412 MR MILXE ON THE PARALLEL ROADS OF LOCHABER. 



naiTow outlet from Loch Treig, and continuously into Glen Spean. Such a shelf 

 could not have been formed, and would have been obliterated by any glacier mov- 

 ing out of Loch Treig. 



(2.) But assuming all these facts to be as M. Agassiz states them, do they 

 present unequivocal proofs of the movement of glaciers, and the formation of mo- 

 raines ? Scratches on polished rocks, may be made by various causes ; and if a 

 moraine existed on Moeldhu, surely some trace of it, or of the great blocks which 

 generally accompany moraines, would have been particularly observable there ;— 

 whereas there is scarcely a block or a patch of gravel to be seen in that part of 

 the valley. 



Farther, I would observe, that the valley supposed to have been the birth- 

 place of the glacier, which produced this Moeldhu Moraine, is about two miles 

 distant from Moeldhu, with an undulating country between them, which is most 

 unlikely to have formed the channel or bed of a glacier. Dr Buckland and M. 

 Agassiz speak of this glen, as connected with Ben Nevis. But here, again, there 

 is apparently some mistake. The valley in question is Larich Leachich, and runs 

 up, not in a NW. direction towards Ben Nevis, but in a SW. direction towards the 

 head of Loch Treig. It is an extremely short glen, and rises to no great height. 



Finally, supposing, that if, in spite of all these objections, it were allowed that 

 a glacier had moved down this little valley, and across the very uneven country 

 to Moeldhu, so as to block up Glen Roy and Glen Spean, it would still remain to 

 explain the blockage of Glen Gluoy, which, by no possibility, could be accounted 

 for by a moraine at or near Moeldhu. 



That there are certain appearances in the valleys of Lochaber, which must 

 have been produced by attrition of some kind, I am free to admit. Water, ac- 

 companied by gravel and other detritus, appears, however, to have been the agent, 

 and not ice. At the Monessie Falls, the valley is compressed to a narrow gorge, 

 and the rocks forming the east side, present evident marks of attrition on a large 

 scale, the rough faces of the rock being all down the valley. The rocks are here 

 covered by sand and gravel, which indicate the flowing of water and of drift at that 

 height, when these rocks were worn down. In like manner, at the outlet of Loch 

 Treig, there are immense expanses of rock, all smoothed and rounded on the sides 

 facing the SW. or WSW. by compass.* These smoothed rock-faces prevail to a 

 lieiglit of about 786 feet above the lake, and ] 680 feet above the sea, above which 

 level they are no longer visible. There are many boulders lying on these 

 smoothed surfaces, all of rounded forms. That these boulders have come from 



* The general line or axis of the lake is north and soutli by compass, the upper part being to- 

 wards the south, so that the motion of a glacier down this valley would have smoothed all the south 

 faces of the rocks. It is also important to remark, that, on the west side of the lake, the rocks 

 facing the lake are, as compared with those on the other side, exceedingly rough, shewing still more 

 clearly that the smoothing agent had crossed the valley of Loch Treig, in a direction not parallel 

 with its longer axis, but obliquely to it. 



