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Darwin Correspondence Project

From James Croll   17 August 1871


August 17th 1871

Dear Sir,

I am much obliged to you for your letter of 19th ult. which I received through Mr. Youmans.1

This gentleman wished me to write a small treatise on Geol. Time. But I explained to him, that in the present state of the question nothing satisfactory could be written on it, which would be of any service to general readers2   I believe he left satisfied that the better plan was to let this subject lie over, for some time to come.

I have been doing little for some time back, owing to pain in the head;3 but I expect to have a long paper in the Oct number of the Phil. Mag. on Dr Carpenter theory of Ocean Currents.4

I am | yours most sincerely | James Croll

Charles Darwin Esqre Ma. FRS.—


CD’s letter to Croll of 19 July [1871] was a letter of introduction for Edward Livingston Youmans, who was commissioning books for the International Scientific Series published by the Appleton publishing company of New York. CD’s son George had suggested Croll to Youmans as a possible author for a small monograph (see letter from G. H. Darwin, [17 July 1871]).
The question of the age of the earth had since the late 1860s been one of the most hotly debated topics in British science, involving not only Croll but such senior figures as William Thomson (later Lord Kelvin) and Charles Lyell. For an overview of Croll’s contributions to the debate, see Burchfield 1990, especially chapter 3. See letter from G. H. Darwin, [17 July 1871], n. 2.
Croll had suffered head pains since childhood. Their intensity increased sharply in 1871, requiring him to take intermittent leave from his work at the Geological Survey of Scotland (Irons 1896).
Croll refers to the second part of his paper on the physical causes of ocean currents (Croll 1870–4, pp. 241–80); it was published in the Philosophical Magazine in October 1871 as a response to William Benjamin Carpenter’s paper, ‘On the Gibraltar current, the Gulf Stream, and general oceanic circulation’ (Carpenter 1871).


Burchfield, Joe D. 1990. Lord Kelvin and the age of the earth. With a new afterword. Chicago and London: University of Chicago Press.

Carpenter, William Benjamin. 1871. On the Gibraltar current, the Gulf Stream, and the general oceanic circulation. [Read 9 January 1871.] Proceedings of the Royal Geographical Society 15: 54–91.

Croll, James. 1870–4. On ocean-currents.– Part I. Philosophical Magazine 4th ser. 39 (February 1870): 81–106; Part II. Philosophical Magazine 4th ser. 39 (March 1870): 180–94; Part III. Philosophical Magazine 4th ser. 40 (October 1870): 233–59; 42 (October 1871): 241–80; 47 (February 1874): 94–122, (March 1874): 168–90.

Irons, James Campbell. 1896. Autobiographical sketch of James Croll: with memoir of his life and work. London: E. Stanford.


Refused to write a treatise on geological time.

His paper on W. B. Carpenter’s theory of ocean currents is appearing soon.

Letter details

Letter no.
James Croll
Charles Robert Darwin
Sent from
Source of text
DAR 161: 266
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 7908,” accessed on 26 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 19