70 M. Cb. Martins on the 



Instead of stopping, like the glacier, at the foot of the 

 mountain named Chapeau, the right lateral morairie is 

 lengthened in the form of an immense mound, which bars 

 the valley of Chamonix, and has the hamlet of Lavangi placed 

 upon it. The Arve has worn out for itself a narrow passage 

 between this mound and the northern declivity of the valley. 

 In order to follow this route, we are obliged to enter upon 

 this natural mole, and we are thus enabled to convince our- 

 selves that it is composed of sand, pebbles, and large angular 

 blocks confusedly heaped upon each other as in existing 

 moraines. One of these blocks, placed on the ridge, is known 

 by the name of Pierre de Lisholi. This mound is the ancient 

 lateral moraine of the Mer de Glace ; but the forest which 

 covers it proves, that, for a long while, the surface of the gla- 

 cier has sunk to the level where we now see it. Already, 

 Saussure* had detected the existence of this ancient moraine, 

 which appears with a distinctness of evidence which the most 

 prejudiced mind cannot deny. It extends itself by ascending 

 the valley as far as the hamlet of lies, at 2 kilometres from 

 the village of Argentiere. The Arve, checked in its course 

 by the moraine of Lavangi, formerly formed a lake, the suc- 

 cessive levels of which are still indicated by the horizontal 

 terraces which border the course of the torrent. 



From the top of this lateral moraine, an attentive observer 

 may perceive in the valley the ancient terminal moraine 

 of the Mer de Glace, at the period of its smallest extension. 

 The form of this moraine is characteristic ; it is that of an 

 arc whose concavity is turned up the valley. The village of 

 Chamonix is partly built upon the moraine, and with the 

 erratic blocks which compose it. The small mount situate on 

 the left bank of the Arve, in front of the Union hotel, is one 

 of its most salient points. In 1845, 1 could study the interior 

 structure of this small mount while they were digging the 

 foundations of the new hotel, erected in front of the one I 

 have named, and I found that it was identical with that of 

 the actual moraines. 



But, it will be said, where is the proof that the erratic 



* Voyages dans les Alps, § 623. 



