PART ONE 



FROM THE STRATOSPHERE TO THE SEA-BED 



i: In the Stratosphere 



THE technical means called upon for the exploration of the high 

 atmosphere and the submarine depths present such striking 

 analogies that my editor has asked me briefly to review the conquest 

 of the stratosphere.! This work essentially aims at the description 

 of my bathyscaphe and its voyages. Why did the achievement of the 

 FNRS, for such was the name of my stratospheric balloon, precede 

 that of the bathyscaphe ? This is what I want to explain. 



From the beginning of the last century it had been noticed that 

 gases reputed to be perfect insulators for electricity could in reality, 

 in certain conditions, conduct it. It had been observed, in particular, 

 that the passage of electricity through the gases was possible when 

 these gases were exposed to the radiation of radio-active bodies. But, 

 what was surprising, these observations made in a balloon, for the 

 atmosphere at altitudes of 2-J- miles to 53- miles,^ revealed an increase 

 of conductivity, while, as the distance from the earth and its radio- 

 active bodies increased, it had been expected that a decrease would be 

 observed. This led physicists to adduce the existence of another 

 phenomenon, that of cosmic rays coming from outer space. 



It was to enlarge our knowledge in this domain that I, a physicist, 

 conceived the idea of ascending into the stratosphere. 



Let us recall in a few lines what this word signifies. The higher we 

 rise in our atmosphere, the lower are the temperatures we encounter. 

 But, as Teisserenc de Bort discovered by means of his sounding- 

 balloons, between 3f miles and 10 miles, according to the latitude and 

 the season, we encounter a very marked limit beyond which the 

 temperature ceases to fall, or even increases slightly, with the altitude. 

 Here, from the meteorological point of view, begins the stratosphere, 

 the region where the vertical displacements of air, which produce the 



1 On this subject see my book : ' Above the Clouds ' {Au-dessus des nuages^ ; 

 Bernard Grasset, éd. 



2 These and all following calculations are suitable approximations to the 

 figures in Professor Piccard's book. (Translator.) 



[ I ] 



