Paper, 'On a relation between the coefficient of the Thomson effect and certain other physical properties of metals' by Shelford Bidwell

Description

Bidwell writes: 'The magnitude and direction of the Thomson effect depend upon a coefficient which is always the same for the same metal, but varies with different metals. Professor Everett, in his “Units and Physical Constants,” p. 151, gives a table based upon Tait’s thermoelectric diagram (“Trans. R. S. E.,” vol. xxvii, p. 125), in which the thermoelectric values of a number of metals, referred to lead as zero, are given in the form α + βt,where β is a number which for a given metal is proportional to the tangent of the inclination of the line representing the metal in Tait’s diagram, and therefore to the coefficient of the Thomson effect. Since all the physical properties of a metal are to some extent affected by heat, it seemed probable that a connexion might be found to exist between certain of these properties and the Thomson effect. A short examination showed that, as a rule, the coefficient of the Thomson effect is positive in those metals which have a great specific electrical resistance and specific heat, and negative in those which are distinguished by a great coefficient of expansion. I therefore made several attempts to ascertain whether the Thomson coefficient might not be some definite function of the specific resistance, specific heat, and coefficient of expansion; and though I have not been perfectly successful, it appears from the subjoined table that there is a close relation between them.'

Annotations in pencil and ink.

Subject: Physics

Received 23 April 1884. Read 1 May 1884.

A version of this paper was published in volume 37 of the Proceedings of the Royal Society as 'On a relation between the coefficient of the Thomson effect and certain other physical properties of metals'.

Reference number

PP/5/3

Earliest possible date

1884

Physical description

Ink and graphite pencil on paper

Page extent

9 pages

Format

Manuscript