Royal Observatory Greenwich | S. E. | 1858 May 3
My dear Sir
I have been reading with great interest your paper about Glaciers.1 I would beg leave to ask you one question upon it: not I hope quite idly, as I have had some castle-in-the-air ideas of visiting the Grimsel2 this year: to which place I have not been for nearly 30 years.
Philos. Mag. 1858 May.
Page 380. From this reasoning I conclude that in the ordinary conditions of a glacier and excepting the near approach to a cataract, the laminae at the middle are transverse to the valley.
Page 383, diagram & p. 384: it would seem from these that the laminae at the middle are longitudinal, not only a little below A where the squeeze of the interfering glaciers is sufficiently obvious, but also towards RS3 where the glacier must have long since, assumed its normal conditions as a single ice-stream.
Am I correct in either of these interpretations? and if in both, how are they reconciled?
I am, my dear Sir, | Yours very faithfully | GB Airy
Professor Tyndall
RI MS JT/1/A/33
RI MS JT/1/TYP/1/23
your paper about Glaciers: J. Tyndall and T. H. Huxley, ‘On the Structure and Motion of Glaciers’, Phil. Mag., 15 (1858), pp. 365–88. This is a reprint of the original article in Phil. Trans., which was published in the May edition.
Grimsel: the mountain pass separating the upper valley of the river Aare from the upper valley of the Rhône.
RS: on a diagram in ‘On the Structure and Motion of Glaciers’ (see n. 1), the line between points R and S on a glacier experiment Tyndall had performed that represent a point past when two merging glaciers have formed a single glacier.
Please cite as “Tyndall1517,” in Ɛpsilon: The John Tyndall Collection accessed on