Dear Professor Tyndall,
I took the liberty of sending you a few days ago a paper of mine2 published in the Bib-univ on the nocturnal radiation of the earth—The latter part alone has any claims to novelty, consisting of some experiments I have made lately on the effects of nocturnal radiation on the lake of Geneva—I have made an extract of it in English & send it enclosed, in case you should think it worth inserting in the Philosophical Magazine.
I have to thank you for your paper3 on the absorption and radiation of heat by gases & vapours, which I received last week, & your more recent lecture4 on the Physical basis of solar Chemistry, which interested me much. The contents of the first paper I need hardly tell you I was already acquainted with since you were kind enough last year to show me some of your results at the Royal Institution.
We much regretted seeing nothing of you at Geneva on your return from the mountains. Your last expedition was most interesting, but as far as I could judge, full of danger. I have not heard that you attempted the Matterhorn, as you had an idea of doing last year, at least, if I understood you rightly, so I suppose you have thought better of it or put it off to another year.5
Believe me, dear Dr Tyndall | Yours ever truly | F Marcet
Geneva Novr. 30th. 1861
RI MS JT/1/M/49
François Marcet: (1803–83), Anglo-Swiss physicist.
a paper of mine: François Marcet, ‘Remarques sur un mémoire de Charles MARTINS relative à l’accroissement nocturne de la temperature avec la hateur danes les couches sur les effets du rayonnement nocturne au-dessus des grandes surfaces d’eau’, Bibliothèque Universelle: Archives des Sciences Physiques et Naturelles 12 (1861): 267–87. English extract published in Phil. Mag. 23 (1862), pp. 9–12.
your paper: Tyndall (1861).
your more recent lecture: John Tyndall’s lecture ‘On the Physical Basis of Solar Chemistry,’ delivered at the RI on Friday, 7 June 1861.
put it off to another year: Tyndall had contemplated climbing the Matterhorn in August but decided against it. The first successful ascent was in 1865. Tyndall made it to the summit in 1868. See Roland Jackson, The Ascent of John Tyndall (Oxford: Oxford University Press, 2018), pp. 224–40.
Please cite as “Tyndall1834,” in Ɛpsilon: The John Tyndall Collection accessed on