Rensselaer Union, Volume 9, Number 27, Rensselaer, Jasper County, 22 March 1877 — How the Telepnone Operates. [ARTICLE]

How the Telepnone Operates.

As the telephone, the new invention, of Prof. A. Gr&li&m Bell, is but little understood, the fdllowing reprint of-a description and explanation of the instrument may not be amiss: The telephone in its present form consists of a powerful compound, permanent magnet, to the poles of which are attached ordinary telegraph coils of insulated wire. In front of the poles, surrounded by these coils of wire, is placed a diaphragm of iron. A mouthpiece to converge the sound upon this diaphragm substantially completes the arrangement. The motion of steel or iron in front of the poles of a magnet creates a current of electricity in coils surrounding the poles of the magnet, and in the duration of this current of electricity coincides with the duration of the motion of the steel or iron moved or vibrated in the proximity of the magnet. When the human voice causes the diaphragm to vibrate, electrical undulations are induced in the coils environing the magnets precisely analogous to the undulations of the air produced by that voice. These coils are connected with the line wire, which may be of any length, provideo the insulation be good. Tne undulations which are induced in these coils travel through the line wire, and, passing through the coils of an instrument of precisely similar construction at the distant station, are again resolved into air undulations by the diaphragm of this instrument—Boston Commercial Bulletin.