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 149
Fro. 115.—Hamilton pole. Fra. 116.—Overhouse iron pole. TELEORAFH LINES 139 Game guards.—In some distriots the birds are warned ofthe presence of tlie line wires by small alnmiiiium flags,which are attached to them so as to swing qiiite freely.Fig. 118 shows how the game guard is attached to a…
Telegraph
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