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 96
dthat exerted by a current—are acting at the sametime upon the small mag-net needle then it takesup a position where thesetwo forces balance. Thelines of force due to theearth are equidistant andparallel, and to insure thesame condition with thelines of force developedby the current the needlemust… … 86 ELEMENTARY TELEGRAPHY Post (Mce form of tlie iiistnmient shown in Fig. 66 is(lifEerential, each coil having a resistance of 160 and so connected that whenterminals (2) and 3 arejoined the coils are inseries between terminals1 and (4). The shnnt coils,giving valnes ith, iV^^^iith, J^th. sVtli,…
Telegraph
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