A dictionary of electrical words, terms and phrases (1898)
Houston, Edwin J. (Edwin James), 1847-1914 · New York, The W. J. Johnston company · leaf 524
Fig. S35 Single-Needle Telegraphic Apparatus. signals transmitted are received-by observingthe movements of a vertical needle over adial. … of the observer represent the dashes, and move-ments to the left, the dots of the Morse alpha-bet. The single-needle apparatus of Wheatstone andCookes system is shown in Figs. 535, and 536.Fig. 535, shows the external appearance, and Fig.
Electricity · Electrical engineering
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