National Telegraphic Union · New York : N.T.U. · leaf 260
ntail great inconvenience, and, in some instances,positive danger. Another difficulty of this nature some-times arises in the transmitting key, as usually made atthe present day, the brass lever which closes the circuitfrequently becoming worn after much use, and failing tocomplete the connection… … Fig: 2. iiirnr umimimnmnimiinimHulmunmnnnffin be understood by the annexed engraving and description.Figure 1 represents a side elevation of a telegraphickey of the usual coustruction, to which this improvementhas been applied. A represents a metallic slide of the formshown in perspective in figure…
Telegraph
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