Telegraph engineering : a manual for practicing telegraph engineers and engineering students (1922)
Hausmann, Erich, 1886- · New York : D. Van Nostrand Company · leaf 24
key closes or makes thecircuit and releasing the key opensor breaks the circuit. Occasionally horizontally-oper-ated keys with double contactsare employed, requiring but halfthe motions in the formation oftelegraphic characters that arenecessary with the usual vertically-operated keys. Fig. 5 shows… … Fig. 5. lO TELEGRAPH ENGINEERING U-shaped piece, mounted on, but insulated from, the base.This connects with the binding post, the other terminalbeing the post which supports the lever. In operating thekey, the knob should be allowed free play between thumband finger, and the hand given a sidewise…
Telegraph
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