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 139
ularly vulnera])le at the end grain ; inordinary cases a sheet metal or cast iron pole roof is em-l)loyed, or a wooden finial where an ornamental finish isdesired. A single wire is sometimes carried on an insidator iixedat the top of the pole by meajis of a saddle hradict (Fig. 10,1);in such cases… … 128 ELEMENTARY TELEGEAPHY stay being secured to the pole by coacli screws ]>assi]igthrough triangular wooden blocks. When a line of wiresis carried rmmd the outside of a curve on a road, theinsulator nearest the road on eacharm is provided with a guard toprevent a loose wire overhangingthe…
Telegraph
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