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Watch Glossary

Analog Display —Time, that is being displayed by the hour and minute hands.

Automatic —the type of mechanical timepiece that is being wound while the wrist is in motion. The motion forces the rotor pivot around an arbor connected to the mainspring via number of rotating wheels.

Bezel —the outside ring that surrounds the watch dial. There are several types of bezels, such as: stationary, rotating, or performing special functions, like indicating minutes, various scales, city names, etc. Some bezels feature pretty simple designs, while others are full of intricate details with various treatments.

Calendar —the mechanism that shows the date, the day of the week, the year and the month. The calendar displays can be digital or analog.

Chronograph —the kind of a stopwatch measuring continuous and discontinous intervals of time as well as showing the time of a day. The chronograph can be started, stopped and reset at any given moment by pressing push-buttons. Also, certain chronographs can be used in conjunction with various specific scales featured on the face of the watch. It performs following useful functions, such as tachometer, telemeter or pulsemeter.

Chronometer —the kind of mechanical movement that has been carefully tested under various temperatures, varied horizontal or vertical positions, etc., and upon successful completion of those tests being presented with the certificate of official chronometer. One of the most prominent certifications is Swiss C.O.S.C. (Controle Officiel Suisse des Chronometres).

Crown — the button usually on the side of the watch's case used for adjusting the time, date, month, etc. On a mechanical watches with manual winding. It also used for winding the mainspring. There different types of crowns, such as: regular, screw-in, screw-down, etc. Some crowns are protected by protective horns set on the outside of the case.

Crystal —the clear glass cover on top of the dial or the case back of the watch, made of natural glass crystals or synthetic sapphires.

Digital watch —the kind of watch that displays time by digits as opposed to analog displays, showing time via hour and minute hands.

Engine-turned dial (Guilloche) —the kind of engraving on the watch's dial in which thin lines are interwoven, creating various kinds of patterns. These patterns vary in style and complexity. This treatment evokes certain visual appeal and mostly being used on the high-end dials.

Escapement —the device in mechanical watches, that controls operation of the movement's wheels and rotation of the hands.

Fly-back function —the chronograph sweep hand that can be reset to "zero" position without stopping the chronograph function.

Index —a design used to indicate a period of time on a dial, such as hours, minutes and seconds. Markers can also be used to show remaining time left on a power reserve indicator, the heartbeats on a pulsimeter, etc. Indexes are usually placed instead of numbers on the dial.

Jewels —the rubies or sapphires grown synthetically that used being used as bearings to reduce friction between watch movement elements. Some of them have capacity to retain lubricants by capillary action. The number of jewels varies depending on the complexity of the movement. The more complicated movements require larger number of jewels.

Jumping Hour —the design that shows a number through a window. The term "jumping hour" is used because the numeral representing an hour changes suddenly as opposed to the hour hand in traditional watches. One of the largest watchmakers, that incorporates this design into his watches is Gerald Genta.

Lugs —projections on the watch's case where the watch strap or bracelet are attached. The lugs can be stationary or flexible.

Minute Repeater —a quite complex and sophisticated device that makes chimes for different intervals of time, such as an hour, quarter-hour, or a minute. This device was invented a long time ago to let people know the time during night hours. This device is still being produced by high-end watch manufacturers for the luxury purposes to commemorate the invention of the minute repeater. This device doesn't carry a real significance today since the invention of various luminous or tritium coatings being applied to the hour markers and hands.

Moon-phases —the indicator featuring a drawing of the moon rotating beneath the dial in accordance with the astronomical rotations of the moon.

Movement —the main inner mechanism of any produced watch, that allows to keep time, perform all complication's movements and move hands. There are two kinds of movements–mechanical and quartz.

  • a mechanical movement is a movement operated by a mainspring and a balance wheel.
  • a quartz movement is a movement powered by by a quartz crystal and a battery.

Perpetual calendar —the kind of calendar that automatically adjusts for different lengths of months (28, 29, 30, 31) and for leap years.

Power reserve indicator —a counter on the dial of mechanical watches showing the remaining time before the movement has to be wound again.

Pulsemeter —A scale on the watch's bezel graduated in indications representing heartbeats (for the most part 30). The readindgs from this scale work in conjunction with chronograph function, producing the number of heartbeats in one minute. This function proves to be quite helpful for people involved in athletic activities.

Rotating bezel —the kind of bezel that can be rotated via turning it by hand. There are two kinds of rotating bezels–uni-directional and bi-directional. The uni-directional bezel is used mostly in diver's watches, and rotates in the counter-clockwise direction for safety reasons. The bi-directional bezel is used on pilot's watches as part of a slide rule for many computations. The rotating bezels are also used in "World Time" indicators in conjunction with second time zone hand displaying time in the showcased cities on the bezel.

Rotor —the part of an automatic watch that winds the mainspring. It's a thin piece produced from different precious metals or steel resembling semi-circle, that moves back and forth with the motion of the person's wrist.

Sapphire crystal —a solid, transparent, shock-resistant, anti-scratch synthetic sapphire glass covering the face of the watch and , in some instances, the back of the watch. This kind of crystal is being used in high-end watches.

Screw-down crown —the kind of crown that contributes to the water-resistance of the watches. This crown needs to be unscrewed to wind the mainspring, and then, screwed back in to establish water-resistance.

Second time-zone indicator —a subdial with an hour hand only used to indicate the time in any other city of the world in conjunction with main minute hand since the minutes remain the same everywhere.

Second time-zone hand —the second hour hand used to indicate the time in any other place in the world. This hand usually differs in its design from the main hour hand and it's being set via crown or button pushers.

Shock-absorber — a resilient bearing designed to withstand shocks that are brought to bear on the balance-staff pivots.

Split-second chronograph —a chronograph watch with two second hands, that allows timing of several events simultaneously with different duration in time. The first hand is operated with one push- button, and the other one has its own push button. This function is extremely useful in competitions involving several athletes, which times need to be recorded separately.

Stopwatch —a timer used for timing elapsed time only.

Sub-dial —a small dial located on the main watch's dial. There are individual functions assigned to sub-dials, such as small seconds indicator, 30-minute indicator, month counter, etc.

Sweep second hand —the second hand mounted in the center of the dial along with an hour and a minute hands.

Tachometer —the measurement scale that determines the speed at which the wearer of the watch has traveled over a measured distance.

Telemeter —the kind of scale measured in kilometers or miles used in conjunction with chronograph, that determines the distance through sound.

Tourbillon —on of the most complex mechanisms that corrects errors in timekeeping due to the effect of gravity on a watch in vertical positions: in a regular escapement/balance mechanism, the center of gravity shifts, depending on the position of the watch in space (horizontal, vertical, or any imaginable angle), thus affecting its rate. With the tourbillon, the escapement is mounted on a carriage that rotates once per minute, so the center of gravity will be situated alternatively a little high for half the time and little low for the other half, and these errors will cancel each other. The tourbillon was invented in 1795 and patented in 1801 by one of the most prominent watchmakers in history—Abraham-Louis Breguet.

Water resistance —the ability of a watch to keep the water from penetrating inside the case.

World Time —the kind of watch that tells time in up to 24 time zones around the world. Time zones are represented by the names of the cities belonging to each particular zone, and they printed or engraved on the watch's bezel or dial.