Discusses papers by JC dealing with erosion. Comments on papers on the subject by J. B. Jukes, A. C. Ramsay, and William Whitaker. Formerly believed in power of the sea. Never fully realised the truth until reading JC’s papers.

Sends two papers; glad CD appreciates two he has already sent. Cannot send two others on glaciers (Philosophical Magazine, 1866 and 1867).

Comments on glaciers in North America.

Asks if glacial periods have occurred alternately in the Northern and Southern Hemispheres. Relevant to his glacial discoveries in South America: "it would have been an immense relief to my mind if I could have assumed … this". CD wishes to discuss subject in new edition of Origin [5th].

Sends abstract of his views on change of climate and a copy of a paper.

Glacial climates.

Argues for great age of earth before the Cambrian period. Opposes measuring age from secular cooling. Opposes Sir William Thomson. Lyell’s error on secular cooling.

Thanks for Moseley citation ["On the mechanical possibility of the descent of glaciers", Proc. R. Soc. Lond. 17 (1869): 202–8].

In Edinburgh he feels out of touch with latest developments.

Thanks for abstract of Moseley’s paper on motion of glaciers [see 6599]. Reading it convinced him that Tyndall’s received view is wrong. Has formed a new view, which he has sent to Philosophical Magazine [4th ser. 37 (1869): 201–6].

Thanks for presentation copy of Origin [5th ed.].

Clarifies his point on north and south glacial periods. Supports CD’s view that temperate plants will move up mountains during the alternation.