14th Nov. 1856
Dear Mr Sorby
You have every reason to think hardly of me for not replying to your last letter,1 but the fact is I mislaid it and after hunting for it many a time—hoping that chance also might assist in causing it to ‘turn up’—I have come to the resolution of saying to you that if you repeat your question I shall at once see Faraday upon the subject2 and obtain for you the information you require.
Believe me | most sinc[ere]ly yours | John Tyndall
With regard to the structure of the ice it was the hope that it was for me a case of cleavage that took me upon the glaciers.3 It is a difficult question,4 but I hope within the ensuing six weeks to let you know something of my notions (which are now quite unripe) upon the subject.5
Sheffield Archives SLPS/51/77 – 14 Nov 1856
your last letter: see letter 1275, Henry Sorby to John Tyndall, 1 September 1856, Tyndall Correspondence, vol. 5.
upon the subject: not identified.
a case of cleavage that took me upon the glaciers: see J. Tyndall, ‘Comparative View of the Cleavage of Crystals and Slate Rocks’, Phil. Mag., 12 (1856), pp. 35–48. Tyndall explained cleavage in rocks as occurring by the exertion of compression perpendicular to the cleavage planes (a mechanical model), and not because of crystalline (polar) forces.
a difficult question: beginning in the summer of 1856 Tyndall investigated the structure and movement of glaciers in the Alps and his explanation for glacial motion brought him into conflict with James Forbes and others. See letter 1306, n. 8 and n. 10; and J. Tyndall and T. H. Huxley, ‘On the Structure and Motion of Glaciers’, Phil. Trans., 147 (1857), pp. 327–46.
to let you know something of my notions… upon the subject: see letter 1344, n. 2.
Please cite as “Tyndall1295,” in Ɛpsilon: The John Tyndall Collection accessed on