TELEPHONIC.

Waikato Times, Volume X, Issue 916, 7 May 1878, Page 3

TELEPHONIC.

The Hon. Rollo Russell sends ' Nature ' somo notes on experiments ' he '-'lias-made which go to prove that there is no need to insulate the wires connecting a pair of telephones, at least when used for short distances. No. 18 uncovered copper wire was laid along grass and trees 418 yards, the two lines being kept well apart. Articulation and a small musical box were very well heard. The same wire buried for three yards m wet clay, the lines being about five feet apart, and the telephones twenty yards apart, gave good results, and it appears that the bare wires may be taken under roads, without diminution of the audible effect. With the same wire taken across a pond, the lines being submerged m wafer about 40 yards, and lying on the grass the rest of the distance, aboat 28 yards—the wires were about a yard apaet m the water — conyersation m low tones was distinctly heard when not overpowered by the noise of a strong wind blowing at the time. Probably No. 18 copper wire, uninsulated, might be laid across rivers and l>> straits and used for telephonic purposes without appreciable loss of time, as Mr Russell, not m any ©f the above case?, noticed a feebler effect than with insulated wires.