‎"JOULE, JAMES PRESCOTT. - THE MECHANICAL EQUIVALENT OF HEAT.‎
‎Ueber die mechanische Wärme-Aequivalent.‎

‎Leipzig, Johann Ambrosius Barth, 1854. Conemp. hcalf. 5 raised bands, gilt spine and gilt lettering to spine. A few scratches to spine. Light wear to spine ends. A small nick to top of spine. Small stamp on verso of first -and general- titlepage and small stamps to verso of plates. In: ""Annalen der Physik und Chemie. Hrsg. von J.C. Poggendorff"", Ergänzungsband IV. VIII,632 pp. and 2 folded engraved plates. Joule's paper: pp. 601-632. Internally celan and fine.‎

Reference : 43531

‎First German edition of one of the most importent papers in 1900th century physics, and the culmination of Joule's work. The offered paper is a translation of Joule's great memoir ""On the Mechanical equivalent of Heat"", published 1850, and one of the founding papers of the principle of ""The conservation of energy"", - Joule here gave the experimental proof of the conservation law.""Joule was not the first to determine the mechanical equivalent of heat. Rumford had attempted it but had come out with a value that was far too high. Mayer produced a fairly good value before Joule did, but it was Joule who was most accurate (up to his time), who backed up his figure with a large variety of careful experimental data, and who /with Thomson's help) forced the view on the world of science. He therefore gets the credit, and in his honour a unit of work, equal to 10,000,000 ergs, is called the Joule.""(Asimov). - Dibner, Heralds of Science No.158 (the 1843 paper).Joule's first measurement of the mechanical equivalent of heat was published...in 1843. It was made by comparing the heat generated by the current of a magnetoelectric machine with the excess of work which was used in turning the machine when the circuit was closed above that used when it was open....In the following papers in which the mechanical equivalent was measured in different ways we find the same elaborate description of the experiments and a brief statement of the final results. This is particularly true of the GREAT MEMOIR OF 1850 IN WHICH JOULE'S WORK CULMINATED. (Magie ""Source Book in Physics"" p. 203).The volume contains further STOKES, G.G.: ""Ueber die Veränderung der Brechbarkeit des Lichts."" Pp. 177-345 in first German edition.‎