Ancient Extent of the Glaciers of Chamonix. 71 



blocks of the moraine of Chamonix have been deposited there 

 by the Mer de Glace % Is it not more natural to suppose 

 that they have descended from the Brevent, whose eboule- 

 ments continually threaten the village, and form the large 

 delta, the eastern angle of which it occupies ? The answer 

 is easy. The Brevent is a gneiss mountain, and almost all 

 the blocks of the moraine are of protogine, a species of cha- 

 racteristic granite which constitutes the mass of Mont Blanc, 

 and of the sharp peaks with which it is surrounded. 



Continue to descend along the valley. After crossing the 

 Arve on a wooden bridge, you arrive at the hamlet of Mont- 

 cuar, which is surrounded on every side by immense blocks 

 of protogine. The ground, from being level, becomes un- 

 equal, and the route passes over numerous low mounds. 

 You are on a new terminal moraine, corresponding to a 

 greater extension of the Mer de Glace, and the glacier of 

 the Bossons united ; it is that of Montcuar, the breadth 

 of which, on the banks of the Arve, is about 400 metres. 

 This moraine terminates a little beyond the torrent which 

 issues from the glacier of Taconnay. The blocks compos- 

 ing it are truly gigantic. All strangers remark those found 

 in the small wood which runs along the side of the torrent. 

 One of these blocks, named Pierre Belle, is not less than 24 

 metres 7 decimetres long, by 9 metres in breadth, and fffc 

 least 12 in height. It is not a stone, but a true hill, rising 

 above all the trees which surround it. If he retain some 

 doubts as to the nature of the agent which transported these 

 blocks, the observer who is not afraid of difficult paths, has 

 only to ascend to the heights which overlook the right bank 

 of the Arve. In the rude pathway which leads to the hamlet 

 of Merlet, he will find, between 336 and 350 metres above the 

 valley, moutonned rocks, that is to say, rocks rounded and po- 

 lished like those we meet with under existing glaciers. 



After traversing the moraine of Montcuar, the traveller 

 advances along a ground formed of rolled pebbles, conveyed 

 by torrents, whose dried up beds he may yet perceive ; but, 

 if he cast his eye on the right bank of the Arve, he perceives 

 in the distance erratic blocks and large polished surfaces al- 

 most in a vertical position. He then finds himself near the 



