1830 English Marine Chronometer with Arnold Escapement and Gimbals

• Ivory - Ivory is a hard white material that comes from the tusks of elephants, mammoth, walrus and boar, or from the teeth of hippopotamus and whales. The ivory from the African elephant is the most prized source of ivory. Although the mammoth is extinct, tusks are still being unearthed in Russia and offered for sale.
  
  Ivory has been used since the earliest times as a material for sculpture of small items, both in Europe and the east, principally China and Japan.
  
  In Asia ivory has been carved for netsuke, seals, okimono, card cases, fan supports, animals and other figures and even as carved tusks.
  
  In the last 200 years in Europe ivory has been used to carve figures, for elaborate tankards, snuff boxes, cane handles, embroidery and sewing accessories, in jewellery and as inlay on furniture. Its more practical uses include being used for billiard balls, buttons, and a veneers on the top of piano keys.
  
  The use and trade of elephant ivory have become controversial because they have contributed to Due to the decline in elephant populations because of the trade in ivory, the Asian elephant was placed on Appendix One of the Convention on International Trade in Endangered Species (CITES), in 1975, and in January 1990, the African elephant was similarly listed. Under Appendix One, international trade in Asian or African elephant ivory between member countries is forbidden. Unlike trade in elephant tusks, trade in mammoth tusks is legal.
  
  Since the invention of plastics, there have been many attempts to create an artificial ivory
• Movement - The technical name for the workings of a clock or watch, and does not include the dial or case.
• Bevel / Chamfer - In furniture making, a chamfered corner refers to a technique used to create a smooth, angled edge on the corner of a piece of furniture. This is typically done by cutting away a small portion of the corner at an angle, typically 45 degrees, creating a diagonal edge, rather than a sharp 90-degree angle. This technique can be used on various parts of a piece of furniture such as table legs, drawer fronts, or door frames. Chamfering can add visual interest to a piece and can help to soften the overall look of a piece of furniture. It is often used in conjunction with other techniques, such as rounding edges or using contrasting wood species to create a more elegant, sophisticated look. Chamfering is a simple way to add a touch of elegance to a piece of furniture and it is a common technique used by furniture makers.
• Bezel - On a clock or watch, the bezel is the metal frame into which the watch or clock glass is fitted. In clocks, the bezel may include a hinge and a flange, in effect a door to the face of the clock. In jewellery the bezel is a band of metal with a projecting lip that holds the gemstone in its setting.
• Fusee - The fusee movement was used in clocks and pocket watches from the mid 17th century. The fusee is a cone shaped drum within the works that is linked to the barrel of the spring, usually by a length of chain.
  
  As the mainspring loses its tension over time, the cone shaped barrel compensates for this by increasing the tension, by pulling the mainspring tighter, thus ensuring the time remains constant.
  
  Use of the fusee in clocks was superseded by the "going barrel" in the mid 19th century and for pocket watches at the beginning of the 19th century.
  
  The fusee continued to be used in marine chronometers until the 1970s.
• 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.
• 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.

This item has been included into following indexes:

• chronometers and deck watches - marine 88