WCP4868

Letter (WCP4868.5269)

[1]

9, St. Mark’s Crescent N.W.

Dec[embe]r 5th. [1868]1

Dear Sir Charles

Thanks for the many interesting papers and the copy of the "Elements"2; — I think I have now all the materials necessary. I must read and digest a little more & then I shall be able to write straight on.

In the Phil[osophical]. Mag[azine].(1863)3 I have hit upon Prof. Challis'4 theory of the Sun’s heat, as being due to etherial5 vibrations excited by the stars— This is part of an [2] overwhelming mathematical theory of Gravitation[,] light[,] heat &c. worked out from atoms & ether. Have you ever heard Sir J[ohn]. Herschell6 [sic] or any other good authority speak of this as feasible, or at all generally accepted, — or even possible, — for it at once & completely answers Sir W[illiam]. Thomson’s7& Croll’s8limitation of Geolog[ical] time on account of loss of Suns’ heat. At all events if Prof. Challis [3] as a Mathematician & Physicist is at all on a par with Sir W. Thomson, it shows that the latter’s views are not so absolutely certain as Croll states.

Prof. Challis also has a theory of the Zodaical light, — also etherial.9 He says observations show that it extends beyond the earth’s orbit, & therefore can not be due to a crowd of meteors, — which it is supposed to be by Thomson & co. & to cause the Sun’s heat by continually falling in to line.

[4] How do the Physicists account for Gravitation? It is a constant force always doing work, in drawing the planets &c. out of their straight courses, & yet never diminishing? Ought they not to maintain that it too must come to an end?

The question of the temperature in periods of great excentricity seems very difficult. Supposing we were 1/5 nearer the sun in winter than in Summer, — our winter at but 500 — 550 would be spring no doubt; but would winter inside the polar circle be very much milder? Would the nearness of the sun make any difference during 2 — 3 — 4 — or 5 months night, — which would be the very time we were nearest? If not, all Croll’s arguments about perpetual spring at the pole fail.

Yours very faithfully | Alfred R. Wallace [signature]10

1
The year '1868' is written in pencil in an unknown hand.
2
Lyell, C. 1865. Elements of Geology. 6th edition. London: John Murray.
3
Challis, J. 1863. On the Source and Maintenance of the Sun's Heat. Philosophical Magazine. 25(170): 460-467.
4
Challis, James (1803-1882). British astronomer and physicist. Plumian Professor of Astronomy and Experimental Philosophy 1836-83; Director of the Cambridge Observatory 1836-61.
5
Archaic form of ethereal.
6
Herschel, John Frederick William (1792-1871). British mathematician and astronomer.
7
Thomson, William (1824-1907). First Baron Kelvin. British mathematician and physicist.
8
Croll, James (1821-1890). British geologist and climatologist. Developed a theory of climate change based on the earth’s orbit around the sun.
9
See Challis, J. A. 1863. Theory of the Zodiacal Light. Philosophical Magazine. 25(166,167): 117-125, 183-189.
10
The valediction and signature are written vertically in the left-hand margin of page 4.

Editorial information

Status: Edited (but not proofed) transcription [Letter (WCP4868.5269)]

For more information about the transcriptions and metadata, see https://wallaceletters.myspecies.info/content/epsilon

Revision history

Transcribed by Sloyan, Victoria [2013-01-15] Transcription checked by Catchpole, Caroline [2013-01-15] Transcription checked by Beros, Matt [2020-12-31]

Please cite as “WCP4868,” in Beccaloni, G. W. (ed.), Ɛpsilon: The Alfred Russel Wallace Collection accessed on 8 May 2024, https://epsilon.ac.uk/view/wallace/letters/WCP4868