Charles Babbage to Faraday   20 January 1837

Dear Faraday

I do not recollect whether I pointed out to you one of the consequences namely a species of radiation which seems to result from almost any law in which there is one central atom attracting an atmosphere of minor atoms each of which repels all its kindred¹

Let A be the central and let it be surrounded by an atmosphere and let the circle be its limit. Then whatever be the law if any atom of the atmosphere gets beyond the circle or rather spherical superficies then it will go off in a right line in consequence of the repulsion of all its neighbours being greater than the attraction of its central. Now if in any direction K for instance a line of atmo‑spheric atoms are driven against the central and its atmosphere - those moving atoms must displace the quiescent ones in consequence of their momentum. They will therefore push some of the supercial [sic] ones a little beyond the limits of the atom, and consequently there will go on a continued radiation from all parts of its surface except the point at which the new ones enter. Thus it would appear that the radiation of perhaps to us imponderable matter would result from a multitude of laws besides that of the inverse square. If we conceive more than one body each will radiate in all directions and if through every point of space such lines of atoms passed then it is Le Sage's² theory of gravity³. I almost fear I cannot hear you tomorrow⁴ as I am so occupied if I do it will be incog[nito] in the gallery[.]

I scarcely remember what Plana's⁵ letter⁶ said but will trust you not to read any part which might appear to an English audience exag[g]erated[.]

Very Truly Yours | C. Babbage

2AM. 20 Jan 1837

P.S. Of course such central atoms must have as large atm[ospher]es as they are capable of retaining before radiation commences.

Address: M. Faraday Esq | Royal Institution | Albemarle Street