Soc. Journ. iv., 1848, pages 315-323. (An extract from a letter to Lyell, 1847, is of interest in connection with this essay:--"Would you be so good (if you know it) as to put Maclaren's address on the enclosed letter and post it. It is chiefly to enquire in what paper he has described the Boulders on Arthur's Seat. Mr. D. Milne in the last Edinburgh 'New Phil. Journal' [1847], has a long paper on it. He says: 'Some glacialists have ventured to explain the transportation of boulders even in the situation of those now referred to, by imagining that they were transported on ice floes,' etc. He treats this view, and the scratching of rocks by icebergs, as almost absurd...he has finally stirred me up so, that (without you would answer him) I think I will send a paper in opposition to the same Journal. I can thus introduce some old remarks of mine, and some new, and will insist on your capital observations in N. America. It is a bore to stop one's work, but he has made me quite wroth.")
The article "Geology," in the Admiralty Manual of Scientific Enquiry (1849), pages 156-195. This was written in the spring of 1848.
"On British Fossil Lepadidae," 'Geol. Soc. Journ.' vi., 1850, pages 439- 440.
"Analogy of the structure of some Volcanic Rocks with that of Glaciers," 'Edin. Roy. Soc. Proc.' ii., 1851, pages 17-18.
Professor Geikie has been so good as to give me (in a letter dated November 1885) his impressions of my father's article in the 'Admiralty Manual.' He mentions the following points as characteristic of the work:--
"1. Great breadth of view. No one who had not practically studied and profoundly reflected on the questions discussed could have written it.
"2. The insight so remarkable in all that Mr. Darwin ever did. The way in which he points out lines of enquiry that would elucidate geological problems is eminently typical of him. Some of these lines have never yet been adequately followed; so with regard to them he was in advance of his time.
"3. Interesting and sympathetic treatment. The author at once puts his readers into harmony with him. He gives them enough of information to show how delightful the field is to which he invites them, and how much they might accomplish in it. There is a broad sketch of the subject which everybody can follow, and there is enough of detail to instruct and guide a beginner and start him on the right track.
"Of course, geology has made great strides since 1849, and the article, if written now, would need to take notice of other branches of inquiry, and to modify statements which are not now quite accurate; but most of the advice Mr. Darwin gives is as needful and valuable now as when it was given. It is curious to see with what unerring instinct he seems to have fastened on the principles that would stand the test of time."
In a letter to Lyell (1853) my father wrote, "I went up for a paper by the Arctic Dr. Sutherland, on ice action, read only in abstract, but I should think with much good matter. It was very pleasant to hear that it was written owing to the Admiralty Manual."
To give some idea of the retired life which now began for my father at Down, I have noted from his diary the short periods during which he was away from home between the autumn of 1842, when he came to Down, and the end of 1854.
1843 July.--Week at Maer and Shrewsbury. October.--Twelve days at Shrewsbury.
1844 April.--Week at Maer and Shrewsbury. July.--Twelve days at Shrewsbury.
1845 September 15.--Six weeks, "Shrewsbury, Lincolnshire, York, the Dean of Manchester, Waterton, Chatsworth."
1846 February.--Eleven days at Shrewsbury. July.--Ten days at Shrewsbury. September.--Ten days at Southampton, etc., for the British Association.
1847 February.--Twelve days at Shrewsbury. June.--Ten days at Oxford, etc., for the British Association. October.--Fortnight at Shrewsbury.
1848 May.--Fortnight at Shrewsbury. July.--Week at Swanage. October.--Fortnight at Shrewsbury. November.--Eleven days at Shrewsbury.