Clocks, Master & Slave Electric master clock (horloge maitresse electrique), 1900

Clocks, Master & Slave Electric master clock (horloge maitresse electrique), 1900. This invention patented in 1900 by Fischer of Zurich, Switzerland, enables time indications to be transmitted from a central master clock to distant indicating or slave dials. The electrical circuit remains closed throughout, and every minute the armature of a simple dynamo, driven by the clock weight, is sharply rotated, sending a pulse of current to its subsidiary dials. Successive rotations are in alternate directions and so are the pulses of current. The system has been used to a considerable extent, both in the United Kingdom, under the trade name Magneta, and throughout Europe. ©SSPL/Science Museum