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Darwin Correspondence Project

To A. C. Ramsay   10 October [1846]

Down Farnborough Kent

Oct. 10th.

Dear Sir

Having just read your excellent memoir on Denudation,1 I have taken the liberty to send you a copy of my volume on S. America, finding that we have discussed some related questions.— I wish I had profited by your memoir before publishing my volume.— I see that we entirely agree on the sea’s great power compared with ordinary alluvial action, & likewise on the frequency of grand oscillations of level & on several other points. If you had time to read parts of my volume, I should much like to discuss with you many cases, such as my notion of subsidence being necessary for the formation of high sea-cliffs, as inferred from the nature of the sea’s bottom off them,2 likewise the horizontal elevation of the Cordillera, as inferred from the sloping gravel fringes in the valleys3 —on the non-horizontality of lines of escarpments round old bays, &c &c—4

I grieve to see how diametrically opposite our views are (I being a follower of Lyell) on the probability of great & sudden elevations of mountain-chains: I cannot but think, that you would have estimated existing forces, as more than “petty” & entertained some doubt about their being “conflicting”5 had you inspected with your own eyes the wide area of recently elevated & similarly affected districts in S. America. There is much which I could say on this head, but I will not intrude on you. May I ask, whether you do not admit Mr Hopkin’s views of mountain-chains being the subordinate effects of fractures consequent on changes of level in the surrounding areas;6 & does not all the evidence, which we possess, tend to show that widely-extended elevations are slow, & may we not infer from this that the formation of mountain-chains is likewise probably slow.— I cannot see any difficulty, after a line of fracture has been once formed, in fluidifyed rock being pumped in by as many strokes, as it is pumped out in a common volcano, & yet producing a symmetrical effect.—

But I much fear that I have cause to apologise for having written at such unreasonable length: the interest excited in me by your Memoir, must plead my excuse, & trusting that you will forgive the liberty I have taken | I remain, dear Sir | Yours faithfully | C. Darwin


Ramsay 1846.
See South America, pp. 25–6, and letter to Charles Lyell, [3 October 1846], n. 3.
CD believed that gravel terraces along the valleys of the Cordillera were marine deposits laid down as the land was gradually elevated (South America, pp. 62–7).
CD believed that the non-horizontal inclination of step-like terraces along the valleys of Coquimbo and Guasco was due to the elevation of land around bays (South America, pp. 41–6).


Thanks ACR for paper and comments on it ["On the denudation of South Wales", Mem. Geol. Surv. G. B. 1 (1846): 297–335].

Sends copy of South America.

Discusses action of the sea.

Criticises ACR’s views on sudden elevation of mountain chains.

Letter details

Letter no.
Charles Robert Darwin
Andrew Crombie Ramsay
Sent from
Source of text
Imperial College of Science, Technology, and Medicine Archives
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 1008,” accessed on 22 July 2019,

Also published in The Correspondence of Charles Darwin, vol. 3