Page:Popular Science Monthly Volume 70.djvu/235

Rh entire telephone equipment supplied to subscribers by the early telephone exchanges. For as rapidly as other operating companies came into existence, they copied or adopted Mr. Coy's equipment, modified more or less according to the mechanical or artistic views of the local manager or his manufacturer. A modification used in Richmond, Va., is shown in Fig. 9.

In one sense these magneto systems might be properly termed central-energy exchanges. For though no batteries were required to operate these pioneer hand telephones, all the current required to signal 'central' or 'subscriber' was supplied from a 'common-battery'

set of gravity cells maintained in the exchange and operating on a closed circuit.

When a subscriber desired 'Central,' he touched the metal push button, shown in Fig. 8, which actuated a single-stroke bell in the exchange and released a drop in the ordinary house-annunciator attached to the switchboard, thus indicating the respective party-line. On hearing the bell, the boy-operator would leave whatever other work he was engaged upon, walk leisurely over to the board, glance at the annunciator, turn the single switch to the metallic strip to bring his telephone in circuit with the calling subscriber, and loudly enquire: 'What do you want?' then place his telephone to his ear just too late to catch the full reply. Louder explanations on both sides would follow, and sometimes the subscriber's remarks were not of a character suitable