‎"KIRCHHOFF, GUSTAVE ROBERT. - THE VELOCITY OF ELECTRICITY DETERMINED.‎
‎Ueber die Bewegung der Elektricität in Drähten.‎

‎Leipzig, Johann Ambrosius Barth, 1857. Without wrappers. In ""Annalen der Physik und Chemie. Hrsg. von J.C. Poggendorff"", Bd. 100, No 2 . Pp. 177-252 a. 1 plate. (Entire issue offered). Kirchhoff's paper: pp. 193-217. With titlepage to volume 100.‎

Reference : 45075

‎First printing of an importent papers on the theory of electricity in conductors, telegraph-cables etc., determining the velocity of the electrical propagation. He found that the propagation velocity of electricity to be ""very close to the velocity of light in empty space"".""The work of Thomson on signalling along cables was followed in 1857 (the paper offered) by a celebrated investigation by Kirchhoff's, on the propagation of electrical disturbance along a telegraph wire of circular cross-section. (Whittaker ""A History of the Theories of Aether and Electricity"", pp. 230 ff.).""The field was still open (the nature of the electric current) when Kirchhoff entered it in 1857 with his own general theory of the motion of electricity in conductors. His first paper, in which he treated linear conductors from the same premises as Weber, turned out to coincide in all essentials with an investigation carried out by Weber shortly before but delayed in publication. Both physicists noticed a remarkable implication of their theory: in a perfectly conducting circuit, oscillating currents could be propagated with a constant velocity, independent of the nature of the conductors, and numerically equal to the velocity of light. Both Kirchhoff and Weber, however, pointing to the extreme character of the condition of infinite conductivity, dismissed this result as a mere accidental coincidence.""(DSB)‎