Monday, May 26, 2008

A Trolley Telephone


Passengers riding on the electric railway between West Farms and Mount Vernon have the privilege of listening to an acoustic manifestation that in a remarkable manner illustrates some of the earlier experiments in developing the telephone.

The track is a single one, and the potential of the current is high. Its amperage is also considerable as a result, when a car is waiting on a switch for one coming in an opposite direction, the approach of the latter is audible at the distance of a mile to the passengers in the waiting car. The sound vibrations are carried along the wire, through the trolley, to the wooden roof of the car. This acts as a diaphragm, which faithfully reproduces the rumble of the approaching car. A mile away the noise of the wheels is distinctly audible, and at the distance of 1,000 feet the sound becomes a loud roar outside the car, however, practically nothing is heard until the moving car is within a few hundred feet of the switch. — Brooklyn Eagle.

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