The Telephone / An Account of the Phenomena of Electricity, Magnetism, and Sound, as Involved in Its Action

by A. E. Dolbear

6. The induction of a vibrating magnet upon an electric circuit.

7. The origination of electric waves in a circuit by a sounding magnet.

8. The discovery of the action of the air in a sounding organ-pipe.

9. Two or three methods for studying the vibrations of membranes.

10. Lissajous forks for enlarged projections of sound vibrations.

As soon, therefore, as I gave attention to the subject of telephony, I was able, with a few preliminary experiments, to determine the proper conditions for the transmission of speech in an electric circuit; and, without the slightest knowledge of the mechanism which Prof. Bell had used, I devised the following arrangement for a speaking-telephone.

FIG. 14.—MY FIRST SPEAKING TELEPHONE.