t the eastern part of Glen Spean.[B]

Prepossessed as I was with the idea of glacial agency in times anterior
to ours, these phenomena appeared to me under a new aspect. I found the
bottom of Glen Spean so worn by glacial action as to leave no doubt in
my mind that it must have been the bed of a great glacier, and Dr.
Buckland fully concurred with me in this impression. Indeed, the face of
the country throughout that region presents not only the glacier-marks
in great perfection, but other evidences of the ancient presence of
glaciers. There are moraines at the lower end of Glen Spean, remodelled,
it is true, by the action of currents, but still retaining enough of
their ancient character to be easily recognized; and some of the finest
examples of the _roches moutonnees_ I have seen in Scotland are to be
found at the entrance of the valley of Loch Treig, a lateral valley
opening into Glen Spean on its southern side, and, as we shall see
hereafter, intimately connected with the history of the parallel roads
of Glen Roy. These _roches moutonnees_ may very fairly be compared with
those of the Grimsel, and exhibit all the characteristic features of the
Alpine ones. One of them, lying on the western side of the valley where
it opens into Glen Spean, is crossed by a trap-dike. The general surface
of the hill, consisting of rather soft mica, has been slightly worn down
by atmospheric agencies, so that the dike stands out some three-quarters
of an inch above it. On the dike, however, the glacier-marks extend for
its whole length in great perfection, while they have entirely
disappeared from the surrounding surfaces, so as to leave the dike thus
standing out in full relief. This is an instructive case, showing how
little disintegration has gone on since the drift-period. All the
currents that have swept over it, all the rains that have beaten upon
it, have not worn away one inch from the original surface of the hill. I
have observed many other _roches moutonnees_ in Scotland, especially
about the neighborhood of Loch Awe, Loch Fyne, and Loch Etive. In fact,
they may be found in almost all the glens of Scotland, in the
lake-region of England, and in the valleys of Wales and Ireland.

Following the glacial indications wherever we could find them in the
country about Glen Roy, it became evident to me that the whole western
range of the Grampian Hills had once been a great centre of glaciers,
that they had come down toward Glen Spea