# To G. H. Darwin   2 June [1876]1

Hopedene | Surrey

June 2d.

My dear G.

Your letter has told us a lot of interesting news.— I am extremely glad that your work is coming to a satisfactory end. Its value I expect under a geological point of view is mainly negative, as Geologists require a much greater change of climate within a rather recent period.— There were Luxuriant forests in Spitbergen during the middle Tertiary period.2

There is a map in Wallace’s new book on Geographical Distribution, showing depth of sea according to all recent data & a calculation of its average depth viz 12,000 ft.— Humboldt estimated average height of land at 1000 ft. See p. 36 & 37 of this book.—3 I think the most interesting & probable supposition wd. be to submerge in the N. $\frac{1}{2}$ or $\frac{1}{4}$ hemisphere taking St George’s Channel4 as centre of subsidence to depth of 12000 ft, & raise at the antipodes $\frac{1}{2}$ or $\frac{1}{4}$ of hemisphere (where ever there is water) to height of 1000 ft & see the result.— There is reason to suspect that there has been great & recent subsidence in Antarctic region & near N. Zealand.—5

I hardly dare venture to hope that your astronomical problem about obliquity &c will really work.6

Frank has made a really fine zoological discovery.—7

## Footnotes

The year is established by the relationship between this letter and the letter from G. H. Darwin, 1 June 1876.
See letter from G. H. Darwin, 1 June 1876; see also letter from G. H. Darwin, 31 May 1876. George had written about his work on how the obliquity of the ecliptic and the position of the North and South Poles might be affected by changes in the conformation of the globe (see G. H. Darwin 1876b and 1877). In G. H. Darwin 1876b, p. 305, George speculated that changes in the earth’s axis, for example, the North Pole’s moving to the present location of Greenland, could have caused local climate changes that were later mistaken for a symptom of general glaciation. CD learned about the Miocene (Tertiary) flora of Spitzbergen from Heer 1869 (see Correspondence vol. 20, letter to Oswald Heer, 4 August [1872–4]).
There is an annotated copy of Alfred Russel Wallace’s The geographical distribution of animals, with a study of the relations of living and extinct faunas as elucidating the past changes of the earth’s surface (Wallace 1876a) in the Darwin Library–CUL (see Marginalia 1: 837–40). The map showing sea depth is the frontispiece to the first volume; the reference to Alexander von Humboldt’s estimate of the mean height of all land surfaces is in Wallace 1876a, 1: 36.
St George’s Channel was the name of the sea channel running between Wales and Ireland.
See Wallace 1876a, 1: 401, 460–2.
Francis had discovered protoplasmic filaments protruding from the glandular hairs of the cups of common or fuller’s teasel (Dipsacus sylvestris, now D. fullonum; see letter from Francis Darwin, [28 May 1876]). Francis thought that the filaments might enable the plant to absorb nitrogenous matter dissolved in the water in the cups formed by some of the leaves (see F. Darwin 1877b). CD may have described this as a zoological discovery by mistake or in allusion to the animal-like nature of the plant’s digestive processes.

## Bibliography

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

Darwin, George Howard. 1877. On a suggested explanation of the obliquity of planets to their orbits. Philosophical Magazine 5th ser. 3: 188–92.

Heer, Oswald. 1869. Die miocene Flora und Fauna Spitzenbergens. Kongliga Svenska Vetenskaps-Akademiens Handlingar 8: no. 7, pp. 1–98.

Marginalia: Charles Darwin’s marginalia. Edited by Mario A. Di Gregorio with the assistance of Nicholas W. Gill. Vol. 1. New York and London: Garland Publishing. 1990.

## Summary

Further comments on GHD’s work on the influence of geological changes on the earth’s axis.

Frank [Francis Darwin] has made a fine zoological discovery.

## Letter details

Letter no.
DCP-LETT-10528
From
Charles Robert Darwin
To
George Howard Darwin
Sent from
Hopedene, Dorking
Source of text
DAR 210.1: 54
Physical description
4pp