XXV.—Thermo-Electric Diagram from −200° C. to 100° C., deduced from the observations of Professors Dewar and Fleming

Abstract

In 1895 Professors Dewar and Fleming made an extensive and careful series of observations connecting temperature and the thermo-electromotive force of some twenty metals compared with lead. The greatest care was taken in the preparation for, and in the conduct of, the experiments, and about thirty readings, at temperatures ranging over the 300° between the boiling point of oxygen and the boiling point of water, were recorded for each metal. A full description of the mode of experimenting, with the results for each metal, was published in the Philosophical Magazine, July 1895. In their discussion of the results a further examination of them was promised, but has not appeared. Professor Fleming, however, in a Friday Evening Discourse at the Royal Institution in 1896, indicated that the lines of thermo-electric power did not appear as straight lines although they were approximately so.