Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems (1921)
Smith, Arthur Bessey, b. 1875, Campbell, Wilson Lee · New York : McGraw-Hill · leaf 56
AUTOMATIC ELECTRIC COMPANYS APPARATUS 39 … Fig. 37.—Wall telephone instrument. consists of a dial pivoted at its center, so that it may be turned in a clock-wise direction. For convenience in turning the dial it has finger holes,ten in number, around its outer edge. Through each finger hole a num-ber is seen; these numbers areconsecutive…
Telephone
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