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magnetite

(Encyclopedia)magnetite măgˈnətīt [key], lustrous black, magnetic mineral, Fe3O4. It occurs in crystals of the cubic system, in masses, and as a loose sand. It is one of the important ores of iron (magnetic iro...

Glaisher, James

(Encyclopedia)Glaisher, James glāˈshər [key], 1809–1903, English meteorologist and balloonist, b. London. He served as superintendent of the department of meteorology and magnetism at Greenwich Observatory fro...

philosophy of science

(Encyclopedia)philosophy of science, branch of philosophy that emerged as an autonomous discipline in the 19th cent., especially through the work of Auguste Comte, J. S. Mill, and William Whewell. Several of the is...

Sloane, T(homas) O'Conor

(Encyclopedia)Sloane, T(homas) O'Conor, 1851–1940, American scientist, lecturer, writer, and periodical editor, Ph.D. Columbia, 1876. Sloane was a member of the editorial staff of the Scientific American, where h...

Van Vleck, John Hasbrouck

(Encyclopedia)Van Vleck, John Hasbrouck, 1899–1980, American physicist, b. Middletown, Conn., Ph.D. Harvard, 1922. As a professor at Harvard, Van Vleck developed fundamental theories on the quantum mechanics of m...

Langevin, Paul

(Encyclopedia)Langevin, Paul läNzhəvăNˈ [key], 1872–1946, French physicist and chemist. He was professor of experimental physics at the Collège de France from 1909 and at the École municipale de Physique e...

lightning rod

(Encyclopedia)lightning rod, a rod made of materials, especially metals, that are good conductors of electricity, which is mounted on top of a building or other structure and attached to the ground by a cable. By v...

Aepinus, Franz Ulrich Theodosius

(Encyclopedia)Aepinus, Franz Ulrich Theodosius fränts o͝olˈrĭkh tāˌōdōˈzēo͝os âpēˈno͝os [key], 1724–1802, German physicist. He studied at Jena and Rostock and taught mathematics at Rostock from 174...

Peregrinus, Petrus

(Encyclopedia)Peregrinus, Petrus (Peter the Pilgrim) pēˈtrəs pĕrəgrĭnˈəs [key], c.1220–?, medieval scholar and soldier. The tutor of Roger Bacon, he wrote the first important study of magnetism, Epistola ...

relay

(Encyclopedia)relay, electromechanical switch operated by a flow of electricity in one circuit and controlling the flow of electricity in another circuit. A relay consists basically of an electromagnet with a soft ...
 

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