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.[1]
Another of his early transmitters was a rough model of the human ear, carved in oak, and provided with a drum which actuated a bent and pivoted lever of platinum, making it open and close a springy contact of platinum foil in the metallic circuit of the current. He devised some ten or twelve different forms, each an improvement on its predecessors, which transmitted music fairly well, and even a word or two of speech with more or less perfection. But the apparatus failed as a practical means of talking to a distance.
- ↑ It is now in the museum of the Reichs Post-Amt, Berlin.
