With the highest consideration, I am, Monsieur le Baron, your well-affectionate, CHRISTIAN R. 82. JOHN HERSCHEL TO HUMBOLDT. COLLINGWOOD, _21st Dec. 1843_. HAWKHURST, KENT. MY DEAR BARON: It is now a considerable time since I received your valued and most interesting work on Central Asia, which I should have long ago acknowledged, but that I was unwilling, and indeed unable, in proper terms to thank you for so flattering and pleasing a mark of your attention, till I had made myself at least in some degree acquainted with the contents. This, however, the continued pressure of occupations which leave me little time and liberty for reading has not yet allowed me to do otherwise than partially—and, in fact, it is a work of such close research that I despair of ever being able fully to master all its details. In consequence I have hitherto limited myself chiefly to the climatological researches in the third volume, and especially to the memoir on the causes of the flexures of the isothermal lines, which I have read with the greatest interest and which appear to me to contain by far the most complete and masterly coup-d’œil of that important subject which I have ever met with. In reading this and other parts of your work on this subject, and of the “Physique du globe” in all its departments—that which strikes me with astonishment is the perfect familiarity and freshness of recollection of every detail, which seems to confer on you in some degree the attribute of ubiquity on the surface of this our planet—so vividly present does the picture of its various regions seem to be in your imagination, and so completely do you succeed in making it so to that of your readers. The account of the auriferous and platiniferous deposits in the Ural and the zone in 56 lat. has also very much interested me, as well as the curious facts respecting the distribution of the Grecian germs in those regions. I could not forbear translating and sending to the “Athenæum” (the best of our literary and scientific periodicals) the singular account of the “monstre” of Taschkow Targanka—(citing of course your work as the source of the history)—in vol. III. p. 597. The idea of availing ourselves of the information contained in the works of Chinese geographers, for the purpose of improving our geographical knowledge of Central Asia, appears to me as happy as it is likely to prove fertile; especially now that the literature of that singular country is becoming more accessible daily by the importation of Chinese books. What you have stated respecting the magnetic chariots and hodometers of the Emperor Tching-wang—if you can entirely rely on your authority—gives a far higher idea of the ancient civilization of China than any other fact which has yet been produced.