SECT. 5] 



DEEP SUBMERSIBLKS FOR OCEANOGRAPH1C RESEARCH 



501 



operated in the French Mediterranean, off North Africa, off Portugal and off 

 Japan, captained by Houot. In 1954 the FNRS-3 attained its maximum depth 

 of 4050 m in the Atlantic off Dakar. In principle, the FNRS-3 is similar to the 

 Trieste which is discussed at some length below. For fuller details regarding the 

 FNRS-3, the reader is referred to Houot and Willm (1955). Numerous papers, 

 chiefly biological and especially by Peres, have appeared (Bernard, 1955; 

 Peres and Picard, 1956; Peres, Picard and Ruivo, 1957; Peres, 1958, 1959; 

 Tregouboff, 1956, 1958). 



A new French bathyscaph is reported to be under active construction by 

 the French Navy at Toulon which will be capable of dives to 11,000 m. It will 

 be identical in principle to the FNRS-3. The new sphere will measure 2.1 m 



Fig. 3. The bathyscaph Trieste in Italy, 1957. (Official U.S. Navy photo.) 



inside diameter and the shell will be 15 cm thick as contrasted with 2.0 m and 

 9 cm for the FNRS-3. It will be forged of a special nickel-chromium-molyb- 

 denum steel ; the FNRS-3 was cast. The sphere will have a safety factor of 

 2 at 11,000 m ; that is, when under a static pressure of 1155 kg/cm 2 , it will be 

 at only half of its elastic limit. The reinforcement that exists in the FNRS-3 

 sphere in the vicinity of the port and the door will be avoided since strains in 

 these zones are not easily calculated ; the sphere of the new bathyscaph will 

 have a constant thickness. The ports will be of very small dimensions so that 

 observations will have to be made through them with the assistance of a 



