ead March 1st and April 5th,
1847.]), which I had not then received, owing to the porter having been
out when I last sent to the Geological Society. I have read your paper
with the greatest interest, and have been much struck with the novelty
and importance of many of your facts. I beg to thank you for the
courteous manner in which you combat me, and I plead quite guilty to
your rebuke about demonstration. (521/2. Mr. Milne quotes a passage from
Mr. Darwin's paper ("Phil. Trans. R. Soc." 1839, page 56), in which the
latter speaks of the marine origin of the parallel roads of Lochaber as
appearing to him as having been demonstrated. Mr. Milne adds: "I regret
that Mr. Darwin should have expressed himself in these very decided and
confident terms, especially as his survey was incomplete; for I venture
to think that it can be satisfactorily established that the parallel
roads of Lochaber were formed by fresh-water lakes" (Milne, loc. cit.,
page 400).) You have misunderstood my paper on a few points, but I do
not doubt that is owing to its being badly and tediously written. You
will, I fear, think me very obstinate when I say that I am not in the
least convinced about the barriers (521/3. Mr. Milne believed that the
lower parts of the valleys were filled with detritus, which constituted
barriers and thus dammed up the waters into lakes.): they remain to me
as improbable as ever. But the oddest result of your paper on me (and I
assure you, as far as I know myself, it is not perversity) is that I
am very much staggered in favour of the ice-lake theory of Agassiz and
Buckland (521/4. Agassiz and Buckland believed that the lakes which
formed the "roads" were confined by glaciers or moraines. See "The
Glacial Theory and its Recent Progress," by Louis Agassiz, "Edinb. New
Phil. Journ." Volume XXXIII., page 217, 1842 (with map).): until I read
your important discovery of the outlet in Glen Glaster I never thought
this theory at all tenable. (521/5. Mr. Milne discovered that the middle
shelf of Glen Roy, which Mr. Darwin stated was "not on a level with
any watershed" (Darwin, loc. cit., page 43), exactly coincided with a
watershed at the head of Glen Glaster (Milne, loc. cit., page 398).) Now
it appears to me that a very good case can be made in its favour. I am
not, however, as yet a believer in the ice-lake theory, but I tremble
for the result. I have had a good deal of talk with Mr. Lyell on
the subject, and from his advice I am go