Miller, Kempster Blanchard, 1870-1933 · New York : McGraw publishing company · leaf 232
one operators position ecpiipped. From this view a betteridea may be obtained as to the arrangement* of the plugs and kevs, … FIG. 193.-TW()-IOSITION SWITCH-EOARD, and It is also instructive as showing the method commonly used ofarranging for a greater ultimate equipment of cords, plugs and keysthan that required in the first installation. As will be seen, 15 pairsof cords and plugs are equipped in the switch-board of…
Telephone
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