lJU Charles Maclarcn on 



one another, sometimes standing apart. Four or five ridges of 

 small size may be seen at the foot of the upper glacier of 

 Grindelwald, one behind another. There are three or four 

 ancient ones in the valley of Lutchen, not far from Interlaken, 

 forming a continuous mass, nearly a mile in length, of great 

 depth, and with an undulating surface, like those in Glen- 

 sluan. The glacier of the Rhone in 1826 had nine terminal 

 moraines, one behind another, which Mr Desor, with reference 

 to their form, calls (digues) embankments. In the Vosges 

 mountains, where traces of ancient glaciers abound, the de- 

 scriptions and sections of the moraines given in the work of 

 Mr Collomb, would apply very accurately to those in Glen- 

 sluan. Lastly, in position, the mounds of Glensluan have the 

 same correspondence with the frontal moraines of glaciers; that 

 is, they stretch across the foot of a valley, which, if it existed 

 in the Alps, at the proper elevation, would contain a glacier. 



Long valleys open at both ends, and nearly level, are not 

 favourable to the existence of glaciers, which, it must be re- 

 membered, are moving masses of ice. There should be a cavity 

 above to collect the snow and ice, and a certain fall in the 

 ground to give it motion. The cavity is generally wider than 

 the glacier- valley, and has received the names of " Reservoir," 

 " Amphitheatre," " Basin d' Alimentation," and when very 

 large, " Mer de Glace." The upper part of Glensluan, which 

 is somewhat wider than the under part, is a very perfect amphi- 

 theatre, well fitted both to store up the materials of a glacier, 

 and to set them in motion. Professor Forbes has shown, that 

 the motion of a glacier is that of a semifluid mass, whose mo- 

 bility increases with its breadth and depth ; and when we find 

 that even a valley, like Glen Eck, open at both ends, and with 

 its bottom nearly level, has been the scene of glacier agency, 

 as demonstrated by its powerfully abraded and grooved rocks, 

 we cannot doubt that the same agent would act with still greater 

 effect in Glensluan, which has, in the first place, a rather 

 highly inclined bottom ; and, in the second, has a wall of rock 

 nearly vertical, at its head, to serve as a point oVappui, and 

 urge the gravitating mass northward. "With regard to the 

 other traces of glacial agency, I saw distinct marks of abrasion 

 on the protruding rocks of the western declivity, and I have 



