which was nearly a mile across. This branch had formerly filled the fiord, and had apparently covered the place to which I refer at no very remote date. Tremendous evidences of its power had been left behind. The gneiss upon the shores was literally levelled, and extended for hundreds of yards in continuous sheets, with polished surfaces destitute of all detritus, difficult to walk upon, for there was nothing to arrest the feet when they slipped. In these rocks there were two great veins of quartz, each three to four feet thick, which attracted notice at a considerable distance by their excessive brilliancy when the sun fell upon them. These ran roughly parallel to each other for about eighty yards, and throughout that distance their direction had nearly coincided with that in which the glacier had moved. The glacier had passed over them at an angle of about 10°. Upon this quartz my hammer danced and rang, and made scarcely any impression. I chipped away the gneiss without difficulty. The glacier had worked upon two substances of unequal resistancy. Yet, if a line had been stretched between the highest points across any hundred feet of these sheets of rock, I do not think that any part of the rock would have been depressed one foot below the cord. The quartz, instead of standing up in ridges, as I thought it might have done, was cut down to the same level as the gneiss; the keenest scrutiny could not detect the least difference.
It was evident, from the entire obliteration of form, that these rocks had had enormous power exerted upon them, and that a not inconsiderable depth of rock had been removed. It is immaterial whether the effects had been produced by comparatively limited force spread over an enormous length of time, or whether by greater force in a less time. The same effects would have been produced if the same amount of abrading power had been exerted over an equal area of similar rock in the Alps. But it is doubtful, perhaps, if there is in the Alps an equal area of rock which can be compared for perfection pf glaciation to that of which I have spoken. I think it may certainly be asserted that there is not either in the Valley of the Rhone or in the Valley of Aosta. The glacier-eroded rocks of those valleys, and of the Alps generally, are notable for their con-
