French Marble Clock with Gilded Lady Bust

• 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.
• Spelter - Spelter was the name given to an alloy of zinc and brass or copper used in the 19th century for statuary and lighting. It is a brittle bluish-white metal. It was used as a cheap replacement for bronze, but being brittle easily breaks and can't be repaired. When finished it can often be mistaken for bronze, but if discreet a scratch on the base displays shows a greyish colour, the metal is spelter, if a golden colour the metal is most likely bronze.
• Movement - The technical name for the workings of a clock or watch, and does not include the dial or case.
• Circa - A Latin term meaning 'about', often used in the antique trade to give an approximate date for the piece, usually considered to be five years on either side of the circa year. Thus, circa 1900 means the piece was made about 1900, probably between 1895 and 1905. The expression is sometimes abbreviated to c.1900.
• Gilding - Gilding is a method of ornamentation whereby a thin sheet of gold metal is applied to items made of wood, leather, ceramics, glass and silver for decorative purposes.
  
  For furniture including mirrors, the sheet of gold is usually applied over a coating of gesso. Gesso is a mixture of plaster of Paris and gypsum mixed with water and then applied to the carved wooden frames of mirrors and picture frames as a base for applying the gold leaf. After numerous coats of gesso have been applied, allowed to dry and then sanded a coat of "bole", a usually red coloured mixture of clay and glue is brushed on and allowed to dry, after which the gold leaf is applied. Over time parts of the gilding will rub off so the base colour can be seen. In water gilding, this was generally a blue colour, while in oil gilding, the under layer was often yellow. In Victorian times, gilders frequently used red as a pigment beneath the gold leaf.
  
  Metal was often gilded by a process known as fire gilding. Gold mixed with mercury was applied and heated, causing the mercury to evaporate, the long-term effect of which was to kill or disable the craftsman or woman from mercury poisoning. The pursuit of beauty has claimed many victims, not the least of which were the artists who made those pieces so highly sought after today.
• Incised - A record of a name, date or inscription, or a decoration scratched into a surface, usually of a glass or ceramic item with a blunt instrument to make a coarse indentation. Compare with engraving where the surface is cut with a sharp instrument such as a metal needle or rotating tool to achieve a fine indentation.

This item has been included into following indexes:

• clocks, type - figural 706