New Kind of Bell Insulator

[Trade Journal]

Publication: The Mechanics Magazine

London, England
vol. 52, no. 1378, p. 12-13, col. 1-2



Sir,—In your Magazine of last week, No. 1377, Mr. Gilbert, in answer to my letter, suggests, that " if each wire had a kind of spiral twist, at proper distances apart, it would expand or give way sufficiently to counteract the contraction of the metal." Mr. Gilbert is probably not aware that the wires wind up only twice in every mile, and that the wire (No. 8, not No. 1, as printed in No. 1876) being one-sixth of an inch only in diameter, the twist would not bear the strain on it, about three hundred weight.

In my former letter I mentioned that a n