The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 75
iron, being clamped close in front ofthe end of the magnet by a cap in which was turned a funnel-shaped mouth or ear piece with a small opening in the centre. The action of the later forms is similar to that of the originalform, except that the pulsatory currents are wholly developedby the… … Fig. 35 joined up, as shown in Fig. 37, but two instruments weregenerally used at each end to save the constant changingfrom mouth to ear, and vice versa. The received sounds, although very clear, were rather faint,so much so that the telephone would have come but slowlyinto general use if an…
Telephone
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