4: The Construction of the FNRS 2 



AFTER these general considerations, let us return to our first 

 bathyscaphe. We gave it the name of FNRS 2 in memory of the 

 first stratospheric balloon, the FNRS, and to record once more our 

 gratitude to the Fonds National, that magnificent institution to which 

 Belgian science owes so much and which one can say without exaggera- 

 tion has stimulated the creation of similar institutes in other countries. 



Taking into consideration the limited credits at our disposal, we 

 chose for this bathyscaphe the non-towable form: this decision was 

 not taken without ripe reflection nor without having discussed with 

 the specialists the possibilities of operating on the high seas by 

 employing the cranes of a cargo-boat. 



Here is the construction in detail. 



THE CABIN 



The spherical cabin is naturally one of the main portions of the 

 bathyscaphe. It must conform to the following requirements : 



It must resist the enormous pressures which it will sustain at 

 great depths and that with all desirable safety; 



It must be perfectly watertight; and be fitted with an equally 

 strong and watertight hatch ; 



It must have portholes which will allow the occupants to observe 

 and to photograph the external world; these windows naturally 

 must also be strong, watertight and perfectly transparent; 



The cabin must be spacious enough for the crew — a pilot and 

 an observer — to be able to remain there without being too re- 

 stricted in their movement, in spite of the presence of numerous 

 instruments necessary for piloting, for renewing the air and for 

 observation. 



For the stratospheric balloon I had fixed the diameter of the cabin at 

 6-90 ft. (2-10 m.). This cabin was constructed of a light aluminium 

 sheeting of only 0-1375 in. (3-5 mm.) thick: we were able to allow our- 

 selves this luxury. But the cabin of the submarine represents, in itself, 

 the main source of weight, the problem being to maintain it in 

 equilibrium in the water : all the dimensions of the bathyscaphe and 

 consequently its cost depend thus in large measure upon the weight 

 of this cabin. We had to be modest. 



[40] 



