is to the captive balloon. No longer attached, it would be truly 

 independent. 



The submarine free balloon would have the advantages in the water 

 that free balloons have in the air: at first it would go down, as the 

 balloon rises, as soon as it is let go : then, it would be able to rise 

 again as desired just as the balloon can descend whenever desired. 

 That is what has been arrived at with the bathyscaphe, or deep-sea 

 ship.l 



The idea of such a ship ià not new to me. 



I was a first-year student at the Zurich Polytechnic School when by 

 chance I read the fine book of Carl Chun recounting the océanographie 

 expedition of the Valdivia. Nets let down to considerably over a 

 thousand fathoms brought back submarine fauna to the deck of the 

 ship. They worked day and night. When a net was brought up in 

 complete darkness, the oceanographers, leaning over the rails, were 

 struck by the multitude of phosphorescent animals which the net 

 contained in its seine. Certain fish were endowed with veritable head- 

 lights. But very quickly these lights grew pale and went out. The fish 

 could no more endure the low pressure and the high temperature of 

 the surface water than we could have endured the enormous weight 

 of the masses of water beneath which they live. 



To observe these fish in their natural setting, there is only one 

 means, to go down ourselves to the deepest part of the ocean. It must 

 be possible, I said to myself, to build a watertight cabin, resisting 

 submarine pressure and furnished with portholes, to allow an observer 

 to admire a new world. This cabin would be heavier than the water 

 displaced. It would be necessary then, in complete analogy with the 

 free balloon, to suspend it from a large vessel filled with a substance 

 lighter than water. 



The fundamental principle of the bathyscaphe was born. 

 The idea never occurred to me to use a suspension cable for my 

 cabin. Even at this time the cable would not have seemed to me safe 

 enough. However, at that time I should naturally have been incapable 

 of resolving all the problems conjured up by the construction of such 

 a device. 



The student became an engineer, then also a physicist. The idea of 

 submarine exploration in a free balloon never left him, although for a 



1 The name is composed from two Greek words: bathos, deep, and scaphos, 

 ship. 



[26] 



