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AERONAUTICAL JOURNAL. 


A QUARTERLY ILLUSTRATED MAGAZINE DEVOTED 


TO ALL SUBJECTS CONNECTED WITH 


THE NAVIGATION OF THE AIR. 


PornisHeD BY THE AERONAUTICAL Soctety oF Great BRITAIN AND PRINTED BY 
Kina, Sent, anp Oupine, Lrp., 27, Caancery Lane, Lonpon, W.C. 











ee 











THE AERONAUTICAL JOURNAL. 


JANUARY, 


1907. 








The Aeronautical Journal. 
(PUBLISHED QUARTERLY.) 
SusscripTion PER ANNUM (post free), 4s. 


0 
Communications respecting Advertisements to 
be addressed to the Publishers, ‘* Aéronautical 
Journal,” 
Messrs. KING, SELL & OLDING, Ltd., 
27, Chancery Lane, W.C. 
Editorial communications should be addressed 
to the Editor, 
58, Victoria Street, 
Westminster, London, S.W. 








NOTICES 
Che 


Acronautical Society 
of Great rita. 


ad 





At a meeting of the Council of the Aéro- 
nautical Society of Great Britain, held at 
the Society of Arts, John Street, Adelphi, 
on Friday, December 7th, 1906, the follow- 
ing gentlemen were elected members of the 
Society. 

Lord Monracu oF BEAULIEU. 
Mr. LioneEL CALiscH. 

Mr. Witt1am Epwarp BuRGEss. 
Colonel SELDEN ALLEN Day. 
Lieutenant GEoRGE Gipps, R.N. 
Mr. Water JAMES GRIFFITHS. 
Mr. ALFRED HarpIeE. 

Mr. Jocetyn Hore Hvupson. 
Mr. Samvuet Eric NEAL. 

Mr. Witi1aM R. Patrerson. 
Lieutenant ArTHUR Rice, R.N. 
Mr. Harotp F. SMALMAN-SMITH. 


The following gentleman was elected a 
member of the Council : — 


Bt. Colonel J. E. Capren, C.B., R.E. 


| 


| 
| 


FORTHCOMING GENERAL MEETING. 


The second meeting of the 42nd session 
of the Aéronautical Society of Great Britain 
will be held at the Society of Arts, John 
Street, Adelphi, in March next, the date of 
which will be duly announced. The follow- 
ing papers will be read:—‘* Wings v. 
Screws,’’ by Colonel J. D. Fullerton, R.E., 
M.Aér.Soc.; ‘* Theory of Sailing Flight,”’ 
by Mr. José Weiss, M.Aér.Soc.; and “A 
Study of Model Gliders,’’ by Mr. A. V. 
Roe. 


KITE DISPLAY. 

It has been arranged to hold a kite dis- 
play at Sunningdale on the occasion of 
the summer meeting of the Aéronautical 
Society of Great Britain in July next. 
Members and others who may wish to dis- 
play kites at this meeting are requested to 
communicate with the Honorary Secretary 
of the Aéronautical Society of Great 
Britain, 53, Victoria Street, Westminster, 
London, S8.W., as soon as possible. 

To members there wil! be no entrance fee 
for this display, but to non-members there 
will be an entrance fee of five shillings for 
the privilege of displaying their kites on 
the ground acquired by the Council of the 
Aéronautical Society of Great Britain. 

All kites displayed will have to be ap- 
proved by the Council of the Aéronautical 
Society of Great Britain. 


THE LIBRARY. 

The following publications have been pre- 
sented to the library :— 

By Major B. Baden-Powell, ‘‘ Right to 
Fly’ (Nadar), ‘‘ First Aérial Voyage in 
Eneland’’ (Lunardi), ‘‘ Crochets in the 
Air’? (J. Poole), ‘‘ Balloon Ascents ’’ 
(Rush), and “ Aéronautics ’ (Mason). 

By the editor of Knowledge and 
Scientific News, ‘‘ The Science Year Book, 
1907.”’ 

By Colonel F. C. Trollope, ‘* Institut 
Aérodynamique de Koutchino,’’ ‘* Qua- 
triéme Conférence de la Commission Inter- 








national pour L’Aérostation Scientifique,”’ 
publications of the International Com- 
mission, for scientific aéronautics, January, 
1904. 

By Dr. Richard Assman, ‘‘ Ergebnisse 
der Arbeiten des Kdéniglich Preuhiscen 
Aéronautischen Observatoriums bei Linden- 
burg.”’ 

By the Meteorological Office, ‘* Publica- 
tions of the International Commission. for 
Scientific Aéronautics,’’ January, 1905. 

From D. Riabauchinsky, ‘‘ Bulletin de 
L’Institut Aérodynamique de Koutchino.”’ 

From the French Minister of Commerce, 
‘*Congrés International D’Aéronautique, 
Septembre, 1900.’’ 

By D. Pecho Vives Y. Vich, ‘* Avance de 
los Resaltados Obtendos en las Observa- 
ciones del Eclipse Total de Sol de 30 De 


- 9) 


Agosto de 1905. 
ERIC STUART BRUCE, 
Honorary Secretary. 


GENERAL MEETING. 


The opening meeting of the 42nd session 
of the Aéronautical Society of Great Britain 
was held at the Society of Arts, John Street, 
Adelphi, on Friday, December 7th, 1906. 
The President, Major B. Baden-Powell, oc- 
cupied the chair. 

The Present: Gentlemen, the Honor- 
ary Secretary will now read the minutes of 
the last meeting. 

The Hon. Secretary read the minutes. 


On the Use of Kites in 
Meteorological Research. 


NAPIER 
F.R.S. 


By WILLIAM SHAW, 


C.D... 


The exploration of the upper air by means 
of kites was formally adopted as part of the 
regular scheme of operations of the Meteoro- 
logical Office in the summer of 1905, when 
Mr. W. H. Dines, F.R.S., whose work in 
connection with a joint committee of the 
Royal Meteorological Society and _ the 


British Association is well known, was ap- 
pointed to organise and control experiments 
in that line of meteorological research. The 
objects to be kept in view were stated to 
be: — 

(1) ‘‘ The maintenance of a depot for the 
construction and testing of apparatus. 


THE AERONAUTICAL YOURNAL. 





[January, 1907. 


(2) ‘‘ The investigation of the upper air 
over the British Isles by a series of simul- 
taneous ascents on the days of the inter- 
national ascents (kites and unmanned 
balloons being used if practicable). Three 
stations for each day of ascent are to be 
arranged if possible within a range of 200 
miles in the first instance, one of them being 
on the coast. For the two of these ascents 
not at the depot station, the central depot 
would supply apparatus and instruct the ob- 
servers, but would not be responsible for 
making any payment to the observers. 

(3) ‘* The supply of apparatus and instru- 
ments for the observations of the upper air 
‘o vessels of the Navy or of the Mercantile 
Marine, of which the officers might be will- 
ing to take charge of the ascents, and the 
instruction of the observers.’’ 

The scheme of co-operation outlined by 
the statement of objects has been realised 
in nearly all particulars. Working at his 
own house at Oxshott, Mr. Dines has carried 
out a large number of kite ascents with re- 
markably little loss and no serious mis- 
adventure, except an unfortunate injury to 
his hand. He has now transferred his base 
to Watlington, in Oxfordshire, where con- 
ditions are more favourable for operations 
involving the use of a greater length of steel 
wire than at Oxshott. 

Mr. C. J. P. Cave, who had already made 
some successful experiments with kites in 
Barbados, has established an effective sta- 
tion at Ditcham Park, in Hampshire, and 
has worked in hearty co-operation with Mr. 
Dines. Mr. 8. H. R. Salmon also joined 
the scheme from the first, and, considering 
the restriction imposed by the use of a 
hand winch, has carried out a number of 
successful ascents from the Brighton downs, 
and has, in particular, explored the upper 
air on several occasions of sea fog with very 
interesting results. 

In the meantime Dr. G. C. Simpson, 
lecturer in Meteorology in the University 
of Manchester, took up the work in con- 
nection with the joint committee to which 
already reference has been made, and a con- 
siderable amount of work had been done in 
selecting a suitable site at Glossop Moor 
for experiments in the Derbyshire hills and 
in remaking the old winding gear, lent for 
the experiments, after a collapse attended 
with some thrilling experiences at the first 
ascent. By the time the new apparatus 
was ready, Dr. Simpson had accepted an 
appointment as assistant to the Meteoro- 
togical Reporter to the Government of India, 











January 1907.) 





and Mr. J. E. Petavel, of the Physical 
Laboratory of the University of Manchester, 
took charge of experiments at Glossop Moor 
in the summer when kite ascents were not 
practicable at Oxshott for want of wind. 

At sea Captain A. Simpson, of the steam- 
ship Moravian, an enthusiastic meteoro- 
logist and a skilled observer, has made some 
preliminary experiments with apparatus sup- 
plied from Oxshott, the central depot, and 
a set of apparatus was prepared for Lieut. 
the Hon. C. F. Cavendish, of H.M.S. 
Suffolk, who expressed his willingness to 
make a trial of observations at sea, but in 
the multitude of occupations in other direc- 
tions I fear that the instruments have not 
yet been dispatched to that officer. 

Thus the observations so far secured 
have been the kite observations at Oxshott, 
Ditcham Park, Brighton, and Glossop 
Moor, of which there have been altogether 
upwards of 150. Mr. Petavel did, indeed, 
send up an unmanned balloon from Man- 
chester, which came down safely near 
Huddersfield, but the curiosity of the North 
was too much for the perishable record 
which was so overlaid with superfluous 
marking as not to be decipherable. 

Colonel Capper, of the Aldershot Balloon 
Factory, has also contributed observations 
upon change of direction of wind with 
height. 

The meteorograph which was designed by 
Mr. Dines for use in the kite ascents, has 
been enriched by the addition of a simple 
means of recording the wind velocity. It 
consists of a light sphere attached by a long 
cotton thread to a pen controlled by a 
spring. Thus pressure, temperature, 
humidity, and wind velocity are all recorded 
on the chart carried by the kite. 

Mr. Dines has also designed and con- 
structed new and extraordinarily light in- 
struments, for recording variation of 
pressure and temperature, which were ex- 
hibited at the Office on July 6 preparatory 
to their being sent as part of the British 
Government exhibit to the International Ex- 
hibition at Christchurch, New Zealand, but 
with them the present: paper is not immedi- 
ately concerned. 

From the commencement. of the current 
year a brief summary of the results ob- 
tained by the various observers taking part 
in the co-operation for the exploration of 
the upper air has been published from week 
to week in the weekly weather report of 
the Meteorological Office. That form of 
publication was chosen because the Weekly 


| 





THE AERONAUTICAL ¥OURNAL. 3 


Report includes maps of the barometric, 
thermometric, and weather conditions over 
Europe for each day of the week. The 
scale of the maps is small, but it is enough 
to indicate the general conditions prevail- 
ing during the ascents of which the results 
are given, and to enable those who wish to 
follow up the meteorological suggestions 
which arise from the results to form a pre- 
liminary idea of the line to be pursued. 

The summary of the ascents given in the 
Weekly Report is almost unmercifully brief. 
It gives only the bare figures for tempera- 
ture, humidity, wind velocity, and wind 
direction at the ground level and at the 
fixed heights 1,660 feet (500 metres), 3,320 
feet (1,000 metres), 5,000 feet (1,500 
metres), and so on, with a short note in a 
‘‘remarks’’ column of any conspicuous 
feature of the ascent. 

The question may fairly be asked whether 
there is any useful information to be got 
out of such a curt record, or if it would not 
be better to wait till the observers have 
had time and opportunity to discuss the 
bearing of all their observations on various 
meteorological questions before calling in 
the printer at all. It is to that question 
that I propose to direct your attention to- 
night. I will not speak of the use of a 
brief summary, such as that which you see 
in the Report, as an index which would 
enable anyone who wished to make a study 
of the subject to select the ascents likely 
to give him the information wanted for an 
answer to any particular question. I will 
take the more directly pertinent question 
whether the information given enlarges our 
knowledge of the upper air. From this 
point of view I have only the same ad- 
vantages as the ordinary reader of the 
Weekly Weather Report; that is to say, I 
base what I have to say upon what is pub- 
lished, and not on the more expressive in- 
formation contained in the original records, 
of which, as a matter of fact, I have seen 
very few. 

Before entering upon the consideration 
of the results I shall not stay to argue 
whether a knowledge of the upper air is of 
any practical advantage. I take that for 
granted, but I should like to explain that 
what I mean by knowledge of the upper 
air is not merely a remembrance of what 
has once been found to occur there, but 
rather a guide to what does occur there 
‘fas arule.’’ That is to say, our experi- 
ence is of little use unless we can draw some 
eeneral conclusions from it, and thus get 














4 THE AERONAUTICAL $¥OURNAL. 


(January, 1907. 





some guide towards practical application or 
future investigation. 

I hope to show you that the records of 
the year’s work, even in the curt form of 
publication which you have seen, do advance 
our knowledge from both those points of 
view. 

I am indebted to Mr. Gold, Superintend- 
ent of Instruments at the Meteorological 
Office, for enabling me to show you some 
of the general results of the year’s work, by 
providing me with a number of diagrams to 
which I will direct your attention. 

Let me put down some questions to 
which we will endeavour to obtain answers 
from the diagrams, I will set them out as 
an examination paper. 

(1) Does the temperature of the air de- 
crease regularly or irregularly with height? 
Gradually or suddenly! Within what limits 
is the rate of variation with height confined 
at different stages? Is the rate of variation 
the same for different directions of the 
wind, or different for different winds in 
any regular manner! 

(2) Does the wind velocity increase aloft 
in manner for winds from the 
various directions? Is there any height at 
which the wind velocity practically ceases 
to increase! Is there any sudden transi- 
tion in direction or in velocity / 

(3) Does the humidity of the air always 
increase with height and consequent reduc- 
tion temperature until saturation is 
reached, and after saturation is reached 
and cloud formed does the saturation con- 
tinue to greater heights, or can we find 
evidence of dry layers above moist ones? 

(4) In those sections of the atmosphere 
where there is no extraordinary change in 
the temperature with height is the com- 
position of the atmosphere homogeneous, 
or, to be more precise, are the proportions 
of water vapour and dry air at different 
levels such as would be the case if the air 
within the section were churned up and 
thoroughly mixed and then allowed to 
settle, or is the atmosphere, as we find it, 
stratitied in layers of different composition ? 

Now let us turn to the diagrams to see 
what suggestions we can get for answers to 
these. questions. To many of them any ex- 
pert in aéronautics would doubtless be able 
to give an answer off-hand from his own 
experience, but I wish you to consider 
whether answers can be obtained from the 
meagre information of the published results 
of the kite ascents. 


the same 


of 








The diagrams have an element of novelty 
about them in that the condition of the air 
at 1,660 feet (500 metres) has been taken 
as the datum in each case, instead of that 
at the surface. The reason for this is that 
the surface is liable to all sorts of local dis- 
turbing causes. There may be local effects 
in the way of warming—indeed, the thermo- 
graph trace may not be in proper working 
order at the start; the wind velocity at the 
surface is a purely local matter depending 
upon the screening due to trees, buildings, 
or other obstacles, or what may be called 
for brevity the friction of the ground. In- 
deed, it is only at Oxshott, where there is 
a stationary anemometer, that the surface 
velocity of the wind is given. There are 
difficulties about determining the velocity 
with the kite close to the ground. And in 
like manner the local influence of the ground 
upon the humidity or air-composition as 
regards water vapour may be very great ; 
consequently the condition of affairs at the 
ground level gives bad datum values to 
which to refer the variations shown above. 
The 500 metre level has been chosen instead, 
because it is next in the published tables. 
I am not prepared to say that the selection 
of that particular level is the most appro- 
priate. That is a question upon which I 
should like the opinion of those who are in 
2 position to study the details of the re- 
cords. 

The first three sets of diagrams, then, 
show the variations in temperature, wind 
velocity, and humidity from the values of 
those quantities in the several ascents at the 
500 metre level. Heights are shown by 
vertical distances and increases of tempera- 
ture, wind velocity, and humidity by dis- 
tances measured from left to right and vice 
versa according to a scale indicated on the 
drawings. 

In order to get the general results, rather 
than the individual details, the diagrams 
originally drawn to show the values for the 
individual ascents have been generalised in 
those represented on the screen by drawing 
lines to represent changes approximately 
indicated by the members of a group of 
ascents. The lines are thus average lines, 
and the number of ascents which each line 
represents for each stage is given by a 
figure against the line. Thus, in the tem- 
perature diagram for Oxshott, S.W. winds, 
the full line, between the two dotted lines, 
represents the mean result of twenty ascents, 
and the full line beyond the dotted line re- 
presents the mean result of eleven ascents. 














January, 1907. THE AERONAUTICAL FOURNAL. 


TEMPERATURE. 


OXSHOTT. 


1000 — 


s00— 





| a N.W. Winds, 





a ac 


f é S.W. Winds, 








N.E. Winds, 





S.E, Winds, 


SOP 


ROE LESSEE NE RAPS 








500 — 


6 





THE AERONAUTICAL $OURNAL. 


(January, 1907. 








WIND VELOCITY. 


OXSHOTT. 


500 meres — 





N.E, Winds. 








S.W. Winds, 


S.E. Winds, 





H 
§ 








January, 1907.) THE AERONAUTICAL YOURNAL. - 


HUMIDITY. 


OXSHOTT. 


'SOOmeres s_ 
. 





900 — 


co 
é 








N.W. Winds, 








N.E. Winds. 


Dotted lines show extreme variations, 


1SOOmaetres 


1000 — 


300 — 
soo— 














S.W. Winds, S.E. Winds, 














8 THE A ERONA UTIC AL JOURNAL. (January, 1907, 





MASS OF VAPOUR 


“8 PER CUBIC METRE. 


MASS OF AIR 


RATIO 


OXSHOTT. 










/\\ 
/ \WN 
/ \WN 


N.W. Winds. N.E. Winds. 






ane 
000 — 
Scale. 
. 100 represents 
Scale. trains of water 
100 represents 8 grains of va‘er vapour per cubic 
/ vapour per cubic metre nearly metre nearly. 
| * y . i 
SE ee ee ae 500 oe oe 
f N \ 
Hi lh VN a. ‘. 
’ a ~ * 
o— 2 =—- 
S.W. Winds. S.E. Winds. 


Tke dotted line shows how the ratio would change with saturation from the beginning and adiabatic 
temperature gradient 








January, 1907-1 


THE AERONAUTICAL JOURNAL. 9 





In order to give the reader an immediate 
impression of the numerical distribution, the 
thickness of the lines in the diagrams has 
been adjusted so that the thickest lines 
indicate the most numerous groups. 

Let me next explain the dotted lines in 
the diagrams. In those relating to tem- 
perature they correspond with certain lines 
of theoretical variation of temperature 
known as the adiabatic lines for dry air 
and saturated air respectively. The line of 
less slope, indicating more rapid fall of 
temperature with increasing height, is a line 
of adiabatic change for ‘‘dry’’ air. If a 
mass of air could be isolated and completely 
protected against any gain or loss of heat 
during its travels, its temperature would 
diminish as it rose and increase as it fell 
simply in consequence of its expansion under 
the release of pressure in the first case, and 
its compression under the added pressure 
in the second. The change of temperature 
with height would be indicated by the 
dotted line of less slope for ascending or 
descending air so long as the air caused no 
cloud of water drops. When the air carries 
water drops the temperature changes are 
less, because evaporation or condensation 
of water interferes, and we get. a thinning of 
the cloud instead of the full warming in 
descent and thickening of the cloud instead 
of the full cooling in ascent. Air actually 
ascending or descending with any consider- 
able rapidity is practically freed from any 
accessions or losses of heat, consequently 
we may anticipate that its change of tem- 
perature with height should be along the 
dotted line of less slope if it is free from 
water drops, or along the dotted line of 
greater slope if it contains water drops. 
We cannot easily explain changes of tem- 
perature in an isolated mass of air more 
rapid than the ‘‘ dry ’’ adiabatic rate or less 
rapid than the ‘‘ saturated ’’ adiabatic rate ; 
consequently the presence of lines in the 
temperature diagrams outside the region 
between the two dotted lines affords 
material for speculation and further in- 
vestigation. It must be remarked that. in 
plotting the results of a kite ascent we do 
not record the successive temperatures of 
the same specimen of air, or even of the 
same section, but of different points of 
successive sections as the whole stream flows 
past the kite, so that all sorts of variations 
may be expected unless the stream under 
investigation is steady and persistent. We 
need not, therefore, be surprised at irregu- 
lar changes, but in due time we might be 





able to account for them in some rational 
manner. Thus the cases when the varia- 
tions shown in the diagrams are outside the 
limits of the two adiabatics may be regarded 
as affording material for another examina- 
tion paper in the future. 

On the humidity diagrams the changes 
shown in the humidity of the air are much 
more violent and sudden than in the dia- 
grams of the other elements. The dotted 
lines on those diagrams indicate the ex- 
treme variations recorded in the ascents re- 
ported in the published results. 

The diagrams here reproduced represent 
the results for Oxshott, grouped according 
to the direction of the wind which raised 
the kites, for the four quadrants, N. to E., 
E. to S., S. to W., and W. to N. On this 
occasion time does not allow of the com- 
parison of the results with those obtained 
at the other stations mentioned. Moreover, 
the numbers of ascents for the different 
quadrants are very unequal, and, therefore, 
such general conclusions as may be drawn 
from them are liable to modification with 
more extended experience. 

With these preliminary explanations let 
us turn to our examination paper. 

(1) The winds in the N.E. quadrant show 
remarkably regular decrease of temperature 
nearly at the ‘‘dry’’ adiabatic rate up to 
5,000 feet (1,500 metres), but at each stage 
there are ascents which indicate a cessation 
of the decrease. For the S.E. quadrant the 
ascents are few (only five), but with one 
exception they show a decrease nearly at 
the ‘‘ saturation’’ adiabatic rate, slacken- 
ing off at 1,500 metres. For the S.W. 
quadrant, below 500 metres, there are two 
groups, one of 20 with an average gradient 
intermediate between the ‘‘dry’’ and 
‘“ saturation ’’ adiabatics, and one of 11 
with gradient greater than the ‘‘dry”’ 
adiabatic, which may be due to special sur- 
face heating. Above 500 metres there is a 
marked bifurcation: 19 go on in continua- 
tion of the line of the large group of the 
first stage, but eight show very slight fall 
of temperature, and for one there is a 
marked inversion of temperature change. 
The next stage is also marked by irregu- 
larities. The N.W. wind seems again to 
be more steady as to its gradient, with one 
marked exception. Thus we may fairly say 
that the temperature changes lie for the 
most part between the ‘‘dry’’ and ‘‘ satu- 
rated ’’ adiabatic rates, that the northern 
winds show the steadier changes, but that 
sudden and comparatively violent changes, 











ly THE AERONAUTICAL $OURNAL. 


[January, 1907. 





most frequent in the S.W. quadrant, which 
happens to be also the quadrant of most 
frequent ascents, are liable to occur. 

(2) The diagrams of wind velocity are 
particularly interesting. The average line 
ior the winds of the N.E. quadrant shows 
only an increase of nine miles per hour up 
to 500 metres; beyond that the average 
variation is practically very small, though 
there are special cases of sudden change in 
either direction which indicate a distinct 
change of current. The S.E. quadrant 
shows an average increase of 16 miles per 
hour up to 500 metres; beyond that very 
little increase on the average, and a general 
diminution in the cases of three ascents, 
which went beyond 1,500 metres. For the 
S.W. quadrant an increase of 18 miles per 
hour shown in the average for 24 ascents 
for the first stage there is comparatively 
little variation in the average, although for 
five ascents to 1,500 metres and three be- 
yond that stage the velocity does go on 
increasing right up to the highest limit. 
The theoretical bearing of this result is of 
great interest. The N.W. quadrant again 
shows considerable increase for the first 
stage, but beyond that, on the average, 
practically none. 

Thus it appears that whatever be the law 
of variation of velocity with height the 
increase of velocity which at Oxshott is 
greatest for south-westerly winds and least 
for north-easterly, has practically ceased at 
500 metres, except in certain cases, which 
suggest the existence of special meteoro- 
logical conditions requiring further investi- 
gation. 

Temporary fluctuations of wind velocity 
are apparently to be expected at any height. 
At Glossop Moor, where observations were 
conducted in August and September, the 
wind, if sufficient to raise a kite at all, rises 
so rapidly at considerable heights as fre- 
quently to wreck the kite, thus rendering 
observations at that station particularly 
difficult. 

(3) The humidity diagrams do not admit 
of any such simple descriptions as those for 
temperature and wind velocity. All sorts 
of variations are shown at all heights, ex- 
cept in the case of north-westerly winds, 
of which there are, however, very few ex- 
amples. That is the only quadrant for which 
no diminution of humidity is shown at any 
stage of an ascent. That result may be 
purely fortuitous. In the indications of 
bewildering variety of changes shown in the 
other diagrams as, for example, in that for 











the S.W. quadrant, we may have a tend- 
ency towards a maximum of humidity at 500 
metres; there are 22 examples of humidity 
increasing for the first stage, 12 of diminu- 
tion for the next stage. Higher up the 
tendency of the air to become drier is still 
more marked. Six ascents show drier air 
at the third stage, four no change, and only 
four increased humidity at that stage. 

For the N.E. quadrant the tendency to- 
wards diminished humidity does not show 
itself until after the second stage is passed. 

The great irregularities in the variations 
of humidity with height are doubtless due 
to the facility with which cloud forms in 
air, cooled by the expansion due to the 
diminishing pressure of rising air. In this 
respect the properties of moisture are differ- 
ent from those of the other constituents of 
the air, and the proportion of moisture to 
dry air in a certain mass of the mixture 
may be taken as a criterion for determining 
the points suggested in the fourth question 
of the paper. 

(4) To answer this question special dia- 
grams have been prepared representing the 
variation with height of the ratio of the 
mass of vapour to the mass of air per cubic 
metre. For these the lines of the separate 
ascents are shown because it is difficult to 
select representative average lines as in the 
case of the other elements. The run of the 
lines may be compared with one or other of 
two theoretical lines. Of these two lines 
the first represents what would happen if 
the air could be regarded as having been 
thoroughly stirred ; in that case the ratio of 
water vapour to air in a cubic metre would 
be the same at all heights, and the limiting 
or test line in that case would be simply a 
vertical line. The second represents the 
changes that would be incidental to a cloudy 
atmosphere, 7z.e., complete saturation, at 
every stage. In this case the actual 
umount of water present compared with the 
dry air would diminish with height, be- 
cause the temperature falls and less water 
is required to saturate air at lower tempera- 
ture. The second line has been calculated 
by Mr. Gold and plotted as a dotted line 
in the diagram. 

It will be seen that we cannot generalise 
the lines on the diagram at any stage by 
referring them to the vertical line or the 
saturation line. Clearly the composition of 
the air does not remain the same at all 
heights. For the most part there is less 
water in proportion to dry air up above 
than lower down, but there are evidently 





i 





















January, 1907.) 


striking exceptions in the one direction or 
in the other. 

We have thus definite evidence of more 
or less horizontal stratification in the at- 
mosphere, which is borne out by numerous 
examples in the other diagrams, the sudden 
changes of wind velocity, the sudden changes 
of relative humidity, and the changes of 
temperature gradient all point to stratitica- 
tion, disturbed, perhaps, but not obliterated 
by the convection currents which must be 
produced by various sources of local heating 
at the surface or elsewhere. And if we con- 
sider for a moment, we can gather plenty of 
ocular evidence of stratification. The 
ordinary stratus cloud must represent a 
more or less horizontal layer of stratified 
air covering a vast area, many thousands of 
square miles; an overcast day without rain 
must mean the persistence of that stratifica- 
tion for a very long time without much 
change. The evidence from our kite ascents 
shows us that there are many examples of 
stratification in the atmosphere, and, in- 
deed, it is not too much to say that the two 
well-known forms of cloud, the cumulus and 
the stratus, represent two types of condi- 
tion in the atmosphere which must be re 
presented in the kite ascents if we extract 
all their meaning. 

The convective condition illustrated by 
the cumulus cloud is of limited horizontal 
extent. It is sometimes referred to in the 
notes of the observers, and it is represented 
in the results by those cases in which the 
temperature gradient is adiabatic, either 
‘“‘ saturated ’’ for rising air in clouds, or 
“dry ’’ for descending air. The stratified 
condition represented below by stratus cloud 
is shown in the kite results by the changes 
in the composition of the air at different 
levels. 

I am sorry that I have not time or space 
to refer to the comparison of the results for 
different stations. As a matter of fact that 
part of the initial programme which referred 
to simultaneous ascents at three stations has 
not been carried out as fully as could be 
wished, because each observer has had to 
wait an opportunity, and the opportunities 
have seldom been coincident, so that the 
comparison of the results from the different 
stations would practically involve merely the 
comparison of the general results drawn 
from each. But I should like to refer again 
to the cases of ascents at Brighton under 
the conditions of sea fog. The only ex- 
amples that I happened to notice in the 
course of the year showed a conspicuous 





THE AERONAUTICAL $¥OURNAL. it 


increase of temperature in the fog at the 
first stage of 500 metres. This is as it 
should be if sea fog is due to the cooling of 
the surface layer of a warm current by cold 
sea water, and there is a good deal of evi- 
dence for that view of the origin of many 
sea fogs, but in compiling the results Mr. 
Gold came across other examples of Mr. 
Salmon’s observations, which showed no 
increase of temperature for the first stage, 
but in one case a decrease nearly ap- 
proaching the adiabatic rate. It may be 
remarked that a sea fog might not extend 
so high as 1,000 feet, and that there may 
be room for a reversal of the gradient be- 
tween the ground level and the first stage. 
These and other suggestions which would 
account either for an abnormally high sur- 
face temperature or an abnormally low 
reading at 500 metres, require further ex- 
amination. 

I have made no remarks about the varia- 
tion of wind direction. The estimations of 
direction in the upper air are, in any case, 
difficult, and when the top kite is hidden 
by clouds, not possible. As a general rule, 
but not always, the wind veers slightly 
aloft. No case ig reported of a kite reach- 
ing a current of markedly different direc- 
tion by sudden transition. Thus it would 
appear that the sudden changes which take 
place in the composition of the atmosphere 
or the velocity of the wind are not accom- 
panied by equally sudden and extensive 
changes in wind direction. 

I have now completed the examination 
paper, and I think we may regard the 
general conclusions as to the tailing off of 
the increase of wind with height and the 
differences in the increase of velocity for 
different directions and for the first stage 
as information of very considerable impor- 
tance. Ina similar way we may regard the 
evidence for the stratification of the atmo- 
sphere drawn from the humidity results and 
confirmed by them for wind velocity and 
temperature as equally striking and valu- 
able. It only remains to consider what 
indications the results give us for future 
guidance. 

First and most evidently, whether the 
general statements that have been made 
here on rather slender foundation can be 
laid down with greater security; whether 
the exceptions as in the case of the increase 
of temperature aloft in a sea fog can be ex- 
plained without abandoning the general 
statement, as, for example, by some acci- 
dental initial warming of the thermograph. 








I ? 


Next we want to know more exactly the 
shape of the curve of variation of wind 
velocity with height for the various direc- 
tions from which the wind comes. For this 
purpose the jump from the ground to 500 
metres is too great: we want to know about 
the intermediate portion. Next we want 
to know what are the meteorological condi- 
tions under which the wind fails at higher 
levels or goes on increasing up to the high- 
est limit. Also some more precise infor- 
mation about the wind direction at the 
upper levels is very desirable. It is evi- 
dent to the casual observer on some days 
that the upper clouds move directly oppo- 
site to the lower clouds. How is the transi- 
tion between the two effected? By a 
gradual alteration in direction, or by a 
falling off in the velocity until a calm layer 
is reached and then gradual increase in the 
new direction ? 

Next we want a more careful study of the 
boundary region between two stratified 
layers of different composition. If, as I 
have said, the atmospheric processes may 
be resolved into convection and stratifica- 
tion, the careful examination of either or 
both would be most valuable. For this the 
observer would have to train himself to 
recognise the signs of a marked stratifica- 
tion and a marked convection and manipu- 
late the kite to get a prolonged record in 
the region to be specially examined. 

Finally there is the part of the programme 
of co-operation still to be taken in hand, 
namely, concurrent observations at the 
same time in different places. Such com- 
parisons as are possible from the published 
results show that the phenomena at the 
two stations, Oxshott and Ditcham Park, 
though similar, are not identical, and the 
examination of the records for salient points 
of difference is well worth the effort  re- 
quired to make it. Perhaps it may be 
possible to arrange for the opportunities to 
occur simultaneously at the four stations 
where ascents are now made, and I hope 
before another year elapses that further 
progress may be made with the work by 
means of unmanned balloons so that a 
greater height may be brought under re- 
view. 

As it is, I wish most cordially to con- 
gratulate the observers at the several sta- 
tions who have contributed in their various 
ways to the results which I have sketched in 
this paper upon the year’s work. 

Mr. Dives: Dr. Shaw has taken 
metres as a starting point, so to speak. 


500 
It 


12 THE AERONAUTICAL YOURNAL. 





| 


(January, 1907, 





is not possible to publish results of observa- 
tions in very great detail, and it is, there- 
fore, necessary to take some point to start 
from, for the sake of comparisons. It may 
occur to you to wonder why some lower 
point might not be taken. It would be an 
advantage if we could leave a kite at a few 
hundred feet above the surface so as to get 
the temperature conditions uninfluenced by 
the surface, and I should like to do so if it 
were possible, but in practical work, as a 
rule, it is not possible. On calm days one 
often has to wait some time before one gets 
a chance of going through the surface wind, 
and the kite soon falls to the ground. Then 
on days when the wind is strong, particu- 
larly when there is a west wind, it is most 
likely to be broken, because the wind is 
gusty. I always try to get a kite through 
that region of surface wind as quickly as 
possible. 

Dr. Shaw pointed out one case in which 
the temperature decrease exceeded the adia- 
batic rate. I think this must be some in- 
strumental error, and that it is not the 
rule. I may point out that the temperature 
shown at 500 feet was not simultaneous 
with the temperature at the surface, so that 
it does not follow that the actual tempera- 
ture at that height showed a greater de- 
crease than the adiabatic decrease at the 
same time, because the two observations 
were not simultaneous. 

With reference to the question of the wind 
decrease, unfortunately there are consider- 
able limitations in the use of kites. To 
begin with, we cannot fly without some 
wind, and if the wind fails, we cannot keep 
in any particular stratum of air, hence it 
may be that in those charts the height is 
limited to 1,000 metres because of the wind 
decrease above that height. There are 
many cases when the wind fails at 1,000 
metres or so. That is incontestably the 
case with winds from the east and north- 
east ; it seldom happens with a south-west 
wind. 

These ascents were all made in the day- 
time. I do not think that makes any 
difference above 500 metres, but the tem- 
perature decrease is far more rapid in the 
day-time, because it is warmer in the day 
at the surface, and it is an established fact 
that when we get a few thousand feet up, 
the surface temperature vanishes, and the 
air temperature is the same night and day. 

With reference to the change of wind 
above, there was one undisputable case with 
a north-east wind, in which the wind in- 

















January, 1907.) 


creased rapidly. This was due to the fact 
that a rain squall passed over when the kite 
was highest. 

Generally speaking, the humidity in- 
creases as the instrument rises, until the 
cloud level is reached. Then if you do not 
reach the clouds you may be fairly certain 
of the height by the decreasing humidity. 
When a kite passes through clouds, a few 
hundred feet above the cloud level, the air 
is curiously dry. Temperature inversion 
occurs just above the cloud level, and you 
find dry air. Then frequently you get a 
sudden rise of temperature, and then a de 
crease, and I imagine that there are two 
or three cloud levels, as the same thing 
may happen time after time. 

The observations as to cumulus clouds 
and the uprushes of air are interesting, but 
they are not so pleasant to the man who is 
flying the kites as to the man who works 
them up. It has happened to me several 
times that my kite has got into one of 
these uprushes and been carried up 1,000 
feet or so, and in a few minutes the wire 
has broken, which is not exactly what one 
wishes. 

As to the question of co-operation. It 
would be useful if we could get ascents on 
the same day and at the same time, but it is 
a difficult matter, because my observers, to 
whom I am grateful for making the ob- 
servations, are voluntary observers, some 
have regular business, and they cannot 
always set apart a time for kite flying. 
Also if a time is pre-arranged, it probably 
happens there is no wind at that time. 

I think Mr. Cody is here, and if he will 
give us the result of his experience as to 
decrease and increase of wind with different 
directions it would be interesting. 

Mr. Copy: I have frequently found that 
the kites get to a certain height and will 
not go higher. I have known occasions 
where a man has gone up at night-time 500 
feet in a dead calm; we let the lifter go, 
and the man went right up with no wind at 
all with his carrier kite, so there must be 
wind high up. Only a few days ago we had 
balloons up with a perfect gale blowing to 
400 feet, and at the ground we could not 
have flown a piece of tissue paper. I went 
up to see the conditions, and found the 
wind did not blow at all at starting, but 
higher up there was a great deal. If the 
Society is interested in meteorological re- 
search, I could guarantee to give them read- 
ings at 100 feet or at any height up to 
1,000 or 2,000 feet, either in a dead calm 


THE AERONAUTICAL $OURNAL. 





13 


or a heavy wind. I could tie my kite to 
any heitht that was wanted. So that if 
there is any interest in having a certain 
height, if the Society will communicate with 
me, I will give them the necessary readings. 

Mr. Reap: I would like to say one word 
about the importance of these readings. It 
shows the interdependence of one branch of 
science on another. Meteorologists bring 
us fresh information, especially that of the 
increase of wind at 500 metres, and this is 
a practical point for aéronauts. It has 
another bearing, too, with regard to the 
future; when we are going through the 
wind at a great rate—for instance, in the 
future, when we make our week-end trips 
in balloons—we shall have to consider what 
precautions must be taken to prevent colli- 
sions. When we are travelling 100 miles 
an hour, it is all very well on a railway, but 
in the air if you come across another ap- 
paratus travelling the same pace as your- 
self, there is bound to be a collision. The 
only rule of the road, then, will be the 
upper and lower airs. On the ground or 
water we have only two directions, but in 
the air there are four. It is important that 
we should get a knowledge of these layers 
of the atmosphere before we start on our 
journeys, and we are indebted to the author 
of the paper for having shown us that we 
have layers of this kind. 

With regard to the sea fog, I think there 
is a solution for both cases. An east wind 
will bring us rain on the east coast, when 
the water is warm, but not when the water 
is cold. 

Mr. Doveias ARCHIBALD: Some years 
ago I found that the result of the observa- 
tions up to a height of 1,500 feet above the 
ground was that the velocity of the wind 
always increased up to that height. The 
increase of velocity was greatest with a 
south-west wind, exactly Dr. Shaw 
found. I am glad to see that in almost 
every respect the observations taken now 
under the direction of the Weather Office 
agree with and corroborate the ones I took 
then. We made these observations for 
three years, and mostly in the summer time, 
but sometimes in the spring, and, there- 
fore, there were a good many variations in 
the wind, and I collected them under differ- 
ent heads, and certainly proved that the 
north-east current is the shortest, and the 
south-west is the tallest. I certainly think 
that what Dr. Shaw has shown us to-night 
has a bearing rather on aéronautics than 
on pure meteorology, because he did not 


as 








i4 THE AERONAUTICAL JOURNAL. 


(January, 1907. 








show us how these observations would en- 
large our knowledge of the conditions of 
the weather so much as the physical condi- 
tions of the atmosphere, and from that 
point of view they appear to me a necessary 
accompaniment of any aéronaut. It is 
much in the same way as the hydrographer 
to the Admiralty shows the currents of the 
sea that aid the mariner who is floating his 
ship, and the more that is known of the 
conditions up above by the aid of kites, 
certainly the better for the journeys of those 
flying machinists who are going to greatly 
develop their machines shortly. When 
they do, the first thing they will find out 
will be what a great variation occurs in 
different parts of the atmosphere. So far 
as the actual observations of kites have 
shown up to date, I think the work that 
has been done recently in America is one 
of the best instances in which the observa- 
tions from kites have shown fruit. Pro- 
fessor Bigelow has taken all the observa- 
tions that have been made over in America 


and a great many that have _ been 
made in Europe, and by combining 


them he has shown the conditions of the 
atmosphere with regard to the cyclones and 
anti-cyclones; in fact, he has developed a 
new theory as to cyclones and anti-cyclones 
which had never been attempted before. So 
far as I have seen, I think it is some of the 
best work in meteorological science that 
has been done in the last few years. I am 
glad that kite observations have been the 
basis of this work. The idea was started a 
few years ago; I may claim a little towards 
starting it, the only observation of the kind 
before my own being in 1847, which had 
practically been forgotten when I started 
mine in 1883. By the aid of these observa- 
tions all over the world, meteorological 
science has advanced by leaps and bounds, 
and I think it is a pleasant fact that Dr. 
Shaw has included these observations in the 
ordinary weekly weather maps so that they 
may be utilised by the public and made 
part of the development of the science. 

Mr. Bucnanan: I think the most im- 
portant observation that has been made to- 
night is the proposal of Mr. Cody to give 
readings at definite heights, and I presume 
over a period of 24 hours. We have had 
ordinary kite flying and balloon observa- 
tions lasting over an hour or two, and we 
now have an opportunity of getting what 
is the most important thing, a 24-hours’ 
record. 

There is one other remark I should like 


\ 


to make. When Dr. Shaw was pointing 
out the fall of temperature in one case Mr. 
Dines showed that it might be accidental. 
There is a similar thing in the observations 
at Grand Moulet, which is like a mountain 
station, but the observations at Bosch have 
a difference of temperature of quite as much 
as 20°C. per 100 metres. 

Colonel TroLttore: For some years Pro- 
fessor Hergesell, of Strasburg, has been 
sending out man-carrying balloons and 
kites on a certain day to make meteorologi- 
cal observations. Mr. Bruce has these 
papers, and if we can correspond with him 
with regard to a date, I think we shall get 
valuable data. 

Dr. SuHaw: It is too late at present to 
detain the audience by going fully into the 
points that have been raised. I think the 
discussion has been more interesting than 
the original paper. I am glad Mr. Douglas 
Archibald said what he did. I knew the 
time would be short, and I purposely com- 
pressed what I had to say in the smallest 
possible compass, or I should have been 
glad to compare my results with the results 
he obtained some years ago. I did keep 
myself off the meteorological side of things 
as much as possible. I think the question 
as to whether there is a limit to the velocity 
of the wind is one of the most important 
theoretical meteorological questions before 
any investigator. I think Mr. Dines’ ex- 
planations were only suggestive, and I am 
looking forward to next year’s work. 

The Presient: You will all agree that 
this paper is one of great interest, and I 
may say important, considering both the 
name of the reader and the names of those 
who have taken part in the discussion. 
Some of our most eminent meteorologists 
have come here to-night to discuss these 
matters. There are letters from other 
authorities who express their regret at not 
being able to be present at this lecture. It 
seems to me of especial value that the wind 
has been found to increase up to 500 metres, 
and probably does not increase much more. 
We have known that it did increase as one 
went up, but there was a doubt as whether 
it went on increasing or if there was a limit. 
Now it seems there is a limit to the rate of 
increase. 

There is one point I should like to bring 
forward, that very often in a balloon ascent, 
when you get above the clouds, if there is a 
decided layer of clouds hanging around, 
when you rise above this, the direction of 











aA a Owe mk 








January, 1907.) 


the wind changes. I am only speaking 
from a limited experience of three or four 
times, but it would be interesting to know 
whether aéronauts have found a change in 
the direction of the wind where there is a 
large bank of clouds. 

I can only now propose a vote of thanks 
to the lecturer for his valuable paper to- 
night. 

The vote of thanks was carried unani- 
mousiy. 


The Gordon-Bennett Cup 


of 1906. 


By Br. COLONEL J. E. CAPPER, C.B., 
R.E. 


‘ 


The Gordon-Bennett Cup is the ‘* cordon 
bleu ’’ of the aéronautical world. 

It was presented by Mr. James Gordon- 
Bennett, the proprietor of the Vew York 
Herald, to the International Aéronautical 
Federation, to be competed for yearly under 
the following conditions :— 

(1) That it should be an International 
Challenge Cup. 

(2) Every competing nation to have the 
right to enter three balloons; no balloon 
to be more than 77,000 cubic feet and none 
less than 31,500 cubic feet. 

(3) Each balloon must be piloted by a 
member of the nation which he represents. 

(4) All balloons to start on the same | 
date, and the cup to be won by the balloon 
which descends furthest from the starting 
point. 

If the weather conditions are unsuitable 
for a long-distance contest, the Committee 
may decide it shall be won by the balloon | 





which stays longest in the air. | 

(5) The Cup to be competed for under | 
the auspices of the Club which holds it. 
The first contest, viz., in 1906, taking place 
under the auspices of the Aéro Club of 
France. 

(6) The Cup to be held by the Club and 
not by any individual. 

(7) Any nation winning it three years in 
succession to keep it. 

The race for the Cup this year started 
from Paris. It excited a great deal of 
interest in the aéronautical world, and the 
entry was very fine. France, Germany, | 
Great Britain, and Spain each sent three 





|} milk. 


THE AERONAUTICAL JOURNAL. 15 


balloons, America two, and Belgium and 
Italy each one. 

The British representatives were Mr. 
Frank Hedges Butler, accompanied by Mr. 
Griffith Brewer, in the ‘‘ City of London ”’ ; 
Professor A. K. Huntington, accompanied 
by Mr. M. C. Pollock, in the ‘‘ Zephyr ’’ ; 
and the Hon. C. S. Rolls, accompanied by 
Colonel J. E. Capper, in the ‘‘ Britannia.”’ 

All the British balloons were constructed 
specially for this race, and were of 77,000 
cubic feet capacity. 

Among the foreign pilots the best known 
were M. Santos Dumont and Comte Henri 
de la Vaulx. 

The competing balloons were all spherical 
with the exception of the ‘‘ City of Lon- 
don’’ (Mr. Butler’s), which was _pear- 
shaped. 

M. Santos Dumont had his car fitted with 
an engine and lifting screws to utilise in- 
stead of ballast. 

The smallest balloon used was of 52,500 
cubic feet capacity. 

Most of the balloons were of varnished 
cotton; two were of varnished silk, and 
two of rubbered cotton. Twelve were en- 
tirely new, and nearly all were in excellent 
condition. 

The contest was fixed for September 30, 
the hope being that the strong easterly 
winds usual at that time of year would give 
a long course westwards over Europe, and 
thus permit of a record run being made. 

In anticipation of these winds and of a 
journey in the air extending over two days, 
during the second of which we might ex- 
pect to reach great heights, we had laid in 
an ample provision of food and drink. We 
also had cylinders of oxygen, and a very 
ample supply of warm clothing. 

We ourselves had forgotten to lay in a 


| stock of water, though well provided with 


Professor Huntington, who had had 
the foresight to provide an ample quantity, 
most kindly gave us a large tin at the last 
moment, and this we found most valuable. 
Mr. Butler had also ordered two pints of 


| champagne to be placed in each of the 


British cars, and when wearied out, the next 
evening, we much appreciated the extra 
fillip it gave us. 

The balloons had to be in Paris on Sep- 
tember 29, each being certified by its Club 
committee as complying with the regula- 
tions, and they were there inspected by the 
organising Committee. 

The French Aéro Club kindly invited all 
contestants to a dinner on the 29th, and 








16 


there they were hospitably entertained and a 
few pleasant speeches made, notably by 
Prince Jerome Bonaparte and by Mr. 
Roger Wallace, who delighted all by the 
facility with which he rendered his witticisms 
in a foreign idiom. 

The arrangements for the contest were 
admirably organised by the Club Secretary, 
M. Besancon; whilst the English competi- 
tors owe a great deal to the Secretary of 
the British Aéro Club, Mr. Perrin. 

The 30th was a great day. The west end 
of the Tuileries Garden was simply full of 
balloons, 16 great, glossy spheres, mostly 
of a translucent yellow, one of chocolate 
colour, and two of a brilliant chrome, and 
so close together that it seemed almost im- 
possible to start them. 

Gas mains were laid along this part of 
the garden, with branches to each balloon, 
and by three o’clock all the huge globes 
were filled. 

Each balloon was furnished with the flag 
of its nation and a huge number on the car 
to make identification easy ; whilst a num- 
ber of sappers from the military Pare 
d’Aérostation were told off to assist in 
handling the balloons, each man wearing 
on the arm a brassard with the number of 
the balloon to which he was appointed. 

A crowd of gaily-dressed visitors was ac- 
commodated on the raised terraces on three 
sides of the enclosure allotted to the 
balloons, but neither gold nor interest could 
gain admission to this enclosure to any but 
the competitors, a few journalists, and the 
appointed officials. 

At 3 o’clock a flight of 3,000 carrier 
pigeons was launched in the air. Several 
of these were so attracted by the unusual 
scene in the Tuileries Garden that instead 
of starting on their proper journey they 
paid the balloons a visit, some of them even 
remaining on the balloons during their de- 
parture. 

The interval before the departure of the 
first balloon was occupied by the ascent of 
numerous pilot balloons of comical shapes, 
which elicited shouts of amusement from 
the populace, and a swarm of beautiful 
small toy balloons, sent up by ‘‘ La Vie au 
Grand Air.’’ There must have been hun- 
dreds of these despatched at the same 
moment, and the diverse currents of the air 
were well shown by the way in which they 
scattered. ; 

The general direction of the wind as 
shown by these pilots was W. by S., and 
great was the disappointment; numerous 


THE AERONAUTICAL YOURNAL. 





(January, 1907 








prophecies being made that the contest 
would be a short one, and end on the shores 
of the Atlantic. 

We ourselves, thanks to a telegram sent 
by the Meteorological Society, hoped to 
eet currents trending in a north-westerly 
direction at the higher altitudes, and we 
were, therefore, careful to provide ourselves 
with a map of England, besides the general 
map of Europe, and large scale maps of 
Northern and Western France. 

No time was lost in ballasting up, and 
punctual to the minute at 4 o’clock the first 
balloon, ‘‘ The Elfe,’’ of Italy, manned by 
Mr. Vonwiller and Lieut. Cianetti, sailed 
eracefully off amid the cheers of the popu- 
lace. Thence on, at regular intervals of 
five minutes, a fresh balloon, brought to 
the same point of departure, sailed off on 
its appointed mission, till all had been des- 
patched. 

The ‘‘ Britannia,’’? on which I was a 
passenger, was the fifth, and henceforward 
my description can only be of our owa 
doings. 

Starting at 4.20 we were wafted slowly 
from the Gardens, over the Place de la Con- 
corde, which was a mass of human beings, 
close to the Eiffel Tower at the elevation of 
its summit, over the Bois de Boulogne and 
St. Cloud, then over Nancy, where dusk 
began to enclose us. Ahead and astern 
were our competitors, seeming to be going 
in all directions. Mr. Rolls, with his eye 
fixed on the statoscope, continually threw 
out small shovelfuls of sand, to compensate 
for the cooling of the gas, till by 6.30 
eight of our thirty-seven bags of ballast had 
been expended. My duties were to keep 
the log and ascertain our course—no diffi- 
cult matter while daylight lasted. 

About 6 the sun set in all its splendour, 
and we had recourse to electric lights to 
read our maps and instruments. Half an 
hour later the moon rose, throwing a silvery 
radiance on the earth beneath, but even 
with its assistance the course was hard to 
track. 

We had been going steadily just south 
of west when darkness surrounded us, and 
when railways below us gave the next op- 
portunity of locating our position, we found 
none on the map that tallied with those on 
the ground. For some little time we were 
in doubt, but about 8 p.m. we came to a 
large well-lighted town which, knowing our 
probable rate of progress and the time 
from the last point we had identified, must 
surely be recognisable. We searched the 

















ist 
he 








January, 1907.) 





map, but no such town could we find in our 
line, and it was evident we had changed 
direction after dark. Consulting the next 
map to the north we identified the town 
by its size and the direction of the railways 
and roads as undoubtedly Evreux, and ques- 
tions shouted down (which were reported in 
the French press as cries for help) brought 
back the reassuring news that we were 
really there, and were going in a north- 
westerly direction. This was the best of 
news, as it promised fair for a run to the 
West of England, or even to Ireland, instead 
of our journey being brought to an abrupt 
termination by the Atlantic. 

From that point on we were never in 
doubt as to our position, and we hoped 
shortly to make the mouth of the Seine 
and a long crossing of the Channel to 
Devonshire. Our hopes, alas! were doomed 
to be frustrated. For some reason we rose 
to about 3,000 feet and were taken at that 
altitude more and more to the north, finally 
reaching the Seine about 10 miles west of 
Youen, and here we lingered, drifting slowly 
along, nearly becalmed for several hours, 
going finally north-east. 

At 11.20 we saw below us a balloon hurry- 
ing N.W., and it became a question whether 
we should descend and follow it, or remain 
up in the hope of getting a stronger current 
in the morning which would bear us N.E. 
to Norway. On the whole, we decided for 
the latter. We knew it was improbable 
that anyone else would have got this easterly 
set, whilst several, if not all, would cross 
to England. Our chances there were only 
equal to theirs, but if we could get to Nor- 
way we must distance everyone. 

There was nothing to do, the balloon 
stayed at its elevation; we had thrown out 
no ballast since evening; and in turns we 
tried to sleep, the smallness of the car and 
its numerous contents making our efforts 
in this direction somewhat ineffective. 

About 2.30 a.m. we moved off again, the 
treacherous wind taking us nearly due 
north, and it became apparent that we must 
try for England after all, greatly handi- 
capped by the drift we had already taken 
to the east. 

At 3 a.m. the revolving light west of 
Dieppe saluted us some 20 miles off, and at 
4.30 the moon fell behind a heavy bank of 
clouds, appearing for a few moments be- 
neath them as she sank far west into the 
sea, sending a gleam of glittering silver 
over the water as she disappeared. Then 
the pale light of dawn appeared in the east, 





THE AERONAUTICAL FOURNAL. 17 


the country gradually became visible, till 
at 5.20 we left the coast of France west of 
Dieppe and ventured on the Channel cross- 
ing. 

It is curious to think that by that hour 
two of our competitors had already de- 
scended in England, having kept low down 
in the faster breeze whilst we had been 
sauntering over the reaches of the Seine. 

The morning was hazy, and 10 miles out 
we lost the coast of France, England being 
still invisible behind the mist. Far away 
to the north we saw another balloon (the 
‘* Zephyr ’’), and knew that at least one 
had crossed before us. 

On the sea nothing was visible except an 
occasional fishing boat and steamer. 

We found we were going too far to the 
east, and comine down in order to strike 
westward, trailed for some time in the 
Channel, passing close to a steamboat and 
exchanging greetings with the crew. 

There is something peculiarly fascinating 
in crossing the sea out of sight of all land 
as we were; the feeling is even more peace- 
ful than going over land, whilst the gentle 
murmur of the waves far below adds to the 
restful sensations of a balloon voyage. 

After keeping low down for a consider- 
able time we decided to ascend to see if we 
could find the English coast, as it is diffi- 
cult to estimate one’s course with only the 
sea to guide one. 

Ascending to 5,000 feet we saw again 
our friendly competitor away to the N.E., 
and then, alas! far to the N.W., made out 
the white cliff of Beachy Head. Again the 
valve was pulled to bring us down into the 
more westerly currents, the higher ones 
still trending eastwards, and we kept down 
till England was close in front, on one oc- 
casion shouting to a steamer to avoid our 
trail rope. A look at the map and our 
knowledge of the coast showed Hastings in 
front, and rapidly a telegram was written 
and, together with half-a-crown, fastened to 
a small rubber balloon, and ballast thrown 
to take us over the town. The small balloon 
fluttered to the ground, and we saw it safely 
descend in the garden of a small house on 
the outskirts of the town. 

The crossing had taken just five hours. 

Over England our course was again 
easterly, and we had to keep as near the 
ground as possible, which entailed a liberal 
expenditure of gas and ballast in order to 
keep up to the north. Trailing was mostly 
out of the question, as entailing too much 
damage, but we were enabled to enjoy short 








18 


periods, striving to make every inch to the 
west we could. Passing over the Medway 
near Chatham we had a splendid view of 
the channels of even that muddy stream, 
an object lesson as to the utility of a balloon 
for conning purposes; then coming down 
we trailed across the Thames and the marsh 
land on either side. And so on northwards, 
hoping against hope to make as far west as 
Ely, so that we could run up Lincolnshire 
and possibly to York—but it was not to 
be. Bury St. Edmunds was crossed late 
in the afternoon, and dusk overtook us, 
tired with our exertions and disappointed 
in our hopes, with no prospect of even 
touching the Wash. The wind had risen 
to 30 miles an hour, and we sped on in the 
vathering gloom 1,000 feet above the earth, 
till with but seven miles of unknown coun- 
try between us and the open sea, we had 
reluctantly to come down. Tearing past a 
cottage we shouted to the occupants to come 
on half a mile to help us, and there, in an 
open root field, we touched the eround. I 
was too mixed up with attempting to keep 
myself from the shock of landing and at 
the same time keep ready to fling the heavy 
anchor, to notice exactly what happened, 
but Mr. Rolls ripped the balloon at exactly 
the right moment, the grapnel tore through 
the roots for a few yards, the car fell gently 
on its side, and the balloon, no longer 
beautiful, spread out an inert mass to lee 
ward of it. Our journey was over, assist- 
ance came, we packed with the aid of our 
electric torches, and the hospitable vicar of 
Shernborne (Mr. Waters) entertained us for 
the. night. 

Next morning we learnt, on arrival at 
the station, of the ‘‘ mysterious disappear- 
ance’’ of the ‘‘ Britannia,’’ and learnt, 
too, for a certainty that at least two 
balloons had beaten us. Lieutenant Lahm, 
of America, assisted by Major Hersey, a 
meteorological expert, who is acting 
engineer to the Wellman Polar Expedition, 
gained a well-earned victory, due both to 
his own determination and management, 
and to the unrivalled knowledge of air cur- 
rents possessed by his aide. He descended 
near Whitby. 

Second was M. Vonwiller, of Italy, with 
his companion, Lieut. Cianetti, of the 
Italian Military Pare d’Aérostation, who 
reached as far asthe Humber. It is probable 
that had they kept at a low elevation they 
would have been the winners, but an experi- 
ence near Alton, where they got mixed up 
with someone’s chimneys, decided them to 


THE AERONAUTICAL JOURNAL. 








[January, 1907. 





keep up higher, and, getting to about 
12,000 feet, they drifted steadily east of 
north. On the descent their ripping panel 
failed to tear quite through, and some gas 
remained in the envelope long enough to 
carry the balloon and car across a cottage, 
the inmates of which were considerably 
alarmed to see a huge flapping monster ap- 
parently attempt to devour their house. No 
one was injured to any extent, but the ex- 
perience was a sufficiently unpleasant one. 

Third place was given to the 
‘‘ Britannia,’’ after very careful calcula- 
tions, the ‘‘ Walhalla,’’ manned by Comte 
de la Vaulx and Comte d’Oultremont, 
having descended quite close near Great 
Walsingham. It was a near thing, but the 
British balloon was held to have won by 
about a mile—much to our delight. 

Three other balloons crossed the Channel 
—the ‘‘Zephyr’’ (Prof. Huntington) de- 
scending in Kent, and the ‘‘ Ville de Cha- 


teauroux ’’ (M. Balsan) with the ‘‘ Mon- 
taner’’ (M. Kindelan) descending in 
Sussex. 


The remainder all descended in France, 
nearly all on the coast, for fear of being 
carried to the Atlantic, whilst if they had 
only known their position, most might have 
safely crossed to England. 

The Belgian balloon apparently leaked, 
and made but a short run, whilst an acci- 
dent M. Santos Dumont met. with to his 
arm from his motor necessitated his de- 
scent in order to see a doctor. 

It is interesting to note the number of 
each nation who crossed the Channel :— 


Italy: The only one entered. 
France: Two out of three. 

Great Britain: Two out of three. 
America: One out of two. 
Spain: One out of three. 
Belgium: None—one entered. 
Germany: None out of three. 


The contest, though not involving any 
great distances, was most interesting, and 
the race went to the bold and to those who 
best judged and utilised the currents of the 
air. 

The Cup remains in the hands of the Aéro 
Club of America, who will organise the next 
year’s contest. 

It is to be hoped our champions will make 
a bold bid to gain it, and that the entries 
will be as good as this year, and the con- 
test carried through with the same spirit 
of friendly rivalry as in the initial contest 
of 1906, 




















January, 1907.) 


The Present: I will propose a vote of 
thanks to Colonel Capper for having kindly 
given us a full account of his very interest- 
ing trip. 

The vote was carried unanimously. 


The Aéroplane Experiments 
of M. Santos Dumont. 


By ERIC STUART BRUCE, M.A. Oxon., 
F.R. Met. Soc. 





At whatever value the aéronautical 
achievements of M. Santos Dumont may be 
placed in the history of aérial navigation, 
there can be no doubt that there is a per- 
sonality about the Brazilian aéronaut that 
has done more to convince the world of the 
possibilities of human flight than any other 
cause. Whenever M. Santos Dumont be- 
gins to experiment there is a thrill of en- 
thusiasm throughout the civilised world, 
and everywhere we hear the cry that the 
conquest of the air is at hand. Such a 


THE AERONAUTICAL JOURNAL. 19 


have given M. Santos Dumont an almost 
mesmeric influence on mankind, because 
they do not come within the scope of this 
Society. But whether or no it is the work 
of the man or his individuality that has con- 
vinced the world of the possibilities of the 
aéroplane, in any case I think he must be 
congratulated that he has succeeded in do- 
ing so. And this is a moment of special 
jubilation for the Aéronautical Society of 
Great Britain, who, forty-two years ago, 
was the pioneer of the world’s aéronautical 
societies. For by this Society more atten- 
tion has been paid to the subject of aérial 
navigation by bodies heavier than air than 
has been by any other aéronautical society 
in the world. 

Our library is full of the records of the 
valuable papers read before this Society in 
the past, that little by little have contri- 
buted to the issues that are just beginning 
to be realised at the present time. We feel 
bound to think that had the light petroleum 
motor not come so tardily, the dreams of 
many of those members whose lips are 
for ever closed might ere now have come to 


| pass. 


faith as this was, indeed, inspired when, in | 
1901, M. Santos Dumont rounded the Eiffel | 


Tower in his navigable balloon to win the 
Deutsch prize. When his navigable balloon 
experiments ceased, the public faith again 
grew dim. It has been but a few days ago 
again revived with still more general ac- 
cord by his experiments with a motor-driven 
aéroplane. And yet, since M. Santos 
Dumont won the Deutsch prize, and before 
he began experimenting with his aéroplane, 
two undoubtedly greater achievements in 
aérial navigation have been accomplished 
than have fallen to his lot. I refer to the 
development of the Lebaudy navigable 
balloon and the experiments of the brothers 
Wright in America. 

Though, in the former case has been evi- 
denced the cleverest piece of engineering 
work that has yet been done with a 
navigable balloon, and in the latter case the 
accomplishment of a flight of 25 miles in a 
motor-driven aéroplane, yet these two ex- 
amples of really practical progress did not 
raise the public pulse to any like degree as 
did the navigable balloon experiments of 





M. Santos Dumont in 1901, and his com- | 
paratively short aéroplane flights in Paris | 


the other day. 
I will not attempt in this paper to ac- 
count for the psychological reasons which 


But one industry has to wait for another. 
So interdependent are the affairs of human 
life! The light petroleum motor is, in- 
deed, one of the chief factors in the de 
velopment of the aéroplane. Its want was 
felt as long ago as 1868, when a £100 prize 
was offered by this Society for a light engine 
and boiler for an aéroplane, a prize won 
by Mr. Stringfellow. But light steam 
motors did not supply the want that is be 
ing satisfied in modern petroleum motors. 

At the present moment when the flights 
of M. Santos Dumont are creating an inter- 
est in aéronautics that is, perhaps, without 
precedent, it is, I think, all important to 
real progress that those who are experiment- 
ing or about to experiment should keep their 
heads and balance enthusiasm with the re 
quisite amount of prudence and reason. 

We must remember that the period of 
public excitement which was evoked by M. 
Santos Dumont’s former evolutions round 
the Eiffel Tower was followed by a period 
of fatal accidents and consequent depression. 
It is important in the interests of aéro- 
nautical science that the present second 
period of exultation should be followed by 
neither. We have still in our memory the 
tragedies of ‘‘La Paix’’ and the ‘De 
Bradsky.’’ The deaths of Severo and 
De Bradsky and their respective engineers 


, Were caused by neglect of ordinary pre- 








20 


cautions in the one case and the absence of 
common engineering knowledge in the other. 

Though just a little progress has been 
made in aéroplane manipulation, still the 
work that has yet to be done before we can 
claim to have secured the stability of our 
structures amidst the ocean of air, with its 
subtle currents as yet unstudied and un- 
fathomed, is gigantic in its proportions. Is 
not this the truth? And at the present 
moment, when there is an exaggeration 
going on about progress made, which is, I 
fear, misleading the public, it is important 
that within the walls of a learned society 
the truth should be spoken. 

At this moment of encouragement let us, 
in this Society, both collectively and in- 
dividually, apply ourselves with increased 
zeal to the task the founders of this Society 
set us in 1866, but at the same time with 
precaution and with the methods of science. 
In eight years’ time this Society will be 
keeping its jubilee. In what better way 
could we keep our jubilee than by showing 
the world that the work of 50 years has 
brought us near the goal? 

I hear that M. Santos Dumont has lately 
given advice to those who take part in com- 
petitions to fly low. That advice is sound, 
for it is commensurate with our present 
progress. Just as the child learns to walk 
by tumbles, so the first flyers will not 
escape their falls. By flying very near the 
ground, man must first learn to use his 
wings. But the time will come when he 
will seek higher flight. Will not his best 
precaution then be to fly over the surface 
of water, accompanied by the rescue boat? 
I know this method has been lately 
criticised on account of the danger of the 
flyer being entangled in his machine in the 
water and drowned before rescue can be ac- 
complished. But it would seem that when 
man first seeks higher flight it will be the 
choice of two evils, and of two evils one 
must choose the least. Tumbles at a cer- 
tain height over solid earth must mean de- 
struction. Tumbles over water may mean 
drowning, but there is, perhaps, an equal 
chance of rescue and preservation. 

Concerning the apparatus and actual ex- 
periments of M. Santos Dumont, neither at 
present gives scope for a lengthy paper. In 
the October number of this journal there 
appeared a picture of the machine. The 
supporting surface may be described as a 
multiple box kite. It reminds us of the 
part which Mr. Hargrave, an honoured 
member of this Society, has played in the 


THE AERONAUTICAL FOURNAL. 





[ January, 1907. 





development of the aéroplane, for from kite 
we are passing to flying machine. The 
success of the box kite in scientific aérial 
exploration has done much to familiarise us 


_ with the idea of the possible stability of 


bodies heavier than air, and enticed man 
io abolish the string and apply instead the 
motor. 

In M. Santos Dumont’s machine the two 
wings are slightly inclined so as to form a 
V. Each of the wings is fixed at one end 
of a long protruding girder. This girder 
carries the car, and at its other end is the 
box-shaped rudder. This rudder can be 
moved in any direction, the up and down 
movements regulating the rising and falling 
of the machine. The two-bladed aluminium 
propeller is fixed behind the wings, and is 
worked by a petrol motor, which, in the 
earlier experiments, was of 24-h.p., but 
which has now been replaced by an 
Antoinette motor of 50-h.p. 

The machine has already been the sub- 
ject of much criticism; for instance, the 
following criticism was made by Colonel 
Fullerton during his recent lecture at the 
Royal United Service Institution. He then 
said, ‘‘ On the whole, this machine worked 
fairly well; the lifting power is, however, 
indifferent, and the steering apparatus is 
much too powerful for such a small machine. 
The centre of gravity appears to be unduly 
close to the centre of pressure.” 

I have received the following criticism in 
a letter from Mr. A. J. Winship. He says: 

“T had the pleasure, some time ago, 


of working with Mr. E, P. Frost, of West 
Wratting Hall, Cambs., a member of the Aéro- 


nautical Society, in his experiments with 
natural and _ close-imitation-natural wing 
machines; and in the course of the work I 


learnt from him this most momentous fact, to 
which Mr. Frost was, I believe, the first to 
draw attention, and that is that for any degree 
of safety in the use of these parts it is abso- 
lutely essential for the posterior edge as well 
as the extreme ends of aéroplanes to be as 
near infinite flexibility as it is possible to make 
them. On this point birds derend for their 
safety and *..tumatic balance when soaring. 
The importance of this fact is further power- 
fully emphasised by the remembrance of the 
death of Dr. Lilienthal, and our poor Pilcher, 
both of whom used machines with unyielding 
posterior edges. The latter made his last 
ascent on a windy day, and was earnestly en- 
treated by Mr. Frost previously not to at- 
tempt an ascent in such a machine, on such a 
day at any rate, as disaster would, he said, 





























Jantiary, 1907.) 


surely follow. Pilcher disregarded this advice | 


with the result, as you know, of his death. 

You may be sure, therefore, with what grave 
concern I saw the illustrations of the defective 
apparatus M. Santos Dumont is now using; 
and I am writing to you in the hope that you 
may, by some means or other, see your way to 
bring this matter before M. Dumont’s notice. 
Mr. Frost will, I know, be only too pleased 
to do all in his power to prevent the disaster 
which both he and I feel sure will accrue from 
persistent use of his machine in its present 
form,” 


Regarding the actual achievements of M. 
Santos Dumont with his machine, there has 
been a great discrepancy in the reports of 
the distances he has flown. Therefore, I 
have obtained through the coui.esy of M. 
De Besangon, Secretary of the French Aéro- 
Club, the exact measurements of his third 
and fourth ascents of November 12th, 1906, 
at Bagatelle. The first and second ascents 
took place in the morning, and were not 
chronometrically registered. The third and 
fourth ascents, which took place in the 
afternoon of the same day, were officially 
checked by the Sport Committee of the 
Aéro Club. 

In the third attempt the start was at 
4.9 p.m. There were two flights. The 
first of about 50 metres, not chronometri- 
cally registered. The second of 82 metres 
69, in 75 seconds, chronometrically regis- 
tered, which is at the rate of 11 metres 47, 
the second, or 41 kilometres 292, the hour. 

In the fourth attempt the start was at 
4.45 p.m. There was a flight of 220 metres, 
in 21 seconds }, chronometrically recorded ; 
that is, 10 metres 38 the second, or 37 
kilometres 358, the hour. 

The third experiment, therefore, at this 
moment, is the official record of speed, and 
the fourth the official record of distance and 
time in the air. 

After the reading of this paper the Presi- 
dent exhibited a model of the Santos 
Dumont aéroplane made by himself, which 
excited great interest. 

Mr. Copy: I have seen M. Santos 
Dumont’s machine, and I consider it is an 
excellent. structure, and just as likely a 
machine to fly successfully as anything I 
have seen. I believe in a large spread, and 
in carrying light weight. 

The Preswent: I should like to propose 
a vote of thanks to Mr. Bruce for his paper. 


The vote was carried unanimously. 


THE AERONAUTICAL JOURNAL 21 








The Stability of the Conic 
Shape in Kites and Flying 
Machines. 


By REGINALD M. BALSTON, M.Aér.Soc. 


In following such able lecturers as Dr. 
Napier Shaw and Col. Capper, with the 
added interest of lantern illustrations, I 
feel that, in presenting myself to you, I 
labour under a serious disadvantage, and I 
must ask you to deal indulgently with me, 
the more so that I am a newcomer amongst 
you. 

Though it is only lately that I have had 
the honour of becoming a member of this 
Society, I am not, however, altogether a 
novice in matters where aéronautics are 
concerned. 

As long ago as 1889 I had finished a 
model of a flying machine, and since then 
I have been studying them pretty closely. 
To the best of my recollection it is Jules 
Verne who was responsible for arousing my 
interest in the subject, although I fear I 
am ungrateful enough to remember nothing 
about his book beyond the fact that it in- 
spired me to base my first attempts at fly- 
ing machines upon his theories of screws as 
lifters. Soon, however, I discarded this 
type of machine in favour of those with 
wings, and the study of kites also naturally 
occupied a large share of my attention. I 
found them to be of absorbing interest. 
Perhaps the greatest fascination about a 
kite or flying machine lies in one’s efforts 
to make it behave as one is convinced that 
it should, which it very often fails to do. 
But such an element of uncertainty is no 
new thing. We know by her books that in 
the times of Jane Austen the simplest forms 
of aéronautics demanded a considerable 
exercise of patience, for in her novel, 
‘*Emma,’’ she illustrates the calm and self- 
control of one of her characters by setting 
him to fly kites for a little boy. Even in 
these days of modern kites and their de- 
velopments the difficulty of preserving one’s 
equanimity where such things are concerned 
has not entirely disappeared. Often a kite 
goes so closely to the fulfilment of one’s 
best hopes—it rises with a rocket-like sweep 
into the air, hangs motionless for a moment, 
then sinks slowly, preparatory to a second 
rush upwards, when the next gust of wind 
comes. But now, perhaps, its rise is not 








22 THE AERONAUTICAL JOURNAL, 


[ January,” 1907. 


so straight, the wind catches it at a [ Now if you depart slightly from the conic 


slightly different angle, and, to meet the 
current, the kite turns on one side and then 
back again, when the true wind strikes it 
oncs more. In its endeavours to find each 
new position it gets up a pendulum-like 
motion, moving from side to side, until 
eventually it overbalances, and turns head 
downwards towards the ground. Possibly 
it may, once or twice, recover itself, but in 
the end it is bound to descend head fore- 
most, and it is indeed fortunate if the 
wooden frame is not, in consequence, 
snapped in two. 

But why is it that a kite proves so re- 
iractory! Surely it is because, in nine 
cases out of ten, its stability is defective, 
and so, to put it briefly, it cannot stay the 
right way up. 

This question of instability, however, 
does not present an insurmountable diffi- 
culty. There is, to my mind, a way in 
which it can be obviated, though I need not 
say that, in approaching the subject of the 
conical shape with regard to stability, I am 
fully aware that I am introducing no fresh 
principle to your notice. But the point 
which I wish to draw your attention is that 
the theory of the dihedral angle, with which 
we are all familiar, should be carried some- 
what further. The dihedral angle is con- 
fined to sections of a flying machine in one 
direction only, namely, that one which 
passes through the wings, and, in con- 
sequence, the stability is merely lateral. 
Two points only of support are considered, 
whereas to ensure complete stability a third 
one must be recognised. In birds this 
point is supplied by the tail, while in the 
generality of insects the two hind wings 
have the function in question. 

The most stable form in which any ex- 
panse of material can be spread out to form 
an efficient resistance to the air is that of a 
flat inverted cone, or, to put it in another 
way, the underside of an inverted cone is 
the form of surface which combines most 
stability and opposition to falling. The 
apex of the cone must lie somewhere near 
the centre of the surface exposed, and all 
portions of the surface which lie nearer to 
the circumference must be superposed on 
those nearer to the apex when the machine 
is in equilibrium. The more acute the 
angle at the apex, the greater the stability 
obtained, but what is gained in stability is 
lost in resistance to falling. These two 
shapes I have here will illustrate this. (Ex- 
periments shown.) 


shape and make your model with sides 
which curve upwards, instead of following 
straight lines, a very stable shape is ob- 
tained. An umbrella is a good example of 
this. Its stability is perfect, and it will 
even retain its equilibrium, though its 
centre of gravity is so high as to be actually 
above its centre of support. 

An alternative in which will probably be 
found the meeting-point of the two require- 
ments, stability and efficient aéroplaner 
arrangement, is a conic surface, if it may 
so be described, decreasing in gradient as 
you proceed from the apex towards the cir- 
cumference. With some difficulty, but with 
excellent results, I have reproduced this 
shape ina wire model. I do not, however, 
intend to proceed further in this direction, 
since my object to-night is merely to draw 
attention to the fact that in the conic sur- 
face lies the secret of stability. 

To make use of it in its entirety is, of 
course, unnecessary. For all practical pur- 
poses well-chosen portions are all that are 
required. A chair or table supported at 
four or even three points will, under 
ordinary conditions, maintain its equili- 
brium, and the same thing holds good with 
the supporting surfaces of a kite. 

The reason why the conic shape conduces 
thus admirably to stability is not far to 
seek. A body suspended in air is bound to 
commence a downward passage, owing to 
the influence of gravity to which it is sub- 
jected. By impelling its aéroplane surface 
in one direction or another, the machine 
may be caused to rise, but the ascent is 
merely due to the fact that fresh layers of 
air are placed beneath the surfaces more 
quickly than the flying machine is able to 
fall through them ; and in a body’s descent 
that part of it which offers least resistance 
to the air through which it is passing will 
naturally fall first. By shaping the body 
as a cone, its surface is so formed that it 
finds its balanced resistance to its down- 
ward passage by falling point—or, rather, 
I should say—apex foremost. We will all 
agree that in making a shape of aéroplane 
which will fall slowly in equilibrium, we 
have gone a long way towards finding the 
right aéroplaner arrangement for a body 
intended to be put in motion horizontally. 

We have here a slide of the Cody kite. 
This kite is one in use by His Majesty’s 
Government, which, of course, ensures to it 
all up-to-date improvements. You see that 
Mr. Cody has made use of the angle in one 














January, 1907.] 


direction, and has turned the wings up- 
wards. You have, in consequence, a kite 
which will fly steadily without rushing from 
side to side. 
know whether Mr. Cody has ever attempted 
to introduce an angle in the other direc- 
tion, for, though it might have the disad- 
vantage of slightly decreasing the lifting 


efficiency, it would put all fear of swooping | 


out of the question. Possibly the kite does 
not, even as it is, do such a thing in Mr. 
Cody’s hands, but such kites are liable to 
this defect, whereas if they were so made 
that their after aéroplanes met the wind at 
a lesser angle than the front ones, it would 
not happen. The after aéroplanes would be 
the first to lose their lifting power when 
the head of the kite was depressed, thus 
allowing the weight. of the stern of the kite 
to restore the balance. In a butterfly’s 
flight we find a clear example of this 
principle. I have set the wings of a speci- 
men in an approximate conical shape, a 
position which the insect doubtless assumes 
instinctively. You see how it falls to the 
ground in perfect equilibrium. (Experi- 
ments shown.) 

As I have said before, in propounding 
this theory of the stability of the conical 
shape I am anxious that my meaning should 
not be taken too literally. I wish, rather, 
to draw attention to the fact that in this 
form lies the clue which will aid us to adapt 
to our own requirements those perfect 
natural mechanics which are disclosed to 
us in the hovering of the insect and the 
sweeping flight of the bird; for, after all, 
it is to Nature that we must turn for teach- 
ing where aéronautics are concerned. 

Mr. Doveras ArcniBaLD: The box kite 
is so satisfactory that it is a question 
whether there is any necessity for any other. 
In America there was a pretty exhaustive 
book about kites, in which all the different 
shapes were tried, and I think the most 
satisfactory they got was a _ pentagonal 
shape. Professor Marvin takes this shape. 
It is a box kite with a pentagonal front, 
and he found it the most satisfactory of any. 

Mr. Barston: In a box kite there is one 
disadvantage: you are bound to have your 
surfaces over each other, and when you are 
going slow, or stopping, the top ones lose 
their power. 

The Present: Talking of umbrellas, I 
once broke the handle off an umbrella and 
tied a string to the end. It formed an 
extremely stable kite. The more the um- 
brella revolves the more it is bound to re- 


It would be interesting to | 








THE AERONAUTICAL JOURNAL. 23 


main in the same position. There is one 
matter which Mr. Balston did not mention. 
A kite will remain on the level at which you 
put it, and, therefore, if you stand at an 
elevation and fly your kite, you can fly it 
on your own level perfectly stable if you 
weight it in the right way, though it is 
rather difficult to get the balance. I 
originally thought that might be a method 
of getting a rope ashore from a ship. If a 
ship were stranded on a lee shore you might 
get a rope ashore with an ordinary um- 
brella, and it would be a handy apparatus. 
I made a number of experiments with con- 
vex kites, and found that the more convex 
it was—that is, the more bent back the 
edges were, the less it was liable to rise and 
get a good angle. 

I will now ask you to record your vote of 
thanks to Mr. Balston for the interesting 
paper and models he has shown us. 

The vote of thanks was carried unani- 
mously. 

Colonel TroLLore: Ladies and gentlemen, 
you will all join with me in giving a vote 
of thanks to our able chairman, who has 
presided over this most interesting meet- 
ing. 

Mr. E. P. Frost: I shall be very pleased, 
ladies and gentlemen, to second that pro- 
position. 

The vote of thanks having been carried 
unanimously, the proceedings then ter- 
minated. 


The Balloons in The Gordon-Bennett 
Race. 


With reference to the report on “‘ Some 
Technical Features of the Competing Bal- 
loons,” by Major B. Baden-Powell, in the 
October number of the “ Aéronautical 
Journal,” Messrs. Short Brothers have written 
to point out that each of the British balloons 
supplied by them (the ‘‘ Britannia” and the 
“ Zephyr”) were fitted with awnings over the 
valves. 


Applications for Patents. 


(Made in October, November, and December, 
1906.) 

The following list of Applications for Patents con- 
nected with Aéronautics has been specially 
compiled for the AzRonauTICAL JoURNAL by 
Messrs. BromHEeaD & Co., Patent Agents, 33, 
Cannon Street, London, E.C. 





OCTOBER. 
21884. October 4th. Wrrrram CocHRAne. 
Improvements in and relating to Dirigable 
Flying Machines and Airships. 








24 


THE AERONAUTICAL iinaamniails 


(January, 1907. 





22352. October 10th. E.A. Forster. Aero- 
— Flying Machine. 

22517. October 11th. F. Smrons and J, W. 

Murcurr. Improvements in Controllers or 


Governors for Steam and other engines or | 


Motors, Motor Propelled Vehicles 
vessels of all kinds, including Submarines, 
Flying Machines, and the like. 


} 


and | 


Im- 


22977. October 17. W. R. Greson. 
provements in Box Kites oranalogous Aerial | 
Toys, 

23037. October 18th. J. L. Garsep. Im- 


for Aerial Machines. 
23036. October 18th. J. L. Gansep. 
provements in the method of and means 
employed for prope.ling and steering Aerial 
Machines. 
23085. October 18th. 
Aeroplane-Orthoptere. 
23415. October 22. 


J. B. Passat. New 


J. S. CHENHALL. Im- 


Im- | 


provements in Electrical Aerial Apparatus | 


for the conveyance of passengers, goods, 
and the like. 

23476. October 23rd. C.A.Witcnett. Im- 
provements in connection with Mechanisms 
for Learning to Fly. 


26612. November 23rd. A.M. Lover. Im- 
provements in and relating to the main- 
tenance of stability in Airships, Flying 
Machines, and the like. 


26764. November 24th. M. Vanrman.  Im- 
provements in Aeroplanes. 

26784. November 26th. B.R.Apams. Im- 
proved form of Propeller for Flying 
Machines. 

27000. November 27th. J. R. Porter. Im- 


provements in Airships and in apparatus 


provements in Wings, Vanes, or Propellers | for propelling the same. 


27141. November 29th. A. A. Fris. Im- 
provements in Flying Machines. 
27266. November 30th. H. 

Improvements in Air ships. 
27312. November 30th. W. P. Txompson. 
Improvements in or appertaining to Aero- 


stats. 
DECEMBER. 


27528. December 3rd. H. van pE WEYDE. 
Improvements in Balloons both ordinary 


H. Jonnson. 


and dirigible. 


23493. October 23rd. B.L.Gmtman. Im- 
proved Kite. 

23855. October 26th. A.J.Brerczron. Tail- 
less Kite which can be taken to pieces. | 

23872. October 26th. R. M, Batsron. Im- | 


provements in relation to Kites and similar | 


apparatus for Aerial Flight. 

24122. October 30th. J. L. Ganrsep. 
provements in Aeroplanes or Aerostats. 

24140. October 30th. A. B. Taytor and 
Witu1am Toorzy. Musical Kites. 

24489. November2nd. J. L. Garsep. 
provements in Aeroplanes or Aerostats. 

NOVEMBER. 

25387. November 10th. A. H. P. Bunt. 
Improved Flying Machine. 

26089. November 19th. A. V. RoE 
provements in Flying Machines. 


Im- 


Im- 


Im- 


26588. November 23rd. S. R. Sarr and 
G. Perry. Flying Machines. 
26602. November 23rd. D. E. Hipwe ru. 


Improvements in Flying Machines. 


2'7554. December 4th. W.A.S tater. Appli- 
cation of the principle of the Screw 
Propeller. 

27612. December 4th. J. N. Waker. Im- 


provements in Flying Machines. 
27751. December 6th. J. S. Harnsworta. 


| Improvements in Airships. 


27816. December 6th. J. Derxter. Im- 
provements in Airships. 

27817. December 6th. J. Dexter. Improve- 
ments in Propeler-driven Airships. 

27886. December 7th. B. R. Apams. Form 


of apparatus for propelling and control- 


| ling a Flying Machine. 


27978. December 8th. A. Brrxpeck, Im- 
provements in Machines for Aerial Naviga- 


| tion. 


28270. December 11th. W. Friese-Greene. 
Improvements in and relating to Air Cars 
or Airships. 

28386. December 12th. E. Jonzs. 
ments in Flying Machines. 

28710. December 15th. T. W. K. Crarke. 
Improvements in Aeronautical Machines. 


Improve- 





BACK NUMBERS. 


Back Numbers may be obtained from the Publishers: 
Messrs. KING, SELL & OLDING, LTD., 27, Chancery Lane, W.C. 





The following are some articles of special interest which have appeared during last few years :— 


The Paris International Aéronautical Congress. 
January, Igor. 

The Experiments with the Zeppelin Airship, 
April, rgor. 

Aéronautics in France. 
VIELLE. July, 1901. 

The Chief Scientific Uses of Kites. 
LawRENCE Rotcu. October, rgor. 

Aérial Navigation by Means of Bodies heavier 
than Air. By Sir Hiram Maxim. 

Atmospheric Currents. By WiILLiAM Marriott. 
January, 1902. 

The Berlin Congress of the International Aéro- 
nautical Commission. July, 1902. 

The ‘ Peace” Balloon of the late Senhor 
Augusto Severo. By Dr, Carros Sampaio. 
October, 1902. 


By WILFRED DE Fon- 


By A. 


| The Santos Dumont, No. xiv. 


Recent Aéronautical Progress. By Major 
B. BaDEN-PoWELL. January, 1903. 

Contributions of Balloon Investigations to 
Meteorology. By Dr. W. N. Suaw, F.R.S. 

Photographs of the Paths of Aérial Gliders. 
By Professor G. H. Bryan, F.R.S., and W. E, 
Wituiams. July, 1904. 


Scientific Balloon Ascents. By CHARLES 


HarpinG. October, 1904. 

Automatic Stability. By E. C. Hawkins, J.P. 
April, 1905. 

Notes on a Bird-Like Flying Machine. By 
Dr. F. W. H: Hutcuinson, M.A. July, 
1905. 


October, 1905.