On the vibrations and tones produced by the contact of bodies having different temperature

The author introduces the subject of his paper by a brief description of the labours which have preceded his own, from the discovery of the phænomenon by Schwartz in 1805 to its revival and further examination by Trevelyan, Faraday, Forbes and Seebeck. The peculiar views of Prof. Forbes, who regards the effects as due to a new species of mechanical agency in heat, were the chief inducement to the resumption of the subject by the author. He examines the ground on which the theory of Prof. Forbes is based, and tests by experiment the general laws at which he has arrived.