The Encyclopedia britannica; a dictionary of arts, sciences, and general literatureWith new maps, and original American articles by eminent writersWith American revisions and additions, bringing each volume up to date . A of the Samesmall cups formedtwo electrodes e, eposo of insertingcircuit The suitable forwas wood- charcoal Between these a light rod material is supported on in C, C. To the blocks are connected for the pur- ^^r-, the instrument in an electrict tnrial which Hughes found * the carbon blocks and rod metallized by heating it to redness and plunging it while hot into merc
The Encyclopedia britannica; a dictionary of arts, sciences, and general literatureWith new maps, and original American articles by eminent writersWith American revisions and additions, bringing each volume up to date . A of the Samesmall cups formedtwo electrodes e, eposo of insertingcircuit The suitable forwas wood- charcoal Between these a light rod material is supported on in C, C. To the blocks are connected for the pur- ^^r-, the instrument in an electrict tnrial which Hughes found * the carbon blocks and rod metallized by heating it to redness and plunging it while hot into mercury. If this microphone is joined in circuit with a telephone and a small battery, say one or tw« small Daniel! cells, the vibration pro- _Hughcss nncrophone. duced by a fly walking on no. ii t f the D can be distinctly heard la the telephone. The saine apparatus will also act as a microphone transmitter, but the sonnds arc apt to be harsh. A better form for this purpose is shown in 12 In this a light pencil of carbon M A s pivoted at h and his one end resting on two blocks of C? carbon c. c. the lower one being to the base. jj_j g#f-hliH:1J ! *i The pressure of M ^^ on the carbon blockis regu
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Keywords: ., bookcentury1800, bookdecade1890, bookidencyclopedia, bookyear1892
