The telephone system of the British post office. A practical handbook (1901)
Herbert, Thomas Ernest · London, New York, Whittaker and Co. · leaf 45
ether,thus little variation in the degree of contact took place. The packingtrouble does not manifest itself until the transmitter has been in use somelittle time. The transmitter must always be in the vertical position, 30 t>eckert Transmttier. otherwise the granules will settle down, and the… … FiGnRE 20 adopted by the Post Office, for whom it is manufactured by the GeneralElectric Company. The object of all the improvements which have been
Telephone · Postal service
Internet Archive · Cornell University Library · Public Domain Mark 1.0. Free to use for anything.
