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Darwin Correspondence Project

To G. G. Stokes   28 May 1879

Down, | Beckenham, Kent. | (Railway Station | Orpington. S.E.R.)

May 28 | 1879—


Mr Prestwich’s paper on the Parallel Roads of Lochaber seems to me a very valuable contribution to this long disputed subject, & I strongly recommend it to be printed in extenso in the Transactions; for although the abstract is remarkably clear, the full details are necessary for any final judgment & would be indispensable to any one hereafter revisiting the district.1 There are also many valuable, incidental discussions on glacial action. It is to be regretted that the author does not explain how it was (considering the height of the surrounding mountains) that during the second glacial period the valleys were not swept clear of their detritus, including the parallel roads. With respect to illustrations, Map I is indispensable: Map II does not seem necessary, but only advantageous.2 Of the wood-cuts Fig. 3 (viz a sketch of Glenroy) is hardly necessary, & perhaps two or three of the smaller diagrams might be omitted, but their cost would be trifling.3

Finally, I ought perhaps to caution the Council, that from having formerly attended to the Parallel Roads, I may over-estimate the interest of the present memoir.4 On the other hand every one will admit that so unique a phenomenon deserves the fullest consideration, standing as it does, in intimate connection with one of the most remarkable of all the epochs in the earth’s history, namely the Glacial Period.

I remain. Sir | Your obedient servant | Charles Darwin

To the Secy | R. Socy.

P.S. Paper despatched today by Rail


Joseph Prestwich’s paper ‘On the origin of the parallel roads of Lochaber and their bearing on other phenomena of the glacial period’ was read on 1 May 1879 and an abstract was published in Proceedings of the Royal Society of London 29 (1879): 6–21. The paper was published in full in Philosophical Transactions of the Royal Society of London (Prestwich 1879).
In the event, only map 1 was published (Prestwich 1879, plate 46).
The figure mentioned was published; see Prestwich 1879, p. 673.
In 1839, CD had written ‘Parallel roads of Glen Roy’, suggesting a marine origin for the three terraces that run parallel to one another along the sides of Glen Roy in Lochaber, Scotland, but later accepted the theory that they were the result of glacial lakes (see Correspondence vol. 10, letter to Charles Lyell, 14 October [1862] and n. 3).


‘Parallel roads of Glen Roy’: Observations on the parallel roads of Glen Roy, and of other parts of Lochaber in Scotland, with an attempt to prove that they are of marine origin. By Charles Darwin. [Read 7 February 1839.] Philosophical Transactions of the Royal Society of London 129: 39–81. [Shorter publications, pp. 50–88.]

Prestwich, Joseph. 1879. On the origin of the parallel roads of Lochaber and their bearing on other phenomena of the glacial period. [Read 1 May 1879.] Philosophical Transactions of the Royal Society of London 170: 663–726.


Reports on Joseph Prestwich’s paper, "On the origin of the parallel roads of Lochaber" [read 1 May 1879]. Strongly recommends that the paper be published in Philosophical Transactions [Philos. Trans. R. Soc. Lond. 170 (1880): 663–726].

Letter details

Letter no.
Charles Robert Darwin
George Gabriel Stokes, 1st baronet
Sent from
Source of text
The Royal Society (RR8: 183)
Physical description
LS(A) 3pp

Please cite as

Darwin Correspondence Project, “Letter no. 12066,” accessed on 7 June 2023,