Theory and practice of the electric telegraph; a manual for operators and students (1875)
Churchill, Charles Henry, d. 1904. [from old catalog] · Oberlin, Ohio, Sherman & bros. · leaf 59
hap. I,) is suspend-ed by a very fine plat-inum wire is a glass(case. A flat helix ofpbnnany convolutions ofH the finest insulatedigcopper wire is sup-~-\JT^^~ ~:~~ v^-ported on a wooden^ ;—_ -■: /^ _ ■—-- or ebonite frame so ^ ~The Galvanometer. that the lower needle. is enclosed within it and can… … OF INDUCED CURRENTS. 3 9 may be turned so as to place its wires parallel to any positionof the needle. 3. What are some of the uses to which it is applied? The special use of the galvanometer is to reveal the pres-ence of a feeble current and to measure its force. It may beemployed to detect an…
Telegraph
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