THE EARTH'S SURFACE ICE ACTION. 61 



to have a greater power than the sea in one respect 

 viz., that it is capable of lifting up blocks out of 

 their places and eventually carrying them away. In 

 West Galway, during winter, the water will freeze 

 under large blocks of stone and lift them, though tons 

 in weight ; now in a glacier the lifting power ought 

 to be much greater, when the ice is not only under 

 the blocks but all round them. Fractured rock, such 

 as that which fills a fissure, is more liable to be 

 denuded and carried away than unbroken rock ; 

 therefore, if ice moves over ground traversed by 

 fissures, especially if the direction of its movement 

 coincides with the bearing of these breaks, the ice, as 

 it moves along, must catch up and carry away all the 

 loose portions ; and if parts of a dyke of fault-rock 

 are softer or looser than the rest, the ice will scoop 

 out hollows in those places. If two or more fissures 

 cross one another at one "or different points, the rocks 

 in the vicinity of the points of contact will be broken, 

 and at such places ice should be able to work with 

 facility and excavate out hollows, the size of these, 

 both as to depth and width, being in accordance 

 with the amount of rock ruptured and the magnitude 

 of the moving glacier that acted on them. From 

 this it is apparent, that when fissures cross one 

 another there would be a large irregular basin opened 

 out, while if two fissures with broken rock between 



