Telephone

(tel'e-fon.)n. [Gr. tēle, afar, phone, sound.] A mechanical contrivance, used in connection with the electric telegraph, whereby sound produced at one end ofa wire is conducted to the other extremity and there reproduced. The currents are caused by the sound striking against a diaphragm, and the intensity greatly augmented by the introduction of a piece of prepared carbon within the circuit. All T. employ a diaphragm at the receiving end capable of responding to the acoustic vibrations caused by the sound; all employ a diaphragm at the receiving end capable of being thrown into vibrations by the action of the electric current, corresponding to the vibrations of the transmitting diaphragm, and all depend for their action upon undulating electric currents. To follow out this brief description of the principle of the working of the T., the reader is referred to The Speaking T. and Other Electric [s. 981]