13. How deep has man gone in the ocean? 



On January 23, 1960, Jacques Piccard and Lt. Donald Walsh, USN, 

 descended In the bathyscaph TRIESTE to a depth of 35,800 feet at the 

 bottom of the Challenger Deep (Marianas Trench), the deepest spot in 

 the ocean known at that time (see question 1). At that depth, the 

 temperature was 2.4° C (36.5° F). 

 During the descent they passed 

 a minimum temperature of 1 .4°C 

 at 2,000 fathoms. 



The TRIESTE was designed 

 and constructed by Jacques' 

 father, Auguste Piccard, the fa- 

 mous Swiss explorer of the strato- 

 sphere. It was launched in the 

 Mediterranean in 1953 and ac- 

 quired by the U. S. Navy in 1958. 



The record descent of the 

 TRIESTE took 4 hours and 48 

 minutes. The return to the surface required 3 hours and 17 minutes. 



Gaskell, T. F. 



World Beneath the Oceans, American Museum of Natural History, 



1964. 

 Piccard, Jacques, and Robert S. Dietz 



Seven Miles Down, G. P. Putnam's Sons, 1961. 

 Soule, Gardner 



The Ocean Adventure, Appleton-Century, 1966. 



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