been called the 'Napoleon of Invention,' and the aptness
of the title is enhanced by his personal resemblance to the great
conqueror. But the phonograph is his victory of Austerlitz; and, like
the printing-press of Gutenberg, it will assuredly immortalise his name.

'The phonograph,' said Edison of his favourite, 'is my baby, and I
expect it to grow up a big fellow and support me in my old age.' Some
people are still in doubt whether it will prove more than a curious
plaything; but even now it seems to be coming into practical use in
America, if not in Europe.

After the publication of the phonograph, Edison, owing, it is stated,
to an erroneous description of the instrument by a reporter, received
letters from deaf people inquiring whether it would enable them to hear
well. This, coupled with the fact that he is deaf himself, turned his
thoughts to the invention of the 'megaphone,' a combination of one large
speaking and two ear-trumpets, intended for carrying on a conversation
beyond the ordinary range of the voice--in short, a mile or two. It is
said to render a whisper audible at a distance of 1000 yards; but its
very sensitiveness is a drawback, since it gathers up extraneous sounds.

To the same category belongs the 'aerophone,' which may be described
as a gigantic tympanum, vibrated by a piston working in a cylinder of
compressed air, which is regulated by the vibrations of the sound to be
magnified. It was designed to call out fog or other warnings in a loud
and penetrating tone, but it has not been successful.

The 'magnetic ore separator' is an application of magnetism to the
extraction of iron particles from powdered ores and unmagnetic matter.
The ground material is poured through a funnel or 'hopper,' and falls in
a shower between the poles of a powerful electro-magnet, which draws the
metal aside, thus removing it from the dress.

Among Edison's toys and minor inventions may be mentioned a 'voice
mill,' or wheel driven by the vibrations of the air set up in speaking.
It consists of a tympanum or drum, having a stylus attached as in the
phonograph. When the tympanum vibrates under the influence of the voice,
the stylus acts as a pawl and turns a ratchet-wheel. An ingenious smith
might apply it to the construction of a lock which would operate at the
command of 'Open, Sesame!' Another trifle perhaps worthy of note is his
ink, which rises on the paper and solidifies, so that a blind person can
read the wr