George III Chinoiserie long case clock, circa 1760's, 240 cm

• 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.
• 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.
• Spandrel - An architectural term that in horology refers to the triangular ornamental decoration in the corners of of the dial plate. The spandrels are usually of cast brass and may be additonally chased and engraved. On painted dial clocks the spandrels are also usually painted.
• George Iii - George III (1738 - 1820) was King of Great Britain and Ireland from 1760 to 1820.
• Pagoda Top - A shape based loosely on that of a Chinese pagoda, that is, pyramidal with sloped sides and a top cap. However there are many variations on the basic shape from a relatively flat pagoda to a tall pagoda with almost parallel concave sides to a true pagoda shape. As found on a pagoda, the pagoda top is often surmounted by a fancy finial. The pagoda top is most frequently found on the hoods of 18th century long case clocks, and on bracket clocks, and sometimes on Chinese Chippendale style furniture.
• Chinoiserie - Furniture and decorative items decorated in imitation of a Western interpretation of the Chinese style. The Chinoiserie style first became popular in the late 17th century, though there were frequent revivals, notably by Chippendale (hence 'Chinese Chippendale') during the Regency period, and the Anglo-Japanese style in the second half of the 19th century.
  
  The ubiquitous 'willow pattern' is the most common 'Chinese' theme used in porcelain, while on furniture the Chinoiserie style usually has black or red painted and lacquered decoration, though the hallmark of the furniture style is the use of fretwork in geometrical patterns, pagodas and other decorative forms.
  
  Japonaiseries, as the name implies, are motifs in imitation of the Japanese taste.
  
  See also "Chinese Chippendale".

This item has been included into following indexes:

• clocks, grandfather / longcase, period or age - 18th century, other 108
• clocks, grandfather / longcase, type - Chinoiserie and lacquer 32