THE USEFULNESS OF EARTHQUAKES. 235 



there can be no doubt that there was then no visible 

 land above the surface of the water ; the ocean must 

 have formed a uniformly deep covering to the sub- 

 merged surface of the solid globe. In this state of 

 things, nothing but the earth's subterranean forces 

 could tend to the production of continents and islands. 

 Let us be understood. "We are not referring to the 

 possibility or impossibility that lands and seas should 

 suddenly have assumed their present figure without 

 convulsion of any sort ; this might have happened, 

 since the Creator of all things can doubtless modify all 

 things according to His will ; we merely say that, 

 assuming that in the beginning, as now, He permitted 

 all things to work according to the laws He has ap- 

 pointed, then, undoubtedly, the submerged earth must 

 have risen above the sea by the action of those very 

 forms of force which produce the earthquake in our 

 own times. 



However this may be, it is quite certain that when 

 once continents and islands had been formed, there 

 immediately began a struggle between destructive and 

 restorative (rather, perhaps, than preservative) forces. 



The great enemy of the land is water, and water 

 works the destruction of the land in two principal 

 ways. 



In the first place, the sea tends to destroy the land 

 by beating on its shores, and thus continually washing 

 it away. It may seem at first sight that this process 



