Modern practice of the electric telegraph. A handbook for electricians and operators (1872)
Pope, Frank L. (Franklin Leonard), 1840-1895 · New York : D. Van Nostrand · leaf 74
If exposed to the direct action of rain itought always to be placed in a perpendicular position.It will be noticed that this insulator holds the line wireby suspension. 95. THE LEFFERTS INSULATOR.—This is composed of asuspension hook fixed in a socket of glass, of the formrepresented in Fig. 35.… … 96. THE BROOKS INSULATOR.—Figs. 36 and 37 showthe construction of this insulator, which consists of asuspension hook cemented into an inverted blown glassbottle, which is again cemented into a cast iron shell,provided with an arm which screws into the pole, as inFig. 36. Another form is made,…
Telegraph
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