zero of geographical ignorance of the reader; but I not knowing a single place, was occasionally rather plagued in tracing your course. Sometimes in the beginning of a chapter, in one paragraph your course was traced through a half dozen places; anyone, as ignorant as myself, if he could be found, would prefer such a disturbing paragraph left out. I cut your map loose, and I found that a great comfort; I could not follow your engraved track. I think in a second edition, interspaces here and there of one line open, would be an improvement. By the way, I take credit to myself in giving my Journal a less scientific air in having printed all names of species and genera in Romans; the printing looks, also, better. All the illustrations strike me as capital, and the map is an admirable volume in itself. If your 'Principles' had not met with such universal admiration, I should have feared there would have been too much geology in this for the general reader; certainly all that the most clear and light style could do, has been done. To myself the geology was an excellent, well-condensed, well-digested resume of all that has been made out in North America, and every geologist ought to be grateful to you. The summing up of the Niagara chapter appeared to me the grandest part; I was also deeply interested by your discussion on the origin of the Silurian formations. I have made scores of SCORES marking passages hereafter useful to me.
All the coal theory appeared to me very good; but it is no use going on enumerating in this manner. I wish there had been more Natural History; I liked ALL the scattered fragments. I have now given you an exact transcript of my thoughts, but they are hardly worth your reading...
CHARLES DARWIN TO C. LYELL. Down, August 25th [1845].
My dear Lyell,
This is literally the first day on which I have had any time to spare; and I will amuse myself by beginning a letter to you...