Scientific amusements . Mode of using the Telephone. the binding screws. In front of the magnet is a thincircular iron plate, in which is the mouthpiece. Thedrawings will explain the instrument. Mr. Edison also invented a Telephone like Grays, andmade the discovery, that when properly prepared, carbon?would change its resistance with pressure, and that theratio of these changes corresponded with the solved the problem of the production of carbon is placed between two plates of platinumconnected in the circuit and near the diaphragm, and 186 SOUND. the carbon receives t
Scientific amusements . Mode of using the Telephone. the binding screws. In front of the magnet is a thincircular iron plate, in which is the mouthpiece. Thedrawings will explain the instrument. Mr. Edison also invented a Telephone like Grays, andmade the discovery, that when properly prepared, carbon?would change its resistance with pressure, and that theratio of these changes corresponded with the solved the problem of the production of carbon is placed between two plates of platinumconnected in the circuit and near the diaphragm, and 186 SOUND. the carbon receives the pressure from it by means of Q Wheii we come to MAGNETISM and Electricity wemay have something more to say respecting the mysteriesof the Teliiphone and its later developments. At present THE PHONOGRAPH. 187 we are only concerned with it as a sound conveyer, and itanswers its purpose admirably, although somewhat liable toattract other sounds or vibrations from neighbouring wires. The Phonograph, a mechanical invention of Mr. Edison,does not make use of electricity, although the vibratorymotion of the diaphragm is utilized. It, in a simple form,consists of a diaphragm so arranged as to operate upon asmall stylus placed just opposite and below the centre,and a brass cylinder, six or eight inches long, by threeor four in diameter, mounted upon a horizontal axis,extending each way beyond its ends for a distance aboutits own length. A spiral groove is cut in the circumference of thecylinder, from one end to the other, each spiral of thegroove being separated from its neighbour by about one-tenth of an inch. The shaft
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Keywords: ., bookcentury1800, bookdecade189, booksubjectscientificrecreations
