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 to have redeemed his promises with regard to it. Notwithstanding his deafness, the development of the instrument has been a labour of love to him; and those who knew his rare inventive skill believed that he would some time achieve success. It is his favourite, his most original, and novel work. For many triumphs of mind over matter Edison has 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