To Daniel Mackintosh 9 October 1879
Down | Beckenham Kent
Oct 9/79.
Dear Sir.
I hope that you will allow me to have the pleasure of thanking you for the very great pleasure which I have derived from just reading your paper on erratic blocks— The Map is wonderful. & what labour each of those lines show!1 I have thought for some years that the agency of floating ice, which nearly a century ago was overrated, has of late been underrated—2 You are the sole man who has ever noticed the distinction suggested by me between flat or planed scored rocks & mamillated scored rocks.—3
I do not think that I ever published any notice on the Ashley Heath Boulder—nor can I tell where to look for my memoranda of its size, when I had the ground excavated on one side & partly beneath it—but I remember that the hole was deep.—4 The block rested on rounded lumps of new Red Sandstone about as big as a child’s or man’s head; & one of these had been split into two halves & was deeply-scored, though the scores were short. I thought at the time that the boulder had fallen off floating ice, & had crushed & scored the block If it had fallen through the air so soft a rock would have been crushed into powder—
with great admiration for your paper | I remain dear Sir. | Yours faithfully | Ch Darwin.
Footnotes
Bibliography
Agassiz, Louis. 1837. Upon glaciers, moraines, and erratic blocks; being the address delivered at the opening of the Helvetic Natural History Society, at Neuchâtel, on the 24th of July 1837. Edinburgh New Philosophical Journal 24 (1837–8): 364–83.
‘Ancient glaciers of Caernarvonshire’: Notes on the effects produced by the ancient glaciers of Caernarvonshire, and on the boulders transported by floating ice. By Charles Darwin. Philosophical Magazine 3d ser. 21 (1842): 180–8. [Shorter publications, pp. 140–7.]
Lyell, Charles. 1830–3. Principles of geology, being an attempt to explain the former changes of the earth’s surface, by reference to causes now in operation. 3 vols. London: John Murray.
Mackintosh, Daniel. 1879. Results of a systematic survey, in 1878, of the directions and limits of dispersion, mode of occurrence, and relation to drift-deposits of the erratic blocks or boulders of the West of England and east of Wales, including a revision of many years’ previous observations. [Read 26 March 1879.] Quarterly Journal of the Geological Society of London 35: 425–55.
Mills, William. 1983. Darwin and the iceberg theory. Notes and Records of the Royal Society 38: 109–27.
Rudwick, Martin John Spencer. 1969. The glacial theory. History of Science 8: 136–57.
Summary
Comments on DM’s ["Drift deposits of west of England", Q. J. Geol. Soc. Lond. 35 (1879): 425–55].
Letter details
- Letter no.
- DCP-LETT-12252
- From
- Charles Robert Darwin
- To
- Daniel Mackintosh
- Sent from
- Down
- Source of text
- DAR 146: 333
- Physical description
- C 2pp
Please cite as
Darwin Correspondence Project, “Letter no. 12252,” accessed on 23 April 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-12252.xml