Twentieth century manual of railway and commercial telegraphy (1905)
Meyer, Frederic Louis, b. 1875 · Chicago, New York, Rand, McNally & Company · leaf 25
22 THE TWENTIETH CENTUKY certain sounder, without af-fecting the work at otherinstruments, the sound beingentirely confined to tlie instru-ment. It is especially adaptedfor receiving operators usingthe typewriter, or for allsituations where the soundof the instrument is subject tooutside… … Fig. 14.Stationary Eesonator. LESSON IV.Circuits. 80UNDEB
Telegraph
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