22 4 THE SEAS 



depths of the ocean the pressures are therefore enormous, 

 as much as three tons to the square inch. Yet there is no 

 part in the sea in which animals cannot live. At first 

 sight it seems remarkable that any living creature could 

 endure such enormous pressures, but we must realize that 

 that is their natural environment. We, on land, live 

 always with a pressure of 14 lbs. to the square inch on our 

 bodies, but we are not conscious of it ; when the barometer 

 rises by one inch the increase of pressure on our body 

 surface may be as much as one ton, yet this is not noticeable. 



The great pressures in the depths of the ocean have a 

 slight effect on the density of the water, but because water 

 is almost incompressible the increase in density with depth 

 is extremely small. It can in no way be sufficient to support 

 a persistent and erroneous popular belief that, owing to 

 the increasing density, objects sinking will find their own 

 level before they reach the bottom, a level in which the 

 density of the water is the same as theirs and below which 

 they cannot sink because the density of the water becomes 

 greater. Sir Wyville Thomson in " The Depths of the 

 Sea " remarks, "There was a curious popular notion, in 

 which I well remember sharing when a boy, that, in going 

 down, the sea water became gradually under the pressure 

 heavier and heavier, and that all the loose things in the 

 sea floated at different levels, according to their specific 

 weight : skeletons of men, anchors and shot and cannon, 

 and last of all the broad gold pieces wrecked in the loss of 

 many a galleon on the Spanish Main ; the whole forming 

 a kind of " false bottom " to the ocean, beneath which 

 there lay all the depth of'clear still water, which was heavier 

 than molten gold." 



It has been suggested for instance that the Titanic 

 thus sank to a false bottom but under the increasing 

 pressure sealed air chambers would become " imploded " or 



