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Darwin Correspondence Project

To T. M. Hughes   24 May 1875

Down | Beckenham | Kent.

May 24. 75

My dear Sir

I understand from my son that you wish to hear about my short geological tour with Prof: Sedgwick in North Wales during the summer of 1831; but it is so long ago that I can tell you very little.1 As I desired to learn something about Geology Prof: Henslow asked Sedgwick to allow me to accompany him on his tour & he assented to this in the readiest & kindest manner2   he came to my Father’s house at Shrewsbury, & I remember how spirited & amusing his conversation was during the whole evening; but he talked so much about his health & uncomfortable feelings, that my father who was a doctor thought that he was a confirmed hypochondriac.3 We started next morning, & after a day or two he sent me across the country in a line parallel to his course, telling me to collect specimens of the rocks & to note the stratification.4 In the evening he discussed what I had seen; & this of course encouraged me greatly & made me exceedingly proud; but I now suspect that it was done merely for the sake of teaching me, & not for anything of value which I could have told him. I remember one little incident: we left Conway5 early in the morning, & for the first two or three miles of our walk he was gloomy & hardly spoke a word. He then suddenly burst forth “I know that the damned fellow never gave her the sixpence; I’ll go back at once” & turned to return to Conway. I was amazed for I never heard before, or since, anything like an oath from him.

On inquiry I found that he was convinced that the waiter had not given to the chambermaid the sixpence which he had left for her. He had no reason whatever excepting that he thought the waiter an “ill looking fellow.” On my hinting that he could hardly accuse a man of theft on such grounds, he consented to proceed; but for some time he grumbled & growled. At last his brow cleared & we had a delightful day; & he was as energetic as on all former occasions in climbing the mountains.

We spent nearly a whole day in Cwm Idwal examining the rocks carefully, as he was very desirous to find fossils.6 I have often thought of this day as a good instance of how easy it is for any one to overlook new phenomena, however conspicuous they may be. The valley is glaciated in the plainest manner the rocks being mammillated; deeply scored, with many perched boulders & well defined moraines; yet none of these phenomena were observed by Prof: Sedgwick, nor of course by me. Nevertheless they are so plain, that as I saw in 1842 the presence of a glacier filling up the valley would have rendered the evidence less distinct.7 Shortly afterwards I left Prof. Sedgwick & struck across the country in another direction, & reported by letter what I saw. In his answer he discussed my ignorant remarks in his usual generous & frank manner.8 I am sorry to say that I can tell you nothg more about our little tour—

I find that I have kept only one letter from Prof. Sedgwick, which he wrote after receiving a copy of my Origin of Species. His judgement naturally does not seem to me quite a fair one; but I think that the letter is characteristic of the man, & you are at liberty to publish it if you should so desire9

Believe me my dear Sir | Yours sincerely | Charles Darwin


CD’s notes on the geological tour he took with Adam Sedgwick in 1831 are in DAR 5; he also gave a short account of the tour in his autobiography (see ‘Recollections’, pp. 382–3). Thomas McKenny Hughes was preparing a biography of Sedgwick, and included this letter in the work after expressing his regret that neither CD nor Sedgwick had written down their impressions of the other in 1831 (John Willis Clark and Hughes 1890, 1: 379, 380–1). CD probably learned that Hughes wanted information on the 1831 trip from George Howard Darwin, as both Hughes and George were in Cambridge.
In 1838, CD noted in his ‘Journal’ that John Stevens Henslow had encouraged him to take up geology in 1831 (see Correspondence vol. 1, Appendix I).
CD later recalled that his father, Robert Waring Darwin, possessed a remarkable power of ‘reading the characters, & even the thoughts of those whom he saw even for a short time’ (‘Recollections’, p. 361).
CD’s observations proved to be of importance in determining the geological structure of the Vale of Clwyd (see Secord 1991, pp. 145–50). For an overview of CD’s trip to Wales, see Roberts 2001.
Conway: Conwy in North Wales.
Cwm Idwal is in the mountainous region of North Wales. Sedgwick was looking for fossils in order to establish a continuous stratigraphical sequence downwards into the lower unknown strata of North Wales; the trip was Sedgwick’s first geological excursion to investigate the older fossiliferous rocks in Britain, which became known (from 1835) as ‘Cambrian’ (Secord 1986, p. 60). CD found fossil madrepores (reef-building stony corals) at Cwm Idwal on his way home from his trip with Sedgwick (see Correspondence vol. 1, letter from Adam Sedgwick, 4 September 1831).
CD returned to North Wales in the summer of 1842 in order to see the effects of glaciation on Cwm Idwal (see Correspondence vol. 2, letter to W. H. Fitton, [c. 28 June 1842] and n. 2); he published his observations in ‘Ancient glaciers of Caernarvonshire’. Cwm Idwal is a hanging valley that has been carved out by a small tributary glacier that joined a much larger glacier. The differential rates of erosion of the two glaciers resulted in the valley produced by the tributary glacier being left ‘hanging’ above the level of the valley shaped by the larger glacier.
CD’s letter to Sedgwick has not been found, but for Sedgwick’s reply, see Correspondence vol. 1, letter from Adam Sedgwick, 4 September 1831.
CD refers to the letter from Adam Sedgwick, 24 November 1859 (see Correspondence vol. 7), which was included almost in its entirety in the biography of Sedgwick commenced by Hughes (John Willis Clark and Hughes 1890, 2: 356–9). In addition to this letter, CD had in fact kept four letters from Sedgwick (see Correspondence vol. 1, letters from Adam Sedgwick, 4 September 1831 and 18 September 1831; Correspondence vol. 16, letter from Adam Sedgwick, 11 [October 1868]; Correspondence vol. 18, letter from Adam Sedgwick, 30 May 1870).


‘Ancient glaciers of Caernarvonshire’: Notes on the effects produced by the ancient glaciers of Caernarvonshire, and on the boulders transported by floating ice. By Charles Darwin. Philosophical Magazine 3d ser. 21 (1842): 180–8. [Shorter publications, pp. 140–7.]

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

‘Recollections’: Recollections of the development of my mind and character. By Charles Darwin. In Evolutionary writings, edited by James A. Secord. Oxford: Oxford University Press. 2008.

Roberts, Michael. 2001. Just before the Beagle: Charles Darwin’s geological fieldwork in Wales, summer 1831. Endeavour 25: 33–7.

Secord, James Andrew. 1986. Controversy in Victorian geology: the Cambrian–Silurian dispute. Princeton, N.J.: Princeton University Press.

Secord, James Andrew. 1991. The discovery of a vocation: Darwin’s early geology. British Journal for the History of Science 24: 133–57.


Reports some details of the geological tour he took with Sedgwick in North Wales in 1831. Recalls how neither he nor Sedgwick saw the obvious signs of past glaciation.

Letter details

Letter no.
Charles Robert Darwin
Thomas McKenny Hughes
Sent from
Source of text
Sedgwick Museum of Earth Sciences (Archive DDF Box 720)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 9993,” accessed on 16 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 23