From 'Alarm Watch' to 'Zodiac'...

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This page is a glossary of terms associated with horology, watches and watchmaking, please click one of the links above. If you would like us to list any other words that you think may be helpful, please contact me direct chris@christopherward.co.uk  

A - WATCH WORDS

Alarm Watch
A watch provided with a movement capable of releasing an acoustic sound at the time set. A second crown is dedicated to the winding, setting and release of the striking-work; an additional center hand indicates the time set. The section of the movement dedicated to the alarm device is made up by a series of wheels linked with the barrel, an escapement and a hammer striking a gong or bell. Works much like a normal alarm clock. back to top

Amplitude
Maximum angle by which a balance or pendulum wings from its rest position. back to top

Analog or Analogue
A watch displaying time indications by means of hands. back to top

Analog Quartz
The most commonly-used term in referring to any analog timepiece that operates on a battery or on solar power and is regulated by a quartz crystal. back to top

Annual Calendar
The automatic allowances for the different lengths of each month of a year in the calendar module of a watch. This type of watch also usually shows the month and date, and sometimes the day of the week and the phase of the moon. back to top

Antimagnetic
Mechanical movements can be influenced by the magnetic fields often found in common everyday places. This problem is generally countered by using anti- or nonmagnetic components in the movement as in the eta 2824-2 which we use for the Malvern Automatic. back to top

Antireflection, Antireflective
A film created by steaming the crystal to eliminate light reflection and improve legibility. This film can scratch quite easily so at CWL we choose only to use this treatment on the inside of the crystal glass although Dubey and Schaldenbrand are unusual in that they prefer to coat both sides of all their wristwatches. back to top

Arbor
Bearing element of a gear(s) or balance, whose ends, called pivots, run in jewel holes or brass bushings.

Atmosphere (ATM)
Unit of pressure used in watch making to indicate water-resistance. back to top

Atomic Time Standard
Provided by the U.S. National Institute of Standards and Technology, Time and Frequency Division, Boulder, Colorado, atomic time is measured through vibrations of atoms in a metal isotope that resembles mercury. The result is extremely accurate time that can be measured on instruments. Radio waves transmit this exact time throughout North America and some "atomic" watches can receive them and correct to the exact time. back to top

Automatic
A watch whose mechanical movement is wound automatically. A rotor makes short oscillations due to the movements of the wrist. Through a series of gears, oscillations transmit motion to the barrel, thus winding the mainspring progressively. back to top

Automatic Winding
A rotating weight, set into motion by moving the wrist, winds the spring barrel via the gear train of a mechanical watch movement. Automatic winding was invented during the pocket watch era in 1770 by Abraham-Louis Perrelet, who created a watch with a weight swinging back and forth (that of a pocket watch usually makes vertical movements contrary to a wristwatch). The first automatic –winding wristwatches, invented by John Harwood in the 1920’s, utilised so-called hammer winding, whereby a weight swung in an arc between two banking pins. The breakthrough automatic winding movement via rotor began with the ball bearing Eterna-Matic in the late 1940’s, and the technology hasn’t changed fundamentally since. The Eterna-Matic is the grandfather of our own automatic movements. Eterna became ETA and is now owned by The Swatch Group. back to top

Automation
Figures, placed on the dial or case of watches, provided with parts of the body or other elements moving at the same time as the sonnerie strikes. The moving parts are linked, through an aperture on the dial or caseback, with the sonnerie hammers striking a gong. back to top

B - WATCH WORDS

Baguette
Ladies style watch with a thin, elongated face; usually rectangular in shape but may be oval. back to top

Balance
Oscillating device that, together with the balance spring, makes up the movement's heart in as much as its oscillations determine the frequency of its functioning and precision. back to top

Balance Spring
Component of the regulating unit that, together with the balance, determines the movement's precision. The material used is mostly a steel alloy (e.g. Nivarox, s.), an extremely stable metal compound. In order to prevent the system's center of gravity from continuous shifts, hence differences in rate due to the watch's position, some modifications were adopted. These modifications included Breguet's overcoil (closing the terminal part of the spring partly on itself, so as to assure an almost perfect centering) and Philips curve (helping to eliminate the lateral pressure of the balance-staff pivots against their bearings). Today, thanks to the quality of materials, it is possible to assure an excellent precision of movement working even with a flat spring. back to top

Bar or Cock
A metal plate fastened to the base plate at one point, leaving room for a gear wheel or pinion. The balance is usually attached to a bar called the balance cock. back to top

Barrel
Component of the movement containing the mainspring, whose toothed rim meshes with the pinion of the first gear of the train. Due to the fact that the whole movement - made up of barrel and mainspring - transmits the motive force, it is also considered to be the very motor. Inside the barrel, the mainspring is wound around an arbor turned by the winding crown or, in the case of automatic movements, also by the gear powered by the rotor. back to top

Base Metal
Any non-precious metal. back to top

Battery
Device that converts chemical energy into electricity. Most watch batteries are silver oxide type delivering 1.5 volts. Much longer-lasting lithium batteries are 3 volt. back to top

Battery Life
The minimum period of time that a battery will continue to provide power to run the watch. Life begins at the point of manufacture when the factory initially installs the battery. back to top

Battery Reserve Indicator
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. back to top

Bearing
Part on which a pivot turns, in watches it is represented mostly by jewels. back to top

Bevelling
Chamfering of edges of levers, bridges and other elements of a movement by 45º, a treatment typically found in high-grade movements. back to top

Bezel
Top part of case, often in a shape of the ring surrounding the watch face, sometimes holds the crystal. It may be integrated with the case middle or may be a separate element. It is snapped or screwed on to the middle. back to top

Blued Screw
Swiss watch making tradition dictates that a movement should contain blued screws for aesthetic reasons. Polished steel screws are heated, or tempered, to relax the steel, turning it a deep blue colour in the process. All Christopher Ward movements use the chemically induced version that ensures an even colour every time. back to top

Bracelet
A metal band attached to the case. It is called integral if there is no apparent discontinuity between case and bracelet and the profile of attachments is similar to the first link. back to top

Bridge
Structural metal element of a movement - sometimes called cock or bar - supporting the wheel train, balance, escapement and barrel. Each bridge is fastened to the plate by means of screws and locked in a specific position by pins. In high-quality movements the sight surface is finished with various types of decoration. back to top

Brushed, Brushing
Topical finishing giving metals a line finish, a clean and uniform look. back to top

Buckle
Usually matching the case, it attaches the two parts of the leather strap around the wrist. back to top

Button
Push piece controls, usually at 2 o'clock and/or 4 o'clock on the dial to control special functions such as the chronograph or the alarm. back to top

C - WATCH WORDS

Cabochon
Any kind of precious stone, such as sapphire, ruby or emerald, uncut and only polished, generally of a half-spherical shape, mainly used as an ornament of the winding crown or certain elements of the case. back to top

Calendar, Annual
The automatic allowances for the different lengths of each month of a year in the calendar module of a watch. This type of watch also usually shows the month and date, and sometimes the day of the week and the phase of the moon. back to top

Calendar, Full
Displaying date, day of the week and month on the dial, but needing a manual correction at the end of a month with less than 31 days. It is often combined with the moonphase. back to top

Calendar, Perpetual
This is the most complex horology complication related to the calendar feature, as it indicates the date, day, month and leap year and does not need manual corrections until the year 2100 (when the leap year will be ignored). back to top

Calibre
This term refers to each different type of watch movement e.g. ETA 2824-2. back to top

Cannon
An element in the shape of a hollow cylinder, sometimes also called pipe or bush, for instance the pipe of the hour wheel bearing the hour hand. back to top

Carat (Karat)
Unit of gold fineness (and gemstone weight). Pure gold is 24k. 18k gold is 75% pure. back to top

Carousel
Device similar to the tourbillon, but with the carriage not driven by the fourth wheel, but by the third wheel. back to top

Carriage or Tourbillon Carriage
Rotating frame of a tourbillon device, carrying the balance and escapement. This structural element is essential for a perfect balance of the whole system and its stability, in spite of its reduced weight. As today's tourbillon carriages make a rotation per minute, errors of rate in the vertical position are eliminated. Because of the widespread use of transparent dials, carriages became elements of aesthetic attractiveness. back to top

Case
Container housing and protecting the movement, usually made up of three parts: middle, bezel, and back. back to top

Center Second Hand
A sweep second hand, i.e. a second hand mounted on the center of the main dial. back to top

Center-Wheel
The minute wheel in a going-train. back to top

Champleve
Hand-made treatment of the dial or case surface. The pattern is obtained by hollowing a metal sheet with a graver and subsequently filling the hollows with enamel. back to top

Chapter-Ring
Hour-circle, i.e. the hour numerals arranged on a dial. back to top

Chime
Striking-work equipped with a set of bells that may be capable of playing a complete melody. A watch provided with such a feature is called chiming watch. back to top

Chronograph
From the Greek words for time, chronos, and to write, graphein. Originally a chronograph literally inscribed the time elapsed on a piece of paper, with the help of a pencil attaché to a type of hand. We use the term today to describe watches that show not only the time of day, but also certain time intervals via independent hands that may be started or stopped at will as in the C4 Peregrine shown here. back to top

Chronometer
A high-precision watch. According to the Swiss law, a manufacture may put the word "chronometer" on a model only after each individual piece has passed a series of tests and obtained a running bulletin and a chronometer certificate by an acknowledged Swiss control authority, such as the COSC. back to top

Circular Graining
Superficial decoration applied to bridges, rotors and pillar-plates in the shape of numerous slightly superposed small grains, obtained by using a plain cutter and abrasives. Also called Pearlage or Pearling. back to top

Clasp
The attachment used to connect the two ends of the watch bracelet or strap around the wrist. Deployment Buckle - A three-folding enclosure, which secures the two ends of the bracelet and allows enough room for placing the watch on the wrist when fully deployed. When closed, the buckle covers the two-piece folding mechanism. Hook Lock - Two separate units each fitting on either end of the bracelet which allows the watch to be laid out. One end of the closure hooks onto the other to secure the two ends of the bracelet. Jeweller's Clasp - A closure that is generally used on better bracelets. Also allows it to lie flat. Sliding Clasp - Also a hook type method but allows for easy sizing of the bracelet by sliding up. Twist Lock - A closure similar to Jeweler's Clasp used on ladies jewelry bracelets. back to top

Cloisonne
A kind of enamel work - mainly used for the decoration of dials - in which the outlines of the drawing are formed by thin metal wires. The colored enamel fills the hollows formed in this way. After oven firing, the surface is smoothed until the gold threads appear again. back to top

Clous de Paris
Decoration of metal parts characterized by numerous small pyramids. back to top

Cock
A metal plate fastened to the base plate at one point, leaving room for a gear wheel or pinion. The balance is usually attached to a bar called the balance cock. back to top

Colimaconnage
Decoration with a spiral pattern, mainly used on the barrel wheel or on big-sized full wheels. back to top

Column-Wheel
Part of chronograph movements, governing the functions of various levers and parts of the chronograph operation, in the shape of a small-toothed steel cylinder. It is controlled by pushers through levers that hold and release it. It is a very precise and usually preferred type of chronograph operation. back to top

Complication
Additional function with respect to the manual-winding basic movement for the display of hours, minutes and seconds. Today, certain features, such as automatic winding or date, are taken for granted, although they should be defined as complications. The main complications are moonphase, power reserve, GMT, and full calendar. Further functions are performed by the so-called great complications, such as split-second chronograph, perpetual calendar, tourbilon device, and minute repeater. back to top

Corrector
Pusher positioned on the case side that is normally actuated by a special tool for the quick setting of different indications, such as date, GMT, full or perpetual calendar. back to top

COSC
Abbreviation of "Contrôle Officiel Suisse des Chronomètres" the most important Swiss institution responsible for the functioning and precision tests of movements of chronometers. Tests are performed on each individual watch at different temperatures and in different positions before a functioning bulletin and a chronometer certificate are issued, for which a maximum gap of -4..+4 seconds per day is tolerated. back to top

Cotes Circulaires
Decoration of rotors and bridges of movements, whose pattern consists of a series of concentric ribs. back to top

Cotes de Geneve
Decoration applied mainly to high-quality movements, appearing as a series of parallel ribs, realized by repeated cuts of a cutter leaving thin stripes. back to top

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 the time runs out. These are useful in events such as certain kinds of races. back to top

Counter
Additional hand on a chronograph, indicating the time elapsed since the beginning of the measuring. On modern watches the second counter is placed at the center, while minute and hour counters have off-center hands in special zones, also called subdials. back to top

Crown
The crown is used to wind and set a watch. A few simple turns of the crown will get an automatic movement started (as with The Malvern Automatic and Aviator models), while a manual watch is completely wound by the crown. The crown is also used for the setting of various functions, almost always including at least the hours, minutes, seconds and date. A screwed down crown like the one on the Malvern Aviator can be tightened to prevent water entering the case or any mishaps while performing extreme sports like diving. back to top

Crown Wheel
Wheel meshing with the winding pinion and with the ratchet wheel on the barrel-arbor. back to top

Crystal
The clean cover over the watch face. Three types of crystals are commonly found in watches: acrylic crystal, mineral crystal and sapphire crystal. back to top

D - WATCH WORDS

Depth Alarm
An alarm on a divers' watch that sounds when the wearer exceeds a pre-set depth. back to top

Depth Meter or Depth Sensor
A device on a divers' watch that determines the wearer's depth by measuring water pressure. It shows the depth either by analog hands and a scale on the watch face or through a digital display. back to top

Deck Watch
A large-sized ship's chronometer. back to top

Deviation
A progressive natural change of a watch's rate with respect to objective time. In case of a watch's faster rate, the deviation is defined positive, in the opposite case negative. back to top

Dial
Face of a watch, on which time and further functions are displayed by markers, hands, discs or through windows. Normally it is made of brass - sometimes silver or gold. back to top

Digital Watch
Said of watches whose indications are displayed mostly inside an aperture or window on the dial. back to top

Divers Watch
A watch that is water resistant to 200M. Has a unidirectional rotating bezel and a screw-on crown and back. Has a metal or rubber strap (not leather). May have a sapphire crystal and possibly, a wet-suit extension. back to top

E - WATCH WORDS

Ebauche
Incomplete (jeweled or non-jeweled) watch movement without regulating organs, mainspring, dial and hands. back to top

Eco-Drive
A name for a patented power mechanism found on some Citizen watches. This mechanism uses ordinary light to keep a rechargeable battery powered for watch operation. This technology is very sophisticated allowing some watch models to remain powered for up to 5 years in the dark. Watches with Eco-Drive technology will never need to have the battery replaced. back to top

Elapsed Time Rotating Bezel
A graduated 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. back to top

Electroplating Process
Process of covering metal articles with a film of other metals. The article is immersed in a chemical solution; electric current (D.C.) flows through the solution from a piece of metal (anode) to the article (cathode), depositing metal thereon by electrolysis. back to top

Endstone
Undrilled jewel, placed on the balance jewel with the tip of the balance-staff pivot resting against its flat surface, to reduce pivot friction. Sometimes used also for pallet staffs and escape wheels. back to top

Engine-Turned
A surface decoration usually applied to the dial and the rotor using a grooving tool with a sharp tip, such as a rose engine, to cut an even pattern onto a level surface. back to top

Equation of Time
Indication of the difference, expressed in minutes, between conventional mean time and real solar time. This difference varies from -16 to +16 seconds between one day and the other. back to top

Equinox
The time when day and night are of equal length, when the sun is on the plane of the equator. Such times occur twice in a year: the vernal equinox on March 21st-22nd and the autumnal equinox on September 22nd-23rd. back to top

Escapement
The combination of the balance, balance spring, pallets and escape wheel, a subgroup which divides the impulses coming from the spring barrel into small, accurately proportioned doses. It guarantees that the gear train runs smoothly and efficiently. back to top

Escape Wheel
A wheel belonging to the mechanism called escapement. back to top

F - WATCH WORDS

Flange
The usually inclined ring that separates the crystal from the dial. The flange is sometimes equipped with features such as tachymetric scales and pulsometers. back to top

Flinque
Engraving on the dial or case of a watch, covered with an enamel layer. back to top

Fluted
Said of surfaces worked with thin parallel grooves, mostly on dials or case bezels. back to top

Fly-back
Feature combined with chronograph functions, that allows a new measurement starting from zero (and interrupting a measuring already under way) by pressing down a single pusher, i.e. without stopping, zeroing and restarting the whole mechanism. Originally, this function was developed to meet the needs of air forces. back to top

Fold-Over Clasp
Hinged and jointed element, normally of the same material as the one used for the case. It allows easy fastening of the bracelet on the wrist. Often provided with a snap-in locking device, sometimes with an additional clip or push-piece. back to top

Fourth Wheel
The seconds wheel in going-train. back to top

Frequency
Generally defined as the number of cycles per time unit; in horology it is the number of oscillations of a balance every two seconds or of its vibrations per second. For practical purposes, frequency is expressed in vibrations per hour (vph). See also Vibration. back to top

Fusee
A conical part with a spiral groove on which a chain or cord attached to the barrel is wound. Its purpose is to equalize the driving power transmitted to the train. back to top

G - WATCH WORDS

Glass
Thin plate of glass or transparent synthetic material, for protecting the dial of the watch. back to top

Glucydur
Bronze and beryllium alloy used for high-quality balances. This alloy assures high elasticity and hardness values; it is non-magnetic, rustproof and has a very reduced dilatation coefficient, which makes the balance very stable and assures high accuracy of the movement. back to top

GMT
GMT, or Greenwich Mean Time, is based on the globe being divided into 24 time zones as established in the London Meridian Conference of 1884. The zero meridian runs through the Royal Observatory in the London suburb of Greenwich. In contemporary watch terminology, GMT is often used to describe a wristwatch that displays a second time zone or a 24hour indication. back to top

Gong
Harmonic flattened bell in a steel alloy, generally positioned along the circumference of the movement and struck by hammers to indicate time by sounds. Size and thickness determine the resulting note and tone. In watches provided with minute-repeaters, there are often two gongs and the hammers strike one note to indicate hours, both notes together to indicate quarters and the other note for the remaining minutes. In more complex models, equipped also with en-passant sonnerie devices, there may be up to four gongs producing different notes and playing even simple melodies such as the chime of London's Westminster Clock Tower or 'Big Ben' as it is commonly known. back to top

Guilloche
A surface decoration usually applied to the dial and the rotor using a grooving tool with a sharp tip, to cut an even pattern onto a level surface. back to top