VI. On the practical measurement of temperature: Experiments made at the Cavendish laboratory, Cambridge

In view of the enormous discrepancies at present existing in estimates of high temperatures, it is exceedingly desirable that strictly comparable thermometric standards should be issued by some recognised authority. Professor J. J. Thomson, in the course of a conversation which I had with him towards the close of 1885, suggested th at such standards could be issued in the form of platinum wire, the change of electrical resistance with temperature being determined by comparison for each specimen before issuing. The object of the present investigation was to test whether, in spite of the B. A. report on the Siemens pyrometer (1874), pure platinum wire might not be possessed of the necessary qualifications for such a standard.