Writes concerning CD’s "geometrico-geological problem". Attempts to square some of CD’s observations with certain geometrical theories concerning geological elevation.

CD brought some plants in spirits from Tierra del Fuego. Did JDH see them?

Problems of explaining formation of coalfields. Comments on recent work on coal formation.

Responds to LH’s comments on South America.

Thinks it unsound to designate a geological epoch after man. Doubts people’s confidence in date of man’s introduction.

Criticises A. D. d’Orbigny’s theory of elevation of the Cordillera.

Lists sections of South America of special interest.

Discussion of CD’s geological problem, relating to elevation of laminated beds around a rising granitic ridge.

Returns letter from CD to J. L. Stokes [see 940 and 1030].

Acknowledges receipt of draft. When does JH want the money for the new farmhouse? Bankers are Robarts, Curtis & Co. JH to pay them the rent directly.

ACVDdO asks CD to assist him in finding correspondents willing to provide British fossil shells for his proposed work, Paléontologie universelle, in exchange for parts of ACVDdO’s palaeontological works.

Variation in Mollusca.

Arrangements for publishing [South America].

B. J. Sulivan has just arrived with fossil bones from Patagonia. Wants to arrange meeting.

Does not remember where specimens came from. CD picked fossils most likely to contain Infusoria. Discusses composition of Tertiary strata of South America from which they came. Questions WCW’s statement that they contained siliceous matter.

Regrets he cannot visit JDH.

Has been talking with Lyell about coal, which he finds utterly perplexing.

Is delighted with the generalisations in latest numbers of Flora Antarctica.

Is slaving at South America – ¾ finished.

Has discovered geologists never read each other’s works – "the only object in writing a book is a proof of earnestness … Geology is at present very oral".

Has completed descriptions of S. American fossil shells [for South America]. Proposes to name a Nautilus after A. D. d’Orbigny.

Comments on forthcoming edition [7th (1847)] of CL’s Principles. Mentions other books relevant to CL’s needs by Hooker, H. G. Bronn, Edward Forbes, and J. G. Kölreuter. Discusses his own books on volcanoes and the geology of S. America.

Mentions expected visit to Down by the Lyells.

Thanks RM for "Dynamics of earthquakes" [Trans. R. Irish Acad. 21 (1848): 50–106]. It has cleared up his ideas on undulations. Now wishes he had said nothing about them in Journal of researches. Sends his paper ["Certain volcanic phenomena in S. America", Collected papers 1: 53–86]. Wishes RM would investigate Chile. Speculates whether earthquakes coincide with moon or tides.

Discusses proposed survey of Glen Roy. Mentions Glen Roy theories of Agassiz and William Buckland. Includes a memorandum calling for a careful survey of the parallel roads of Glen Roy. Mentions M. A. Bravais ["On the lines of ancient level of the sea in Finmark", Q. J. Geol. Soc. Lond. 1 (1845): 534].

Has done Edmondston’s Galapagos plants.

Dispute between Edward Forbes and H. C. Watson.

Returns corrected proof of his descriptions of S. American fossil shells [South America, appendix].

Has nearly finished South America.

Pleased to hear JDH has worked out identical and representative species of N. Temperate and Antarctic regions.

Geoffroy Saint Hilaire’s "loi du balancement" as applied to plants.

CD jaded by, but has nearly completed, South America.