CLOUDS AND RIVERS, ICE AND GLACIERS. i>7 



tOO hours, at the end of which time the spaces passed 

 over by the points of swiftest motion of the three linos 

 Trore as follows : — 



Maximum Motion in 100 Hours. 



First line . . . .56 inches. 

 Second line . . . . 4o „ 

 Third line . . . . 30 „ 



246. Here then is a demonstration that the upper 

 portions of the Morteratsch glacier are advancing on 

 the lower ones. In 1871 the motion of a point on the 

 middle of the glacier near its snout was found to be less 

 than two inches a day ! 



247. What, then, is the consequence of this swifter 

 march of the upper glacier? Obviously to squeeze this 

 medial moraine longitudinally, and to cause it to spread 

 out laterally. We have here distinctly revealed the cause 

 of the widening of the medial moraine. 



248. Tt has been a question much discussed, whether a 

 glacier is competent to scoop out or deepen the valley 

 through which it moves, and this very Morteratsch 

 glacier has been cited to prove that such is not the case. 

 Observers went to the snout of the glacier, and finding 

 it sensibly quiescent, they concluded that no scooping 

 occurred. But those who contended for the power of 

 glaciers to excavate valleys never stated, or meant to 

 state, that it was the snout of the glacier which did 

 the work. In the Morteratsch glacier the work of 

 excavation, which certainly goes on to a greater or 



