembles an illuini- 
natirig gas works, especially in its seizure of profitable by-pro- 
ducts. A ton of slack costing in England $1.46 yields 90 pounds 
of ammonia sulphate worth $1.92 or thereabout.^ 

I^'or many years flames from blast furnaces and coke ovens testi 
fied to the waste of valuable gases, in especial the combustible car- 
bon monoxide which is the main ingredient in 
Blast Furnace i)ro(lucer gas. When we learn that coal or coke 
in iron-smelting ])arts with but three per cent, 
of its heat to the ore, we begin to see how grievous was the waste 
so' long endured. I'or a few 3'ears past the gases sent forth from 
blast furnaces have beeti employed to heat the incoming air for 
the blowers, and to raise steam for engines. Wdth twice the effi- 
ciency of steam motors the gas engine renders it well worth while 
to rid furnace gases of their dust and dirt so that they may not 
injure the mechanism they inqiel. An effective cleanser acts hv 
separating the gases from their admixtures by centrifugal force. 
At the Lackawanna Steel Works, Iluffalo, N. Y., eight gas-en- 
gines, each of t,ooo horse-])ower, are run on blast furnace gases. 
It may well prove that installations of this kind will bring other 
blast furnaces into cities where the sale of electricity will form a 
large item in the jirofits. 

The first gas engines used gas and air at ordinary atmospheric 
pressure ;'ht due intervals the charge was exjiloded by a glowing 
hot tube exposed by a slide-valve, or, according 
Gas Engines. to the practice now general, by an electric spark 
of the jump variety. In 1862 De Rochas 

^“Producer-gas and Gas-producers,’’ by Samuel S. kVyer, is a treatise* 
of value, fully illustrated. New York, Engineering and Mining Journal. 
1906. $4.00. 



patented, and in 1876 Otto built, an engine on a model still in 
favor. Its cardinal feature is the compression of each charge. 
In the field of steam practice, we know how great economy is real- 
i;'ed by beginning work with high pressures. A similar g^jin at- 

Foiir-cycle gas engine. 1, admission v.ulvc. 
O, exhaust valve. 

tends the compression of gases in a cylinder before explosion ; 
whatever their pressure before ignition, it is trel^led or quadruf)le(l 
by ignition, returning a' handsome profit on the work of compres- 
sion. The four-cycle operation devised by ])e Rochas proceeds 
thus .-—First, by drawing in a mixture of gas and air in due per- 
centages during an outward stroke of the inston. Second, this 
charge is compressed by an inward piston stroke. Third, the com- 
pression charge is ignited, preferably by an electric spark, when 



the piston, moves outward by virtue of a pressure initially ex- 
treme. Fourth, the exhaust valve opens and the spent gases are 
ejected as the piston returns to complete its cycle. As but one of 
the four piston journeys is a working stroke, it is necessary to 
employ a heavy llywheel to equalize the motion of the engine. 
When two or more engines are united, their piston rods are so 
connected to a common shaft as to distribute the working strokes 
with the best balancing effect. With four engines their piston 
rods may be arranged at distances a])art of (jo degrees, so that one 
wf)rking stroke is always being exerted. This plan is adopted for 
the gasoline engines of automobiles so that they are served by 
fly-wheels com])aratively small. 

In his work on the gas engine, Frofessor 1". R. Hutton dis- 
ciiss('s t!ie advantages amf disadvantages of that motor. ^ By his 
kind i>c rmissinn his main conclusions may be thus summarized, 
first as to advantages: — 

The heat energy acts directly upon the ])iston. without inter- 
vening a])i)liances. f uel economy is greater than with steam, be- 
cause there is no furnace or chimney to waste any heat. No fuel 
is wasted in starting the motor, or after the engine* sto])s. The 
bulk, weight and cost of a furnace and boiler are eliminated, as 
well as their losses by radiation. A gas inotiu* Ixis a iiortability 
which lends itself to inii)ortant industries, as logging and lumber- 
ing. Tt may be started at once, with no delay as in getting up a 
lire under a boiler; wlu'ii the fuel-su])ply is cut off, the motor 
stojis and needs no attention : these are important in automobile 
practice, (las engines are gainfully united to systems of gas 
storage so that a ])r(^ducer may be run at high efficiency when C(ai- 
venient, and its gas held in holders till needed : this is helpful 
wdien a jdant is worked overtime, or is liable to stresses of ex- 
treme demand at certain hours of the day. Incident to this is the 
advantage of subdividing pow er units in a large plant : each motor 
may receive its gas in tripes wdthout loss, to be operated at wall. 
'Vho ra]')idity of fiaine pnq^agation renders possible a high num- 

^ “The Gas-eiii^ine: a treatise on -the internal-conihnstion engine usini? 
ji:as, j>as()line. kef<’>sene, or other hydro-cart on as source of energy.” By 
I'. R. llntton, professor of mechanical engineering in Colnml)ia University. 
New York. John Wiley & Sons. $5 (X). 



ber of shaft rotations per niiiuUo, so that a nuilti-cylindcr engine 
weighs little in coinparis(')n with its power. There is no liability 
to boiler explosion, or trouble from im]nirities deposited by water 
in a boiler. There is no ex])osed ilame or fuel-bed recjuiring at- 
tention. 'Idle mechanism of the motor is simple, and its moving 
parts arc few. A gas or oil engine furthermore enjoys a com- 
bustion which is smokeless. T be fuel recjuires no diluting excess 
of air, with its cooling effect and incidental waste of energy. 
Dust, sparks and ashes are avoided, with diminished risk cT fire. 
Li(juid or gaseous fuel can be served by pumiis or blowers so that 
the cost of handling is avoided. 

As to disadvantages : — In a four-cycle engine there is but one 
working stroke in four piston traverses. In a two-cycle engine 
there is one working stroke in two traverses, b'or a given mean 
])ressure the cylinder of a gas engine must be larger than a double 
acting steam cylinder. In single cylinder gas engines the crank 
effort is irregular; hence a heavy lly-wheel is re(|uired, or, a num- 
ber of cylinders must be joined together, adding much weight. 
'The motor does not start lyv the simjde motion (^f a lever or valve. 
It has to be started by an auxiliary apparatus stored with energy 
enough to cause one working stroke. A steam engine may be 
overkxided to meet brief demands for extra power: not so with 
a gas engine. The extreme temjieratures of the cylinder re([uire 
cooling systems by air or water, adding weight and involving 
waste of energy; these temperatures furthermore may seriously 
distort the mechanism while rendering lubrication difficult and 
uncertain. lAxjjkrsions of some violence may occur in exhaust pijies 
and passages, unless the engine is carefully adjusted and o|)er- 
ated. Im])erfect combustion clogs the working ])arts wdth soot or 
lampblack, especially injuring the ignition appliances. Initial 
pressures are so high as to cause vibration and jar. (loverning is 
not easy, since ex])losion .is all but instantaneous, d'hc normal 
motor runs at maximum efficiency fmly wdien running at a certain 
speed. To varv that sj^eed is much more tnniblesfnne and waste- 
ful of energy than with the steam engine. 

Gas engines united to gas jiroducers have been em])loycd with 
success on shipboard. This field, wdth its high premium on fuel 
reduction, w'hicli means more space for cargo, is likely to be 



largely developed in the near future. Soon, also, vve may cxpec: 
locomotives to exhibit a like combination with profitable results. 

During 1904 and 1905 the U. S. Geological Survey compared 
at vSt. Louis a steam engine with a gas engine, each of 250 horse- 
j)ower, using 24 varieties of lignites and bitu- 
ininous coals. The steam engine was of a 
Compared simjdc, uon-condensiiig, un jacketed Corliss 
type, from the Allis-Chalmers Company, Mil- 
waukee. The gas engine was a three-cylinder, vertical model 
from the Westinglnjuse Machine Company, Pittsburg. Its gas 
was sup])lied by a 'i'aylor gas producer furnished by R. D. Wood 
Company, Philadelphia, of the design illustralfed on page 460. 
The official report in ^hree parts, fully illustrated, presenting 
the tests in detail, was published by the Survey early in 1906. On 
l)age 97<S, of the second ])art, 14 comparative tests are summarized. 
They show that in the gas ])lant on an average 1.70 pounds of fuel 
were consumed in ])roducing for one hour one electrical horse- 
power ; in the steam i)lant the consumption was 4.29 pounds, two 
and a half times as much. With ai)])aratus ada])ted to a particular 
fuel, with larger and more economical engines, better results 
would have been shown both by steam and gas. Yet competent 
critics believe that the ratio of net results would have remained 

much the same, ddie most imi)ortant fact brought out in the 
tests is that some fuels, lignites from North Dakota for example, 
have little worth in raising steam, and high value in producing 
gas ; their moisture is a detriment under a boiler, it is an advantage 
in a gas j^roducer. d'he cost of this investigation is likely to be 
repaid many thousand- fold in pointing out the best way to use 
fuels whicb abound in the Western and Northwestern States and 

in Canada. See note, page 24T. 

In some cases petroleum is the best available fuel for an engine, 
essentially much the same as a gas motor. A carburetor, or atom- 
izer, blows the oil into a fine mist almost as in- 
Oil Engines. flammable 4s gas. In small sizes for launches, 
threshing machines, or work-shops of limited 
area, the petroleum engine is a cajdtal servant. In sizes of 75 
horse-power and upward the Diesel engine is not only the best oil 
engine but the most efficient heat-motor ever invented. It involves 


a principle as important as that of W'att's separate t'ondenser for 
the steam from his cylinder. 

To understand the Diesel principle let us he,i»in hv remembering 
that to the compression of a charge in a gas engine there is a 
moderate limit; if this he exceeded the heat of compression 
prematurely ignites the gases, so as to i)revent due action. The 
air in a bicycle tire is Cfinipressed but iiKnlerately, and yet every 
man who has worked a bicycle air-]nimp with energy knows that 
soon its cylinder gnnvs warm to the touch. ( )n this very ])rin- 
ciple, that mechanical work is convertible into heat, our grand- 
fathers had an ingenious mode of producing fire. In a syringe 
with a glass ifarrel they jdaced a piston fitting snugly. In a cavity 
of this piston they fastened a bit of^ cotton wool soaked in bisul- 
phide of carbon. On forcing the piston suddenly into the cylinder, 

Fire Syringe. 

the air, quickly compressed, became hot enough to set tlie cotton 
wool on fire. The heat evolved in the compression of air is turned 
to account in the Diesel oil engine so as to make it the most eco- 
nomical converter of heat into work ever devised, f irst the me- 
chanism compresses air alone to 500 ])ounds iier sipiare inch, then 
and then only the oil for combustion is injected, to take fire in- 
stantly from the heat of the compressed air. A governor regu- 
lates the period of burning; this is usually during one tenth jiart 
of the stroke, the exjxinsion of the burned products com])Ieting 
the stroke. Tlecause 500 i)ounds is a jiressiire out of tlu‘ (jtu'stion 
for the compression of the mixed charge of air and combustible 
gas in an ordinary gas cylinder, the l)i(*sel engine excels in econ- 
omy any gas engine thus far built. At (dient in 1^03 a Diesel en- 
gine develoned 765 bmke liorse-t^ower from crude I exas oil with 
the extraordinary net efficiency of 32.3 per cent. At the .St. Louis 



J^xposition, J904, three Diesel engines, using oil costing three 
cents per gallon, delivered for seven months, during eleven hours 
each day, at half -load, an average of 250 kilowatts at an expense 
for fuel of hut three tenths of one cent per kilowatt hour on 
the switcliboard, including all generator and line losses. En- 
gineers of the first rank are convinced that the Diesel principle 

may be successfull\ diodied in gas engines. That done, with a 

success approaching the effectiveness of Diesel’s oil motor, we 
may ex])ect steam engines and turbines to be largely dismissed 
from service. 

(iasoline, although higher in price than petroleum, is commonly 
used in automobiles and launches. It can be atomized more 
(juickly and fully, and without heat. To equal- 
Gasoline Engines, ize motion, minimize jars, and reduce the 
weight of its fly-wheel, an automobile of high 
power has usually four cylinders with cranks set at an angle of 90 
degrees with each other. The inlet valve is operated positively 
and, as a rule, is interchangeable with the exhaust valve. The 
ignition sjiark is furnished by a uKHor-driven magneto, or by a 
battery operating an induction coil; the lubricant is distributed by 
a sight-feed system, hand regulated. Cooling is effected by water 
circulated by a ])ump through jackets surrounding all cylinders 
and valves, each jacket having a surface of the utmost extent upon 
which a swiftly rotated fan drives a stream of air. 

l"or S(Mne years h'rance and Cermany have used alcohol as a 
fuel in engines, no excise tax being imposed on alcohol employed 
for industrial ])ur]X)ses. On January i, 1907, 
Alcohol Engines, this will also be the case in the Cnited States, so 
that we may expect alcohol to take a leading 
place as fuel in motors. “It has,” says Professor Elihu Thom- 
son, ^‘gallon for gallon less heating jx^wer than gasoline, but ecjual 
efficiency in an internal combustion engine, because it throws away 
less heat in waste gases and in the water jacket. A mixture of 
alcohol vapor with air stands a much higher compression than 
docs a mixture of gasoline and air without premature explosion. 
. . . There is now beginning an application of the internal com- 
bustion engine f(U* railroad cars on short lines which are feeders 
to main lines. The growth of this business may be hampered in 


the near future by the cost of gasoline. Tn this case alcohol, pro- 
ducible in unlimited ‘amount, could be substituted.” 

An important advantage in using alct^hol is its comparative 
safety. In case of fire oils and gasolines Ih^it on the water in- 
tended to quench a blaze; alcohol blends with that water and the 
flame is subdued. 

Whether oil, gasoline or alcohol be their fuel, internal com- 
bustion motors gain steadily in public acceptance. On the farm 
they are gradually displacing the horse. An engine, which costs 
nothing when it is idle, shells corn, saws wood, cuts fodder, grinds 
feed, separates and churns cream, drives a thrasher, turns a mill, 
lifts water, and performs a hundred other chores ([iiickly, simply 
and cheaply. 

Mr. Henry (]. Stott, chief engineer of the Interborough Rapid 
Transit Company, New York, has recently discussed ])ower plant 
economies in so thorough and suggestive a 
manner as to elicit the interest t)f engineers the steam and Gas 
world over.’ ilasing his remarks on the records Motors United, 
of the huge plant of his Comi)any at 74th Street 
and the East River, New York, he ])resents this table of the 
average losses in converting the heat from one pound of coal into 

Heat of the coal as hurned, 14,150 llritish thennal units 100.0% 

Returned by feed water heater 3.r 

“ ‘‘ economizer 6.8 


T.oss in ashes 2.4% 

T.oss to stack 22.7 

T.oss in boiler radiation and leakaj^e 8.0 

Loss in pipe radiation 0.2 

Delivered to circulator 1.6 

“ “ feed pump 1.4 

T.oss in Icakaj^e and high pressure drips i.i 

Delivered to small auxiliaries 0.4 

Heating 0.2 

Loss in engine friction 0.8 

^Before the American Institute of Electrical Engineers, New York, 
January 26, 1906. 



Electrical losses 0.3 

Engine racliatifm losses t 0.2 

Rejected to condenser 60.1 

To house auxiliaries 0.2 99.6 

Deliv'cred to biis-har 10.3% 

Carlion (Iiox.i(le (CXT) is absorbed by a solution of caustic pot- 
ash. The Ados recorder based upon this absorption has enabled 
IVlr. Stott to learn the ])ro])ortion of carlx^n dioxide in the gases 
passing to the stack, the higher that proportion, the more thorough 
the combustion. He finds first as an element oi economy careful 
firing, so as to avoid “holes” or thin places in a fire, through 
which air waste fully pours, chilling the furnace. Next in im- 
pcjrtance is adajiting draft to fuel: small anthracite requires a 
draft of 1.5 inches of water; with a draft of but .2 inch of water 
one pound of dry bituminous coal has cva])orated to.6 pounds of 
water, with a draft of i inch this fell to 8.7 ])ounds. Mr. Stott 
CvStimates that scientific methods of firing can reduce losses to the 
stack, to 12.7 per cent., and possibly to ’o jier cent. 

Resiiecting the loss of 8 ]K‘r cent, in boiler radiation and leak- 
age, he maintains that this is largely due to the inefficient setting 
of brick which, besides permitting radiation, admits much air by 
infiltration, 'file remedy is to employ the best methods of boiler 
setting, such as an iron-jilatc air-tight case enclosing a carbonate 
of magnesia lining outside the brickwork. 

Regarding the main loss, that of 60.1 per cent, to the condenser, 
Mr. Stott iioints out that sujierheating could reduce thisdiy 6 per 
cent. He observes that in the higher pressures of a steam cvcle 
a reci]M’ocating engine has an advantage, while in the lower jires- 
sures a steam turbine is more efficient. Combine them, he re- 
marks, and use each where it is the more profitable. Ihit in his 
view for the utmost economy a new type of plant should unite 
both steam and gas driven units. 

“Over a year ago,” he says, “while watching the effect of 
putting a large steam turbine having a sensitive governor in con- 
nection with recijirocating engine-driven units having sluggish 
governors, it occurred to me that here was the solut’on of the gas 
engine problem ; for the turbine immediately proceeded to act like 


an ideal storage battery; that is, a storage battery whose potential 
will not fall at the nionient of taking up load, lor all the load 
fluctuations of the plant wore taken up by the steam turbine, and 
the reciprocating engin \s went on carrying almost constant loads, 
whilst the turbine load fluctuated between nothing and 8,000 kilo- 
watts in periods of less tlian ten seconds. 

‘The combination of gas engines and steam turbines in a single 
plant promises improved efficiency wliilst removing the o])jeclion 
to the gas engine, namely, its inability to carry heavy overloads. 
A steam turbine can easily be designed to take care of loo per 
cent, overload for a few seconds; and as the load lluctuation in 
any plant will probably not average more than 25 per cent, with a 
maximum of 50 per cent, for a few seconds, it would seem that if 
a plant were designed to operate nonnally with one lialf its ca- 
pacity in gas engines and one half in steam turbines, any thictua- 
tions of load likely to arise in i)ractice could be taken care of.” 

Discussing in detail the ])erformance of such a plant, Mr. Stott 
concludes that its average total thermal efficiency would be 24.5 
per cent., as against to. 3 per cent, in the plant whose record he 
had presented. 

In the bill of particulars drawn up by Mr. Stott it was shown 
that no less than 60,1 per cent, of the total heat from his fuel had 
gone into the condenser where, joined to the 
stream of the East River, it had been wasted. Heating and 
Had he used non-condensing motors the loss in Power Produc 
exhausts would have been larger, and yet when 
a non-condensing motor is joined to a heating ])lant the whole 
investment may be much more profltable than where condensing 
motors throw away all the heal of tlieir exhausts. Long ago some 
pioneer of unrecorded name, using a non-c(jndensing steam en- 
gine, warmed his factory or mill with its exhaust steam. In sum- 
mer that steam sped idly into the air, in winter it saved him so 
much coal that his motive i)ower cost him almost n( 4 hing. ]\y 
thus uniting the production of ])ower and heat he showed, as few 
men have shown, how a great waste may be exchanged for a large 
profit. In the Northern States and in ('anada the main use for 
fuel is for heating not only dwellings, but the furnaces that pour 
out iron and steel, the ovens that bake pottery, tiles, and so on. 



When but .moderate temperatures are desired, as in warming a 
house, exhaust steam serves admirably, and so might ihe exhausts 
from gas engines. Indeed we here strike the key-note of modem 
fuel economy which is that wherever possible fuel should first 
deliver all the motive power that can be squeezed out of it, when 
and only when the remainder of its heat, much the larger part of 
the whole, should be used for warming.’ This plan, already 
adopted in a good many cases, can be vastly extended with profit. 
In blast furnaces the first task of the fuel is performed at an ex- 
treme tem])erature ; that work com])leted the gases of combustion 
may be ])urified and sent into gas engines to ])roduce motive power 
at little cost. 

A word was said on page 380 regarding the method now grow- 
ing in favor for heating machine-shops Ijy sending warmed air 
where it is needed, and not allowing it to go 
Heating and where it w^ould ])roceed of itself and be wasted. 

VentUaUng by illustrations show a Sturtevant ventilating 

fan-wheel, without its casing, and a Afonogram 
exhauster and solid base heater, as used in many modern installa- 
tions. The net gain in send- 
ing warmed air just where it 
does most good is comparable 
with the profit in mechanical 
draft for a furnace as com- 
pared with natural draft. 
Either live or exhaust steam 
may be used in the heating 
coils through which the air is 
forced by the fan. See also 
illustration on page 380. 
Steam jdants which f’u*- 

Sturtevant fan-wheel, without' heat and electricity 

its casing. are being ra]ndly multiplied 

'An excellent work, “The Heating and Ventilating of Buildings,” hy 
Rolla C. Carpenter, professor of experimental engineering, Cornell Uni- 
versity, is published hy John Wiley &: Sons, New York. Fourth edition, 
largely rewritten and fully illu'^trated. 1902, $4.00. It incidentally de- 
scribes the best methods of heating with exhaust steam. 


throughout America. In many cases these plants supply a single 
large hotel, or office building. The installation at the Mutual Life 
Building, New York, is of 2.400 horse-power, vying in dimensions 
with many a central plant. 

In Fostoria and Springfield, 

Ohio, in Milwaukee, Atlanta 
and other large cities, a cen- 
tral station j^rovides heat and 
light and motive power to a 
considerable district. 

At Lockport, New York, a 
city of about 20,000 popula- 
tion, iiKU'e than 350 dwellings 
and business premises are 
heated by the American Dis- 
trict Steam C ompany, a con- 
cern which has installed more 
than 250 similar plants 
throughout the Lin ion. The 
advantages of this system 
arc plain : — cleanliness is pro- 
moted ; customers handle no 
coal or ashes, tend no fires or boilers ; the heat is more steadily 
and equably supplied than if it came from individual boilers ; heat 
is ready day or night during the heating 
season ; the hazard from fire is lowerc<l and District Steam 
the risk of boiler explosion is abolished ; Heating, 
water may be heated for laundries, bath- 
rooms and kitchens. Cheap fuel may be used, and stoked by ma- 
chinery. An individual boiler in a building has to be large enough 
for its heaviest duty; in many cases it is called upon for but one 
tenth to one fifth of its full po\^er, with much incidental waste. 
At a central station only as many boilers of a group are employed 
at a time as may be worked to their full capacity, responding to 
the demands of the weather. 

At Lockport the steam-pipes arc of wrought iron covered with 
sheet asbestos and enclosed in a round tin-lined wood casing, hav- 
ing a shell 4 inches thick, with a dead air space of about one inch 

Sturteviint Monogram exliaii^ter 
and solid base heater. 



between the tin and the aslx^stos. In its largest size this pipe has 
shown a total loss by radiation and conduction of but one part in 
four hundred in one mile ; for the same distance the smallest pipe 
has suffered a loss of six per cent. Live steam is used at Lock- 
port, but as a rule heating plants are supplied with exhaust steam. 
When intensely cold weather prevails this may be supplemented 
by boilers in reserve which supply live steam. 

It is worth while to remark the tendency to unify, on lines of 
the best economy, a service of both heat and electricity. In At- 
lanta there were recently in operation twenty-two isolated electric 
plants. The central station installed a steam heating system, and 
as a result in less than a year all but two of the isolated plants 
went out of business. 

The success of the central station at Atlanta is due to the mod- 
erate scale of its charges. In the past there has been some com- 
])laint of the rates levied by central stations. 

Isolated Plants. In the future this complaint is likely to di- 
minish, hccause an isolated plant for the pro- 
duction of heat and electricity was never before so low in cost, so 
efficient in working, as to-day. Well managed central stations 
broaden their market by putting a premium upon the utmost i)os- 
sible use of electricity. In l>rooklyn, for example, the Edison 
hdectric Company charges lo cents per horse-power hour to cus- 
tomers using loo to 250 horse-power hours per month; as con- 
sumptit)!! increases so do discounts until the customer who buys 
5,000 horse-power hours pays 4 cents. The demand for current in 
all its diverse applications is stimulated with energy and address. 
A house or apartment of seven rooms is wired for twelve lights, 
with all fixtures complete, for $95. Signs for advertising pur- 
jaXscs are provided on condition that they be lighted by the 

Company. The economy of a small ice machine or a refrigerator 
is pointed out all summer long,^while in winter the comfort and 
convenience of electric heat is as plainly kept before the public. 
Such a policy as this takes accouiir of the irrepressible facts of 
present day competition. When gas was the sole illuminant, pro- 
ducible only on a vast scale, served by an elaborate scheme of 
piping that from the nature of the case fell into a single hand, 
there was a liability to extortion. To-day in towns and cities elec- 



tricity, the cliief source of li,i;ht, can he {ground out anywhere 
simply, cheaply and without olTence, incidentally atVording* when 
desired almost as much heat as if the fuel had been hurnt to pro- 
duce nothiniL;' else. Amoni;- the t;ifls bestowed by the electrician 
not the least is this conferring* at the lowest ])rice two ])rime neces- 
sities of life. Ihit however liberal the management of a central 
station, many a fat plum will remain outside its pudding. A huge 
hotel, an oflice-huilding, factory, nr de])artmenl store, is best 
served by a i)lant of its own designed to furnish both hgat and 
electricity, in which case the electric current will cost much less 
than if bought from a central station. 

(^n occasion an' isolated plant sup])lies a neighborhood, and at 
prices lower than those of a large central station which may he at 
a considerable distance. At Newark in the New Jersey h'reie 
Zeitung building a 400 kilowatt plant is installed which supplies 
the neighbors in two blocks with electricity at 6 to tS cents per 
kilowatt hour, according to the extent of their consumption. A 
necessary conduit crosses C'amphell Street in this service'. It 
seems likely that small ])owe‘r-centres of this kind, re(|uiring no 
franchise, ma}' he common in the near future, es])ecially if united 
with heating systems. y\n inviting field for such’ installations is 
in the new residential cjuarters of our cities and towns, where in 
many cases a whole block might he cheaply and effectively served 
from a single plant. 

Heat, light and motive power may he provided either by steam 
or by gas. ?^lodern industry does not tie itself to any ])articular 
servant, hut chooses in turn whichever, under 
the circumstances of a case, will serve it well at Gas for Heat, 
least cost. Where natural gas is to he had at a Light and Power, 
low ])rice it holds the field. I hit the area thus 
favored is smrdl, so that t^roducer gas is emiiloyed on a much 
larger scale. We have already seen f])age 461 ) how coal may he 
gasified, valuable by-products seized, and a clieap gas ])e jiiped for 
miles with no liability to the condensation which befalls steam, 
while available for heating and for motive power. When this gas 
burns at a fairly In’gh temperature, as does Dowson gas, it gives 
with thorium mantles a good light, sn as to he an all round rival 
of electricity. Producer gas is ])rcfera])le to solid coal because 



perfectly clean; it banishes the smoke nuisafice, and is regulated 
by a touch. Mr. F. W. Harbord in his work on Steel (see page 
177), says: — 

‘The ease with which perfect combustion of a gas can be ob- 
tained by regulating the supply of gas and air, the readiness with 
which it can be conducted to any required point, superheated or 
burned under pressure, made to give an oxidizing or a reducing 
flame at pleasure, and the general control that can be exercised 
over the size and temperature of the flame, in most cases more 
than compensate for the reduction in heat units due ‘to gasifica- 
tion. . . . The necessity for superheating the fuel, and for 

keeping solid fuel out of contact with the bath of metal, make 
gaseous fuel indispensable in the open hearth furnace, and until 
Siemens solved the problem of cheap gasification of coal, this pro- 
cess of steel-making was impossible.’^ 

Gaseous fuels arc employed not only in steel making but in the 
manufacture of glass, pottery, chemicals, and much else. 

When gas is used in gas engines to produce motive power, the 
exhausts having high temperatures may be profitably applied to 
heating water, or raising steam, for warming purposes. 

Whether central stations employ steam or gas, or unite both, it 
is certain that a unification of the service of heat, light, and 
motive power including that required for traction, would in all 
our towns and cities be attended by great economy,, by the aboli- 
tion of much discomfort and unnecessary drudgery. A large city, 
such as New York or Chicago, could be supplied with these three 
cardinal necessities from comparatively few centres. 

Such centres may, before many years elapse, be -found stretching 
out into the distant suburbs of cities, and linking town to town. 

This chiefly because electricity has become a 
Electric formidable rival to steam in interurban locomo- 
Tractioa. page is printed, the 

New York Central & Hudson River Railroad will have begun 
operating its suburban trains from New York by electucity. For 
this service locomotives built by the General Electric Company, 
Schenectady, New York, will be in commission. Each will de- 
velop 2,200 to 3,000 horse-power. In careful tests a locomotive 
of this kind reached a speed of fifty miles an hour in 127 seconds, 



whereas a ‘Tacific'\ steam locomotive required 203 ^seconds; an 
important difference, especially where stops are frequent. Each 
locomotive, with its train of cars, weighed 513 tons. The steam 
locomotive with its tender weighed 171 tons; its electric rival 
weighed but 100 tons. So much for the gain in leaving both 
furnace and boiler at home, while their power is received through 
a special rail at rest. 



Why cities gain at the expense of the country . . . The factf)ry system . . . 
Small shops multiplied . . . Subdivided labor has passed due bounds 
and is being modified . . . 'Pendencies against centralization and mo- 
nopoly . . . Dwellings united for new ‘.ervices . . . Self-contained 
houses wanned from a center . . . The literature of invention and dis- 
covery as purve3'ed in 'niblic libraries. 

I N the closing chapter of this hook it may he ])ermissible to 
g^lance hn* a moment at a few of the social and national con- 
setiuences of invention. While, as we have seen in earlier chap- 
ters, the economic ^ains of in.e;enuity surpass com])utation, the 
work of the inventor has brought in its train 
The Drift <^vil as well as .gocKl, and this evil, with the 
to .Cities. further march of invention, is being’ plainly 
lessened year by year. A century ago about 
one tenth of the ])eople in N^orth America lived in cities and 
towns; today these centers of po])ulation hold nearly one half 
the families of the continent. Many observers regard this drift 
from country to city and town with dislike and alarm, without 
recognizing it t(’) be inevitable. They ])aint.])ictures of country 
folk attracted by the su])erficial allurements of the city, a i)oor 
exchange for the wholesomeness and freedom of life in the coun- 
try. They argue that with education the hoys and girls 
reared on the farm will remain there, greatly to the gain of them- 
selves and the nation. These critics leave out of view the feats 
of the inventor. Detween oSjo and i(S8o the self-binding 
harvester was ])erfected and introduced. Defore its advent si.x 
or seven men followed every harvester to tie its shocks of grain. 
After the self-binder came into vogue, five of these men were ik^ 
longer needed. Other inventions, planters, corn-shellers, and the 
like, as economical of labor, have been placed in the farmer’s 



hands within the past thirty years. The result being, ^hat to raise 
on farms the food for a million men, women and children, a 
greatly reduced staff in the field suffices to-day in comparison 
with the numher required thirty or forty years ago. And what 
has become of the country population thus thrown out of work 
by thews of steel and brass? It has quietly betaken itself to 
towns and cities where, for the most part, it is manufacturing 
new comforts and luxuries for all the people, whether in town or 
country. In 1870 out of 100 wage-earners in the United States, 
29 were engaged in manufactures, trade and transportation; in 
1900 the corresponding figure had risen to 40. ICnter this morn- 
ing the house of a thrifty farmer or mechanic: you tread on a 
neat carpet, you see good furniture, a piano in the parlor, a bicycle 
in the barn. On the walls arc attractive pictures, Hanked by 
shelves of books and magazines. In not a few such houses one 
may find a telephone and electric lamps. As recently as 1870 
some of these things did not exist at all, even for the rich. To- 
day they arc enjoyed by millions. So with clothing: it is to-day 
better and cheaiier than ever before, h'ood, t(M), is more varied 
and more wholesome than of yore, thanks to the exj)ress train, 
the quick steamer, the cold storage warehouse. All these agencies 
of betterment, and many more, arc conducted in cities as the 
centers of capital, industry and population. While invention has, 
in the main, tended to make cities bigger than ever, it is now 
modifying that tendency by its rapid trolley lines to suburbs, its 
steamboat and railroad services constantly (|uickencd in pace and 
lowered in fares. On the outskirts of (Greater New York it is 
still possible for a wage-earner to buy land for a house and small 
garden, the burden of rent, liable to yearly increase, being escaped 
for good and all. 

It was in luigland toward the end of the eighteenth century that 
inventors first lifted the .latch for an industrial revolution. When 
James Watt devised his steam engine, and its 
power was applied to s])inning and weaving. The Factory 

these tasks were driven from the home to the System and 

. , , .11 Checks Thereto, 

factory, there to be more economically per- 
formed. Other industries followed, all the way from paint grind- 
ijPg to nail making, so that in a few years a profound change came 


over the fieW of labor. Under a scheme of subdivided toil the^fac- 
tory hand succeeded to the journeyman who, with a few mates, had 
split nails or drawn wire in a shop no bigger than some day he 
might own for himself. With the need to occupy large premises, 
to install engines and elaborate machinery, the capital of an em- 
ployer has to be vastly more than of old, creating a new depen- 
dence on the part of the workman, and rendering it all but ini- 
])ossible that he should ever have a factory of his own. While 
the factory system of production is general in America, it is far 
from universal. Many leading manufactures, those of textiles, 
of boots and shoes, and so on, are usually conducted in factories, 
while some important industries, that of clothing, for example, 
are for the most part carried on at the homes of work jieople, or 
in small shops. IMassachusetts in 1900, according to the U. S. 
census of that year, had 200,508 hands in 1078 textile mills and 
boot and shoe factories. A])art from these industries were 28,102 
factories and shops, employing 291,418 hands, an average of but 
10.57 Taking the United States as a whole, the census for 

1900 reports that the hand trades in small shops representing a 
product of $500 or less each, numbered 127,419. iVesumably in 
all these cases the worker toiled by himself, usually as a repairer 
or a jobber rather than as a maker of new wares. All the other 
manufacturing concerns, 512,675 in number, employed on an 
average only 10.36 persons each. Tt is clear that the American 
factory is not as engulfing as many critics believe it to be. In 
larger measure than is commonly supposed workmen arc to-day 
their own masters, or are busy in shops small enough to give 
sco|x: to individual ingenuity and skill. us grant that a shoemaker, say in St. Louis, at work in a 
stall of his own is a better and happier man than if in a nearby 
factory he fastened eyelets, or burnished heels, day in and day out 
for years together. While the harm to the toiler wrought by 
extreme subdivision of labor is plain, its evils are lacing abated 
in more ways than one. First of all the productiveness of the 
modern factory has so augfneiited the joint dividend of capital 

' Quoted by Edward Atkinson in a paper on the tendencies of manufac* 
turing. American Social Science Association, 1904. 





and labor that whilo) the working- day grows shorter,^ wages are 
increased, every earned dollar buying more manufactured wares 
than ever before. Secondly, in some large railroad and other 
shops the workmen arc given a variety of tasks in succession, so 
as to be more versatile, more useful in emergencies, than if ever, 
punching steel, or threading holts. Even if the result of such a 
plan is to diminislt the total output in the course of a year, it is 
worth while to lose some money that human nature may be re- 
deemed from stupefying monotony of toil. High wages and 
large dividends cost too much when bought at the expense of hurt 
to muscle, nerve and brain. 

And a notable group of artisans, few in number but steadily 
increasing, with electric motors at their elbows, to-day enj(\v com- 
plete emancipation from the factory bell. A 
woodcarver, bookbinder, leather stam])cr, 
forger of ornamental iron, rug weaver, potter, 
lens grinder, or printer, can have to-day a shop of his own and 
take pleasure in the chosen and constantly varied toil that gives 
him bread. In their simpler forms the modern lathe, loom, print- 
ing press, are cheap enough to be within the means of ])oor men, 
while their jiroduct when it disjilays taste and originality is sure 
of a market. In times ])ast Palissy, Hargreaves, and many an- 
other master of a handicraft, has perfected a remarkable inven- 
tion in a small shop. We may expect the arts to receive golden 
gifts in the future from the successors of these men, feeling as 
they do the stimulus of a broadening demand for work executed 
on new lines of excellence. 

Until within a few years past economic forces in America 
threatened soon to jdace its chief industries in the hands of a few 
men, so .strong and unscrupulous as to be able 
to extort weighty and increasing tribute, b'or 
this danger remedies legislative and judicial 
are being sought, with the pnxspect of eventual 
success. In this jilace it may be allowable to remark how the 
progress of invention is working hand in hand with the aims of 
social justice. In the pages immediately ])reccding this chapter 
we. have seen how cities and towns art working themselves loose 
fjoni monopoly. A gas supjily, on the old basis of manufacture 





at least, mijst be a unit, with a strong temptation to overcharge 
its customers. To-day the lighting field is shared with electricity, 
showing many isolated i)lants ; when these purvey heat as well as 
light their rivalry with central stations may l)ecome formidable. 
In American villages and small towns the ])rinci])al source of light 
is ])ctroleum, largely controlled by the Standard Oil (Company. 
From its exactions there opens escape as the farmer finds a source 
of cheap alcolKjl in his corn, potatoes and beets, even in his un- 
marketable fruit fn* damaged grain, ready to give him more light 
than petroleum ever did, and besides propel his machinery, or 
carry his cro])s to the nearest market town. The betterment of 
comiiKjn roads throughout the l^nion ])r(X'eeds in earnest. As 
that reform goes forward we may see motor-driven cars and 
wagons exerting a restraining inlluencc on local railroad rates. 
Already the steam railroads are facing keen comi)Ctition from in- 
terurban electric lines. Wherever these lines resist absorption, 
or control, by the steam carriers they serve the farmer so well 
and cheaply as to be one of the chief boons he has received at the 
inventor’s hands. 

Take one instance chosen from many as striking. Dayton, 
Ohio, is a center of interurban lines which enfold in their sweep 
Urbana, Columbus, 1 lamilt(xi and Cincinnati. Upon 220 miles 
of these lines the Southern ( )hio ICxpress Company picks uj^ans 
of milk, cases of eggs, crates of berries, ])ackages of tobacco, 
from a thousand farmsteads. In tlie larger business of carrying 
grain and live stock the ex])ansion is constant, so that the day 
seems near at baud when the company will find profit in i)lacing 
a switch at every farm along its lines, sending cars there for 
everything the farmer has to sell. And the countryman finds 
Dayton as good a place to buy in as to sell in ; its merchants offer 
better and cheaper wares than are to be had in the home village 
ov the neigh 1 )oring small town, 'fo-day a farmer or market- 
gardener, a dairyman or stockbreeder, does not find the smallness 
of his ca])ital the drawback it would have been ten years ago. 
With an interurban line ])assing near his home, or in front of his 
door, with a cheap telephone at hand, and enjoying a free rural 
mail delivery, he can sell his produce when he pleases and at the 
best market prices, paying but a light tax to the middleman, cr 


completing a transaction with a tlircctnoss that leaves ^he middle- 
man out altogether. 

Steam railroads seek large trainloads to he moved long* dis- 
tances ; an electric freight and express service coins dimes into 
dollars by picking up market baskets, bundles for the seamstress 
and the laundress, a bunch or two (^f saplings for the orchard, 
'fhe trunk lines of America, with their wide-spreading hranchevS, 
enable merchants in the cities and the larger ttnvns to replenish 
their counters and shelves every day. Stocks, tlu*refore. need not 
be so large as of old, when, let us say. a whole winter’s goods 
were laid in by October. The change reduces the amount of cajntal 
recpiired, the outlays for rent and insurance, the liability to shrink- 
age and deterioration of values. The intenirban roads are extend- 
ing these advantages to the village storekeejier who, in the morn- 
ing tele])h(nies his wants to Toledo, Cleveland, or Detroit ; and in 
the afternoon dis]ioses the ordered wares on his shelves.' 

.American dwelling houses, whether in city or eoiintr\’, have 
within forty years been nnich ini])roved in plan and e(|uipnient. 
d'o sjieak only of dwellings in cities, we may 
note how designers and inventors have pro- j^ew Domestic 
moted comfort and convenience, healthfulness Architecture, 
and cheer. At the close of the C'ivil \\’ar an 
ordinary house in Philadelphia, or Chicago, as it K‘ft tin* builder’s 
hands was little else than a bare box. Stoves for wanning and 
cooking had to he bnnight into it, wardrobes heavy and clumsy 
were placed beside its walls, cu])boards meant to be moved and 
not moved easily held the raiment and table linen. In laaited 
houses the gas fixtures might belong to the* ti*nant ; when he took 
them away ugly breaks ap])eareel in walls and ceilings. 1'o-day 
all this is of the ])ast : in important details the de*sign of the 
mansion is embe^died in elwellings e'om])aratively small. b'nrnace‘s 
for heating, ranges for. cooking, ff)nn ])art and ])arce‘l (jf the 
building; fixtures for gas and electricity, yielding both light and 
heat, are pre)vided just as water faucets are; e‘ve*ry bedrf)nm has 
its clothes closet instead of the lumbering wardrobe. In the 
kitchen we find dressers and china closets built into the walls; 

Outlook, New York, January 7, 1005. 


the laundry^ has stationary washtiibs and, in some cases, a drying 
ryom as well, so that the laundress does, not care should it rain on 
washing day. The aim throughout is that the house and its 
equipment shall as far as possible make up a unit, that the labor 
of housekeeping be minimized to the utmost by a judicious outlay 
of capital when the house is built. 

Since 1900 the American householder, as well as the American 
business man, has fairly awakenjed to what the telephone can do 
for him. It is estimated that in 1905 the tcl- 
Electricity at ephone ill the United States earned four times 
as much as the telegraph. The day is at hand 
when every household but the poorest will enjen^ the wonderful 
gift of Professor Pell. In somewhat the same fashion it is dawn- 
ing upon the public that electricity stands ready to perform other 
services, each minor, but all, in the aggregate, going far to pro- 
mote health and comfort at home. 

At Schenectady, New York, Mr. II. W. Hillman, apart from 
heating in winter, has adopted electricity for many household 
tasks, wi-th results described and illustrated in the Technical 
World, Chicago, July, 1906. His kitchen outfit for a family of 
five persons comprises an electric table, oven, griddle-cake cooker, 
meat broiler, cereal ccxoker, w\ater heater, egg boiler, potato 
steamer, frying pan, coffee j)crcolator, and a stove for ordinary 
cooking utensils. A three pound nickel plated electric iron is pro- 
*vidcd for the laundry. In the dining-room is an electric chafing 
dish and a percolator. ()n the verandah and in the den are 
electric cigar lighters. In the sewdng-room the machine is driven 
by an electric motor. The bathroom has an electric mug which 
heats water for shaving in less than a minute ; in chilly wxather 
the luminous radiator yields just the slight heat which ensures 
comfort instead of discomfort. Of course, throughout the house 
electric lamps furnish light with the maximum of convenience 
and wholesomeness, the minimum of risk. 

How does this service compare in cost with the employment of 
coal and gas? With coal at $6.50 a ton, and gas at $1.30 per 
thousand cubic feet, the average monthly expense was formerly 
$6.00 ; with electricity the bills are but 69 cents more per month, a 
mere trifle in comparison with the gain in comfort, the saving of 



clrudgery, llic pronir)tion of cleanliness. The rale fer electricity 
used for lighting is lo cents per kilowatt hour, for heating only 
half that rate. 

Mr. Hillman does not use electric heat for ordinary warming: 
it would cost him too much. A good many peoi)le arc puzzled by 
the fact that an electric current, which yields a perfect light at a 
reasonable price, should in the sister task of heating fail in rivalry 
with a common stove or furnace. To solve this puzzle let us 
place our hands above a cluster of 15 k'dison incandescent lamps, 
each of 16 candle power, representing one h(n*se power, yet emit- 
ting no more heat than if three ounces of coal were slowly burn- 
ing away in the course of an hour. This electricity may cost us- 
ten cents an hour, the coal costs but the fifteenth part of one cent. 
In producing mechanical motion at a power-house, the engines 
waste at least ninety i)er cent, of the applied heat. To this heavy 
tax must be added the ex])enses of distribution, administration 
and maintenance. Until, therefore, the electrician reaches a mode 
of creating his current from heat without the enormous losses of 
present practice, we cannot look to him for a system of general 
heating. A word has already been said in this book about methods 
of district heating by steam. Another i)lan is worthy of mention. 
In Brooklyn the Morris Building C'ompany supplies from a ceii' 
tral plant fifty-two dwellings with hot water which serves not 
only for heating, but for cooking and washing also. The water 
is heated in part by live steam, in part by exhausts from steam 

Such an experiment as this, the appliances at work for Mr. 
Hillman, suggest exhibits which might form part of the premises 
of agricultural colleges and technical schools. 

These establishments usually require for their ^^hvt*** 
officers such dwellings as are not too large and 
costly for ordinary householders. These dwellings, carefully de- 
signed and equipped, might serve as examples of the best j)ractice 
in building, planning and appointment; in sound methods of heat- 
ing from a central plant. At suitable times they might be open to 
public inspection. They might range in cost from $i, 0 C 30 to 
$5,000, the cheapest to be built of wood, others to be built in 
brick, stone, or concrete. All the furniture and fittings to be 


clioscn with* an eve to wholesoineness, (liiral)ilfly, and maintenance 
with the least La))or ]K)ssil)le. l^ach house should contain in its 
main room a card lellinf,^ the cost of the hiiildinj;^, with estimates 
of cost if exeewted in other materials. On occasion this plan 
niij^ht he extended to the contents of houses, each item on show 
days to ])e duly labeled. A series of such houses would tend to 
brin^::^ ordinary house-planninjj^ and housekeepinj^ to the level of 
the best. IMany books and journals offer architectural diagrams 
which few can understand, but everybody can see how attractive 
a good ])lan is when realized in a house to which he i)ays a 
leisurely visit. At Expositions, such as those of Chicago and St. 
Louis, tlie appeal of the architect and the exhibitor is rather to 
wonder than to utility. He shows us schlosses from (iermany, 
palaces from Italy, chateaux from 1 'ranee, all appointed with 
cr)slly magnificence. r>ut while the average American wage is 
eleven dollars a week these displays can do little good as models 
for imitation. 



Ibioks oti inventicai and discovery are mentioned here and there throuRh- 
oiit tins volume, d he reader may wish further references, in which case 
he may lind them at tin* public library nearest home. Within the past 
few years the public libraries of America have been laying stress on their 
educational departments, are becoming more and nu^re a worthy comple- 
ment to the public schools. 

At the Carnegie Library, Pillshurg, the department of technology is di- 
rected l)y ]\Ir. Harrison W. ('raver, a graduate of a polytechnical institute, 
who has had experience as a practicing chemist, d'he collection keeps 
mainly to lines of local interest, and includes an ample array of tmde 
journals, fndexes to articles in technical journals are maintained. On 
the shelves are fdes of patents of the leading nations of the world. Short 
lists of hooks on subjects of current interest are from time to time com- 
piled and issued. Workers receive advice and personal assistance from 
soientilically trained men. Questions are answered by mail and telephone. 
Notes (ui hooks are appended to their titles on the catalogue cards, and in 
the monthly bulletin. 

Mr. Graver’s aid extends to other public libraries, among them to that 


at Providence. TTere industrial department contains alu^pt 7600 vol- 
umes, chiefly devoted to the principal industries of the city, — textiles, elec- 
trical arts, machinery, and the arts design, especially in jewelry. A 
room is at the service of draughtsmen : a dark closet is available for copy- 
ists who bring cameras. When a new book comes in the reader or the 
artist likcH' to want it is notilied. 

The Pratt Institute Free Library, l>rookl\n, an applied science refer- 
ence room which receives 115 scientilic, technical and trade journals. It 
has brought together a large collection of trade catalogues, duly classilied, 
and a collection of cuts of machines and mechanical dexiec s. I he custodian 
makes it his business to visit the neighlxu-ing factories and workshoj^s, so 
as to provide every puhlicatum likely to be (d' help. 'The use of this de- 
partment increases steadily, with a marked effect (»n the pro])ortii>n of 
scientific books taken from the general library for home reading. 

Newark, a city of many and diverse manufactures, has a t>ublic libr.ary 
also of the iirst rank. Scientilic books, ris received, are brought to public 
attention through the press, and by means of the monthly lailletin m.ailed 
to any one on rec|ucst. Short lists of selected works on particular branches 
of applied science are prepared for gratuitous di.stribution : in each book of 
a series the full list is pasted as a guide to (‘xtendtal reading. Keadi'rs are 
invited to ask for any book not in the library which they believe would he 
of service to them. 

These are but a few examples of the work the public libraries are doing 
throughout the Union. At the head(|uarters of the .\tnerican Library A>,.so- 
ciation are issued manifold aids hu’ readers and stiuh'nls: a list of ihi'in is 
given on a page followu'ng the index to this book. Let us hope ibat one of 
these days the Association may establish a bnn*au through which llu* 
literature of applied science, and all other worthy literature, may be passed 
upon by a staff of the best critics, for the behoof of all the people. Such 
a service would inure not only to the good of those who borrow books from 
public librarie.s, but would afford help to the men and women who buy 
books for libraries of their own. 


Abbe, Ernst, portrait, facing 182; Jena 
glass, 18 1 ; at first ignorant or prac- 
tical optics, 293. 

Aboriginal art. National Museum, Wash- 
ington, 106; tools, 89. 

Abrasion, manganese steel resists, 171. 

Accident, Nobel profits by an, 411. 

Accidental observation, 289. 

Acheson, E. G., carborundum, loi. 

Achromatism, Newton on, 254. 

Acknowledgments, xxi. 

Actinium, four derivatives, 200. 

Adams, Frank D., proves marble plastic, 

Adams, John Couch, discovers Neptune, 

A • 

Aeronautics, 129. 

Air, compressed. See Compressed air; 
brake catechism, R. II. Itlackall, 428; 
chamber of pumps, 252; churned in 
telescopic tube, 348; compressors, 424- 
427; and multiple cylinders for, 372; 
turbines, reversed as, 372; conducting 
when traversed by X-ray, 282; warm, 
and smoke protect from lightning, 294; 
hardening steel, 172; jet for machine 
tools, 173. 

Aladdin oven, 189, 190. 

Alchemy and radio activity, 203. 

Alcohol, cheap, 452; engines, 468; for 
lighting, 157; lamp with hood, 158. 

Algonquin art, 115. 

Allan Line steamers driven by turbines, 
455. 456. 

Allen, Leicester, on invention, 268. 

Allis-Chalmers steam engines, facing ^48, 
facing 452; Francis vertical turbine, 

Alloy for electro-magnets, 173. 

Alloys, influence of minute admixtures, 
175; made by pressure, W. Spring, 
201; Weston’s for electrical measurers, 
232, 234; anti friction, 174. 

Alternating currents used as produced, 

Alum crystal broken and repaired, 193, 


Aluminium discovered by Wobler, 143; 
properties, 143, 144, 145; separated 

from its compounds by ('. M. Hall; 
uses, 144, 145; i|i lithography, 144; in 
producing great heat, 145; alloys, 145; 
as electrical conductor, 145; 'in iron 
manufacture, 145; mandolin pressed, 

Alundum wheels, loi. 

American Library Association, aids to 
readers and students, 487. 

Ammeter, Weston’s. 233. 

Ammonia sulphate from Mond plant, 461. 

AnSlogy as a guide, 366-369. 

Anderson, Sir William, on formulae, 383. 

Andrews* discovery of continuity in 
states of matter, 212. 


Angles replaced by curves, 48-51. 

.<yiimal frame repeated in machinery, 250. 

Annealing steel, 108. 

Annular drills, 91-93. 

Anthony, W. A., on invention, 268. 

Anti-friction alloys, 174. 

Ants, Warrior, nest, 260. 

A<iuarinni, New York, 76. 

Arhor hollow', ctiolcd, 88. 

Arc-laiiip, 160; inverted, 75, 76. 

Arch, its structural advantage, 42; dis- 
cussed hy W. 1*. 1’. r^mgfcllow, 43; 
as dam, 45; of skull, 250; Saracenic, 
43; bridge, Niagara, 31. 

Arches invcrtc«l as gulleys, ami an- 
chorage, 45; pointcil, 43; united as 
dome, 355. 

Architecture, Egyptian, 1 14; "Japanese, 
Ralph Adams Cram, 114, foot-note; 
materials, 115; modern, Russell Stur- 
gis on, 119; new domestic, 483. 

Areas, irregular, measured, 347. 

Argon iliscovered hy Lord Rayleigh, 213. 

Arm holding ball, 256. 

Arrows, feathers in, 65. 

Aiticulatcd water-pipe, 259. 

Ashes, conveyors for, 447. 

Astatic needles, 149. 

Astronomy advanced hy new Instru- 
ments, 230; aided hy Carnegie Insti- 
tution, 277; co-operation in, E. C. 
IMekering, 278; measurements in, 229, 
2 JO. 

Atkinson, Edw'ard, AladiUn oven, 189; 
on w'indow glass, 72; ‘‘Science of nutri- 
tion,” 190; tendencies in manufactur- 
ing, 480, footjiote. 

Atmosphere, gase.s of, 213, 214. 

.\tom, si/e, 130-32. 

Atwater, W. O., on foods, 243; on energy 
v.aluc of foods, 264; aiiled for re- 
searches on foods, 277. 

Austenite, i6p 

Aut«>mati^ elevices, 329-337; at Tntcr- 
hor.nigli I’ower-housc, 447; stokers, 450. 

Autoiimhile design, 117; gasfiline flriven, 
conslrnclion, 4O8; halaneed cylinders, 
464; racing, 66; radiator, 87. 

Axe tells story, W'm. Metcalf 377- 

Axles, hollow, 40; cooled, 88. 

Tiahoons teach Hottentots and Tlushmen, 
136, 259. 

Rain, Alox.'indcr, on identifyjng f.'iculty, 
360; on pas.sion for experiment, 304; 
on sound juflgment, 385. 

Ralance, beginnings, 208; .ancient Egyp- 
tian, 219, 220; Lavoisier, 209; inter- 
ferometer applied to, 217; measures ir- 
regular areas, 347; requirements for, 
220; at its best, 22 T. 

Ralance wheel in time-pieces, 222; Earn- 
shaw’s compensated, 223. 

Ralanccs, Bureau of Standards, 235. 



Bale, Geo. R., Modern Foundry prac- 
tice, 17O. 

Ball-and-socktt joints, 251. 

Ball bearings, 47, 48. 

“Baltic,” steamer, 127. 

Baltimore truss, 25. 

Bamboo, its uses, 141; for walls and 
roofs, 39; for water carriage, 45; fila- 
ment for electric lamp, 140. 

Bank-swallow, lesson from, 297. 

Bar of metal shaped by pressure, 326; 
for reinforcing concrete^ 436, 437. 

Bark vessel and clay derivative, 115. 

Barnard, E. E., detects a double star, 

Barrel pressed steel, 185. 

Barrett, W. F., experiments with iron 
alloys, 173. 

Basin, experimental, for ship models, 54, 
55; U. S. Navy, lacing 54. 

Baskerville, Charles, researches in tho- 
rium, 200. 

Basket, Bilhoola, 110, in; Porno, 109; 
bowl, Yokut, 1 1 2. 

Baskets imitated from fish traps, 116; 
materials for, 109; waterproof, 143. 

Basketry, materials for, 142; Indian, Otis 
T. Mason, iio, 142. 

Bates, W. H., explains protective re- 
semblances, 289. 

Bearings, ball, 47, 48; roller, 47, 49. 

Bcaufoy, ISIarc, on ship resistances, 52. 

Beauty tlirough use, 104, J05. 

Beaver dams, ingenuity of, 265; tooth, 


Becqucrel, Henri, researches in phos- 
phorescence, 199. 

Beethoven composing, 300. 

Begonia, tuberous, produced, 249. 

Bell, Alexander Graham, portrait frontis- 
piece, facing is Brantford homestead; 
transmissitm of sound by light, 393- 
400; telephone, 393, foot-note, 293. 

Bell, Sir 1. L., manufacture iron and 

steel, 177. 

Bell, Louis, “Art of Illumination, 229, 

Bergman, Torbern, analyzes steel, 163. 

Bessemer, Henry, portrait facing 402; 
early tasks, makes bronze powders, 401; 
improves sugar-cane mill, 402; begins 
experiments with iron, 403; first con- 
verter, 404; illustrated, 406; pulverizes^ 
materials for glass, 407; on “a little 
knowledge,” 408; improves the drying 
of oils, 409; process, 164; steel rails, 14. 

Bicvcle wheel, 382. 

Bi-focal spectacles, 85. 

Bilgram, iTugo, gearing, 67. 

Binding machinery, direct, 342. 

Binocular glasses, 81, 82.^ 

Biological observations, Karl Pearson on, 
277; laboratories, 276. 

Birch-bark vessels, 115. 

Bird’s feet covered with dirt observed by 
Darwin, 280. 

Bilhoola basket, no, in. 

Birds and reptiles, a link discovered by 
K. S. Morse, 287; flight of, studied, 263. 

Bismuth pure and united with tellurium, 

^ 7 '?. 

Blackall, R. IT., air-brake catechism, 428. 

Blanchard lathe, 95-97. 

Blast furnaces curved, 50; gases for 

power, 462. 

Blasting, its utility, 411. 

IBenkinsop’s locomotive, 345. 

Bliss press work, 184-186; forming die, 
184; gcar.s, 67. 

Block.s, hollow concrete, 433-435. 

Blood, circulation of, 25O; pressure, ex- 
periments on, 272. „ 

Blowing machinery. Homestead, Pa., 415. 

Boat, canal, diminishes in resistance 
when quickened, 283. 

Boiler corrugated, 88; economy, 450; out- 
side furnace, 381: plate cut, 91; cop- 
per, how improved or worsened, 176. 

Boiling point water lowered as atmo- 
spheric pressure lessens, 375. 

Boivin burner for alcohol, 157. 

Bolometer, Langley’s, 225, 

Bookcases, sectional, 351. 

Book-shelves with camber, laden and un- 
laden, 36, 37, 254. 

Books reproduced by photography, 324. 

Borderlands of knowledge. Lord Ray- 
leigh on, 275. 

Bourne, George, on beauty of tools, 105. 

Bow-puller studied by E. S. Morse, 288. 

Bowstring bridge, 31; J’hiladclphia, 32; 
invented by Alex. Nasmytli, 308. 

Brace, ratchet bit, 90. 

Brachiopods studied by E. S. Morse, 288. 

J^rahe, Tycho, observations, 229. 

Brain in co-ordination, 257; disease, 
localization, 378; disease treated, 272. 

Brakes, Westinghouse, 428. 

Bramah, planer, 98. 

Brashear, J. A., concave plates for Row- 
land, 237; optical surfaces produced, 
83, 84; lenses and mirrors tor inter- 
ferometer, 217. 

Breakwaters curved, 51; concrete, 430. 

Breech-loader, 379. 

Bricks shaped by pressure, 325. 

Brick- work outlines, 112. 

Bridge, concrete, at .St. Denis, 431; For- 
est Park, St. Louis, 444; Memorial, 
Washington, 1 ^. C., 444; continuous 

girder, 32, 34; deck, 24; pipe-arch. 

Rock Creek, 41; and at Saxonvillc, 
Mass., 41, 42; IMauen, Germany, 42, 
43; rollers, 38; St. I.ouis, 31; strains 
.studied, 25; through, 24; Victoria, 
Montreal, 26-28; Whi]>plc, 25. 

Bridges, 18-38; cantilever, 26; near Que- 
bec, 29, 30; Kentucky river, 30, 31; 
esthetic dcsign.s, 38; railroad, 23; sus- 
pension, 32. 

Bronze powders. Bessemer’s, 401. 

Browne, Addison, on original research, 
^ 73 - 

Brush, Charles F., arc-lamp, 160. 

Bubbles rising in liquid, 127, 128; 

sharpen files, 147. 

Buchanan, William, plans famous en- 
pine, 15. 

Buffalo trails give hints to railroad en- 
gineers, 259. 

Buffon on invention, 27 1. 

Bullock cart with solid wheels, 47. 

Bulrush section, 251. 

Bureau of Ethnology reports, 107, foot- 

Bureau of Standards, Washington, 234- 
236. ♦ 

Burke, Charles G., t'^Iegraphic code, 352, 
353; simplified signals, 354. 

Burner, Boivin, for alcobol, 157, 

INDEX 491 

Burrouglis, John, on ohsiocvation, -vSi. 
lUishnicn learn from baooons, ij6. 
Huttrcsscs for arches, 43. 

Cabin, disadvantaj^cs of its size, 130. 
C'ahles, electric, X-rays examine, 'tjy. 
Cactus adapts itself to environment, -’4S. 
Cadmium rays, Ji8. 

Caliper, micrometer, J36. 

Camber in book-shelves, 36, 37, -:54; in 
bruljtes, 37. 

Campbell, H. II., Manufacture iron and 
steel, 177. 

('anada, ro»)fs in, it8, tio. 

Canal and circulation blood, 256; boat 
iltminishes in resistance wlitn tpiiek- 
ened, 282. 

Candles cojiied in gas-burners, iib; ami 
in electric lamps, 117. 

Cantilever, 2O; bridges, 26-31; where 
best, 35. 

Capital more necessary under factory 
system than before, .^80. 

C'arbon dioxide detected in tine g.ises. 

Carbon in steel, 163, 164; fd^ment giaiih- 
itized, 158. 

('arborundum wheels, lot, to 2. 
Carburetor, 466. 

('ards for catalogues, 340, for notes, 350. 
('arex root in basketry, 110, 143. 

(\'irgo steamer, 50, 61. 

Carnegie Institution for Oiiginal Ke 
search, 276-278; Library, PittsTmrg, 

Canicntcr, Rolla C., “Heating and ven- 
tilating buildings,” 472. 

C'artilagc in joints, .>51. 

C'arving chisels and gouges, 90; by air 
hammers, 418. 

Catenary curve, 43. 

(kathode rays, i<)8. 

('altle-brcc<fing, 249. 

Caves a? store-houses, 137; Virginia and 
Kentucky, 123, 246, 

Cedar for basketry, i to, 142. 

C'eiling, heating coils on, 86; white, as 
reflector, 76, 

('ellulosc filaments for lamps, 261. 

('elts lend forms to bronze, 116. 

Cement, natural, 430; Portland, 430; 

Roman, 420. 

C'emcntite, 164. 

Central stations, teleidionie, 257: man- 
agement, Edison Electric Co., P»iot»k- 
lyn, 474. 

Centralization, tendencies, 481. 

(*erium for gas mantle, 156. 

Chain susp<-nded, 4 1, 4 1. 

('haldean records ()f eeliiiscs, 229. 
Channeling machine, .Saundeis, 342, 
('hanute. Octave, on invention, 2.68. 
Character in research, Tyndall (m, 364. 
Charcoal, 125; produces v.acnum, 3 '8. 
Chemical synthesis, 374 5 theory enlarged 
by iHscovery of radioactivity, 203; 
triggers, 337. 

Chemistry of living bodies, 262. 

Chimneys, why .shorter, 448; reinforced 
^ncrctc, 440, 441. 

Chisel, carving, 90; cold, of two kinds 
steel, T67. 

Chittenden, L. E., lesson from bank- 

swallow, 297. 

Chiircli, Duane 11., inventor watch-mak- 
ing iiiaeliines. 222. ’ 

C Inn eh of St. Reiny, 43, Ntitrc Dame dc 
IJoiisecouis, Montreal, 118. 

Cinders huge and small on health, 120. 
Citu.s, why tliey gain at expense of 
eountiy, 478; sites for, 2.|6. 

“Class in ( ieomelry,’* 122. 

Classi beat ion literature, Melvil Dewey, 

('l.iy imddcd, T02, 103; in the arts, 139. 
( le\ eland Sttme Co, comine.sseil air 
plant, 427. 

( litton .suspension bridge, anchorage, 45. 
Chjiiier ships. 57. 

(‘loaea M.ixinia, Rome, 45. 

Clocks, Rieller, 223, 221; self-winding, 

. dd”- 

Coal, glouing. htoken into fragmenis, 
120; entlei. Ingeisoll. jiS; testing 
plant, C. S. (leologieal .Snivey, foi.t- 
note. 241; washer, i s 1 - 
Cohhett, Willi .nil. on wiitiiig as an ex- 
^ eitei iif flioiight, 300. 

C'oding in telegrapliy, .152-351; in inven- 
tion. 317. 

Coherer, oiigin td, i.}7, 

(‘oigiiet netting for eonerete, -*142. 

('oils, he.'iting, 89. 

< ulleetions. value of, 288. 

Collodion, .Vohol niili/is, 411. 

(’oloi dispi'tsion, 180. 

('olninns of hriilge, .’3; hollow^, 3<). 
Coinbinahilit V <d‘ niattei, lo.p 
Compass ilelleetod by electricity, 230, 231, 

Compasses as tinss model, 20; liipiid, 

. ' P>- 

Comp<‘nsating <]eviias, 148. 

Complexity in ni.ieliitie may he neees- 
^aly, 3tT. 

Compnsstd air, .py-.t.sX; drives tools, 
•117; (Mittei, 418; foi h.’imiiiers, 
f.'K'iiig 418, .}io; air tools fust used 

by dentists, .jk); diill used as ham- 
nier, \\ o<.d hoi er, 420; i.'iminmg, jiav- 
ing. lamping, jjo; drives away chips, 
cools entt<-i, lifts w.itei, .|2i; woi ks 
pninps; for p.iinling. 423; for 

cleansing, 123;, .j-j, j..'5; air 
eoiiipressoi s, I'j |j;; inlei- and outer- 
cooler, I .'fi; iu.ilets foi’. ,|29; in (|uar 
rviiig, .t-'75 \\ esiinglionse hr.ikes and 

sien.aK, 428; foi ti ansmitling powi-r, 

Coinjn < ssimi ia building, 8; memhers 
iiiMst lie of iigid iiialeri.'d, 19. 

( omnnssois, an. 1 1-127; Paisons’, 372. 

Coneh-shells ;is jiitelieis, ic8. 

Coneiete .-inil its r< in foieeinenl, 42<)-4.45: 
vast ns( s eoiM'iete, .1 ? I : bridge ;it St. 
Iteiiis; desii.dile (iii.ilitii s. 411; silos, 
411, 412; tesidenee, h'ort ', Ky., 
,132 and facing 4,12: foi small, cheap 
dwellings, n.;; hloeks, general mann- 
f.ietnie, 113. 111: reinfoieement in- 

troduced by Monier, 43.S; bars for. 
436, 437; Moniir netting; expanded 

oietal. 437. 4^8; nioMs, 438; Pugh 

I’.nibling, C'ineinnati, grain elevators, 
bins. 439; ehiinneys, incorrodihilily,