History, theory, and practice of the electric telegraph (1866)
Prescott, George B.(George Bartlett),1830-1894 · Boston, Ticknor and Fields · leaf 45
niell battery is used upon nearly all telegraph lines inthe United States for a local current. They have been substitut-ed for the Grove, which was formerly exclusively used for localas well as main circuits. They are much superior to the Grovein that they require less attention, are not offensive… … Fig. 4. PROPAGATION OF ELECTRICITY. 27 upon some lines for working main circuits. The following form(Fig. 5) was designed by Messrs. C. T. & J. N. Chester, of New
Telegraph
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