Glossary
Created Saturday 29 June 2024
A
Alarm Watch
A watch provided with a movement capable of releasing an acoustic sound at the time set. Usually, 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.
Amplitude
Maximum angle by which a balance or pendulum wings from its rest position.
Analog or Analogue
A watch displaying time indications by means of hands.
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.
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.
Antimagnetic
Mechanical movements can be influenced by the magnetic fields often found in common everyday places. This problem is generally by using anti- or nonmagnetic components in the movement as in the Sellita SW200 which we use in the C63 Sealander Automatic.
Antireflection, Antireflective
A film created by steaming the crystal to eliminate light reflection and improve legibility. This film can scratch quite easily so at CW 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.
Atmosphere (ATM)
Unit of pressure used in watch making to indicate water-resistance. 1ATM =10m
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.
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.
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.
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.
B
Baguette
Ladies style watch with a thin, elongated face; usually rectangular in shape but may be oval.
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.
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), 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.
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.
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.
Base Metal
Any non-precious metal.
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.
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.
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.
Bearing
Part on which a pivot turns, in watches it represented mostly by jewels.
Beveling
Chamfering of edges of levers, bridges and other elements of a movement, a treatment typically found in high-grade movements.
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.
Blued Screw
Swiss watch making tradition dictates that a movement should contain blued screws for aesthetic reasons. Polished steel screws are heated (or tempered, as it relaxes the steel) to 290 degrees C. This process relaxes the steel, turning it a deep blue in colour.
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.
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.
Brushed, Brushing
Topical finishing giving metals a line finish, a clean and uniform look.
Buckle
Usually matching the case, it attaches the two parts of the leather strap around the wrist.
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.
C
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.
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.
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.
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).
Calibre
This term refers to each different type of watch movement e.g. ETA 2824-2.
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.
Carat (Karat)
Unit of gold fineness (and gemstone weight). Pure gold is 24k. 18k gold is 75% pure.
Carousel
Device similar to the tourbillon, but with the carriage not driven by the fourth wheel, but by the third wheel.
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.
Case
Container housing and protecting the movement, usually made up of three parts: middle, bezel, and back.
Center Second Hand
A sweep second hand, i.e. a second hand mounted on the center of the main dial.
Center-Wheel
The minute wheel in a going-train.
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.
Chapter-Ring
Hour-circle, i.e. the hour numerals arranged on a dial.
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.
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.
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.
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.
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.
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.
Clous de Paris
Decoration of metal parts characterized by numerous small pyramids.
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.
Colimaconnage
Decoration with a spiral pattern, mainly used on the barrel wheel or on big-sized full wheels.
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.
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.
Corrector/span
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.
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.
Cotes Circulaires
Decoration of rotors and bridges of movements, whose pattern consists of a series of concentric ribs.
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.
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 all kinds of race.
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.
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 (pictured here) can be tightened to prevent water entering water entering the case or any mishaps while performing extreme sports like diving.
Crown Wheel
Wheel meshing with the winding pinion and with the ratchet wheel on the barrel-arbor.
Crystal
The clean cover over the watch face. Three types of crystals are commonly found in watches: acrylic crystal, mineral crystal and sapphire crystal.
D
Depth Alarm
An alarm on a divers' watch that sounds when the wearer exceeds a pre-set depth.
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.
Deck Watch
A large ship's chronometer.
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.
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 a brass - sometimes silver or gold.
Digital Watch
Said of watches whose indications are displayed mostly inside an aperture or window on the dial.
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.
E
Ebauche
Incomplete (jeweled or non-jeweled) watch movement without regulating organs, mainspring, dial and hands.
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.
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.
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.
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.
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.
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.
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.
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.
Escape Wheel
A wheel belonging to the mechanism called escapement.
F
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.
Flinque
Engraving on the dial or case of a watch, covered with an enamel layer.
Fluted
Said of surfaces worked with thin parallel grooves, mostly on dials or case bezels.
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.
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.
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.
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.
G
Glass
Thin plate of glass or transparent synthetic material, for protecting the dial of the watch.
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.
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.
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 Big Ben).
Guilloche
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.
H
Hammer
Steel or brass element used in movements provided with a repeater or alarm sonnerie. It strikes a gong or bell (s).
Hand
Indicator for the analogue visualization of hours, minutes and seconds as well as other functions. Normally made of brass (rhodium-plated, gilded or treated otherwise), but also steel or gold. Hands are available in different shapes and take part in the aesthetic result of the whole watch.
Heart-piece
Heart-shaped corn, generally used to realign the hands of chronograph counters.
Helium Valve
When divers spend extended periods at great depths in a diving bell or a pressurized habitat, helium atoms can penetrate the watch case because they are smaller than air molecules. Over time, helium can accumulate inside the watch case as the pressure decreases during ascent. If not properly released, the built-up helium gas can cause the watch crystal or case to pop off due to the pressure differential between the inside of the watch and the external environment. The helium escape valve is a one-way valve that allows the built-up helium gas to escape from the watch case during decompression. It is usually positioned on the side of the watch case and is designed to open automatically when the pressure inside the case becomes significantly higher than the pressure outside. This prevents the watch from being damaged while maintaining its water resistance and integrity.
Hexalite
An artificial glass made of a plastic resin. Back in the 1960's, many watches used either mineral glass or acrylic crystals. These are not difficult to scratch, but very inexpensive to replace. Now though, most all luxury watches use the highly scratch resistant synthetic sapphire crystals, there are some styles/brands that use the Hesalite (a name brand of fine acrylic crystal). The reason for this is directly related to the watch's certification for use in space or in high stress/impact situations. While sapphire crystals are less prone to scratching, they can be shattered. When shattered, they break into tiny fragments that would be hazardous in some environments. So the Hesalite crystal is maintained on some specific models as a safety feature.
Hunter Caliber
A caliber characterized by the seconds hand fitted on an axis perpendicular to the one of the winding stem.
I
Incabloc
Incabloc is a shock-absorber system which help prevent damage from shocks to the balance pivots. Thanks to a retaining spring system, it assures an elastic play of both jewels, thus absorbing the movements of the balance-staff pivots when the watch receives strong shocks. The return to the previous position is due to the return effect of the spring. If such a system is lacking, the shock forces exert an impact on the balance-staff pivots, often causing bending or even breakage.
Invented in 1934 by Swiss engineers Georges Braunschweig and Fritz Marti, at Universal Escapements, Ltd
J
Jewel
To minimise friction, the hardened steel tips of a movement’s rotating gear wheels (called pinions) are lodged in synthetic rubies (fashioned as polished stones with a hole) and lubricated with a very thin layer of special oil. These synthetic rubies are produced in exactly the same way as sapphire crystal using the same material.
Jumping Hour
Feature concerning the digital display of time in a window. The indication changes almost instantaneously at every hour.
L
Lap Timer
A chronograph function that lets the wearer time segments of a race. At the end of a lap, he stops the timer, which then returns to zero to begin timing the next lap.
Leap-Year Cycle
Leap or bissextile years have 366 days and occur every 4 years (with some exceptions, Calendar, Gregorian). Some watches display this datum.
Lepine Caliber
A caliber typical for pocket-watches, characterized by the seconds hand fitted in the axis of the winding-stem.
Lever Set
To set the watch hands, a lever must be pulled out, used to avoid accidently moving the hands as mandated on American Railroad watches.
Lift angle
The angle in degrees between the entry and the release of the impulse pin of the balance wheel on the crown of the pallet fork, is called the lift angle.
The lift angle is necessary to calculate the amplitude.
Most watches have a lift angle between 48 and 54 degrees.
Line
Ancient French measuring unit maintained in horology to indicate the diameter of a movement. A line equals 2.255mm. Lines are not divided into decimals; therefore, to indicate measures inferior to the unit, fractions are used.
Liquid Crystal Display or LCD
A digital watch display that shows the time electronically by means of a liquid held in a thin layer between two transparent plates. All LCD watches have quartz movements.
Lubrication
To reduce friction caused by the running of wheels and other parts. There are points to be lubricated with specific low-density oils such as the pivots turning inside jewels, the sliding areas between levers, and the spring inside the barrel (requiring a special grease), as well as numerous other parts of a movement.
Lug
Double extension of the case middle by which a strap or bracelet is attached. Normally, straps and bracelets are attached with removable spring bars.
Luminescent or Luminous
CW watches use Super-LumiNova, a photo-luminescent non-radioactive material with a long period of phosphorescence. It reaches up to 100 times higher brightness than Tritium. Tritium was the original, radioactive, substance used to coat hands, numerals and hour markers on watch dials to make reading the time in the dark possible.
M
Mainspring
The mainspring, located in the spring barrel, stores energy when tensioned and passes it on to the escapement via the gear train as the tension releases. Today, mainsprings are usually made of Nivaflex, an alloy invented by Swiss engineer Max Straumann in the early 1950’s. This alloy basically comprises iron, nickel, chrome, cobalt and beryllium.
Manual Wind
A mechanical movement in which winding is performed by hand. The motion transmitted from the user's fingers to the crown is forwarded to the movement through the winding stem, from this to the barrel through a series of gears and finally to the mainspring.
Manufacture
Most experts agree that the term, which is from Latin and means “made by hand”, should be used for a company that manufactures at least one calibre, or extremely important parts of it such as the base plate, on the premises. While ten years ago this constituted only a handful of companies in Switzerland and Germany today’s competitive market has forced a number of others to invest in developing their own movements.
Marine Chronometer
A large-sized chronometer watch enclosed in a box (therefore also called box chronometer) mounted on gimbals and used, on board of ships, to determine the respective longitude.
Markers
Elements printed or applied on the dial, sometimes they are luminescent, used as reference points for the hands to indicate hours and fifteen- or five-minute intervals.
Meantime
The mean time of the meridian of the Greenwich Observatory, considered the universal meridian, is used as a standard of the civil time system, counted from midnight to midnight.
Measurement Conversion
A feature, usually consisting of a graduated scale on the watch's bezel, that lets the wearer translate one type of measurement into another - miles into kilometers, for instance, or pounds into kilograms.
Mechanical Movement
A movement powered by a mainspring, working in conjunction with a balance wheel. Most watches today have electronically controlled quartz movements and are powered by a battery. However, mechanical watches are currently enjoying a resurgence in popularity.
Micrometer Screw
Element positioned on the regulator, allowing to shift it by minimal and perfectly gauged ranges so as to obtain accurate regulations of the movement.
Micro-Rotor
See Rotor
Military Time or 24hr Time
When time is measured in 24-hour segments. To convert 12-hour time into 24-hour time, simply add 12 to any p.m. time. To convert 24-hour time into 12-hour time, subtract 12 from any time from 13 to 24.
Mineral Crystal or Mineral Glass
Watch crystal that has been tempered (heat treated) to increase its hardness and scratch resistance.
Minute Repeater
Mechanism indicating time by acoustic sounds. Contrary to the watches provided with en-passant sonnerie devices, that strike the number of hours automatically, repeaters work on demand by actuating a slide or pusher positioned on the case side. Repeaters are normally provided with two hammers and two gongs: one gong for the minutes and one for the hours. The quarters are obtained by the almost simultaneous strike of both hammers. The mechanism of the striking work is among the most complex complications.
Module
Self-contained mechanism, independent of the basic caliber, added to the movement to make an additional function available: chronograph, power reserve, GMT, perpetual or full calendar (s).
Moonphase
A function available in many watches, usually combined with calendar-related features. The moonphase disc advances one tooth every 24 hours. Normally, this wheel has 59 teeth and assures an almost perfect synchronization with the lunation period, i.e. 29.53 days (in fact, the disc shows the moonphases twice during a single revolution). However, the difference of 0.03 days, i.e. 44 minutes each month, implies the need for a manual adjustment every two and a half years to recover one day lost with respect to the real state of moonphase. In some rare case, the transmission ratio between the gears controlling the moonphase are calculated with extreme accuracy so as to require manual correction only once in 100 years.
Mother of Pearl
Iridescent, milky interior shell of the fresh water mollusk that is sliced thin and used on watch dials. While most have a milky white luster, mother-of-pearl also comes in other colors such as silvery gray, gray blue, pink, and salmon.
Movement
The entire mechanism of a watch. Movements are divided into two great families: quartz and mechanical; the latter are available with manual or automatic winding devices.
N
Nivarox
Trade name (from the producer's name) of a steel alloy, resisting magnetization, used for modern self-compensating balance springs. The quality level of this material is indicated by the numeral following the name in decreasing value from 1 to 5.
O
Observatory Chronometer
An observatory-tested precision watch that obtained the relevant rating chronometer certificate.
Oscillation
Complete oscillation or rotation movement of the balance, formed by two vibrations.
Open face Movement
Open face movement is laid out so that the 4th wheel (seconds hand) is 180 opposite the winding stem.
P
Pallets
Device of the escapement transmitting part of the motive force to the balance, in order to maintain the amplitude of oscillations unchanged by freeing a tooth of the escape wheel at one time.
Pillar-Plate or Main Plate
A metal platform having several tiers for the gear train. The base plate of a movement usually incorporates the dial and carries the bearings for the primary pinions of the “first floor” of a gear train.
Pinion
Combines with a wheel and an arbor to form a gear. A pinion has less teeth than a wheel and transmits motive force to a wheel. Pinion teeth (normally 6 to 14) are highly polished to reduce friction to a minimum.
Pin Set
To adjust the hands, first a pin must be depressed on the watch case, found mostly on pocket watches.
Pivot
End of an arbor turning on a jewel support. As their shape and size can influence friction, the pivots of the balance-staff are particularly thin and, hence, fragile, so they are protected by a shockproof system.
Plated
Metal, treated by a galvanizing procedure in order to apply a slight layer of gold or another precious metal (silver, chromium, rhodium or palladium) on a brass or steel base.
Plexiglas
A synthetic resin used for watch crystal.
Poincon de Geneve
Distinction assigned by the Canton of Geneva to movements produced by watchmaker firms of the Region and complying with all the standards of high horology with respect to craftsmanship, small-scale production, working quality, accurate assembly and setting. The Geneva Seal is engraved on at least one bridge and shows the Canton's symbol, i.e. a two-field shield with an eagle and a key respectively in each field.
Polished Finish
Brilliant metal surface obtained on the watch case with fine abrasive. Compare to brushed finish.
Power Reserve
Duration (in hours) of the residual functioning autonomy of a movement after it has reached the winding peak. The duration value is displayed by an instantaneous indicator: analog (hand on a sector) or digital (through a window). The related mechanism is made up of a series of gears linking the winding barrel and hand. Recently, specific modules were introduced which may be combined with the most popular movements.
Precision
Accuracy rate of a watch, a term difficult to define exactly. Usually, a precision watch is a chronometer whose accuracy-standard is certified by an official watch-rating bureau.
Pulsimeter Chronograph
The pulsimeter scale shows, at a glance, the number of pulse beats per minute. The observer releases the chronograph hand when starting to count the beats and stops at the 30th, the 20th or the 15th beat according to the basis of calibration indicated on the dial.
Pusher, Push-Piece or Push Button
Mechanical element mounted on a case for the control of specific functions. Generally, pushers are used in chronographs, but also with other functions.
PVD
Abbreviation of Physical Vapor Deposition, a plating process consisting of the physical transfer of substance by bombardment of electrons.
Q
Quartz
Timekeeping’s technical revolution found its way to the world’s wrists in the late 1960’s. This was principally a Swiss invention (the first working quartz watches were made by Girard-Perregaux and Piaget in a Swiss joint venture) but it was the Japenese firms, primarily Seiko, who were the first to see the advantages of the new technology and came to dominate the market. The quartz movement uses the famously stable vibration frequency of a quartz crystal subjected to the electronic tension (usually 32,868Hz) as its norm. The Malvern Chronograph has the renowned Ronda Calibre 5040D, shown below, as its quartz movement.
Quartz Movement
A movement powered by a quartz crystal. Quartz crystals are very accurate. They can be mass produced which makes them less expensive than most mechanical movements which require a higher degree craftsmanship.
R
Ratchet Wheel
Toothed wheel prevented from moving by a click pressed down by a spring.
Regulating Unit
Made up by balance and balance spring, governing the division of time within the mechanical movement, assuring its regular running and accuracy. As the balance works like a pendulum, the balance spring's function consists of its elastic return and starting of a new oscillation. This combined action determines the frequency, i.e. the number of vibrations per hour, and affects the rotation speed of the different wheels. In fact the balance, by its oscillations, at every vibration (through the action of the pallets), frees a tooth of the escape wheel (see escapement). From this, motion is transmitted to the fourth wheel, which makes a revolution in one minute, to the third and then the center wheel, the latter making a full rotation in one hour. However, everything is determined by the correct time interval of the oscillations of the balance.
Regulator
Regulating the functioning of a movement by lengthening and shortening the active section of the balance spring. It is positioned on the balance-bridge and encompasses the balance spring with its two pins near its fixing point on the bridge itself. By shifting the index, the pins also are moved and, by consequence, the portion of the balance spring capable of bringing the balance back is lengthened or shortened by its elastic force. The shorter it is, the more reactive it tends to be and the more rapidly it brings the balance back and makes the movement run faster. The contrary happens when the active portion of the balance spring is lengthened. Given today's high frequencies of functioning, even slight index shifts entail daily variations of minutes. Recently, even more refined index-regulation systems were adopted (from eccentric to micrometer screws) to limit error margins to very few seconds per day.
Remontoir or Constant-Force
Old term used to denote any mechanism assuring a constant transmission of the driving power to the escape wheel.
Repeater
Mechanism indicating time by acoustic sounds. Contrary to the watches provided with en-passant sonnerie devices, that strike the number of hours automatically, repeaters work on demand by actuating a slide or pusher positioned on the case side. Repeaters are normally provided with two hammers and two gongs: one gong for the minutes and one for the hours. The quarters are obtained by the almost simultaneous strike of both hammers. The mechanism of the striking work is among the most complex complications.
Retrograde
Said of a hand that, instead of making a revolution of 360 before starting a new measurement, moves on an arc scale (generally of 90 to 180 and at the end of its trip comes back instantaneously. Normally, retrograde hands are used to indicate date, day or month in perpetual calendars, but there are also cases of retrograde hours, minutes or seconds. Unlike the case of the classical indication over 360 the retrograde system requires a special mechanism to be inserted into the basic movement.
Roller Table or Roller
Part of the escapement in the shape of a disc fitted to the balance staff and carrying the impulse pin that transmits the impulses given by the pallets to the balance.
Rotating Bezel
A bezel that can be turned. Different types of rotating bezels perform different time keeping and mathematical functions.
Rotor
The rotor is the component that keeps an automatic watch wound. The kinetic motion of this part, which contains a heavy metal weight around its outer edge, winds the mainspring. The rotor seen here is from the specially commissioned ETA 2824-2 movement for the limited edition C5 Malvern Aviator.
S
Sapphire Crystal
Synthetic sapphire crystal is a virtually scratchproof material with a hardness of 9 on the Mohs scale which means only a diamond is harder. The material is known to gemmologists as aluminium oxide or corundum, can be colourless (corundum), red (ruby), blue (sapphire) or green (emerald). It is “grown” using a method invented by Auguste Victore Louis Verneuil in 1902 whereby a process that usually takes a thousand years to complete is accelerated to just a few hours, hence the use of the term synthetic. Unsurprisingly, sapphire crystal has become the material of use to protect the dials of all high end modern wristwatches including all Christopher Ward timepieces.
Scale
Graduation on a measuring instrument, showing the divisions of a whole of values, especially on a dial, bezel. The scales mostly used in horology are related to the following measuring devices: tachometer (indicating the average speed), telemeter (indicating the distance of a simultaneously luminous and acoustic source, e.g. a cannon-shot or a thunder and related lightning), pulsometer (to calculate the total number of heartbeats per minute by counting only a certain quantity of them). For all of these scales, measuring starts at the beginning of the event concerned and stops at its end; the reading refers directly to the chronograph second hand, without requiring further calculations.
Screw Balance
Before the invention of the perfectly weighted balance by use of a smooth ring, balances were fitted with weighted screws to get the exact impetus desired. Today a screw balance is a subtle sign of quality in a movement due to its costly construction.
Screw-Down Crown
A crown which aids water resistance by sealing the crown against the case. The seal is achieved by the matching of a threaded pipe on the case with the crown's internal threads and gasketing while twisting the crown to lock it into place.
Second Time-Zone Indicator
An additional dial that can be set to the time in another time zone. It lets the wearer keep track of local time and the time in another country simultaneously. See also GMT and world time.
Self-Winding
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.
Shockproof or Shock-Resistant
Watches provided with shock-absorber systems (e.g. Incabloc) help prevent damage from shocks to the balance pivots. Thanks to a retaining spring system, it assures an elastic play of both jewels, thus absorbing the movements of the balance-staff pivots when the watch receives strong shocks. The return to the previous position is due to the return effect of the spring. If such a system is lacking, the shock forces exert an impact on the balance-staff pivots, often causing bending or even breakage.
Sidereal Time
The conventional time standard refers to the sidereal year (defined in terms of an average of 365.25636 days) considered to be perfectly regular until very recently, but - even though this is not true - the difference is so slight that it is virtually neglected. As a unit of time, the sidereal day is used mainly by astronomers to define the interval between two upper transits of the vernal point in the plane of the meridian.
Skeleton, Skeletonized
Watches whose bridges and pillar-plates are cut out in a decorative manner, thus revealing all the parts of the movement.
Slide
Part of a mechanism moving with friction on a slide-bar or guide.
Small Second
Time display in which the second hand is placed in a small subdial.
Snailing
Decoration with a spiral pattern, mainly used on the barrel wheel or on big-sized full wheels.
Solar Powered
A watch that uses solar energy (from any light source) to power the quartz movement. Citizen call their solar powered watches "Eco-Drive".
Solar Time
The time standard referred to the relative motion of the Earth and the Sun governing the length of day and night. The true solar day is the period measured after the Sun appears again in the same position from our point of observation. Due to the non-uniform rotation of the Earth around the Sun, this measure is not regular. As an invariable measure unit, the mean solar day corresponds to the average duration of all the days of the year.
Solstice
The time when the sun is farthest from the equator, i.e. on June 21st (Summer solstice) and December 21st (Winter solstice).
Sonnerie (au Passage)
The purpose of the Sonnerie au Passage complication is to audibly signal the passing of time, at regular intervals, providing a harmonious and aesthetically pleasing way to mark the passing hour.
Sonnerie (en Passant)
Function consisting of an acoustic sound, obtained by a striking work made up of two hammers striking gongs (s.) at set hours, quarter- and half-hours. Some devices can emit a chime (with three or even four hammers and gongs). By a slide or an additional pusher it is possible to exclude the sonnerie device and to select a so-called grande sonnerie.
Split-Second Chronograph
Also known in the watch industry by its French name, the rattrapante. A watch with two second hands, one of which can be blocked with a special dial train lever to indicate an intermediate time while the other continues to run. When released, the split-seconds hand jumps ahead to the position of the other second hand.
Spring Barrel
The spring contains the mainspring. It turns freely on an arbour, pulled along by the toothed wheel generally doubling as its lid. This wheel interacts with the first pinion of the movement’s gear train. Some movements contain two or more spring barrels for added power reserve.
Stopwatch
A watch with a seconds hand that measures intervals of time. When a stopwatch is incorporated into a standard watch, both the stopwatch function and the timepiece are referred to as a chronograph.
Stopwork
Traditional device (now obsolete) provided with a finger piece fixed to the barrel arbor and a small wheel in the shape of a Maltese cross mounted on the barrel cover, limiting the extent to which the barrel can be wound.
Striking Work
See Sonnerie and Repeater.
Subdial
A small dial on a watch face used for any of several purposes, such as keeping track of elapsed minutes or hours on a chronograph or indicating the date.
Super-Luminova
Christopher Ward watches use Super-LumiNova, a photo-luminescent non-radioactive material with a long period of phosphorescence. It reaches up to 100 times higher brightness than Tritium. Tritium was the original, radioactive, substance used to coat hands, numerals and hour markers on watch dials to make reading the time in the dark possible.
Sweep Second Hand
A center second hand, i.e. a second hand mounted on the center of the main dial.
T
Tachometer or Tachymeter
A scale on the dial, flange, or bezel of a chronograph that, in conjunction with the second hand , gives the speed of a moving object. A tachymeter takes a value determined in less than a minute and converts it into miles or kilometres per hour. For example, the wearer could measure the time it takes a car to pass between two mile markers on a road. When the car passes the second marker, the second hand will be pointing to the car’s speed in miles per hour on the tachometric scale.
Tank Watch
A rectangular watch designed by Louis Cartier. The bars along the sides of the watch were inspired by the tracks of tanks used in World War I.
Telemeter
Telemeter scale allows to measure the distance of a phenomenon that is both visible and audible. The chronograph hand is released at the instant the phenomenon is seen; it is stopped when the sound is heard, and its position on the scale shows, at a glance, the distance in kilometers or miles separating the phenomenon from the observer. Calibration is based upon the speed at which sound travels through the air (approx. 340 meters or 1115 feet per second). During a thunderstorm, the time that has elapsed between the flash of lightning and the sound of the thunder is registered on the chronograph scale.
Third Wheel
Wheel positioned between the minutes and seconds wheels.
Timer
Instrument used for registering intervals of time (duration, brief times), without any indication of the time of day.
Time Zones
The 24 equal spherical zones unto which the surface of the Earth is conventionally divided, each limited by two meridians. The distance between two adjacent zones is 15 or 1 hour. Each country adopts. the time of its zone, except for countries with more than one zone. The universal standard time is that of the zero zone whose axis is the Greenwich meridian.
Titanium
Titanium is a metal that is 40% stronger and 30% lighter than stainless steel. It is hypoallergenic because it is nickel-free. It is perfect for water sport enthusiasts as it is extremely resistant to salt water and other forms of corrosion and able to withstand extreme temperatures. Many titanium watches are further enhanced with a glass coating for increased scratch resistance.
Tonneau
Particular shape of a watchcase, imitating the profile of a barrel, i.e. with straight, shorter, horizontal sides and curved, longer, vertical sides.
Tourbillon
A technically demanding device invented by Abraham Louis Breguet in 1801 to compensate for the interference of gravity on the balance of a pocket watch, thus improving its rate. In a tourbillon (from the French word for whirlwind), the entire escapement is mounted on an epicyclic train in a “cage” and rotated completely on its axis over regular periods of time, usually once a minute. This superb horological highlight, whilst being completely unnecessary for a wristwatch, is seen as a sign of technological know-how in the modern era. One day we may decide to commission our own CW tourbillon and have had early conversations with a bespoke manufacture of haute horologie. Watch this space.
Train
Part of a mechanism moving with friction on a slide-bar or guide.All the wheels between barrel and escapement.
Tritium
Slightly radioactive material that collects light energy and is used to coat hands, numerals, and hour markers on watch dials in order to make reading the time in the dark possible. Watches bearing tritium must be marked as such, with the letter T on the dial near 6 o'clock. It is gradually being replaced by nonradioactive materials such as Superluminova and Traser due to medical misgivings and expected governmental regulation of its use.
Two-Tone
A term use to indicate that a watch has both "silver" and "gold" tone color which may or may not be genuine gold or silver.
U
Unidirectional Rotating Bezel
An elapsed time rotating bezel, often found on divers' watches, that moves only in a counterclockwise direction. It is designed to prevent a diver who has unwittingly knocked the bezel off its original position from overestimating his remaining air supply. Because the bezel moves in only one direction, the diver can err only on the side of safety when timing his dive. Many divers' watches are ratcheted, so that they lock into place for greater safety.
Universal Time
The mean solar time of the Greenwich meridian, counted from noon to noon, Often confused with the mean time notion.
V
Variation
In horology the term is usually referred to the variation of the daily rate, i.e. the difference between two daily rates specified by a time interval.
Vibration Frequency (VPH)
The ring-shaped balance swings around its own axis and acts as the ruling organ of the movement’s escapement. It’s amplitude (normally about 300 degrees) is restricted by the very thin balance spring, which also provides for the reversing of its direction od rotation. The frequency of the alternating vibrations is measured in Hertz (Hz) or in the more usual vibrations per hour (vph). Most of today’s wristwatches tick at 28,800vph (4Hz, like our own Malvern Automatic ) or 21,600vph (3Hz).
W
Water Resistant or Waterproof
Usually measured in increments of one atmosphere (atm or bar, equal to 10 metres of water pressure) or metres and is often noted on the dial or case back. Swimming or snorkelling require 5 atm whilst scuba diving needs 20 atm to be sure. The record is held by The Hydromax by Bell & Ross which was developed for professional deep sea diving and is resistant to 11,100 metres!
Wheel
Circular element, mostly toothed, combines with an arbor and a pinion to make up a gear. Wheels are normally made of brass, while arbors and pinions are made of steel. The wheels between barrel and escapement make up the so-called train.
Winding Stem
Element transmitting motion from the crown to the gears governing manual winding and setting.
Window
Aperture in the dial, that allows reading the underlying indication, mainly the date, but also indications concerning a second zone's time or jumping hour.
World Time
Additional feature of watches provided with a GMT function, displaying the 24 time zones on the dial or bezel, each zone referenced by a city name, providing instantaneous reading of the time of any country.
Z
Zone
Small additional dial or indicator that may be positioned, or placed off-center on the main dial, used for the display of various functions (e.g. second counters).
Zodiac
Circular belt with the ecliptic in the middle containing the twelve constellations through which the sun seems to pass in the course of a year.
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