The telephone system of the British post office. A practical handbook (1901)
Herbert, Thomas Ernest · London, New York, Whittaker and Co. · leaf 88
lyto batteries, signalling wires, etc., whilst the other side contains the twistedspeaking circuits Each tag is numbered, and thus joining up is an ex- Switck-Springi. n ceedingly simple matter. The manner in which the tags are appropriatedin A, B, and C sections will be found in Appendix C. The… … Figure 62. one-iighth of an inch in thickness, the four springs fitting into straightjicks made in two thick ebonite washers, which are held together byscrews. The shape of the body of the switch-spring is shown in Figure62, and the circular brass tube fits Into the ebonite foundations of…
Telephone · Postal service
Internet Archive · Cornell University Library · Public Domain Mark 1.0. Free to use for anything.
