500 FLIGHT AND FLYING MACHINES. 
I am not sure whether he intended to drive the apparatus by means of 
a traction engine; the figure shows an engine of this kind at one side 
of the platform, which would be, one would think, rather a heavy load 
for the oalloonsand likely to overturn the machine. But M. Pétin said 
very little about the motive power, and that was one of the weak points 
in his scheme. Before concluding this subject, as most of you know 
the Crystal Palace, I should like to call your attention to a picture from 
the same source (the French Histoire des Ballons) of the famous ascent 
of Glaisher at the Crystal Palace. I doubt whether anyone looking at 
M. Tissaudier’s figure would recognize the Crystal Palace, and to make 
things more absurd the description underneath the picture calls it 
“ Ascension de Monsieur Gaisler a Glaisher Palais’?! A few mis- 
cellaneous things I have gathered from the same source are interesting 
as showing how easy it is when a machine would not fly to find excuses 
for it. A kind of aerial machine was proposed by Lanson, who made 
experiments with it, but the results were far from conclusive. A 
certain system of steering a balloon, invented by Monsieur Hellé, was 
never experimented with. Another navigable balloon was constructed 
by M. Dupuy de Lome, but the experiments made during the war did 
not give any result. Of a fourth contrivance a model was made by M. 
Julien, who exhibited it at the Hippodrome, ; it was a small model and 
would not work. That did not prove M. Julien to be wrong, because 
the model was too small to give him a fair chance. If it had been 
made sufficiently large it would have gone all right of course, at least 
the inventor said so. 
Finally, M. de Landelle designed a steam flying machine which is 
described by Pettigrew, having two vertical screws for lifting it into 
the air, standing up like trees, and (if I understand rightly) a 
horizontal aero-plane which, one would think, would hinder the screws 
from lifting it, but this too appears only to have been put on paper and 
never constructed. 
Let us now ask ourselves the question why did all these people fail 
in their experiments? Why did Deeghen have to take to a balloon, 
and why did the Marquis de Bacqueville break his leg? One reason 
was because they tried to run before they could walk. We are now 
just trying to learn to fly, the early experimenters had not even learnt 
their own ignorance of the subject. But there is a much more important , 
reason, which [ should like to dwell on here a little, and that is, that in 
those days it would have been impossible to fly. The only motive power 
that the experimenters then had to depend on was the motive power of 
their own muscles, and we now know that man does not possess sufficient 
horse-power in proportion to his weight to lift himself in the air, and 
therefore the problem was impossible on mechanical grounds. Dr. 
Haughton reckons that men rowing in a boat race exert about one 
quarter of a horse-power, and if we take a man weighing about 12 
stone or 168 lbs. that means that he weighs 672 lbs. per horse-power 
that he is able to exert. Now Mr. Maxim has proved that heavy birds 
only weigh 150 tbs. per horse-power that they are capable of exerting ; 
so that they have about four times the horse-power per lb. that we have. 
The albatross and the vulture probably go up to 250 lbs. per horse- 
