ICE AND GLACIERS. 



the stone, and partly by the freez- 

 ing of water in its crevices, they 

 fall, and for the most part on the 

 edge of the mass of ice. There 

 they either remain lying on the 

 surface, or if they have originally 

 burrowed in the snow, they ulti- 

 mately reappear in consequence of 

 the melting of the superficial layers 

 of ice and snow, and they accumu- 

 late especially at the lower end of 

 the glacier, where more of the ice 

 between them has been melted. 

 The blocks which are gradually 

 borne down to the lower end of 

 the glacier are sometimes quite 

 colossal in size. Solid rocky masses 

 of this kind are met with in the 

 lateral and terminal moraines, 

 which are as large as a two-storied 

 house. 



The masses of stone move in 

 lines which are always nearly pa- 

 rallel to each other and to the lon- 

 gitudinal direction of the glacier. 

 Those, therefore, that are already 

 in the middle remain in the middle, 

 and those that He on the edge 

 remain at the edge. These latter 

 are the more numerous, for during 

 the entire course of the glacier fresh 

 boulders are constantly falling on 

 the edge, but cannot fall on the 

 middle. Thus are formed on the 

 edge of the mass of ice the lateral 

 moraines, the boulders of which 

 partly move along with the ice, 



