SUBTERRANEAN TELEGRAPH WIRES.

New Zealand Times, Volume XXXIII, Issue 5248, 18 January 1878, Page 3

SUBTERRANEAN TELEGRAPH WIRES.

A 'subterranean telegraph-wire has already been in use for twelve months between Berlin and Halle. During the whole period file working of the line has been highly satisfactory. The conductibility of the buried wire instead of decreasing has, on the contrary, somewhat increased, and no fault of the insulation has made itself apparent. The cable is composed of seven thin-copper wires, twisted together so as to form a single conductor for tlie electric fluid, and encased in India-rubber. The other similar lints which are to be laid down, aud some of which , have been already begun, run from Berlin to Cologne, from Berlin to Frankfort, from Berlin to Strasburg, from Berlin to Hamburg and Kiel, from Berlin to Breslau, and from Berlin to Konigsberg. An ingenious ste-am machine has been constructed which excavates the trench in which the wire is buried, places tlie latter in its position, and again fills up the excavation. The first expense of laying them down may be greater ; but the enormous number of posts aud insulators required for the ordinary wires are dispensed with,' and will not have to be replaced, as is now frequently the case, after a very heavy storm.