French Brass Mantel Clock with Pillared Stepped Case

• Ormolu - Ormolu was popular with French craftsmen in the 18th and 19th century for ornamental fittings for furniture, clocks and other decorative items. True ormolu is gilt bronze, that is bronze that has been coated with gold using a mercury amalgam. Due to the health risks associated with using mercury, this method of creating ormolu was discontinued in France in the 1830s. A substitute was developed consisting of about 75% copper and 25% zinc, however it was inferior to the bronze version. It was often lacquered to prevent it tarnishing.
• 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.
• Barrel (in a Clock) - In a clock or watch, the barrel is a cylindrical component that stores the energy from the mainspring. As the mainspring is wound, it stores energy in the barrel. As the clock or watch runs, the energy is gradually released from the barrel, turning the clock's gears and keeping the time.
  
  The barrel is typically located near the centre of the movement (the mechanism that powers the clock) and is connected to the center wheel, which drives the rest of the gears. The barrel typically has teeth on its outer surface that mesh with the gears in the movement, allowing it to transmit energy to the rest of the clock. Some barrels are designed to be wound by hand, while others are automatically wound by the motion of the wearer's arm.
• 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.
• 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.

This item has been included into following indexes:

• clocks, mantle & shelf, material or style
  • gilded 58
  • gilt metal / ormolu 548
• clocks, mantle & shelf, period or origin - French 762
• clocks, type - four panel, four glass 34