National Telegraphic Union · New York : N.T.U. · leaf 320
eirwhole length are surrounded by a coil similar to the coilof the electro-magnets used in telegraphing. One endof this coil is attached to the telegraph wire, the other tothe ground wire, as represented in the figure. At everyinstant that a contact is established at the station wherethe sound is…
Telegraph
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![An illustration from The Telegrapher [microform], 1864, leaf 320](https://img.insideoutlibrary.com/img/1024/ia-telegrapher05nati-320-203.webp)
