life's borderlands 253 



Animals can live on high mountain tops where the air pres- 

 sure is only about 13 inches or even less, about 61/2 pounds 

 to the square inch, and in the ocean deeps under a water pres- 

 sure of about 600 atmospheres, or about 9,000 pounds or 4 1/2 

 tons to the square inch. 



It is interesting to note that of all animals the gastropods or 

 snails have the greatest range, living from above the snow line 

 in the Himalayas to at least 16,000 feet below the surface of 

 the sea. Of the vertebrates the fishes live from high mountain 

 streams down to a depth of feet 19,806 below sea level, though 

 always in water. Of the birds the condor soaring about the 

 Andean peaks in an air pressure of 13 inches or 6 1/2 pounds 

 to a square inch, can without injury to himself drop down to 

 the sea shore where the air pressure is 30 inches or 15 pounds 

 to a square inch. 



