WEBER, W. (WILHELM) AND R. KOHLRAUSCH. - THE VELOCITY OF LIGHT.

Ueber die Elektricitätsmenge, welche bei galvanischen Strömen durch den Querschnitt der Kette fliest.

Leipzig, Johann Ambrosius Barth, 1867. Contemp. hcalf, raised bands, gilt spine with gilt lettering. A few scratches to binding. In "Annalen der Physik und Chemie. Hrsg.von Poggendorff", Bd. 99. (Entire volume offered). (2),X,652 pp. and 4 folded engraved plates. Weber & Kohlrausch's paper:pp. 10-25.

First appearance of this importent paper, the results of which Maxwell later used as a crucial support for his electromagnetical theory of light.

"...The velocity of light c were measured by W. Weber and R. Kohlrausch in 1855 (the paper offered). They used an electrometer to determine the charge of a condnsor in electrostatic units, and a ballistic galvanometer to measure the same charge in electrodynamic units. The resulting value for c was in good agreement with that obtained by Fizeau in 1849, and Maxwell accordingly felt entitled to identify light and electromagnetic vibrations. This conclusion recalls Newton's identification of gravity with universal attraction: it was not only because they obeyed the same formal law, but also because both led to the same mathematical results, that Newton saw fit to combine them."(Taton, Réne in "History of Sciencein The Nineteenth Century", p. 163).

Order-nr.: 43497