Watch Glossary 1

A

Alarm:
A device that sounds a signal at a pre-set time.

Altimeter:
A device that determines altitude by responding to changes in barometric pressure.

Anadigi Display:
A display that shows the time both by means of hour and minute hands (an analog display) and by numbers (a digital display).

Analog Display:
A display that shows the time by means of hands and a dial.

Analog Watch:
A watch with a dial, hands, and numbers or markers that present a total display of 12-hour time span. Analog digital refers to a watch that has both a digital display and hands of a conventional watch.

Aperture:
Small opening. The dials of some watches (in French: montres à guichet) have apertures in which certain indications are given (e.g. the date, the hour, etc).

Assembling:
Process of fitting together the components of a movement. This was formerly done entirely by hand, but the operations have now been largely automated. Nevertheless, the human element is still primordial, especially for inspection and testing.

Automatic Movement:
A mechanical movement that requires no winding because the rotor, part of the automatic mechanism, winds the mainspring every time you move your hand. The first automatic movement was invented in Switzerland by Abraham-Louis Perrelet in the Eighteenth century. When fully wound and left to sit, most automatics have up to 36 hours of reserve power. Mechanical movements are accurate within one minute each day. Automatic movements have gained in popularity the last few years especially with watch connoisseurs and are considered to be Switzerland's mechanical answer to the popularity of the no-winding-needed quartz movements that are standard in Japanese watches.

Auto Repeat Countdown Timer:
A countdown timer that resets itself as soon as the preset time has elapsed and starts the countdown again. It repeats the countdown continuously until the wearer pushes the stop button.

Automatic Watch:
A watch whose mainspring is wound by the movements or accelerations of the wearer's arm. On the basis of the principle of terrestrial attraction, a rotor turns and transmits its energy to the spring by means of an appropriate mechanism. The system was invented in Switzerland by Abraham-Louis Perrelet in the 18th century.

Automatic Winding: (also called "self-winding"):
Winding that occurs through the motion of the wearer's arm rather than through turning the winding stem. It works by means of a rotor that turns in response to motion, thereby winding up the watch's mainspring. An automatic watch that is not worn for a day or two will wind down and need to be wound by hand to get it started again.

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B

Balance Spring:
A very fine spring (also called a "hair spring") in a mechanical watch that returns the balance wheel back to a neutral position.

Balance Wheel:
The part of a mechanical watch movement that oscillates, dividing time into equal segments.

Barrel:
Thin cylindrical box containing the mainspring of a watch. The toothed rim of the barrel drives the train.

Battery Reserve Indicator:
See "power reserve indicator".

Bezel:
The ring, usually made of gold, gold plate or steel, that surrounds the watch face.

Bi-directional Rotating Bezel:
A bezel that can be moved either clockwise or counterclockwise. These are used for mathematical calculations or for keeping track of elapsed time.

Bracelet:
A type of watch band made of elements that resemble links.

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C

Cabochon:
Decorative stone which has been carved into a round shape.

Calendar:
A feature that shows the day of the month, and often the day of the week and the year. There are several types of calendar watches.

Caliber:
A term often used by Swiss watchmakers to denote a particular model type, such as Caliber 48 meaning model 48. More commonly, the term is used to indicate the movement's shape, layout, or size.

Cambered:
Often used in referring to a curved or arched dial or bezel.

Case:
The metal housing of a watch's parts. Stainless steel is the most typical metal used but titanium, gold, silver, and platinum can also be used. Less expensive watches are usually made of brass and plated with gold or silver.

Caseback:
The reverse side of a watch case that lies against the skin. May be transparent to allow viewing of the inner workings of the watch or be solid. Most manufacturers engrave casebacks with their name, water and shock resistance, case metal content and other details.

Chime:
The bell-like sound made when a clock strikes on the hour, half hour, etc. Two familiar chimes traditionally found in clocks are the Westminster chime made by the famous Big Ben in London, and the bim bam, a two note chime.

Chronograph:
A stopwatch, i.e., a timer that can be started and stopped to time an event. There are many variations on the chronograph. Some operate with a center seconds hand which keeps time on the watch's main dial. Others use subdials to elapsed hours, minutes and seconds. Still others show elapsed time on a digital display on the watch face. When a chronograph is used in conjunction with specialized scales on the watch face, it can perform many different functions, such as determining speed or distance. Some chronographs can time more than one event at a time. Do not confuse the term "chronograph" with "chronometer". The latter refers to a timepiece, which may or may not have a chronograph function that has met certain high standards of accuracy set by an official watch institute in Switzerland. Watches that include the chronograph function are themselves called "chronographs".

Chronometer:
This term refers to a precision watch that is tested in various temperatures and positions, thus meeting the accuracy standards set by an official institute in Switzerland. Most watch companies provide a certificate with your chronometer purchase.

Complication:
A watch with other functions besides timekeeping. For example, a chronograph is a watch complication. Other complications coveted by watch collectors include: minute repeater, tourbillon, perpetual calendar, or split second chronograph.

COSC:
The official Swiss Chronometer Testing Institute that puts every chronometer watch through a rigorous, 15-day testing procedure to verify the watch's precision.

Countdown Timer:
A function that lets the wearer keep track of how much of a pre-set period of time has elapsed. Some countdown timers sound a warning signal a few seconds before time runs out -- these are useful in events such as yacht races, where the sailor must maneuver the boat into position before the start of a race.

Crown:
Button on the outside of the case that is used to set the time and the calendar, and, in the mechanical watches, to wind the mainspring.

Crystal:
The transparent cover on the watch face made of glass crystal, synthetic sapphire or plastic.

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