One of the early Bell System wall telephones was the three box phone of 1882. This was the first phone to be manufactured for Bell by the newly acquired Western Electric Company.
The top box measures 5 1/2 inches by 10 1/8 inches and contains a three bar magneto, a ringer and a switchhook. There was no induction coil in the top box. The battery box, with a writing shelf, was a cover for a wet cell battery. The box measures 6 inches by 10 7/8 inches. The middle box was a Blake transmitter with induction coil.
The transmitter, developed by Francis Blake in 1878, became the standard for a number of years into the mid 1890's. For its time, it was know for its sensitivity but it did require careful adjustment (and it came out of adjustment easily).
The receiver is a straight bar magnet attached to a coil on one end near the diaphragm. This monopole receiver has outside terminals for the wire connections. These relatively long receivers are commonly referred to as a long-pole receiver and were used through the turn of the century.
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