Heroes of the Telegraph

In 1837-8 Professor Page, of Massachusetts, had discovered that' a needle or thin bar of iron, placed in the hollow of a coil or bobbin of insulated wire, would emit an audible 'tick' at each interruption of a current, flowing in the coil, and that if these separate ticks followed each other fast enough, by a rapid interruption of the current, they would run together into a continuous hum, to which he gave the name of 'galvanic music.' The pitch of this note would correspond to the rate of interruption of the current. From these and other discoveries which had been made by Noad, Wertheim, Marrian, and others, Reis knew that if the current which had been interrupted by his vibrating diaphragm were conveyed to a distance by a metallic circuit, and there passed through a coil like that of Page, the iron needle would emit a note like that which had caused the oscillation of the transmitting diaphragm. Acting on this knowledge, he constructed a rude telephone. Dr. Messel informs us that his first transmitter consisted of the bung of a beer barrel hollowed out in imitation of the external ear. The cup or mouth-piece thus formed was closed by the skin of a German sausage to serve as a drum or diaphragm. To the back of this he fixed, with a drop of sealing-wax, a little strip of platinum, representing the hammer-bone, which made and broke the metallic circuit of the current as the membrane oscillated under the sounds which impinged against it. The current thus interrupted was conveyed by wires to the receiver, which consisted of a knitting-needle loosely surrounded by a coil of wire fastened to the breast of a violin as a sounding-board. When a musical note was struck near the bung, the drum vibrated in harmony with the pitch of the note, the platinum lever interrupted the metallic circuit of the current, which, after traversing the conducting wire, passed through the coil of the receiver, and made the needle hum the original tone. This primitive arrangement, we are told, astonished all who heard it. [It is now in the museum of the Reichs Post-Amt, Berlin.]