Georgian Mahogany Longcase Clock by Gilbert Allison, Sunderland

• 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.
• George Iii - George III (1738 - 1820) was King of Great Britain and Ireland from 1760 to 1820.
• 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.
• Hood - In longcase clocks, the hood is the wooden case that surrounds the works and dial, and includes the glass front, which is usually hinged, so the door can be opened to wind the clock or adjust the time. In 18th and 19th century longcase clocks the hood usually slides forward for removal, allowing access to the works.
• 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.

This item has been included into following indexes:

• clocks, grandfather / longcase, period or age - 18th century, mahogany cased 122