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 73
ing sufficient spring tension is given to insure a(k>ci(hMl return of tlie lover to the upper stop when the linecurrent ceases. Several thousands oT the Vylc [lolarized sounders arealready in use. I^or the various requirements of practicalwork it was foujid tliat a (lijfercmlidlv^nuWug of… … Fio. 34—rolarized sounder with fix-d adjiistnienls. hliunted with a resistance of 27,000 giving a combinedresistance of 4500.
Telegraph
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
