Royal Observatory Greenwich | S. E. | 1858 May 7
Dear Sir
I am much obliged to your explanation about the Aar Glacier1 and the trouble which you have taken in sending it. The matter is now quite clear.
In the subjects of regelation and viscosity or plasticity,2 it seems to me that there is no essential difference between you and Prof. Forbes: for I can hardly imagine viscosity except as a destruction and restoration of organization: so that, in my view, the regelation is not an opposition to Prof. Forbes’ viscosity, but is an explanation of its details, or of its modus operandi. But in the formation of the laminae of ice, your theories are entirely opposed.
I cannot tell very precisely the probable time of my journey to Switzerland: it depends partly on the time of my sons’ return from College.3 And I cannot well tell my course; it will depend partly on their tastes and partly on weather. But I will keep a watch for you, and should be delighted to fall in with you.
Probably I may start soon after the middle of June, entering I think by Geneva.4
I am, dear Sir, | Very faithfully yours | GB Airy
Professor Tyndall
RI MS JT/1/A/34
RI MS JT/1/TYP/1/23
your explanation about the Aar Glacier: letter missing, but surely Tyndall’s reply to letter 1517. For the Aar Glacier, see letter 1305, n. 2.
subjects of regelation and viscosity or plasticity: see letter 1306, n. 8 and n. 10.
my sons’ return from College: Wilfrid Airy (1836–1925), and Hubert Airy (1838–1903), both attended Trinity College at the University of Cambridge. The Easter (summer) term usually ended in early June. See J. A. Venn (ed.), Alumni Cantabridgienses Part II: From 1752 to 1900, 6 vols (Cambridge: Cambridge University Press, 1940), vol. 1, p. 21–2
Geneva: see letter 1293, n. 3.
Please cite as “Tyndall1518,” in Ɛpsilon: The John Tyndall Collection accessed on