Scarboro’ | 3 Belvoir Terrace | June 4. 60
My dear Sir,
I brought with me here the concluding sheets of your work,1 and found in them much pleasant reading during my journey. I have made no correction, I think, except the substitution of the word ‘oval’ for ‘ellipse’, a change of very minor importance; but though every ellipse is an oval, very few ovals, you know, are ellipses. I think your general statements respecting the structure of glaciers, and of the evidence on which your views rest, extremely clearly put and perfectly comprehensible to any reader of ordinary intelligence. Forbes’s theory of the veined structure2 is unquestionably wrong, and it is impossible for him to either wiggle out of it, or to twist it into any admissible form. He can have no right however to make the slightest complaint of any thing you have said. My impression is in fact that, throughout the whole of your paper on glaciers, you have dealt out the soft solder rather too freely to him. But if an error at all it was assuredly on the right side.
On thinking over your whole work, two omissions occur to me, one of which I ought to have mentioned when I wrote last,3 if I am correct in supposing that the point I allude to is omitted. According to Forbes’s observations on the extremity of one of Chamouni4 glaciers, it appeared that the sliding motion of the surface of the glacier was about one half of the whole motion of the surface of the mass; and a similar result is deducible (or pretty nearly so) from your own observations on the flank of the Mer de Glace. It is just as important therefore to explain how such uniform sliding takes place over the inclined bed of the glacier, as to explain that part of the motion which may be due to the structure and change of form of the glacial mass, or any other cause. Forbes in the first edition of his ‘Travels’5 laid great stress (and some others did at the time) on the difficulty of explaining a uniform, instead of an accelerated, motion down the incline plane of the glacial valley. I believe no one has ventured to express a doubt of my own explanation6 being entirely correct. But in the discussions of glacial motion scarcely any one has ever alluded to it. You have I know distinctly recognised the fact of all glaciers sliding, but I don’t recollect your mention of the explanation I alluded to. However I will not abuse you for the omission, though, should I ever review your book, I must of course correct it.
The other omission I allude to is the explanation which Prof. William Thomson7 gave of the formation of the aqueous strata of liquefied ice, due to the action of pressure in a direction perpendicular to those strata. I recollect its appearing in the Proceedings of the Royal Society,8 and I suppose the explanation due to him, though you have not I think mentioned his name in connection with it. But you will know better than myself what claim he has to such mention. Still I would recommend your giving him whatever he may have just claim to, because of circumstances and associations will naturally tend to place him more or less in the faction opposed to you.
I mentioned to you before that I thought you had said more about light, heat &c than your subject called for. But I object to your ‘Conclusion’9 far more decidedly, as altogether irrelevant to the general purpose of your book. It is not that I object to your views as expressed in it, for you may see in the ‘Fraser’ of this month10 I have expressed very similar views, and the subject is one of great interest and importance at this particular moment; but what, it will be asked, has it do with ‘The Glaciers of the Alps’? You must recollect that your book will have its strong opponents, and you may depend upon it they will not fail to designate your ‘Conclusion’ as altogether mal apropos and introduced for a bit of display, an accusation which, as an earnest and truth-seeking philosopher, I know you would heartily detest. If you wish to express your views publically on the extent to which the applicability of physical research may be legitimate, why not do it independently, and in some way in which you might give it more of that development which so grave a subject demands? But I have said enough, and would not have said half so much, had I not felt sure that the criticism will be taken in good part. Still don’t, I pray you, depend solely upon my judgment, I may be over fastidious on such points. Consult some other friend on the subject, and then judge for yourself.
Believe me | Yours very truly | W. Hopkins.
I send the Review11 by the same post as this letter.
RI MS JT/1/TYP/2/617–19
LT Transcript Only
your work: Glaciers of the Alps, see also letter 1595, n. 4.
Forbes’s theory of the veined structure: Forbes had originally proposed that the veins were small fissures formed in the ice by its motion, that these were filled with the water of the melted ice in summer, which froze in winter so as to form the blue veins (J. D. Forbes, Travels through the Alps of Savoy, p. 377 (see letter 1594, n. 13). He retracted this theory in his ‘Thirteenth Letter’ (J. D. Forbes, Occasional Papers on the Theory of Glaciers, pp. 187–205. This letter was originally published in the Edinburgh New Philosophical Journal, January 1847 as J. D. Forbes, ‘Thirteenth Letter on Glaciers; addressed to Professor Jameson’, Edinburgh New Philosophical Journal, 42 (1847), pp. 136–54; see letter 1620, n. 4). Tyndall was unaware of it when he wrote his first paper on glaciers with Huxley, but believed Forbes had substituted an equally incorrect explanation: see Glaciers of the Alps, p. 380.
when I wrote last: letter 1708.
Chamouni: see letter 1633, n. 2.
‘Travels’: see n. 2.
my own explanation: Hopkins gave his explanation of the importance and mechanism of the sliding of glaciers, and of glacier properties overall, in a later extensive paper: W. Hopkins, ‘On the Theory of the Motion of Glaciers’, Phil. Trans., 152 (1862), pp. 677–745.
Prof. William Thomson: Hopkins appears to be mistaken, as the paper was by William Thomson’s brother James Thomson (1822–92), Professor of Engineering at Queen’s College, Belfast. See n. 8.
in the Proceedings of the Royal Society: J. Thomson, ‘On Recent Theories and Experiments Regarding Ice at or near Its Melting-Point’, Roy. Soc. Proc., 10 (1859), pp. 151–60.
your ‘Conclusion’: Tyndall had originally intended to include in Glaciers of the Alps a section stating his ‘materialist’ position that the visible phenomena of life could be reduced to mechanical attractions and repulsions; i.e. that the processes of life (though not its meaning and purpose) could be explained solely in terms of natural philosophy. This would have been seen by many as highly controversial, and an assault on religion and theology. Tyndall published his views, anonymously, in the Saturday Review just as he left for the Alps: ‘Physics and Metaphysics’, Saturday Review, (4 August 1860), pp. 140–1.
the ‘Fraser’ of this month: W. Hopkins, ‘Physical theories of the Phenomena of Life. Part I’, Fraser’s Magazine, (June 1860), pp. 739–52. See also letter 1703, n. 4 and n. 5.
the Review: see n. 10.
Please cite as “Tyndall1709,” in Ɛpsilon: The John Tyndall Collection accessed on