like to talk over the Jura case with you. I am
tired, so goodbye.

LETTER 518. TO L. HORNER. Down [1846].

(518/1. It was agreed at the British Association meeting held at
Southampton in 1846 "That application be made to Her Majesty's
Government to direct that during the progress of the Ordnance
Trigonometrical Surveys in the North of Scotland, the so-called Parallel
Roads of Glen Roy and the adjoining country be accurately surveyed, with
the view of determining whether they are truly parallel and horizontal,
the intervening distances, and their elevations above the present
sea-level" ("British Association Report," 1846, page xix). The survey
was undertaken by the Government Ordnance Survey Office under Col. Sir
Henry James, who published the results in 1874 ("Notes on the Parallel
Roads of Glen Roy"); the map on which the details are given is sheet 63
(one-inch scale).)

In following your suggestion in drawing out something about Glen Roy for
the Geological Committee, I have been completely puzzled how to do it.
I have written down what I should say if I had to meet the head of the
Survey and wished to persuade him to undertake the task; but as I have
written it, it is too long, ill expressed, seems as if it came from
nobody and was going to nobody, and therefore I send it to you in
despair, and beg you to turn the subject in your mind. I feel a
conviction if it goes through the Geological part of Ordnance Survey it
will be swamped, and as it is a case for mere accurate measurements it
might, I think without offence, go to the head of the real Surveyors.

If Agassiz or Buckland are on the Committee they will sneer at the whole
thing and declare the beaches are those of a glacier-lake, than which I
am sure I could convince you that there never was a more futile theory.

I look forward to Southampton (518/2. The British Association meeting
(1846).) with much interest, and hope to hear to-morrow that the
lodgings are secured to us. You cannot think how thoroughly I enjoyed
our geological talks, and the pleasure of seeing Mrs. Horner and
yourself here. (518/3. This letter is published in the privately printed
"Memoir of Leonard Horner," II., page 103.)

[Here follows Darwin's Memorandum.]

The Parallel Roads of Glen Roy, in Scotland, have been the object of
repeated examination, but they have never hitherto been levelled with
sufficient accuracy. Sir T. Lauder Dick (518/4. "On the Parallel Roads
of Lochaber" (wi