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Darwin Correspondence Project

From Adam Sedgwick   18 September 1831


Sepr. 18. 1831.

Dear Darwin

Before this you will have received a letter I addressed to you, some time since, at Shrewsbury. It contained a statement of what I was doing & had done— I have now resolved to confine myself to this county, & if I can finish it to my satisfaction I shall be well content to turn my back on these mountains for a season— I cannot but be glad at your appointment & I truly hope it will be a source of happiness & honor to you.— I really dont know what to say about books— No. 1 Daubeny.1 No. 2. a book on Geology— D’aubuissions2 work is one of the best tho’ full of Wernerian nonsense.—3 I dont think Bakewell a bad book for a beginner—4 For fossil shells what is to be done?— Go to the Geological Society and introduce yourself to Mr Lonsdale5 as my friend & fellow traveller & he will counsel you— Humboldts personal narrative you will of course get— He will at least show the right spirit with wh. a man should set to work— There is a small paper printed by the Geol. Socy containing directions for travellers &c—6 Lonsdale will give you a copy: but it is a mere horn book7 hardly worth your looking at— Study the Geological Socys. collection as well as you can—& pay them back in specimens— I am to propose you when the meetings begin.8 I am in great hurry as my gig is at the door:—on my way to Clynnog from which place D.V. I hope in ten days to work my way round the great S. Western Promontory of Cardigan bay— I shall then return pack up—& start for Capel Curig—where I must halt again for ye 3d time to make a traverse or two in ye chain— But this depends on the weather— Should it fairly break up I must lodge

The Carnarvon Chain is very troublesome from the number of anticlinal lines wh I have to follow out from hill to hill & valley to valley upways, downways, & cross ways. I will try to give you a notion of one section

[DIAGRAM HERE] a. slate quarries on w. side of Mynydd Mawr b. Mynydd Mawr, a great anticlinal line b.pass of Drws y Coed.. c. Drws-y-Coed — —Do.— — D. Moel Haebog E. Foel Ddu. an anticlinal li〈ne〉 f. Pass of Pont Aberglaslyn— g. 〈Cni〉cht., k. h. hills toward Festiniog.

The prevailing dip in ye Snowdonian chain is S.E with numberless great contortions; & the base of ye series is near ye line of the Slate quarries (a) on ye west side of the Chain.— The strike of the beds in the chain is about N.N.E. with singular uniformity, till you reach the Eastern outskirts & then all is confusion.— The Merioneth chains are elevated in the same direction (as far as I have seen ’em) but ye prevailing tilt seems to be to the N.W. I expect to find (next year!) a great central anticlinal axis in Merioneth.—9 The place marked X in the secn. is the place where the two systems of elevation interfere with each other. But my picture is so detestable and out of all proportion that I fear you cannot comprehend it— I consider poor Ramsays death a grievous loss to the whole University— God bless you & preserve your health of mind & body. Most truly yours | A Sedgwick

I shall be happy to hear from you write to Carnarvon


Sedgwick probably refers to Daubeny 1826 as particularly relevant to South American geology. A much spotted copy in Darwin Library–Down may be the one CD had on board the Beagle (see Correspondence vol. 1, Appendix IV). A pencil drawing of volcanic islands in the section on the Azores (p. 26) and a note ‘Covington Copy’ next to a footnote on trachyte (p. 180) are more characteristic of notes CD made later while at work on the geology of the voyage.
Jean François d’Aubuisson de Voisins.
Abraham Gottlob Werner formulated the so-called Neptunian hypothesis that the rocks of the earth’s crust were formed by depositions from a global ocean. It is not clear whether Sedgwick refers to Aubuisson’s An account of the basalts of Saxony (1814) or to his two-volume more general geological work, the Traité de géognosie (1819), in which Aubuisson modified his Neptunism, though not his admiration of Werner as a founder of the science of geology. Both volumes are in Darwin Library–CUL. The Traité’s title-page bears the inscription ‘C. Darwin HMS Beagle’ and has many more annotations than the Account. CD refers to it frequently in his geological notes during the voyage. There is no evidence that CD also had the Account on board.
Bakewell 1813.
For a good account of William Lonsdale’s contributions to geology and his early evolutionist ideas, see Tasch 1950.
Geological Society, London 1808.
A child’s book of a single sheet in a frame, covered in horn for protection.
CD was not elected a member of the Geological Society until 1836. See letter to J. S. Henslow, 9 July 1836, in which CD remembers this statement as an offer to nominate him.
Sedgwick reported on the geology of North Wales to the Cambridge Philosophical Society on 11 March 1833. An abstract was published in the Philosophical Magazine 2 (1833): 381. His major finding was that ‘the strata of that district are bent into saddles and troughs, of which the anticlinal and synclinal lines occur alternately, and are all nearly parallel to the “great Merionethshire anticlinal line.” ’


Is glad of CD’s appointment and hopes it will be a source of happiness and honour.

Answers a query about books.

Suggests CD go to Geological Society, present himself, as AS’s friend, to William Lonsdale and study the Society’s collection.

Tells CD of his work in Wales; includes a diagram and explanations.

Ramsay’s death a grievous loss.

Letter details

Letter no.
Adam Sedgwick
Charles Robert Darwin
Sent from
Source of text
DAR 204.5
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 129,” accessed on 22 November 2017,

Also published in The Correspondence of Charles Darwin, vol. 1