George III Chiming Table Clock by James McCabe, London

• Movement - The technical name for the workings of a clock or watch, and does not include the dial or case.
• Bob Pendulum - A bob pendulum consists of a brass or steel rod with a disc shaped metal weight at the end. The most common use of a bob pendulum is in a grandfather clock where it oscillates to keep the time. The length of the rod and the weight of the bob are the key parameters for determining the period of oscillation, and the timekeeping of the clock can be accelerated or slowed by altering the height of the bob.
• George Iii - George III (1738 - 1820) was King of Great Britain and Ireland from 1760 to 1820.
• Finial - An architectural decoration, found on the upper parts of of an object. On furniture they are usually found on pediments, canopies and shelf supports. On smaller ceramic or silver items, such as spoons, they may decorate the top of the item itself, or the lid or cover where they provide a useful handle for removal.
  
  Finials have a variety of shapes and forms. They may be urn-shaped, baluster shaped round or spiral, but usually taper into an upper point. Many real life shapes may also be used as finials, such as pineapples, berries, pinecones, buds, lotus and acorns. Sometimes animals such as a lion are depicted, or fish and dolphins.
• Back Plate - On many types of clocks, the movement operates between two plates, usually made of brass, one at the back, and the other at the front, which forms a mount for the dial.
  
  On English bracket, mantle and table clocks the backplate was often visible through a glass door or panel from the late 17th century, and could be profusely engraved with scrolling decorations, flowers, foliage, birds, and figures. The engraving could also include the maker?s name.
  
  The amount of engraving reduced and became simpler as the 18th century progressed, and by 1800, had been reduced to a border, often with the maker's name in the centre. By the early 1800s all decoration had ceased, and only the maker's name was added, and by the Victorian era, most bracket, mantle and table clocks had no engraving.
• Mahogany - Mahogany is a dense, close grained red-coloured timber from the West Indies and Central America. It was first imported into Europe in the the early 18th century and its use continued through the 19th century. It was popular for furniture making because of its strength, the wide boards available, the distinctive grain on some boards, termed flame mahogany and the rich warm colour of the timber when it was polished.. The "flame" was produced where a limb grew out from the trunk of the tree, and this timber was usually sliced into veneers for feature panels on doors, backs and cornices.
  
  Some terms used to describe mahogany relate to the country from which it originally came, such as "Cuban" mahogany, "Honduras" mahogany etc. However unless the wood has been tested the names assigned are more a selling feature, rather than a true indication of the timber's origin.
• 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.
• Verge Escapement - A verge escapement is an early mechanical escapement used in clocks and other timekeeping devices. It is an early form of the escapement mechanism, which is used to regulate the movement of the hands of a clock or watch. The verge escapement consists of a vertical shaft called the verge, which is mounted on the clock's main plate. Attached to the verge are two pallets, which engage with the teeth of the escape wheel. As the escape wheel turns, the pallets alternately lock and release it, allowing the movement of the clock to be regulated. The verge escapement was widely used in early mechanical clocks, but it was eventually replaced by the more accurate and reliable anchor escapement.

This item has been included into following indexes:

• clocks, mantle & shelf, material or style - mahogany 70