National Telegraphic Union · New York : N.T.U. · leaf 12
Vol. IV—No. 1. New-York, Saturday, August 31, 1867. Whole No. 59. Telegraph Insulators at the Paris Exhibition. In view of the increasing interest in the importantsubject of insulation which has manifested itself amongthe members of the telegraphic profession for some timepast, we have concluded to… … to which it is exposed from accidental causes, or fromthe mischievous attacks of stone-throwing school-boys. In most of the European insulators exhibited, this com-bination of strength and insulating qualities is sought tobe obtained by the use of a single material, usually porce-lain or brown…
Telegraph
Internet Archive · Boston Library Consortium · Public Domain Mark 1.0. Free to use for anything.
![An illustration from The Telegrapher [microform], 1864, leaf 12](https://img.insideoutlibrary.com/img/1024/ia-telegrapher04nati-12-4.webp)
