Elementary telegraphy : a manual for students; written specially to meet the requirements of the ordinary grade of the subject as published in the syllabus of the city and guilds of London Institute (1910)
Pendry, H. W. (Henry Walter) · London ; New York : Whittaker & Co. · leaf 80
theinduced currents, Avhich previously passed across the airgap when the tongue was moving from the marking stoji. In single current circuits the relay coils should be joinedin multiple Avhen the resistance of all the circuit, excludingthe relays, is less than half the total series resistance of…
Telegraph
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
