and to level from the beach at one extremity to that at the other, so that
it might be ascertained whether the curvature does exactly correspond with
that of the globe, or, if not, what is the direction of the line of
greatest elevation. Much attention would be requisite in fixing on either
the upper or lower edge of the ancient beaches as the standard of
measurement, and in rendering this line conspicuous. The heights of the
three roads, one above the other and above the level of the sea, ought to
be accurately ascertained. Mr. Darwin observed one short beach-line north
of Glen Roy, and he has indicated, on the authority of Sir David Brewster,
others in the valley of the Spey. If these could be accurately connected,
by careful measurements of their absolute heights or by levelling, with
those of Glen Roy, it would make a most valuable addition to our knowledge
on this subject. Although the observations here specified would probably
be laborious, yet, considering how rarely such evidence is afforded in any
quarter of the world, it cannot be doubted that one of the most important
problems in Geology--namely, the exact manner in which the crust of the
earth rises in mass--would be much elucidated, and a great service done to
geological science.


LETTER 519. R. CHAMBERS TO D. MILNE-HOME.
St. Andrews, September 7th, 1847.

I have had a letter to-day from Mr. Charles Darwin, beseeching me to obtain
for him a copy of your paper on Glen Roy. (519/1. No doubt Mr. Milne's
paper "On the Parallel Roads of Lochaber," "Trans. R. Soc. Edinb." Volume
XVI., page 395, 1849. [Read March 1st and April 5th, 1847.]) I am sure
you will have pleasure in sending him one; his address is "Down,
Farnborough, Kent." I have again read over your paper carefully, and feel
assured that the careful collection and statement of facts which are found