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Darwin Correspondence Project

From G. H. Darwin   25 April 1876

Trin. Coll

Tuesd. Ap 25. 76

My dear Father,

I hope poor Henrietta will have got well eno’ to allow of your coming up to London & after Mother’s letter of yesterday I write to London on spec. Poor old mother too seems to have been baddish by what she says, but I hope she’s mended again now.1 There’s no external news that I know of, but I’m bursting with delight at my work of the last few days. I’ve been thinking day & night over Evans’ suggested problem about the alteration in the axis of the earth.2 After long thought I have got thro’ the hardest part & I think I see exactly what is the mathematical problem involved. What especially delights me is that I feel almost sure now that such an upheaval as he suggests wd. displace the axis, but at the same time I think it wd be a very slight displact. But if my argument is right there is no reason (except as to probabilities of upheavals taking place in the right places & in sufficient amount) why the pole shd.’nt be moved ever so much, & that without the upheavals being piled one on the top of the other, that is to say I conceive that the displaced pole would remain the pole even tho’ the upheaved part were gradually worn away by rivers & sea I have got a good deal of the mathematics down on paper, but there will be some terrible arithmetic to be done.

Altho’ the pole may be displaced in the Earth I don’t yet see what will be the effect on the climate of the earth i.e whether the arctic circle will tend to meet or recede from the tropics   I see however how to attack this question but perhaps the mathcs. will stump me   When I’ve got all of it down on paper—wh. may be some time—I think I shall go & talk to Adams about it, before I grind the arithmetic,—for wh. I hope I shall be able to employ calculators.3

I’m rather counting my chickens before they’re hatched, but I’m regular bursting with ideas on the subject & am at present much elated tho’ doubtless presently I shall get down in the mouth. I thought I never shd be able to master the mechanics of it, when the fertilising idea suddenly came into my head yesterday afternoon   There now I’ve let off a little steam, tho’ I confess I can hardly keep my hands & head off the subject.

I’ve not thrown up the pitch by any means but most of my work at that is purely mechanical & consists of getting my hands frightfully dirty.4 I don’t think I’m working too hard just now & I’ll try not to—but it wont be easy if all goes on well.

I’m sorry to say my liver is going a little wrong again, because the cold in my head has stopped but still I’m better than Ive been for many months & play tennis very vigorously

Your affec. son | G H Darwin


Henrietta Emma Litchfield was ill from 17 to 21 April 1876, delaying CD’s visit to London until 27 April; see letter to J. D. Hooker, 19 April [1876] and n. 2. Emma Darwin’s diary (DAR 242) records that she was in bed with a cold from 20 to 22 March 1876.
In ‘On the influence of geological changes on the earth’s axis of rotation’ (G. H. Darwin 1876b, p. 271), George referred to John Evans’s presidential address to the Geological Society of London (J. Evans 1876, p. 108) as inspiration for his paper on whether upheaval and subsidence of the continents influenced the position of the polar axis.
George thanked John Couch Adams for help with the numerical data and for discussing several other points in G. H. Darwin 1876b, p. 289 n. Adams communicated the paper to the Royal Society of London. For more on the role of human calculators, see Maas 2005, pp. 99–100.
George was making experiments on the flow of pitch as part of his work on tidal friction; see Correspondence vol. 23, letters from G. H. Darwin, 12 October 1875 and [26 October 1875].


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

Evans, John. 1876. The anniversary address of the president. [Read 18 February 1876.] Quarterly Journal of the Geological Society of London 32, Proceedings, pp. 53–121.

Maas, Harro. 2005. William Stanley Jevons and the making of modern economics. Cambridge: Cambridge University Press.


Is elated by his work on the alteration in the earth’s axis and the displacement of the poles. [See 10689.]

Letter details

Letter no.
George Howard Darwin
Charles Robert Darwin
Sent from
Trinity College, Cambridge
Source of text
DAR 210.2: 51
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 10472,” accessed on 1 December 2020,

Also published in The Correspondence of Charles Darwin, vol. 24