[f. ELECTRO- + MAGNET.] A piece of soft iron surrounded by a coil of wire, through which a current of electricity may be passed, rendering the iron temporarily magnetic.
1831. Amer. Jrnl. Sci., XX. 201. Account of a large Electro-Magnet.
1832. W. Sturgeon, in Phil. Mag., XI. 194. On Electro-magnets.
c. 1865. J. Wylde, in Circ. Sc., I. 250/2. A horse-shoe electro-magnet.
1879. G. Prescott, Sp. Telephone, Introd. p. ii. The first simple electro-magnet was made by Sturgeon [of Manchester].
Hence Electro-magnetic, -magnetical adjs., pertaining to electro-magnetism. Electro-magnetically adv., by means of electro-magnetism. Electro-magnetics, the science of electro-magnetism. Electro-magnetism, the phenomena of the production of magnetism by the electric current; also, the influence of a magnet on the electric current.
1823. J. Badcock, Dom. Amusem., 126. The electro-magnetic influence always increased with the number of the plates.
1879. G. Prescott, Sp. Telephone, Introd. p. ii. An electro-magnetic telegraph.
1823. J. Badcock, Dom. Amusem., 126. Electro-magnetical effects.
1881. Sir W. Thomson, in Nature, XXIV. 435/2. To transmit electro-magnetically the work of waterfalls.
1828. F. Watkins (title), A Popular Sketch of Electro-Magnetism.
1830. Sir J. Herschel, Stud. Nat. Phil., 94. Oërsted’s great discovery of electro-magnetism.
1879. G. Prescott, Sp. Telephone, 5. Reproducing tones by electro-magnetism.
