Discoveries and inventions of the nineteenth century (1905)
Routledge, Robert · London : G. Routledge and Sons · leaf 625
ered, porcelain isfound to be the best insulating material for this purpose, since moisture isnot readily deposited on its surface, and even rain runs off without wettingit; and it is durable, strong, and clean. Fig. 293 shows a telegraph post,wirh brown salt-glazed stoneware insulators, shaped… … Fig. 293.— Telegraph Post and Lisidators. tbe wire is simply lifted, and is protected above by a porcelain bell. Thisform, or some modification of it, is that most generally used.
Inventions
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