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Darwin Correspondence Project

From James Croll   15 February 1869


Feby 15th 1869.

Dear Sir,

I am much obliged to you for the copy of Scientific Opinion you sent me containing an abstract of Canon Moseley’s admirable paper on the motion of glaciers1

I have a curious incident to tell you, regarding the matter. The reading of the abstract thoroughly convinced me that the generally received theory of glacier motion, which I believe is that of Tyndall’s,2 must be given up and that some other explanation must be sought. Strange to say, this conviction had hardly got time to settle down, if I may so express myself, before, what I fully believe to be the true cause suggested itself. The cause is so simple, so beautiful, and obvious that I wonder that it should have escaped observation so long.

I have drawn up a short account of the matter and have sent it to the Phil. Mag   I have requested Dr Francis to send me two copies of proof and when they come to hand I shall send you one3

I am | Yours very truly | James Croll

Charles Darwin Esq MA FRS


Croll refers to Henry Moseley. See letter to James Croll, 31 January [1869] and n. 6.
For John Tyndall’s account of his own as well as earlier theories of glacier motion, see Tyndall 1860.
Croll’s paper ‘On the physical cause of the motion of glaciers’ (Croll 1869) appeared in the March 1869 issue of Philosophical Magazine. CD’s copy has not been found. William Francis was the editor of Philosophical Magazine.


Croll, James. 1869. On the physical cause of the motion of glaciers. Philosophical Magazine 37: 201–6.

Tyndall, John. 1860. The glaciers of the Alps. Being a narrative of excursions and ascents, an account of the origin and phenomena of glaciers, and an exposition of the physical principles to which they are related. London: J. Murray.


Thanks for abstract of Moseley’s paper on motion of glaciers [see 6599]. Reading it convinced him that Tyndall’s received view is wrong. Has formed a new view, which he has sent to Philosophical Magazine [4th ser. 37 (1869): 201–6].

Letter details

Letter no.
James Croll
Charles Robert Darwin
Sent from
Source of text
DAR 161: 264
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 6616,” accessed on 21 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 17