364: Arnold Guyot. 



at first vertical or nearly so; but below the rapids, where the 

 slope is gentle and the crevasses become mostly closed, the 

 masses are inclined with the pitch up stream; and this up- 

 stream inclination is reduced, at the termination of the glacier, 

 to a few degrees. The crevasses, although closing up below, 

 are still traceable. He says : The so-called layers are not 

 strictly layers ; but great numbers of cracks remain which give 

 to the mass the appearance of being made up of beds several 

 yards thick, as may be seen in the glaciers of the Grindelwald 

 valley, Aar and others. 



Further: to this pitch in the stratification at the lower 

 extremity, the beds rising outward, Gruyot attributes also the 

 origin of the majestic ice-chambers, whence in most cases flow 

 great streams, as that of the Rhone, of the Arveyron at the foot 

 of the Mer de Glace, of the Lutschinen from the glaciers of 

 Grindelwald. 



The more rapid movement of the center than the sides also was 

 learned from the Rhone glacier and others of steep descent. 

 The crevasses, at first transverse, were found to be arched in 

 front below the rapids, and increasingly arched to the extremity, 

 and the successive crevasse lines were very nearly concentric 

 with the semicircular outline of the extremity of the glacier. 

 He gives a figure of the Rhone glacier as seen from the Maien- 

 wand in illustration ; and other later glacialists have appealed 

 to the same evidence of lateral friction. 



The semicircular outline of the terminal moraine was found 

 to be another result of the cause just mentioned ; and. so also 

 the "eventail" arrangement of the several moraines immedi- 

 ately above the termination. The greater height and breadth 

 of the central moraine is made a consequence of the greater 

 velocity of the ice at the middle of the upper surface, more 

 transportation taking place consequently in a given time. 



Again : The conclusion that the movement of the glacier ivas 

 largely through molecular displacement was supported by his 

 observation that the ice, instead of breaking up and rising into 

 an accumulation of masses on its passage by an isolated rock, 

 or rocky islet in its course, spread around and enveloped it 

 without fracturing; and he refers to a fine example of this at 

 the two isolated islets of rock in the midst of the great Brenva 

 glacier, called the "Eyes of the glacier." "The same thing is 

 observed at the Jardin du Talefre, a true islet in the midst of 

 a mer de glace, having a border of blocks of rock, or of a 

 moraine, cast upon its sides by the march of the glacier, just 

 like the coast dunes of an island in the ocean." 



In view of such facts Gruyot observes: "If it is true that the 

 different parts of a glacier move with different velocities ; if the 

 glacier adapts itself to the form of a valle}*- and fills all depres- 



