Paper, 'The relation between electric energy and radiation in the spectrum of incandescence lamps' by [William De Wiveleslie] Abney and [Edward Robert] Festing

Description

The authors write: 'In the “Philosophical Magazine” for September, 1883, we showed that certain relations existed between potential, current, watts (volt-ampères), and radiation in incandescence lamps, and that if p = the potential, c = current, w = watts, R = radiation, and a and b were constants, then (i) c = ap + bp^(3/2), and consequently that (ii) w = p^2(a + bp^½) ; further we showed that after the carbon filaments attained a certain heat, the radiation varied directly as the energy. (iii) R [is inversely proportional to] (w — m) where m is a constant. We may incidentally mention that this relationship appears to hold good in a properly exhausted lamp, be the filament of carbon or of platinum, or presumably of other metals. In this case the sign in the left hand members of equations (i) and (ii) is changed. On laying down graphically the curve obtained by using the watts as the abscissae and the radiation as ordinates, it was at once evident that the straight part is an asymptote to a curve having its origin at 0. It might, therefore, be presumed that each individual ray should increase in intensity in somewhat the same manner when the energy in the filament was increased, i. e., in some simple curve which would have an asymptote.'

Annotations in pencil and ink. Includes four pages of diagrams and graphs and a photograph of a thermopile.

Subject: Physics

Received 6 June 1884. Read 19 June 1884.

A version of this paper was published in volume 37 of the Proceedings of the Royal Society as 'The relation between electric energy and radiation in the spectrum of incandescence lamps'.

Reference number

PP/5/17

Earliest possible date

1884

Physical description

Ink and graphite pencil on paper

Page extent

22 pages

Format

Manuscript
Diagram
Photograph