ST JOHN FULHAM, MAY ASTROLOGICAL REGULATOR CLOCK

DATE: Sunday 12 July | 12pm

LOCATION: Live Online Virtual Auction – 124 James Street, Leichhardt

Of Special Note in our Bi-Monthly Emporium Auction is Lot 38, A St John Fulham, May Astrological Regulator Clock dated to circa 1850. The clock has a mahogany vase, silvered brass dial, black numerals & hands and a wind movement with mercury pendulum. It was utilised by an Observatory to regulate and measure time when making Astronomical observations. Measures: 180 x 34.5 x 25.5 cm

To own one of these clocks is to own the work of a scientist, engineer and artist, they are a moment in the history of the science of timekeeping.

A history of regulator clocks

Observation that pendulum clocks slowed down in summer brought the realization that thermal expansion and contraction of the pendulum rod with changes in temperature was a source of error. This was solved by the invention of temperature-compensated pendulums; the mercury pendulum by George Graham in 1721

Typical clocks of the day were only accurate to within about 5 minutes per week. But regulators, which are powered by a weighted and geared mechanism, could be accurate to within 10 seconds per month when properly adjusted. These clocks were initially used in observatories and clock and watch shops as the standard of accuracy during repairs, synchronization, and manufacturing.

Notable facts

Regulator Clocks are the most accurate form of pendulum clocks
Regulators were first developed in England around 1720
To ensure their accuracy, they usually omitted complicated features like calendars, instead, each of the clock’s hands worked off a different mechanism.
They were weight-driven devices and featured a deadbeat escapement (an improvement on the anchor design).