"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. 1849 March to June.--Sixteen weeks at Malvern. September.--Eleven days at Birmingham for the British Association. 1850 June.--Week at Malvern. August.--Week at Leith Hill, the house of a relative. October.--Week at the house of another relative. 1851 March.--Week at Malvern. April.--Nine days at Malvern. July.--Twelve days in London.