Electricity for everybody; its nature and uses explained (1895)
Atkinson, Philip · New York, The Century Co. · leaf 238
rent is transmitted to the cen-tral station, by which an an-nunciator tablet, having thispersons telephone number in-scribed on it, is exposed toview. The attendant then in-quires, through the telephone,the number of the person wanted,and being informed, rings a callon the bells in this persons… … Fig. 98. THE TELEGRAPH AND TELEPHONE. 223 Difference Between Telephonic and TelegraphicTransmission.—It should be noticed that transmissionby telephone is effected by varying the strength of a con-stant current in the electric circuit: so that the currentrises and falls in waves, and thus…
Electricity
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