their mouths, which have since been upheaved" ("Geol. Obs. S. America,"
page 24, footnote.), with regard to the shoaling of the deep fiords of T.
del Fuego near their mouths, and which I have remarked would tend, with a
little elevation, to convert such fiords into lakes with a great mound-like
barrier of detritus at their mouths, might, possibly, have been of use to
you with regard to the lakes of Glen Roy.


LETTER 522. TO C. LYELL.
Down, Wednesday, 8th.

Many thanks for your paper. (522/1. "On the Ancient Glaciers of
Forfarshire." "Proc. Geol. Soc." Volume III., page 337, 1840.) I do
admire your zeal on a subject on which you are not immediately at work. I
will give my opinion as briefly as I can, and I have endeavoured my best to
be honest. Poor Mrs. Lyell will have, I foresee, a long letter to read
aloud, but I will try to write better than usual. Imprimis, it is
provoking that Mr. Milne (522/2. "On the Parallel Roads of Lochaber, etc."
"Trans. R. Soc. Edinb." Volume XVI., page 395, 1849. [Read March 1st and
April 5th, 1847.]) has read my paper (522/3. "Observations on the Parallel
Roads of Glen Roy, etc." "Phil. Trans. R. Soc." 1839, page 39. [Read
February 7th, 1839.].) with little attention, for he makes me say several
things which I do not believe--as, that the water sunk suddenly! (page 10),
that the Valley of Glen Roy, page 13, and Spean was filled up with detritus
to level of the lower shelf, against which there is, I conceive, good
evidence, etc., but I suppose it is the consequence of my paper being most
tediously written. He gives me a just snub for talking of demonstration,
and he fights me in a very pleasant manner. Now for business. I utterly
disbelieve in the barriers (522/4. See note, Letter 521.) for his lakes,
and think he has left that point exactly where it was in the time of