e applied, only three have been commercially
realized--namely, the reproduction of musical, including vaudeville or
talking selections, for which purpose a very large proportion of
the phonographs now made is used; the employment of the machine as a
mechanical stenographer, which field has been taken up actively only
within the past few years; and the utilization of the device for the
teaching of languages, for which purpose it has been successfully
employed, for example, by the International Correspondence Schools of
Scranton, Pennsylvania, for several years. The other uses, however,
which were early predicted for the phonograph have not as yet been
worked out practically, although the time seems not far distant when its
general utility will be widely enlarged. Both dolls and clocks have been
made, but thus far the world has not taken them seriously.

The original phonograph, as invented by Edison, remained in its
crude and immature state for almost ten years--still the object of
philosophical interest, and as a convenient text-book illustration of
the effect of sound vibration. It continued to be a theme of curious
interest to the imaginative, and the subject of much fiction, while
its neglected commercial possibilities were still more or less vaguely
referred to. During this period of arrested development, Edison was
continuously working on the invention and commercial exploitation of
the incandescent lamp. In 1887 his time was comparatively free, and the
phonograph was then taken up with renewed energy, and the effort made to
overcome its mechanical defects and to furnish a commercial instrument,
so that its early promise might be realized. The important changes made
from that time up to 1890 converted the phonograph from a scientific toy
into a successful industrial apparatus. The idea of forming the record
on tinfoil had been early abandoned, and in its stead was substituted a
cylinder of wax-like material, in which the record was cut by a minute
chisel-like gouging tool. Such a record or phonogram, as it was then
called, could be removed from the machine or replaced at any time, many
reproductions could be obtained without wearing out the record, and
whenever desired the record could be shaved off by a turning-tool so
as to present a fresh surface on which a new record could be formed,
something like an ancient palimpsest. A wax cylinder having walls less
than one-quarter of an inch in thickness could be used for