Zermatt.1 Thursday. | 12th. Aug. 1858
My dear Sir.
I am anxious to sink a number of minimum thermometers in the snow at the summit of Mont Blanc,2 in order to ascertain the minimum winter temperature at the top of the mountain. I have two thermometers with me, but for the sake of certainty I should like to have two or three more. Mine are of the ordinary construction; spirit3 with a moveable index within, which is drawn back on the contraction of the liquid. You would do me a very great favor if you would send to me to Chamouni4 two or three minimum thermometers of any construction which you might deem suitable for the observations; and if you would send them to me as soon as you can you would add to the obligation. I expect to be in Chamouni in about 10 days from the present time, and shall lose no time in ascending the mountain. I placed a thermometer at the summit of the Finsteraarhorn5 a few days ago, and the day before yesterday I boiled water at the top of Monte Rosa.6
Would you kindly favour me with a line addressed to me Poste Restante7 Visp8 Canton Valais,9 letting me know whether it is possible to obtain the thermometers in Geneva.10 They might be graduated between +40° and -40° Centigrade.
Believe me dear Sir | Ever yours most truly | John Tyndall
If the maker of the thermometers would enclose his account I would send him the amount immediately
RI MS JT/1/T/373
RI MS JT/1/TYP/1/357
Zermatt: see letter 1297, n. 7.
Mont Blanc: see letter 1320, n. 6.
spirit: an alcohol thermometer, an alternative to mercury-in-glass thermometers.
Chamouni: see letter 1353, n. 9.
Finsteraarhorn: see letter 1536, n. 27.
Monte Rosa: see letter 1478, n. 22.
Poste Restante: see letter 1293, n. 5.
Visp: a town in the Rhône valley in the Swiss canton of Valais.
Canton Valais: see letter 1537, n. 34.
Geneva: see letter 1293, n. 3.
Please cite as “Tyndall1543,” in Ɛpsilon: The John Tyndall Collection accessed on