180 Historical 



However, our respiration was not at all affected; we felt no discom- 

 fort, and our situation seemed to us extremely agreeable .... 



We observed our animals at all heights; they did not seem to 

 suffer at all. As for us, we felt no effect, except this acceleration of 

 the pulse rate of which I have already spoken. 



There follows the account of what happened to a greenfinch 

 and a pigeon, freed at 3400 meters; the pigeon opened its wings 

 and let itself fall describing circles like the large birds of prey. 



Gay-Lussac 17 started alone some days after, and rose much 

 higher than the first time. The symptoms of a physiological nature 

 were quite endurable; he speaks of them thus: 



When I had reached the highest point of my ascent, 7016 meters 

 above sea level, my respiration was noticeably hampered; but I was 

 still far from experiencing such severe discomfort as to wish to 

 descend. My pulse and respiratory rate were much accelerated; and so, 

 breathing very frequently in a very dry air, I was not surprised to 

 find my throat so dry that it was painful for me to swallow bread . . . 



These are all the inconveniences I experienced. (P. 89.) 



In regard to this account Robertson made an observation which 

 is interesting because it shows what cause he assigns to the 

 phenomena which he experienced himself: 



I do not think that there is a professor of physics who has not 

 spoken to his hearers of the weight of the column of air which corre- 

 sponds to the body surface of a man, and who has not shown that 

 this enormous weight is made imperceptible to the body by the 

 equilibrium established between the pressure of the outer air and the 

 reaction of the elastic fluids which are part of its inner system. There 

 is none who has not demonstrated what the effects of the rupture 

 of this equilibrium would be. (Mem., vol. I, p. 107.) 



But nothing justified Robertson in drawing from these remarks 

 the strange conclusion which follows: 



I do not think that M. Biot has changed all that. No one can 

 refuse to conclude that the effects experienced by M. Lhoest and my- 

 self, then by M. Sacharoff, are anything but very reasonable; while 

 those experienced by MM. Biot and Gay-Lussac are so contrary to 

 ours that they need to be explained. Now the only explanation 

 possible is that these aeronauts did not rise high enough or that they 

 rose so slowly that there was no rupture of equilibrium for them, 

 otherwise one cannot see what could have kept them from experi- 

 encing the effects which are the inevitable consequences. (Mem., vol. I, 

 p. 108.) 



This doubt unnecessarily cast upon the truth of the observa- 

 tions of scholars like Biot and Gay-Lussac should have had just 



