File:Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous (14803330463).jpg

Identifier: triumphswonderso01boyd (find matches)
Title: Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress ..
Year: 1899 (1890s)
Authors: Boyd, James Penny, 1836-1910
Subjects: Progress Inventions
Publisher: Philadelphia, Pa., A. J. Holman & Co
Contributing Library: The Library of Congress
Digitizing Sponsor: Sloan Foundation

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e, called the helix, the iron core becomes magnetized,and has all the power of a permanent magnet. But as soon as the electriccurrent ceases, the magnetic power of the core is lost. Hence it is called anelectro-magnet, or a temporary magnet, to distinguish it from a permanentmagnet. While the discovery of the electro-magnet was very important in therespect that it afforded great magnetic power by the use of a limited or eco-nomic galvanic force, or, in other words, by the use of smaller and fewerVoltaic batteries, it was not until Faraday began his splendid series of elec-trical discoveries, in 1831, that a new and exhaustless wellspring of electri-city was found to lay at the door of science. Faradays prime discovery wasI that of the induction of electric currents, or, in other words, of manufacturing electricity directly from mag-netism. He began his experiments with what becameknown as an induction coil, which, though then crudein his hands, is the same in principle to-day. It con-
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INDUCTION COIL. 26 TRIUMPHS AND WONDERS OF THE XIX™ CENTURY sists of an iron core wrapped with two coils of insulated wire. One coil is ofvery lengthy, thin wire, and is called the secondary coil. The other is ofshort, thick wire, and is called the primary. When a magnetic current ispassed through the primary coil, with frequent makes and breaks, it inducesan alternating current of very high tension in the secondary coil, thus power-fully increasing its effects. In Faradays further study of electric induction, he showed that when a conductorcarrying a current was brought nearto a second conductor it induced orset up a current in this second. Somagnets were found to have a sim-ilar effect upon one another. The secret of these phenomenawas found to lie in the fact that amagnet, or a conductor carrying acurrent, was the centre of a field offorce of very considerable extent.Such a field of force can be famil-iarly shown by placing a piece ofglass or white paper sprinkled withfine iron f

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