128 



ICE AND GLACIERS. 



Fig. 21. 



n 



partly by the weathering of 

 the stone, and partly by the 

 ^ ^ezing of water in its crevices, 

 1 1 ey fall, and for the most part 

 the edge of the mass of ice. 

 1 Iiere they either remain ly- 

 y on the surface, or if they 

 1 ve originally burrowed in 

 i 1 3 snow, they ultimately re- 

 j pear in consequence of the 

 1 siting of the superficial 

 1 ^ers of ice and snow, and 

 tl sy accumulate especially 

 t the lower end of the gla- 

 sr, where more of the ice 

 I tween them has been 

 I ilted. The blocks which are 

 idually borne down to the 

 I vei end of the glacier are 

 netimes quite colossal in 

 1 e. Solid rocky masses of 

 s kind are met with in the 

 1 iteral and terminal moraines, 

 ^\]lich are as large as a two- 

 storied house. 



The masses of stone move in 

 hues which are always nearly 

 ]) "I rail el to each other and to 

 tli(j longitudinal direction of 

 lh(! glacier. Those, therefore, 

 th it are already in the middle 

 i( main in the middle, and 

 those that lie on the eda'e re- 

 main at the edge. These latter 

 are the more numerous, for 

 during the entire course of the 

 glacier, fresh boulders are con- 



11 



