The telephone system of the British post office. A practical handbook (1901)
Herbert, Thomas Ernest · London, New York, Whittaker and Co. · leaf 138
s obviously it would be out of the question to give to every section fivejunctions to each of I^opdons ten or twelve ^xch^nge; The Telephone System 0/ the British Post Office. 123 CHAPTER XXI. Call Office Circuits. At all Post Office trunk exchanges a silence cabinet is provided, in orderthat the… … Figure 104. may speak to the exchange or to the cabinet, also that the cabinet may beput through to the exchange. Further, an automatic arrangement is madeuse of, which rings an elegtric be}l iiqmediateljr the speaker rises. 124 Counter Communication Switch for One Cabinet, It is the duty of the…
Telephone · Postal service
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