WORLD ACHIEVEMENT

Manawatu Standard, Volume LIX, Issue 48, 25 January 1939, Page 11

WORLD ACHIEVEMENT

THE GHOST LINE. How many of us realise that when we ring up a friend we are really speaking to him b.v wireless? It sounds absurd at first. Everyono knows very well that when you raise tlio telephone receiver and dial a number you are linked with someone by a length of wire, and that however many exchanges it may pass through there in a definite connection between you and tlio one to whom you are speaking.

A'et. in a sense this link is a wireless link, for you must remember that messages travel near the telephone wires, not through them.

This is the secret of the extraordinary announcement made in the early days of 19118 bv ftir George Lee, president of tlio Institute of Electrical Engl ners. Ho informed tlio public that no less than 400 simultaneous conversations can bo carried on over one telephone line. Til proof of this a new tclephnno circuit lias been laid between London, and Birmingham (won to lie extended to Scotland) along which 400 messages may run concurrently. It seems that if there are two wires along which messages are being sent, the billions of electrons somehow create a third “ghost” line for themselves. This idea can be built up until carrier circuits aro multiplied almost indefinitely, and messages may be superimposed one on the other to an astonishing extent. Thus, as the telephone engineers are finding, it is now possible to send as many as 400 messages along one cable, and no doubt this number will bo increased.—(L)