TERRACES IN THE HIGHLANDS. 37 



extent. Fragments of all sizes and shapes are crowded along promiscuously 

 by glaciers, and though some of them are rounded and others ground to powder, 

 there is no separation of one sort and size from another. Wherever we find such 

 separation, however imperfect, we may be sure that the materials, even though 

 originally produced by glaciers, have been remodelled by water. And such are 

 most of those cases which I have seen of supposed moraines in the United States, 

 which I thought strongly to resemble those above alluded to in Scotland. In 

 passing from Fort William to Glen Roy, along the northwest side of Ben Nevis, 

 vast accumulations of such materials occur, which appear to me to have once been 

 sea-beaches or sea-bottoms. In descending towards the Spean on that road, we 

 meet with very fine terraces, sometimes three or four tiers of them. They are, 

 also, seen along the Roy, even beneath the Parallel Roads, where they have been 

 long since figured by Dr. Macculloch, in the Transactions of the London Geological 

 Society. 



These Parallel Roads are certainly the most remarkable terraces I have ever set 

 my eyes upon : peculiar from their narrowness and from their perfect horizontality 

 and parallelism. The first fact may perhaps be explained from their occurrence 

 on hills so steep that they could not retain wide platforms of loose materials. 

 The other facts lead the mind almost irresistibly to the conclusion that the body of 

 water, which once filled these glens, must have paused for a time at the successive 

 roads, as it was drained off. But was it the sea, or a lake, whose barrier towards 

 the ocean has disappeared ? Did not the markings extend towards the ocean below 

 that point on the Roy river, a mile or two above its mouth, where such large quan- 

 tities of detritus lie upon its west side, we might say that the valley at that spot 

 was once choked up with detrital matter to the height of the roads, and subse- 

 quently eroded. But since the terraces can be traced far down the valley of the 

 Spean, where it becomes quite broad, such erosion never could be accomplished by 

 the river. Nothing but the ocean could have opened such a broad valley. To 

 suppose the space to have been choked up by a glacier, descending from Ben 

 Nevis, does not relieve the matter, because the materials now occupying the valley 

 have been most evidently worn and comminuted by water, and are not the simple 

 moraine of a glacier. Moreover, I noticed that in some places at least, the side of 

 the mountains above the highest road, was covered by such sand and pebbles as 

 constitute the terraces. I did not ascertain whether the same is true to the very 

 top of the hills ; yet such was my impression, and if correct, it destroys the idea 

 of lakes and obliges us to admit the presence of the ocean. 



But I fear that I am affording ground for the charge of vanity in venturing an 

 opinion on questions which have divided the judgment of so many able men, who 

 have devoted much more of attention to the phenomena than I have. The new 

 suggestions I have made, in respect to the nature of the materials forming the 

 parallel roads and spread over the sides of the valleys, is my only apology. 



In ascending towards the higher parts of the Highlands, especially on approach- 

 ing Glencoe — that most romantic of all the Highland glens — I found the detritus 

 becoming coarser, and the fragments more angular, with slight evidence of being 

 sorted, very similar, indeed, to the unmodified drift of New England. Just at the 



