Down, September 28th [1861].

It is, I believe, true that Glen Roy shelves (I remember your Indian
letter) were formed by glacial lakes. I persuaded Mr. Jamieson, an
excellent observer, to go and observe them; and this is his result. There
are some great difficulties to be explained, but I presume this will
ultimately be proved the truth...


LETTER 527. TO C. LYELL.
Down, October 1st [1861].

Thank you for the most interesting correspondence. What a wonderful case
that of Bedford. (527/1. No doubt this refers to the discovery of flint
implements in the Valley of the Ouse, near Bedford, in 1861 (see Lyell's
"Antiquity of Man," pages 163 et seq., 1863.) I thought the problem
sufficiently perplexing before, but now it beats anything I ever heard of.
Far from being able to give any hypothesis for any part, I cannot get the
facts into my mind. What a capital observer and reasoner Mr. Jamieson is.
The only way that I can reconcile my memory of Lochaber with the state of
the Welsh valleys is by imagining a great barrier, formed by a terminal
moraine, at the mouth of the Spean, which the river had to cut slowly
through, as it drained the lowest lake after the Glacial period. This
would, I can suppose, account for the sloping terraces along the Spean. I
further presume that sharp transverse moraines would not be formed under
the waters of the lake, where the glacier came out of L. Treig and abutted
against the opposite side of the valley. A nice mess I made of Glen Roy!
I have no spare copy of my Welsh paper (527/2. "Notes on the Effects
produced by the Ancient Glaciers of Caernarvonshire, and on the Boulders
transported by Floating Ice," "Edinb. New Phil. Journ." Volume XXXIII.,