nce.

[C] The wood-cut on p. 730 is a reproduction of the little map
accompanying a paper of mine upon "The Glacial Theory and its Recent
Progress," printed in the "Edinburgh New Philosophical Journal" for
October, 1842. I might have greatly improved the topography, and
represented more accurately the details of the phenomenon, by availing
myself of the much larger and very minute map recently published by
Professor Thomas F. Jamieson, of Aberdeen; but I thought it advisable to
leave my first sketch as I presented it twenty-two years ago, in order
to show that Sir Charles Lyell is mistaken in ascribing (see "Antiquity
of Man," pp. 260, 261) the discovery of the glacier of Loch Treig to
Professor Jamieson. A comparison of his statements with mine will show
that the solution of the problem offered by him is identical with that
proposed by me, as he himself candidly admits ("Quarterly Journal of the
Geological Society" for August, 1863, p. 239). I have only one fault to
find with his observations, and, as I have never revisited the locality
since, this remark may satisfy him that my examination of its features
was not so hurried as he supposes. Professor Jamieson confounds the
effects of two distinct glaciers moving in different valleys as the
action of one and the same glacier. In my paper, it is true, I made no
allusion to the great glacier of Glen Spean, the existence of which I
had recognized along the river from Loch Laggan nearly to the Caledonian
Canal. I publish my observations upon this great central glacier for the
first time in the present article, having omitted them in my
contributions upon this subject to the scientific periodicals of the day
simply because I thought best not to complicate my exposition of the
facts concerning the parallel roads by considerations foreign to their
origin, convinced as I was, from the manner in which the glacial theory
was then received, that they would not be understood, and still less
admitted. But now that all the geologists of Great Britain seem to have
given their adhesion to it, I may be permitted to state that I already
knew then, what Professor Jamieson has overlooked in his latest paper,
that a separate glacier had occupied the valley of the Spean _prior_ to
the formation of the parallel roads, and that at that time the glacier
of Loch Treig was only a lateral tributary of the same, just as the
glacier of the Thierberg is a tributary of the glacier of the Aar. It
was n