The telephone system of the British post office. A practical handbook (1901)
Herbert, Thomas Ernest · London, New York, Whittaker and Co. · leaf 151
hat a small fault upon a short circuit may notcause any disturbance upon that circuit, yet when connected to a longtrunk in perfect condition the disturbances caused will be sufficientlypronounced to prevent speech. A full earth upon a junction line or 136 Symmetrically Twisted Cables. ..ubscribers… … Figure 114. apart may each be silent, yet when connected together are excessivelynoisy. It may be mentioned that the wires in cables are always symmetricallytwisted either in pairs or in fours. In the latter case the diagonal wireshould always be chosen for forming each loop. The Telephone System…
Telephone · Postal service
Internet Archive · Cornell University Library · Public Domain Mark 1.0. Free to use for anything.
