172 DYNAMICAL GEOLOGY. 



acting alone, would ere this have made them of incredible 

 dimensions, and are therefore called elevating agencies. 

 The state of the contest between these two opposite forces 

 at any time, determined the distribution of land and water, 

 the height of continents and mountains, and depth of 

 seas, at that time. The one group roughhews, the other 

 shapes, the forms of the earth. 



