Antique Dutch wall clock with windmill scene
You must be a subscriber, and be logged in to view price and dealer details.
Subscribe Now to view actual auction price for this item
When you subscribe, you have the option of setting the currency in which to display prices to $Au, $US, $NZ or Stg.
- Pendulum - The pendulum was discovered around 1602 by Galileo Galilei, and was adopted for time keeping by the Dutch mathematician and natural philosopher, Christiaan Huygens, who excelled in astronomy, physics, and horology.
The pendulum comprises a metal rod usually of brass or steel with a metal disk, known as a bob, at the end. The movement of the pendulum is driven by weights or a spring, and as a pendulum swings in a regular arc, it was found accuracy could be controlled to within a few seconds a week.
Timekeeping can be adjusted by changing the height of the bob on the rod, making the pendulum either swing slower or faster.
The disadvantage of the pendulum was that changes in temperature also changed the length of the pendulum, interfering with the accuracy of the clock, and so in the 18th century two types of mercurial pendulums were invented which countered the movement in the steel rod.
The pendulum was the world's most accurate timekeeping technology until the invention of the quartz clock, regulated by a quartz crystal, in 1927.
This item has been included into following indexes:
Visually similar items
Pearl strand with flower clasp opera length round strand of Akoya pearls with a 14ct white gold flower clasp, stamped '585' total weight of 82 grams
German pair of figural candelabra depicting two young courting couples & heavily decorated with flowers, with a faux Vienna mark to the base. Height 37 cm
Large embossed Maling bowl, pink thumbprint with embossed flowers, approx 27 cm wide
A Porsche design P6340, flat 6 gents watch Officially certified chronograph quartz movement black enamel dial, with day and date display stainless steel case with black rubber strap. Diameter 44 mm