I 



Altliough Sir Charles Lyell says It is impossible to invent 

 any theory to account for the disappearance of so large a 

 body of water as must have diappeared to explain geo- 

 logical facts, he adopts that of Mr. Darwin, of the sinking 

 down of the ocean bed; commenting upon Ray's geological 

 views he says "the preservation of the dry land may some- 

 times be effected by the subsidence of that part of the 

 earth's crust covered by the ocean" — and again, "The 

 sinking down of the bed of the sea is one of the means by 

 which the submersion of land is prevented" — and he adds, 

 "if we then inquire in what manner the force of earth- 

 quakes must he regulated in order to restore perpetually 

 the inequalities of surface which the levelling power of 

 water is constantly tending to efface, it will be found that 

 the amount of depression must exceed that of elevation. If a 

 counterpoise be derived from this source, the quantity and 

 elevation of land may forever remain the same, and on the 

 other hand the force of the aqueous agents themselves might 

 thus continue forever unimpaired.^^ 



This is a persistent and systematic cause of usefulness 

 that is scarcely to be expected from earthquakes ! and is 

 really a revival of the earlier cavern theory of Liebnitz, for 

 if the ocean's bed is depressed, it really forms an abyss for 

 the superfluous waters to settle down in. 



This means of escape from a serious dilemma will not 

 bear the test of close examination. In thus relieving the 

 surface of the earth of the volume of water, that must be 

 displaced by the solid matter that is carried into every 

 body of water existing upon it, by the subsidence of the 

 bed of the Pacific Ocean, the evaporating surface is con- 

 stantly diminished ; not a de]»ta can form — or the sands of 

 the sea, or the land any where encroach upon the water 

 without a decrease of evaporating surface, unless a corre- 

 sponding water area is somewhere else exposed. 



Evaporation is a very powerful physical agency. Prof. 

 Maury, in "The Physical Geography of the Sea," gave to 



