78. What is the pressure at the deepest part of the ocean? 



The pressure at the deepest part of the ocean is close to 7 tons per 

 square inch, almost a thousand times the atmospheric pressure on the 

 earth's surface. 



At a depth of 3,000 feet, a pressure of 8,100 pounds per square inch 

 is sufficient to squeeze a block of wood to half its volume so that it will 

 sink. 



At a depth of 20,000 feet, air will be compressed so much that it will 

 weigh as much as the surrounding water. 



Bowditch, Nathaniel 



American Practical Navigator, U. S. Naval Oceanographic Office, 



1958. 

 Carrington, Richard 



A Biography of the Sea, Basic Books, 1 960. 

 Stewart, Harris B., Jr. 



Deep Challenge, Van Nostrand, 1966. 



95 



