DIAPASON REGULATOR. The French, who give the name of diapason to the tuning fork, have lately made attempts to use that instrument in connection with clockwork, partly as a means of counting very small intervals of time. ' M. Duhamel made an arrangement in which a cylinder, by means of a screw-tapped end, was made to advance a little in the direction of the axis; this cylinder was covered with blackened paper, and was rotated by means of clockwork. A diapason had a style or marker, made of a small bit of pointed spring, fixed to the end of one of the prongs. On the diapason being sounded in the usual way, and the spring placed lightly against the cylinder, the style traced a sinuous white line on the black paper. The sizmosities became visible representatives of minute intervals of time, the prongs vibrating possibly hundreds of times in a second. M. Lissajous devised an electrical apparatus to prolong the vibrating of the prongs; but it was too complexed for practical use. M. Breguet then proposed clockwork for this purpose, superseding the pendulum and the spiral spring by a diapa son. The diapason regulates the rate of motion of the train of wheels by the equa
bility of the vibration of the prongs, while the train of wheels tends to increase the time during which the prongs vibrate and sound. An index carried by an arbor round a dial, may be made to count or record the vibrations. Breguet's experiments have gone as far as instruments giving 200 simple vibrations (100 double or to-and-fro vibra tions) per second. There arc means of making the diapason more or less acute in sound, or with a greater or less number of vibrations in a second, by mechanical treat ment of the prongs: it can, by a proper distribution of metal, be made to yield any required note within certain limits; and thus, with the aid of the style, the paper, and the cylinder, it may be made to give a kind of visible existence to excessively minute intervals of time, such as part of a second. Fuller details are given in Breguet's description of the apparatus in the _Revue Chronoinetrigue.