CHAPTER VI. 



THE DENUDANTS, OR CARVERS OF THE EARTH'S 

 SURFACE METEORIC ABRASION. 



IN the last two chapters it has been shown that 

 neither the sea nor ice have much power as denudants 

 unless aided by meteoric abrasion. Meteoric abrasion 

 seems to be the most universal performer in the 

 great work of denudation. Besides, it is not merely 

 a surface-worker, as its influence can be found at a 

 considerable depth below the surface. But extreme 

 subeerialists would make their favourite agencies do 

 an enormous quantity of work; and to prove these 

 theories they base their calculations on the fallacy, 

 " that all the surface of the ground is being more 

 or less denuded." This, however, is contrary to fact. 

 In tropical regions there must be an enormous 

 amount of denudation, as the hot winds and sun 

 parch up the surface, forming great thicknesses of 

 debris, to be carried away by torrents during the 

 subsequent rains. Still, even in those climes, 



