The mobile, pointed part of a buckle which pierces the leather strap when the watch is fastened.

A small, often rectangular opening in the dial. Various indications such as date, month, day or hours are displayed through these openings.

The oscillating part of the watch which regularizes the force of the wheelworks and includes a mainspring. Certain makes, such as Patek Philippe and Rolex, have patended balances.

The driving force of quartz watch.

An unfaceted, polished precious gemstone used to decorated the dial or the crown of a watch.

Revolving discs which indicate the succession of days, months and years in the date display or on small dials.

The measurement, in millimetres, which defines the dimensions of the watch movement.

Mechanism indicating the life of a battery.

Or more properly chronoscope. A watch with hands showing the hours, minutes and seconds, together with a mechanism controlling a chronograph-hand mounted in the centre of the dial. By the operation of pushpieces, the cronograph-hand can be set in motion, stopped and returned to zero. It completes one revolution per minute; a second hand, known as a minute-counter hand, counts the revolutions, i.e. the minutes, usually up to 30.

A chronometer is a highprecision watch able to display the seconds and housing a movement that has been tested for 15 days in different possitions at various temperatures by COSC- Control Official Suisse Chronometer.

Any function not directly related to the simple telling of time. Also used to designate a watch which features one or many of these extra functions.

Used to refer to a watch featuring one or many complications.

The mechanism which indicates the time on a digital liquid crystal watch.

The part of the mechanism which regulates force with relation to the balance, keeping it in oscillation via energy obtained from the mainspring. Different types of escapement: verge escapement (in clocks), recoil escapement and the deadbeat escapement.

A watch in which mechanical contact is replaced by a transistor.

The different between real solar time and mean solar time, resulting from the Earth´s erratic orbit. In the course of a year, the equation of time varies by about 16 minutes. Watches featuring an equation of time function are equipped with a mechanism to measure this difference.

This function orginates from the field of aviation. By simply pressing the puchpiece, the "flyback" function returns the direct-drive seconds chronograph hand to zero. It then immediately begins another timing operation.

In quarts watches, the frequency defines the movement´s number of oscillations per second.

Any operation linked to the measurement of time (chronography, date indication, etc.)

In watchmaking, this term means that the master horologist has succeeded in combining a large number of complicated functions within a single watch. When a watch features several complications, it is a "montre á grande complication", or highly complicated watch.

A mark used to indicate the hours on a dial.

Very hard, industrial gems used within the movement to prevent wear and tear. The higher the number of jewels, the higher quality the watch.

The most frequently used unit of measurement for a calibre, corresponding to 2.555 millimetres (0.099 inches)

The indication, usually in a display window, of successive aspects of the moon throughout its monthly cycle.

In the context of watchmaking, this term refers to companies that make the wheelworks which comprise the movement and case, and also assemble the watch.

The complication to end all complications for master watchmakers. It is composed of a system which strikes a chime, via a push-piece or cursor. The most famous minute repetitions are those created by Audemars Piguet and Patek Philippe.

Indicates the state of the moon: new moon, waxing, full of waning.

An automatic calender which takes into account the length of the months as well as leap years.

The indication of the date with automatic regulation of the length of the months and leap years. Also used to designate a watch with a prepetual calender.

A graduated, movable ring located on the upper part of the case, surroundning the dial.

Graduated marks along the dial, bezel or the exterior of the watch case which serve to measure speed, distance, etc.

Highly resistant blue-tinted metal which only melts at extremly temperatures.

An extremly resilient corrosionresistant white metal that is highly prized and more expensive than platinum.

The oscilling movement of a piece from one extremity to the other. Two vibrations make up an oscillation. Usually, the balance of the watch produces 5 vibrations per second, which correspons to 18,000 per hour, but this number can be higher.

Instrument for measuring speed. In watchmaking, a sports timer or chronograph with a graduated dial on which speeds can be read off in kilometres per hour or some other unit. HIII and Stefan Johansson/VÄXJÖ are chronographs.