Malachite Mantel Clock

• 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.
• Chapter Ring - A separate metal plate on the face of a clock, on which the numerals for the hours and sometimes parts of the hours, are displayed, usually wheel shaped and sitting on top of the dial plate. The chapter ring is often a feature of the clock and can be silvered or enamelled to stand as a contrast to its background. The hours are usually shown in Roman numerals, although in the late 19th and earlt 20th century, Arabic numerals became fashionable.
• Malachite - Malachite is bright copper-green coloured stone with concentric layers which displays distinct contrasting veinings. It has been valued in the past for making or decorating small precious objects such as clocks, jewellery, dishes and so. In the Orient it was used for snuff bottles and in Russia and was favoured by the Faberge workshop. larger pieces were used for table tops.
  
  The principal source of supply was Russia but it is to be found in other regions such as Southern Africa, Mexico, Australia and France.
  
  Malachite glass is a manufactured material that was intended to resemble malachite, but often bears more resemblance to a veined coloured marble due to its lower gloss finish and lack of concentric layers. Malachite glass was manufactured by many glassworks in the 19th century including Loetz in Austria and others in Bohemia and Davidson's Greener's and Sowerby in north eastern England.
  
  It was particularly used for scent bottles, bowls, and small vases often decorated with nymphs.
  
  Malachite glass has been manufactured continuously since the late nineteenth century, most is unmarked and it is difficult to distinguish the age or manufacturer of most commercial pieces.

This item has been included into following indexes:

• clocks, material or decoration
  • marble or slate, black 342
  • slate 344