Description

Wooden box with a crank on its right side. The box itself is mounted on a wood board with a bell box (IN-0917), transmitter (IN-0916), and receiver (IN-0921).

Magnetos are generators that use permanent magnets to produce alternating current. In early telephones, hand-cranked magnetos provided the current that caused a bell to ring at the other end of the telephone line (either on a party line or the operator at the telephone exchange). These magnetos had an exterior handle that rotated a large gear inside the box, which in turn drove a smaller gear.

When MIT moved from Boston to Cambridge in 1916, physics professor William Drisko (SB 1895) acquired some discarded telephone equipment from the Walker building. His son John (SB 1917) eventually donated them to the MIT Museum in 1975, and they were mounted together to form a working telephone system. That same year, the musem was planning an exhibition to celebrate the centennial of Alexander Graham Bell’s patent. To their surprise, the components still worked! They rigged up a working two-unit telephone system to model how telephones were used in the 1890s. This magneto was mounted on one of the telephone boards.