MOUNTAIN FORMATION 



though no breakage or cracking of the glass had occurred, 

 and no holes in it could be discovered even by the best 

 microscopes. In other words, it became evident that 

 the water had been slowly but bodily forced through 

 the thick walls of the glass (under a pressure of less than 

 15,000 Ib. to the square inch) in less than an hour's 

 time. Evidently, then, even such a substance as glass 

 will be penetrated by water if the pressure is great 

 enough. 



To make a practical application of these principles, 

 what shall we now say with respect to the ocean bottoms ? 

 In deep places the pressure of the sea-water on them is 

 very great, sufficient to force water through glass. 

 Obviously most of these bottoms will leak, and leak at a 

 rapid rate under the enormous pressure operating in the 

 greatest depths of the sea. The bed of the ocean will 

 not leak with equal rapidity in all places; but almost 

 universal leakage will certainly develop, and the water 

 will be driven back into the earth at various rates. 

 Where the rock is volcanic and badly fractured, or sandy, 

 the leakage will be most rapid ; and where the bed is 

 made of clay or unbroken granite the leakage will be 

 much more gradual. It will also depend on the depth of 

 the sea, and will be greatest where the ocean is deepest, 

 and quite insignificant in shallow water. A rapid rate of 

 leakage would mean that large quantities of water quickly 

 come in contact with the heated rock, and develop 

 correspondingly great steam pressure in the crust which 

 underlies that part of the ocean. One case in which we 

 may suppose a rapid leakage to be taking place is in the 



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