176 Historical 



considerably; the thermometer then dropped quickly to 2°, and stopped 

 at 5V2 below freezing, while the barometer stood at 12 and 4/100 

 inches. Hardly was I in this atmosphere when the discomfort 

 increased; I was in a mental and physical apathy; we could hardly 

 ward off the sleep which we feared like death. Distrusting my 

 strength, and fearing that my companion would succumb to sleep, I 

 had fastened a cord to my thigh and to his; the ends of this cord 

 were in our hands. It was in this state, not much adapted to delicate 

 experiments, that I had to begin the observations that I was planning. 

 (Vol. I, p. 70) ... . 



At this elevation, our state was that of indifference: there, the 

 physicist is no longer sensitive to the glory and the passion of dis- 

 coveries; the very danger which results from the slightest negligence 

 in this journey hardly interests him; it is only by the aid of a little 

 fortifying wine that he succeeds in finding intervals of mental clarity 

 and power. 



As I wish to omit nothing that can cast light on the functions 

 of the animal economy and the operations of nature at this elevation, 

 I ought to mention that when the barometer was still at 12 inches, 

 my companion offered me bread: I made vain efforts to swallow it, 

 but never could succeed. If one considers carefully the state of the 

 surrounding atmosphere, the great rarity of which offered only a 

 slight resistance to my expanding chest; if one considers the small 

 quantity of oxygen contained in the gas in which I was floating, one 

 can believe that my stomach, already filled by a denser gas which was 

 impoverished by the loss of oxygen, was in no state to receive solid 

 food and still less to digest it. I must add that the natural excretions 

 were checked in my friend and myself during the five hours of the 

 journey, and that they were not resumed until three hours after our 

 return to earth .... 



Seventh experiment. I had taken along two birds: at the moment 

 of the experiment I found one of them dead, no doubt on account 

 of the rarefaction of the air; the other seemed drowsy. After placing 

 him on the edge of the basket, I tried to frighten him to make him 

 take flight: he beat his wings, but did not leave his place; then I left 

 him to himself, and he fell perpendicularly with extreme speed. There 

 is no doubt that birds could not support themselves at this elevation. 

 (P. 76) ... . 



One can estimate the height of the balloon, taking account of 

 all the corrections, at 3679 fathoms (7170 meters). 10 (P. 83.) 



The number of March 16, 1876, of the journal Les Mondes says 

 on this subject: 



If, in one passage of his account, Robertson says that he mounted 

 to 7170 meters, in another he says only 7075; calculating by the 

 present tables of the Yearbook of the Bureau of Longitudes on the 

 data of temperature and pressure registered by Robertson, we find 

 only 6881 meters for the maximum height. (Ch. Boissay.) 



Robertson sent the account of his ascent and of the experi- 

 ments in physics which he performed during it to the Galvanic 



