... This was placed opposite an iron diaphragm, which closed a cavity ending in a mouthpiece. He also constructed the instrument which is shown in Fig. 9, and which, he says, was the best instrument he had ever constructed. The bobbin was a large one, and was placed in a soapbox of boxwood, with magnet core and iron diaphragm. Still seeking greater perfection, Meucci, in 1865, tried the bent horseshoe form, shown in Fig. 10, but found it no improvement; and, although he experimented up to the year 1871, he ... — Scientific American Supplement, No. 520, December 19, 1885 • Various
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