An example of a rare electric clock using a coil oscillating between two poles of a magnet and acting as a balance under the control of a large helical spring. The clock, with centre-seconds sweep hand is contained in a four-glass case with door at the front on a marble base containing the battery compartment. The oscillations of the long vertical balance staff are converted to a rotary motion by a ratchet mechanism contained within the movement.
This type of clock is the subject of British patent No. 156408 of 1919, awarded to Frank Holden.
From Antiquarian Horology, December 2002.