be replenished from time to time. A process has also been devised for making copies of the phonograms in metal by electro-deposition, so as to produce permanent records. But even the wax phonogram may be used over and over again, hundreds of times, without diminishing the fidelity of the reproduction.
The entire phonograph is shown in our figure. It consists of a box, B, containing the silent electro-motor which drives the machine, and supporting the works for printing and reproducing the sounds. Apart from the motive power, which might, as in the graphophone, be supplied by foot, the apparatus is purely mechanical, the parts acting with smoothness and precision. These are, chiefly, the barrel or cylinder, C, on which the hollow wax is placed; the spindle, S, which revolves the cylinder and wax; and the two tympana, T, T′, which receive the sounds and impress them on the soft surface of the wax. A governor, G, regulates the movement of the spindle; and there are other ingenious devices for starting and stopping the apparatus. The tympanum T is that which is used for recording the sounds, and M is a mouthpiece, which is fixed to it for speaking purposes. The other tympanum, T′, reproduces the sounds; and E E is a branched ear-piece, conveying them to the two ears of the listener. The separate wax tube, P, is a phonogram with the spiral trace of the sounds already printed on its surface, and ready for posting.
The box below the table contains the voltaic battery which actuates the electro-motor. A machine which aims at recording and reproducing actual speech or music is, of course, capable of infinite refinement, and Edison is still at work improving the instrument, but even now it is substantially perfected.
Phonographs have arrived in London, and through the kindness of Mr. Edison and his English represen-
