Amplitude

The distance between the two extreme points of a movement or periodic phenomenon (a angle).

Battery

A device that transform the energy created by a chemical reaction into electrical energy. Typically, a battery lasts for two to five years. Its lifespan will depend on the type of watch, its size...

Cabochon

A polished precious or fine stone cut into a dome and without facets. Used to decorate a watch dial and sometimes the crown.

Decimal (Revolutionary) (Republican)

A watch or clock dial made in 1793, after the French Revolution which imposed the decimal calendar. The year was divided into 12 months and each month into three 10-day periods known as...

Enamellist

A person who creates enamelwork.

Flirt (independent seconds)

A small rod, driven by a separate train, whose end meshes with the escape-pinion's leaves. The flirt is released every second and makes one complete revolution. This movement is transferred to the...

Grande complication

See complication.

Hardness

The resistance of a material to scratching and wear. Hardness is measured using the Moh's Scale. This scale indicates that one substance can scratch the substance below it and scratch itself. For...

Indicator

A watch's indicators are its dial and hands.

Jasper

An opaque, ornamental stone found in many colours, including white, brown, yellow, red, and green. It is often striped, speckled, and multi-coloured and is used in watch making as a dial. Jasper...

Karrusel

A device similar to the tourbillon, the difference being that the cage is driven by the third wheel. Invented by Bonnicksen, a Danish watchmaker established in London.See complication.

Lever héliaque d'un astre

An annual occurrence which marks the end of a period of invisibility that began with the star's heliacal setting due to conjunction with the rising Sun.

Marcasite

Marcasite is a misnomer for pyrite that has been cut in shiny metallic stones. It is sometimes found on watch bracelets and cases.

Natural pearl

A natural pearl is also called an oriental pearl. This pearl is formed by an oyster, freshwater mussel or other mollusc as a reaction to a tiny invading object that happened to be caught inside...

Organic

Describes a substance produced by a living organism. Pearl, coral and shell are examples of organic substances used in jewellery.

Princess cut

A square-cut stone that has the crown facets of a brilliant cut.

Quartz oscillator

The regulating organ in a quartz clock or watch.

Repairer

The person who repairs watches. A repairer must be outstanding in watchmaking.

Sodalite

Sodalite has a dark blue background with inclusions of white, grey, pink or green. It is used as watch dials.

Test

A watch is tested for water-resistance, thermal resistance, its capacity to resist knocks, corrosion, magnetic fields, etc.

Ultra-complicated watch

Any function other than the indication of hours, minutes and seconds, regardless of whether the mechanism is hand-wound or self-winding, mechanical or electronic, and of movement height. The...

Vibration

Movement of a pendulum or oscillating body between two extreme positions (A' and A''). The balance of a mechanical watch generally makes five vibrations per second, equivalent to 18,000...

Year

A four-digit indication of the current year that changes automatically at midnight on December 31st.

Zinc

A metal applied by electrodeposition (electroplating) to protect iron and steel.