Ɛpsilon

To T. M. Reade   9 February 1877

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R.

Feb 9th 1877

My dear Sir,

I am much obliged for your kind note & the present of your Essay.1 I have read it with great interest & the results are certainly most surprising.2 It appears to me almost monstrous that Prof: Tait should say that the duration of the world has not exceeded 10 million years. The argument which seems the most weighty in favour of the belief that no great number of million of years have elapsed since the world was inhabited by living creatures is the rate at which the temperature of the crust increases; & I wish that I could see this argument answered.3

I hope that you will continue your interesting & laborious researches, & I remain | Yours faithfully | Ch. Darwin

LS

1
CD had requested a copy of Reade’s address, ‘On geological time’ (Reade 1876; see letter from T. M. Reade, 12 January 1877). CD’s copy is in the Darwin Pamphlet collection–CUL. Reade’s letter to CD has not been found.
2
Reade estimated the age of the earth at 526 million years, based on an analysis of the rates of erosion and sedimentation of the earth’s crust (Reade 1876, p. 233). For a discussion of Reade’s method of calculation, see Burchfield 1990, pp. 98–9.
3
Peter Guthrie Tait had estimated that the temperature of the earth’s crust increased by a degree for every 100 feet of descent, and concluded from this estimate that the earth had formed about ten million years ago (see P. G. Tait 1876, pp. 166–8, and Burchfield 1990, pp. 109–10). For a previous discussion of Tait and the age of the earth, see Correspondence vol. 17, letter to J. D. Hooker, 24 July [1869].

Please cite as “DCP-LETT-10836,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-10836