Telegraph Relay

“With a long main-line and many instruments in circuit, the resistance may be so great as to render the main-battery current so feeble that it cannot operate the sounder with sufficient energy to render the signals distinctly audible. This difficulty is met by introducing a ‘local battery,’ and a ‘relay’ at each station on the line.” -Avery 1895

Keywords

Telegraph, instruments, great, long, line, Relay, resistance, main, many

Galleries

Telephone and Telegraph Industry

Source

Elroy M. Avery School Physics (New York: Sheldon and Company, 1895) 567

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