purpose of
paring off an old message, and preparing a fresh surface of the wax for
the reception of a new one. This can be done in advance while the new
record is being made, so that no time is lost in the operation. A small
voltaic battery, placed under the machine, serves to work the electric
motor, and has to 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. [The figure is omitted
from this e-text] 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 representative, Colonel G. E. Gouraud, we have
had an opportunity of testing one. A number of phonograms, taken in
Edison's laboratory, were sent over with the instruments, and several of
them were caused to deliver in our hearing the sounds which were

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