A sub-dial on a chronograph (see chronograph) that can time periods of up to 12 or 24 hours.

A sub-dial on a chronograph (see “chronograph”) that can time periods of up to 30 minutes.

The watch alerts you with beeps at a pre-set time.

A watch that shows the time by means of hour and minute hands (analog display) as well as by numbers (a digital display).

The movement of a mechanical watch can be thrown off balance if it comes in contact with a strong magnetic field; Magnetism is common in loudspeakers, televisions, refrigerators, cars, etc. etc. and these days most watches claim to be anti-magnetic. This is achieved by using alloys for certain parts, among them the balance wheel and escape wheel. Electronic watches are not susceptible to magnetism.

(or self-winding) This term refers to a watch with a mechanical movement (as opposed to a quartz or electrical movement). The watch is wound by the motion of the wearer’s arm rather than through turning the winding stem. A rotor that turns in response to motion winds the watch’s mainspring. If an automatic watch is not worn for a day or two, it will wind down and need to be wound by hand to get it started again.

Some battery operated watches have a feature that indicates when the battery is approaching the end of its life. This is often indicated by the second hand moving in two second intervals instead of each second.

The ring which surrounds the watch dial (or face). The bezel is usually made of gold, gold plate or stainless steel.

A bezel that can be rotated either clockwise or counterclockwise. These are used for mathematical calculations such as average speed or distance (see “slide rule”) or for keeping track of elapsed time(see “elapsed time rotating bezel”).

A feature that shows the date, and often the day of the week. There are several types of calendar watches. Most calendar watches show the information digitally through an aperture on the watch face. Some chronograph watches shoe the information on sub-dials on the watch face.

Materials range from inexpensive cast metal through moulded plastic to solid chunks of steel or gold from which the case is machined. In Great Britain, gold cases are usually 18k, but less expensive watches are 9k. In most other countries, 14k is preferred. Caratage indicates the gold content of metal, stated as the number of parts of gold in every 24 parts, i.e. 18k gold is 18 parts of gold alloyed with six parts of metal. Platinum is becoming increasingly popular, as is titanium for its lightness. Ceramic cases and bracelets -a scratch resistant space age material formed under great pressure and heat from powder -are used by some manufacturers. It does not bear any resemblance to the ceramics used in pottery. Some watches in the middle price ranges are gold plated over brass -9k or 18k plating usually. Vermeil is the term used to describe silver which has been gold plated.

The case of a watch must not only protect the mechanism and hold all the parts together but it must also look good -sometimes to the extent of making a timepiece into a piece of jewellery. A watch case is generally in 3 parts -the bezel, which holds the crystal, -the band or centrepart, which contains the movement, -and the back, either snapped or screwed on, in to which, sometimes, is fitted a crystal so that an intricate mechanical movement watch.

A watch that includes a built in stopwatch function – 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 sub-dials to time elapsed hours, minutes and seconds. Still others show elapsed time on a digital display on the watch face. Some chronographs can be used as a lap timer (see “flyback hand” and “split seconds hand”). The accuracy of the stopwatch function will commonly vary from 1/5th second to 1/100th second depending on the chronograph. Some chronographs will measure elapsed time up to 24 hours. Watches that include the chronograph function are themselves called “chronographs.” 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 (see “tachymeter” and “telemeter”) 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.

One or more features added to a watch in addition to its usual time-telling functions, which normally not only include the hours, minutes and seconds but also date and often the day of the week as well. Complications such as; perpetual calendars, moonphase displays, alarms, repeating mechanisms, quarter strikes as well as stop/start chronograph functions. Power reserve indicators are also usually regarded as ‘complications’.

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 the 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.

Also called a stem or pin, a crown is the button on the outside of the watch case that is used to set the time and date. In a mechanical watch the crown also winds the mainspring. In this case it is also called a “winding stem”. A screw in (or screw down) crown is used to make a watch more water resistant. The crown actually screws into the case, dramatically increasing the water-tightness of the watch.

The transparent cover on a watch face made of glass crystal, synthetic sapphire or plastic. Better watches often have a sapphire crystal which is highly resistant to scratching or shattering.

The watch face.

A watch that shows the time through digits rather than through a dial and hands (analog) display.

A graduated rotating bezel (see rotating bezel”) used to keep track of elapsed time. The bezel can be turned so the wearer can align the zero on the bezel with the watch’s seconds or minutes hand. After a period of time passes, you can read the elapsed time off the bezel. This saves you having to perform the subtraction that would be necessary if you used the watch’s regular dial.

Device in a mechanical movement that controls the rotation of the wheels and thus the motion of the hands.

A seconds hand on a chronograph that can be used to time laps or to determine finishing times for several competitors in a race. Start the chronograph, putting both the flyback hand and the regular chronograph seconds hand in motion. To record a lap time or finishing time, stop the flyback hand. After recording the time, push a button and the hand will “fly back” to catch up with the constantly moving elapsed-time hand. Repeat the process to record as many lap times or finishing times as needed.

GOLD PLATED
JEWELS
JUMPING HOURS
LAP TIMER
MECHANICAL MOVEMENT
MOONPHASE DISPLAY
MOVEMENT
POWER RESERVE INDICATOR
PUSHERS OR PUSH PIECES
QUARTZ MOVEMENT
ROTATING BEZEL
ROTOR
SAPPHIRE CRYSTAL
SCREW-LOCK CROWN
SECOND TIME-ZONE INDICATOR
STOPWATCH
SUB-DIAL
TACHYMETER
TELEMETER
TITANIUM
TONNEAU WATCH
UNI-DIRECTIONAL ROTATING BEZEL