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.

Acknowledges receipt of book and manuscript.

Apologises for having kept JC’s book so long; would like to keep it about ten days more.

Returns book with thanks. "Joyfully accepts" idea of the warming of Southern Hemisphere during glacial period in the Northern. Lyell is unwilling.

Mentions H. N. Moseley’s study of descent of glaciers [Proc. R. Soc. Lond. 17 (1869): 202–8].

CD greatly troubled by problem of age of the earth and calculations of Sir William Thomson. Asks about changes in the form of the globe.

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.

Consoling to CD that JC gives "a little more age to the world".

Cites article by Henry Moseley ["On the mechanical possibility of the descent of glaciers", Proc. R. Soc. Lond. 17 (1869): 202–8].

Mentions article by A. R. Clarke on shape of the globe.

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 JC for his proofs of article on the movement of glaciers.

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.

In response to comments in a paper by JC, JH writes to establish his priority with respect to the significance of the revolution of the apsides of the earth's orbit and the eccentricity of the earth's orbit in affecting temperatures on the earth. JH had spelled this out in an 1830 paper for the Transactions of the Geological Society, and repeated it in his Outlines Astr.

Thanks JC for his paper on the 'Influence of the Tidal Wave on the Moon's Motion.' Expresses disagreement with a number of aspects of JC's argument.

Thanks JC for his papers on 'ice-cap and eccentricities [of planets].' Comments on the papers, noting the interactions between geology and astronomy.

Sending his paper on the causes of change of climate, and would be glad of JH's comments and opinion on its worth.

Thanks for his letter concerning his own paper on the changes in climate. Points out parts where JH seems to have been mistaken in his views as expressed.

Thanks for his letter and comments. Is always pleased to have any omission pointed out. Comments on his theories of the changing of the climates.

Gives various references in answer to JH's queries. Further regarding climatic changes.