arago babbage herschel barlow marsh (1 risultati)

Hardcover. Condizione: Very Good. BABBAGE, Herschel, Barlow & Marsh, and Christie on Arago's Rotations [BABBAGE, Herschel] "Expose des Recherches de Mm. Babbage, Herschell, Christie, Barlow et Marsh, sur le magnetise developpe par la rotations dans le fer d'autres metaux. (Extrait du Journ, of Sc. And Arts. no. 38 et de l'Edinburgh Philosophical Journal no. 25)" in "Bibliotheque Universelle, des Sciences." Geneva, Imprimerie Bibliotheque Universelle, 1825, volume 29, xv, 330pp, 1 folding chart, 2 folding engraved plates. Bound in paper covered boards, gilt stamped title on spine. Provenance: Staatsbibliothek, Berlin, and also from "Kong. Bergwerks Bibliothek", (Royal Mining Library) with their two small stamps on the title page. Ex-library: paper call number on bottom spine, and aside from these two bits there are no other markings. The binding is tight, the book strong and squared, and the text is very fresh and crisp. [++] In 1825, Arago made an important discovery related to the phenomenon of magnetism. Arago's rotations is an observable magnetic phenomenon that involves the interactions between a magnetized needle and a moving metal disk.--(DBPedia). He observed that when a non-magnetic metal or a non-magnetic plate is rotated above a magnetic substance (like a magnet or a current-carrying conductor), the rotation induces an electric current in the metal or plate. The effect was discovered by François Arago in 1824, though he had been working on it since 1822, and then demonstrating it before the Academie des Sciences in 1824 and publishing in 1825. Others had been working in this area at about the same time (including Gambrey in 1824 and Barlow & Marsh in 1825 (publishing in the Edinburgh Philosophical Journal for that year). At the time of their discovery, Arago's rotations were surprising effects that were difficult to explain. The phenomenon was closely studied including by those in 1825 writing the papers offered her though the explanation of the rotations wasn't sufficiently explained until the theory of electromagnetic induction was introduced by Michael Faraday in 1831.[++] "In 1820, elaborating on the work of H.C. Ørsted of Denmark, Arago showed that the passage of an electric current through a cylindrical spiral of copper wire caused it to attract iron filings as if it were a magnet and that the filings fell off when the current ceased. In 1824 he demonstrated that a rotating copper disk produced rotation in a magnetic needle suspended above it. Michael Faraday later proved these to be induction phenomena."(--Encyclopedia Britannica) [++] The Babbage/Herschel paper that is part of the basis of this paper (appearing in the original as "Account of the Repetition of M. Arago's Experiments on the Magnetism Manifested by Various Substances During the Act of Rotation" and originally published in "Philosophical Transactions", volume 115 (1825), pp. 467-496, appears here in Part I on pp 255-6. Babbage and Herschel performed an experiment involving a "copper plate in rotation on a vertical axis. We proceeded to try its effect on a magnetized needle suspended over it." which they did observe, causing a movement in the needle of 10 to 12 degrees." [++] The Christie appears in Part II, ("Experiments on the Magnetism produced by Rotation" in the original), pp 256-7. The Barlow and Marsh appears here in Part III, from their Account of the Repition of Arago on the Magnetism developed during the Act of Rotation, pp 257-264. The Christie section (Part IV) appeared in English as "Experiments on the Magnetism Produced by Rotation ", pp 265-7.