The 12-hour clock is a timekeeping convention in which the 24 hours of the day are divided into two periods called ante meridiem (a.m., from Latin, literally before the middle of the day, idiomatically approaching midday) and post meridiem (p.m., past midday). Each period consists of 12 hours numbered 12 (acting as zero), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11. The a.m. period runs from midnight to noon, while the p.m. period runs from noon to midnight. The most common convention is to assign 12 a.m. to midnight (at the beginning of the day) and 12 p.m. to noon, defining both half days to have a closed (inclusive) beginning and open (exclusive) end. The phrases 12 noon and 12 midnight (or simply noon and midnight) can more clearly express these times (except that for midnight one may need to also specify whether it is the midnight at the beginning or the end of the day in question).


The Latin abbreviations a.m. and p.m. (often written am and pm; AM and PM; and A.M. and P.M.) are used in English and Spanish. In Albanian, the equivalents are PD and MD, in Greek they are ?µ; and µµ, and in Swedish (though in Sweden the 12-hour clock is nowadays rarely used) they are f.m. and e.m.. Most other languages lack formal abbreviations for before noon and after noon and their users use the 12-hour clock only verbally and informally. The 12-hour clock is a timekeeping convention in which the 24 hours of the day are divided into two periods called ante meridiem (a.m., from Latin, literally before the middle of the day, idiomatically approaching midday) and post meridiem (p.m., past midday). Each period consists of 12 hours numbered 12 (acting as zero), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11. The a.m. period runs from midnight to noon, while the p.m. period runs from noon to midnight. The most common convention is to assign 12 a.m. to midnight (at the beginning of the day) and 12 p.m. to noon, defining both half days to have a closed (inclusive) beginning and open (exclusive) end. The phrases 12 noon and 12 midnight (or simply noon and midnight) can more clearly express these times (except that for midnight one may need to also specify whether it is the midnight at the beginning or the end of the day in question).


Chemical description: Polyacrylmethacryl acid squaring. Material for watch crystals also known as plexiglass. Acryl is easy to process. It can be filed, polished or bent. The advantages of Acryl are high resistance to shocks, anti-allergenic qualities, its malleability and the price. The disadvantage is that due to the weakness of the material the surface is liable to scratch. However, light scratches can be removed by polishing. Acrylic resin is one of plastics (resin) generated through chemical reaction by applying polymerization initiator and heat to MMA monomer. Its chemical name is Poly Methyl Methacrylate and is generally called acrylic resin or methacrylic resin. MMA is an abbreviated name of Methyl Methacrylate and is transparent and colorless fluid substance. Monomer means mono molecule and turns into polymer (macro molecule) when bound together by chemical reaction. This chemical reaction is called polymerization. One of main characteristic features of acrylic resin is its high transparency. Its transparency is one of the highest among resins, much higher than inorganic glasses, and is regarded as something like a queen of resins. And with its quality of weather resistance, it does not easily turn yellow or crumble by sunlight. Acrylic resin is used not only for transparent windows in aquariums but also for various items such as signboards in places like convenience stores, taillights of automobiles, cell phone display screens, backlight optical wave guides for liquid crystal displays (LCD) and so on.


An alarm clock is a clock that is designed to make an alert sound at a specific date and/or time. The primary use of these clocks is to awaken people from their sleep in order to start their days in the mornings, but they are sometimes used for other reminders as well. To stop the sound, a button or handle on the clock needs to be pressed, and some stop automatically after a few minutes if left unattended. A classical analog alarm clock has an extra hand that is used to specify the time at which to activate the alarm. Traditional mechanical alarm clocks have a bell on top that rings, but digital alarm clocks can make other noises. Simple battery-powered alarm clocks make a loud buzzing sound, or other similar noise to wake a sleeper, while novelty alarm clocks can speak, laugh, or sing. Some alarm clocks have radios that start playing at specified times, and are known as clock radios. In a mechanical bell-style alarm clock, a spring drives a gear that propels a clacker back and forth between two bells or between the sides inside a single bell. In an electric bell-style alarm clock, the bell rings with an electromagnetic circuit and armature that turns the circuit on and off again repeatedly. Levi Hutchins, of New Hampshire, in the United States, invented the first mechanical alarm clock in 1787. This device he made only for himself however, and it only rang at 4 AM, in order to wake him for his job.[1] The French inventor Antoine Redier was the first to patent an adjustable mechanical alarm clock, in 1847.


The distance between the two extreme points of a movement or periodic phenomenon (? angle).


Watches not, or hardly, affected by magnetic fields. For the balance springs of the balance non-magnetic nickel alloys are used.


Vibrations of the balance per hour. Two vibrations make the well-known tick-tock sound of the mechanical watch, known as one oscillation.


Display of time by means of at least two hands of different length. The position of the short hour and the longer minute hand represent the actual time of day, relative to 12 hours midday. The term analogue display has been used in the watch industry for only 25 years, to differentiate it from the increasingly popular digital display.


Moving part, usually circular, oscillating about its axis of rotation. The hairspring coupled to it makes it swing to and fro, dividing time into exactly equal parts. Each of the to-and-fro movements of the balance (tick-tack) is called an oscillation. One oscillation is composed of two vibrations.


Red arrows indicate the balance wheel on this movement. The balance wheel is the part of a Mechanical Watch that facilitates even passage of time, analogous to a pendulum in a pendulum clock. The balance wheel rotates in both directions, and its movement is controlled by the balance spring. As the wheel rotates back and forth, the impulse jewel strikes the pallet fork, which in turn allows the escape wheel to advance. Since the mass of the balance wheel and the spring coefficient of the balance spring are known, the amount of time between impacts of the impulse jewel and pallet fork is known. By advancing the rest of the wheel train at set intervals of time the watch is able to keep the hands on the face of the watch to the current time. Self-compensating balance wheel A crucial problem with mechanical watches, after Robert Hooke and Christiaan Huygens applied the balance spring to a watch in 1675, was that the spring was very sensitive to temperature changes. If the temperature rose for example, the metal spring would extend due to thermal expansion. However from the timekeeping point of view, what was worse was that the elasticity of the spring changed. Thus the spring would have a lower frequency and the clock would lose time. The key to solving this problem was to modify the construction of the balance wheel to vary the size of the wheel with temperature, employing conservation of angular momentum to speed up or slow down. As an example, think of an ice skater spinning. If she starts spinning with the arms close to her body and then extends her arms outwards, her spin rate will decrease. In other words the radius of gyration changes. This is the fundamental regulation method of the self-compensating balance wheel. It changes shape with temperature. An increase in temperature will make the diameter of the balance wheel smaller and the clock will go faster. This is counter to the typical mechanics of thermal expansion. The trick was to make the balance wheel change shape in such a way that it would cancel out the effect of the spring increasing or decreasing its elasticity. The solution to constructing a balance wheel that would change shape was to use two different metals that would increase differently in length with temperature (a bimetallic strip). If two flat bars of different metals are fixed together and heated, the bar will bend since one of the parts will increase more in length than the other. Instead of using a solid ring as a balance wheel, the wheel was constructed out of two metals, and cut open at two points, resembling an s-shape. The metals were chosen such that with an increase in temperature the arms would bend inwards, thus making the wheel spin faster.


In watchmaking, a barrel is a wheel composed of a toothed disc and a cylindrical box closed by a cover. The barrel turns freely on an arbor and contains a spring such as the mainspring. The spring is hooked to the barrel at its outer end and to the arbor at its inner end. The barrel meshes with the first pinion of the train of a watch. Barrels rotate slowly: for a watch mainspring barrel, the rate of rotation may vary (based on the design) between one ninth and one sixth of a revolution per hour. Hanging Barrel: i.e. fixed to the movement only by its upper portion, under a bar. Plain Barrel: i.e. without teeth, used in fusee watches; the chain, or catgut, was coiled round the plain barrel, connecting it to the fusee.


A metal plate under which the pivots of the wheels and pinions turn. Both ends of the bridge are secured to the plate by screws. Generally a bridge is named according to its function, e.g. centre-wheel bridge, barrel bridge, balance cock, etc.


The plate which bears the various movement parts and in particular the bridges. The dial is usually affixed to the bottom side of the plate. The plate is pierced with holes for the screws and recesses for the jewels in which the pivots of the movement wheels will run.


The carat (abbreviation ct) is a measure of the purity of gold and platinum alloys. In the United States and Canada, the spelling karat is now solely used for the measure of purity, while carat solely refers to the measure of mass weight (see Carat). As a measure of purity, one karat is purity by weight: where X is the carat rating of the material, Mg is the mass of pure gold or platinum in the material, and Mm is the total mass of the material. Therefore 24-carat gold is pure (100% Au w/w), 18-carat gold is 75% gold, 12-carat gold is 50% gold, and so forth. Historically, in England the carat was divisible into four grains, and the grain was divisible into four quarts. For example, a gold alloy of fineness (that is, 99.2% purity) could have been described as being 23-carat, 3-grain, 1-quart gold. The karat system is increasingly being complemented or superseded by the millesimal fineness system in which the purity of precious metals is denoted by parts per thousand of pure metal in the alloy. The most common carats used for gold in bullion, jewellery making and by goldsmiths are:

24 karat (millesimal fineness 999)
22 karat (millesimal fineness 916)
20 karat (millesimal fineness 833)
18 karat (millesimal fineness 750)
15 karat (millesimal fineness 625)
14 karat (millesimal fineness 585)
10 karat (millesimal fineness 417
9 karat (millesimal fineness 375)


Time zones of Europe: Western European Time (UTC+0)Western European Summer Time (UTC+1) Central European Time (UTC+1)Central European Summer Time (UTC+2) Eastern European Time (UTC+2)Eastern European Summer Time (UTC+3) Moscow Time (UTC+3)Moscow Summer Time (UTC+4) Central European Time (CET) is one of the names of the time zone that is 1 hour ahead of Coordinated Universal Time. It is used in most European and some North African countries. Its time offset is UTC+1. During daylight saving time CEST is used instead (UTC+2).


(in french : correcteurs) A button flush with the case middle used for adjusting the different indications, such as the date, by means of a pointed stylus.


A certified chronometer is a high-precision watch capable of displaying the seconds and which has has been tested and certified by an official neutral body (Contrôle Officiel Suisse des Chronomètres – COSC). Each chronometer is unique, identified by a number engraved on its movement and a certification number given by the COSC. Each movement is individually tested for several consecutive days, in 5 positions and at 3 temperatures. Each movement is individually measured. Any watch with the denomination chronometer is provided with a certified movement. The term chronometer is often wrongly applied to timekeeping instruments fitted with an additional mechanism that may be set in motion by pushbuttons to enable measurement of the duration of an event. Such an instrument is in fact a chronograph or chronoscope. It may of course be chronometer-certified, provided it meets the criteria set for the standard.


(In French: chronomètre (définition générale)) A chronometer is, etymologically, an instrument for measuring the time. With usage it has come to mean a high-precision watch-displaying seconds whose movement has been controlled over a period of several days, in different positions and at different temperatures, by an official neutral body. Only mechanisms that have satisfied the criteria for precision of ISO 3159 are issued with an official chronometer certificate. In Switzerland, the Contrôle Officiel Suisse des Chronomètres (COSC) has the power to award these certificates. Based on the requirements of ISO 3159, the COSC has also drawn up a set of specifications for the testing of quartz movements. While a chronograph can be used to measure an interval of time, it can only use the name chronometer if it has been officially certified as such.


A watch indicating hours, minutes and seconds combined with a mechanism whose hand can be started, stopped and returned to zero on demand to measure a duration to one fifth, tenth or even hundredth of a second. Sub counters for the minutes and hours (usually 30 minutes and 12 hours) totalise the number of revolutions by the chronograph hand. The accuracy of these recorded times can only be guaranteed if the chronograph has satisfied the criteria of the chronometer label. The first chronographs deposited drops of ink on their dial; this no longer being the case, strictly speaking a chronograph should be called a chronoscope.


Second display from the centre of the dial with long second hand, rotating on top of the hour and minute hands.


(In French: couronne) Button to wind up and set the watch to time.
The winding crown is a knurled or fluted button of various shapes, held between the thumb and forefinger and used to wind the watch. Some crowns incorporate a mobile pushbutton for operating a chronograph mechanism or to release the cover of a hunter case. The first example of a crown for winding and setting the time appeared on a watch made by John Arnold in 1820. The system was perfected by Breguet for miniature watches circa 1832, and was patented in 1838 by Louis Audemars in Le Brassus. In 1844, Adrien Philippe invented and patented his sliding pinion mechanism which would replace all other systems. In 1847, Charles-Antoine LeCoultre invented his keyless winding system with its rocking bar and side pushbutton to set the time. Related themes : Parts and functions


Display of date on the dial of a watch. In mechanical watches discs or bars are used for this purpose, which are connected to the movement by means of transmission wheels. Display Indication of time or other data, either by means of hands moving over a dial (analogue display) or by means of numerals appearing in one or more windows (digital or numerical display); these numerals may be completed by alphabetical indications (alphanumerical display) or by signs of any other kind. Example: 12.05 MO 12.3 = 12 hours, 5 minutes, Monday 12th March. Such displays can be obtained by mechanicalor electronic means.


The number, in order, of each day in the month.


A dial is also called the face of the watch and in fact it characterises the look of a watch. Analogue watches with show the time by means of the position of the hands on the dial.


A day (symbol: d) is a unit of time equivalent to 24 hours. It is not an SI unit but it is accepted for use with SI[1]. The SI unit of time is the second. The term comes from the Old English dæg, with similar terms common in all other Indo-European languages, such as dies in Latin and dive in Sanskrit.


Term used to denote the difference of time adjustment after 24 hours. There can be differences of up to several seconds per day according to quality and place or quality and wearing conditions.


Mechanism fitted between the train wheels and the regulating organ, the balance wheel, in a mechanical wrist watch. The most common escapement is the Swiss lever escapement. The escapement consists of the escapement wheel and the pallet. The purpose of the escapement is to impede the fast running of the train wheel and regulate it. On the other side, the escapement has to convert the power of the train into oscillations


The escapement wheel and the lever build the escapement. It is the last train wheel.


In watchmaking, the crown wheel is usually an object of circular shape with contrate teeth, which meshes with the winding pinion and with the ratchet-wheel on the barrel-arbor used to wind-up the watch, respectively, to set the time.


Regulating lever to adjust the daily time accurately.


The number of oscillations per second, measured in Hertz. The balance makes a to-and-fro movement at a given frequency (two vibrations). The higher the frequency, the more accurate the watch: 21,600 vibrations/hour (3 Hz), 28,800 vibrations/hour (4 Hz) and 36,000 vibrations/hour (5 Hz).


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 fly back hand and the regular chronograph seconds hand in motion. To record a lap time or finishing time, stop the fly back 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.


Greenwich Mean Time. Greenwich is a district of London, through which the zero meridian passes. The globe is subdivided into 24 time zones. The time displays all over the world are always related to GMT.


Electro deposited layer of gold, the thickness of which is given in microns.


Gold has seduced the world with its beauty, but also because not even acid can alter its natural properties. An estimated 130,000 tons have been extracted from the earth since prehistoric times, of which 100,000 tons in the twentieth century alone. Gold is a malleable substance (with a hardness of just 2.5) and therefore easy to work with. It can be used in an alloy with other metals, often silver and copper. These alloys increase its resistance and change its colour. Contains: For 750 gold, approximately: Yellow gold: 12.5% silver – 75% pure gold – 12.5% copper Pink gold: 6% silver – 19% copper – 60% pure gold – 10% palladium – 5% nickel Red gold: 5.5 % copper – 94.5% pure gold White gold: 10% copper – 10% palladium – 5% nickel – 75% pure gold Blue gold: an alloy of gold and iron. Heat treatment oxidizes the iron molecules at the surface of the metal, producing the blue colour. Green gold: an alloy of gold, silver and copper. Black gold: obtained by heat treatment or through the effect of acids. Brown gold: obtained by heat treatment.


Hand to display the hours on a dial. The hour hand always is shorter and very often also thicker than the minute hand.


A variously shaped indicator made from a thin piece of lightweight metal and which moves round a graduated dial. The majority of watches today have three hands, one each for the hours, minutes and seconds. Early watches only had one hand, for the hours. The English watchmaker Daniel Quare is generally acknowledged as having introduced the minute hand in around 1691, although it only came into widespread use in the early 18th century. The very first hands had to be thick and robust as the dial had yet to be protected by a glass, and because the only way to set the time was to physically move the hand. Towards the mid-18th century, hands adopted a slimmer, more elegant style. They were made by hand and finished with a file or chisel; holes were fashioned with a bow. Circa 1764, watchmakers began using a hammer and punch to stamp hands from a sheet of metal. Later, in around 1800, they were formed using a press and were often decorated with imitation stones. The most common forms are: Baton Dauphine Feuille Sword Spade Poire Breguet or Moon Skeleton.


A watch whose mainspring is wound up daily by means of the winding crown.


Only hands and dial transform a watch movement into a time measuring instrument.


The Incabloc shock protection system is used in mechanical watches, to protect the critical alignment of components in the event of an unexpected physical shock, such as being dropped onto a carpeted floor. The pivots and jewels of the balance are fragile in comparison to the mass they need to support, and without shock protection are the most likely part of the watch to be damaged under impact. The Incabloc system uses a specially shaped spring to allow the delicate jewels and pivots to shift in their settings under impact until a stronger shoulder of the staff contacts the strong metal endpiece. When the impact is over, the springs guide the parts back to their original positions.


Instantaneous date means that the date changes instantaneously at midnight.


The Incabloc shock protection system is used in mechanical watches, to protect the critical alignment of components in the event of an unexpected physical shock, such as being dropped onto a carpeted floor. The pivots and jewels of the balance are fragile in comparison to the mass they need to support, and without shock protection are the most likely part of the watch to be damaged under impact. The Incabloc system uses a specially shaped spring to allow the delicate jewels and pivots to shift in their settings under impact until a stronger shoulder of the staff contacts the strong metal endpiece. When the impact is over, the springs guide the parts back to their original positions.


Instantaneous date means that the date changes instantaneously at midnight.


Lever with pallet of synthetic ruby.


The international term for the jewels (rubies) in a watch movement that are used as bearings for pivots to reduce friction. Generally, a movement has between 15 and 21 jewels.


This tool is used in the production of bezels.


Lume is a short term for the luminous glowing solution applied on watch dials. The most common brand of lume is SuperLuminova, which comes from Switzerland. There are some people who relume watches, or replace faded lume. Formerly lume consisted mostly of tritium; however, tritium is radioactive and has been mostly replaced on new watches by less bright, but less toxic compounds.


The lever escapement is a key component of the typical movement found in most mechanical wristwatches, pocket watches and many small mechanical non-pendulum clocks. The invention of the lever escapement is attributed to Thomas Mudge, and its modern form was developed by subsequent workers including Breguet and Massey. It is a detached escapement, which means that the time-keeping element runs entirely free of interference from the escapement during a portion of the operating cycle. The rotation of the escape wheel is controlled by the pallets. The escape wheel has specially shaped teeth of either ratchet or club form, which interact with the two jewels called the entrance and exit pallets. The escape wheel, except in unusual cases, has 15 teeth and is made of steel. These pallets are attached solidly to the lever, which has at its end a fork to receive the ruby impulse pin of the balance roller. In modern design it is common for the pallet mountings and the fork to be made as a single component. As the escape wheel rotates, a tooth will slide across the sloping impulse plane of the entrance pallet. This will turn the pallets about their axis, which places the exit pallet into the path of the rotating escape wheel. Thus, once the tooth leaves the impulse plane of the entrance pallet, the wheel is only able to turn a small amount (called the drop) until a tooth of the escape wheel lands on the locking face of the exit pallet. The wheel is said to be locked on the exit pallet. From the release from the entrance pallet to this point, the escape wheel will have turned through exactly half of the angle between two teeth. The impulse received by the pallet as the tooth moves over the impulse face is transferred by the lever to the balance wheel via the ruby pin on the roller of the balance. The lever moves until it rests against the banking (either solid, or a pin); it is held in this position by the draw of the pallet jewels; this means that in order to unlock the wheel it must be turned backwards by a small amount. After the drop, the balance wheel will rotate free of interference from the escapement until the impulse pin enters the fork again while moving in the opposite direction. This will unlock the escapement, which releases the escape wheel so that a tooth can slide over the impulse plane of the exit pallet, which transfers an impulse via the lever to the impulse pin. The escape wheel drops against until a tooth locks on the entrance pallet. The cycle then starts again.


The basic meaning of a mechanical watch points to a watch having a metal, operational-base running method. A mechanical watch runs either with a mainspring format for a power source, or a fusee chain-driven format for substituting as a mainspring. Both of these watches use an escapement, a balance wheel, minute-hour-second escapement gears, a time-set lever-set formatting method, and share similar characteristics with each other. Mechanical watches were very popular back from early on, especially from the 1500s, when the Chronometer was created, and therefore perfecting the movement of the watch industry. Watches from the early 1500s to the early 1800s featured the chain-driven fusee movement, which was the only means for substitution of a mainspring format back in the time. The fusees were very brittle, were very easy to break, and often featured many, many problems, especially inaccuracy of timekeeping when the fusee chain became loose or lost its velocity after the lack of maintenance. Mainsprings began to become popular as technological stepping stones improved, and newer designs came to place in the industry, perfecting the movement of a typical mechanical watch. With the new mainspring, the fusee maintenance and chain-loosening problems were now gone, a mainspring-operated watch does not have to be serviced as much as the fusee, and also other time-keeping problems were solved with the evolution of the Mainspring. Mainspring watches were most popular from the 1850s to the 1970s before the evolution of the Quartz Digital operation method came into place. As Manual-wound mechanical watches became less popular and less favored in the 1960s, watch design and industrialists came out with the Automatic Watch Movement. Whereas a mechanically-wound watch must be wound with the pendant or a levered setting, an Automatic watch does not require to be wound by the pendant, but by simply shaking the watch winds the watch automatically. The interior of an Automatic Watch houses a swivelling metal or brass plate, that swivels on its axes when the watch is shaken horizontally. An Automatic watch may come in handy if you do not want to constantly wind a watch manually, because it simply winds itself from its position on your wrist or your arm.


The Canton of Genève has the reputation of being one of the prestigious centres of the Swiss watch industry where de luxe and high quality watches are made. That being so, this indication benefits from a special protection, which is guaranteed by Swiss law, bilateral agreements and international conventions.

The indication “Genève” may lawfully appear on a watch on condition that the following conditions:

• Movement must be Swiss Made
• Assembly in Canton Genève
• Quality Control in Canton Genève
• At least 50% of value added in Canton Genève

All Frédérique Constant timepieces are designed, developed and assembled in Genève using the best components available in Switzerland and following the ultimate Swiss quality standards.


A mechanism is a combination of parts designed to perform a given function. A timepiece (a clock or watch), is a piece of mechanism designed to indicate the time; it includes various organs, each of which is a piece of mechanism with a clearly determined function, e.g.


A metric unit of length equal to one thousandth of a milimetre or one millionth of a metre. The watch industry often expresses tolerances in microns.


The tool used to wind the mainspring before inserting it in the barrel.


A mechanism and display representing the different phases of the moon. A complete lunation takes 29 days, 12 hours, 44 minutes and 2.8 seconds and is divided into four phases. These are new moon, first quarter, full moon, last quarter.


The expression was used initially in the electronic industry and describes an assembly component. For mechanical watches we nowadays speak of modular construction, for instance when an automatic watch is transformed into a chronograph by having a complete chronograph mechanism built on top of it.


Mineral, mostly flat watch crystals. Mineral crystals are hardened after polishing and therefore less sensitive to scratches than plexi crystals.


Produced and assembled in Switzerland.

The law is based on a concept according to which Swiss quality depends on the amount of work actually carried out on a watch in Switzerland, even if some foreign components are used in it. It therefore requires that the assembly work on the movement (the motor of the watch) and on the watch itself (fitting the movement with the dial, hands and the various parts of the case) should be carried out in Switzerland, along with the final testing of the movement. It also requires that at least 50% of the components of the movement should be manufactured in Switzerland.

The indication “Swiss Made” may lawfully appear on a watch on condition that the following conditions:

Movement must be assembled in Switzerland

At least 50% of value added on movement must be in Switzerland Assembly of watch must be in Switzerland

Quality Control of watch must be in Switzerland

All Frédérique Constant timepieces have Swiss Made movements and are assembled in Genève . Therefore all Frédérique Constant watches are Swiss Made.


A detailed document issued by an Observatory or by an official ratings bureau. Only a watch that has received an official rating certificate can be called a chronometer.


In a self-winding movement, a heavy metal disc that turns freely in both directions to wind the mainspring. The natural movement of the arm makes the oscillating weight swing round, thus winding up the mainspring of the automatic watch.


A detailed document issued by an Observatory or by an official ratings bureau. Only a watch that has received an official rating certificate can be called a chronometer.


The pallet fork or pallet lever is an integral component of the lever escapement of a typical mechanical watch. The pallet fork has two jewels; which are called the entry and exit pallets. The jewels interact with the escape wheel and the pallet interacts with the impulse jewel on the balance wheel. On lower priced mechanical watches, non-jeweled pallets were often employed which substituted vertical pins for the jewels, hence the name pin-lever escapements.


Component of the pallet, also called pallet stones. The pallet stones used for wrist and pocket watches are synthetic jewels, cut in a rectangular form, with a front side cut in a precise inclined angle.


Escapement with pinlever. The pinlever escapement was formerly used for simple clocks, wrist and pocket watches. It consists of the pinlever pallet, fitted with hardened steel pins instead of pallet stones meshing with the escape wheel. Pinlever escapements are no longer used.


Watch crystal made of acryl crystal. This material can be processed and polished easily. The advantage for the owner of the watch is the comparatively high resistance to shocks.


English expression for a calendar watch with a hand that points to the date as opposed to a calendar watch where the date appears in a window.


An articulated metal catch that is inserted in a hole in the leather strap then secured by the buckle. The majority of belts fasten this way. A watch can therefore be said to have a pin buckle.


The plate supports the bridges and the various parts of the movement. The movement plate and the bridges build the frame of the movement.


A pin-lever or pin-pallet escapement is a lever escapement used in mechanical watches that uses metal pins on the pallet of the lever, rather than jewels. The pallet is the part of the lever that engages the escape wheel, which is critical for transfering the energy stored in the spring to the balance wheel. Jewelled pallets can be made much smoother than metal pins and therefore lose much less energy due to friction. The metal pins also wear much quicker. Although this technically includes some jeweled watches (the Timex 21 Jewel was an example of a pin-lever design with added jewels), the most common meaning is an inexpensive watch using plain steel pivots rather than jeweled bearings. While these watches could be more rugged than a jeweled mechanical watch, they wore far more quickly and were less likely to maintain a constant rate. By 1980 quartz watches dominated the market, and low-end mechanical production largely ceased.


Small metallic spring pin fixed between the horns of the case to hold the watch strap.


For watches with multi functions, for instance chronographs, more than the crown is needed. Therefore, the watches are equipped with special push buttons.


The power reserve or running reserve is the time the watch runs from when the main spring is completely wound up until it has completely wound down.

Power Reserve Indicator – originally called French: Réserve de Marche – is a function of the watch, which is meant to show how long the watch is going to work until the next winding. In its essence, the power reserve indicator shows how tense the mainspring is at the moment. The indication of the power reserve is represented through a needle. The needle moves from one point of the indicator to another. The zone along which the needle moves, shows how much time is left till the mechanism stops, and when the needle leaves the zone the watch needs to be wound. The indicator itself represents the amount of tension of the mainspring, thus the lower is the tension the less time is left until another winding of the watch.


Physical vapor deposition (PVD) is a technique used to deposit thin films one atom (or molecule) at a time onto various surfaces (e.g., onto semiconductor wafers). The coating source is physical (ie. solid or liquid) rather than chemical as in chemical vapor deposition. The term physical vapor deposition apears originally in the 1966 book Vapor deposition by CF Powell, JH Oxley and JM Blocher Jr but M. Faraday was using PVD to deposit coatings as far back as 1838. Variants of PVD include

Cathodic Arc Deposition
Evaporative deposition
Electron Beam Physical Vapor Deposition
Pulsed laser deposition
Sputter deposition PVD is used in the manufacture of items including semiconductor devices, aluminized PET film for balloons and snack bags, and coated cutting tools for metalworking. Leading manufacturers of PVD tools include Applied Materials (~78.1% market share in 2004), Novellus Systems (~6.2% market share in 2004), and Oerlikon Balzers coatings[1] (~4.8% market share in 2004). Specialty and custom PVD equipment suppliers include Mustang Vacuum Systems[2], Platit, Sulzer Metplas (nee Metaplas Ionon)[3], Angstrom Engineering, Advanced Energy, Johnsen Ultravac[4], Plasma Quest Limited[5], tectra[6] and Denton Vacuum[7]. Besides PVD tools for fabrication special smaller tools mainly for scientific purposes have been developed. They mainly serve the purpose of extreme thin films like atomic layers and are used mostly for small substrates. A good example are mini e-beam evaporators which can deposit monolayers of virtually all materials with melting points up to 3.500°C. Leading consumers of PVD tools for fabrication include Intel, Samsung, and Taiwan Semiconductor.[citation needed] Some of the techniques used to measure the physical properties of PVD coatings are
Calo tester – coating thickness test
Scratch tester – coating adhesion test
Pin on disc tester – wear and friction coefficient test


The part that connects the train wheels and the balance wheel in lever movements for wrist watches. The ends of the two-piece part mesh with the escape wheel. The pallet for wrist watches is made of hardened steel. The pallet stones consist of smoothed synthetic jewels.


Abbreviation for post meridiem. An extra indication of time used in the English speaking world.


Mechanism for the direct setting of the date, to avoid turning the hands over 24 hours.


Watches with analogue or digital display, whose movement is powered by a quartz. The quartz analogue watch: The divison of the time functions by means of quartz, whose vibrations are generated by a battery. The analogue time display is shown by electrically driven hands. In digital watches the display is, in most cases, by liquid crystal numerals.


French for power reserve


A simplified cheap wrist or pocket watch named after the inventor George Frédéric Roskopf (1813 – 1899). A Roskopf watch has no centre wheel and hardened steel pins are substituted for the pallet stones.


Rose gold is a gold and copper alloy widely used for specialized jewelry due to its reddish colour. It is also known as pink gold and red gold. Because it was popular in Russia at the beginning of the nineteenth century it is also known as Russian gold, although this term has become somewhat rare. Since it is an alloy, there is no such thing as pure rose gold; pure gold is yellow and pure copper is reddish. Although the names are often used interchangeably, the difference between red, rose, and pink gold is the copper content: The higher the copper content, the stronger the red coloration. A common alloy for rose gold is three-quarters gold and one-quarter copper. Rose gold is also the name of a commonly-used finish in bell interiors of musical instruments. It consists of a very thin plating of copper over a layer of silver. No actual gold is used. [edit] Different karat alloys The highest karat version of rose gold is also known as crown gold, which is 22 karat. A picture of some coins of this alloy can be found here: 22k crown gold coins. 22k rose gold Lord of the Rings coins. 18 karat rose gold may be made of 25% copper and 75% gold. For 18 karat rose gold, typically about 4% silver is added to the 75% gold and 21% copper to give a rose colour. Pictures of this alloy here: 18k rose gold diamond rings. 14 karat red gold is often found in the Middle East and contains 41.67% copper. Pictures of this alloy here: 14k rose gold jewelry.


Chronograph with double hands. These watches are equipped with two chronograph second hands which can be started either by means of a push button in the crown or a third button on the case. It can be stopped independently by again pressing the chronograph push button. It is therefore possible to stop at an intermediate time.


With fine regulating the watchmaker adjusts a watch to run as accurately as possible (see Fine Time Adjustment).


A red variety of corundum (crystalline aluminium oxide) and a very hard mineral. Of all stones, ruby is the best choice for the bearings in which the pivots of the greatrain or escapement turn. Drilled rubies were used for the first time by Nicholas Facio de Duillier in 1704. Watches today use synthetic rubies known as jewels. Drilled and polished, they are used as bearings for the different pivots to minimise friction and wear. As a general rule, a simple mechanical watch, i.e. one that indicates hours, minutes and seconds, should have at least fifteen jewels at the points most exposed to friction. It must also be fitted with a shock-absorber for the balance-staff pivots, a good quality balance spring and an unbreakable mainspring.


A resilient bearing to dampen shocks on the balance-staff pivots. Also known as shockproofing. The majority of watches today use the Incabloc® system.


Hand for display of seconds on a dial. In wrist watches, there is a difference between second hand from the centre and the so called small second.


By pulling out the crown the time and date can be set. The core of this complex mechanism is the cannon pinion, fitted with a special kind of coupling-clutch. This enables the watch to be set independently from the gear-train.


Principle: the endstone a is subject to the action of a spring b. If an axial shock occurs, the endstone can lift slightly until the shoulder c strikes a fixed part of the setting. To damp lateral shocks, the jewel hole is fitted in a setting comprising an inclined plane d, which provides for a slight lateral shift limited by the collet-arbor or by the roller-arbor e, which strikes a fixed part of the framework.


Silver is a very ductile and malleable (slightly harder than gold) univalent coinage metal with a brilliant white metallic luster that can take a high degree of polish. It has the highest electrical conductivity of all metals, even higher than copper, but its greater cost and tarnishability has prevented it from being widely used in place of copper for electrical purposes, though it was used in the electromagnets used for enriching uranium during World War II (mainly because of the wartime shortage of copper). Pure silver has the highest thermal conductivity, whitest color, the highest optical reflectivity (although aluminium slightly outdoes it in parts of the visible spectrum), and is a poor reflector of ultraviolet light. Silver also has the lowest contact resistance of any metal. Silver halides are photosensitive and are remarkable for the effect of light upon them. This metal is stable in pure air and water, but does tarnish when it is exposed to ozone, hydrogen sulfide, or air containing sulfur. The most common oxidation state of silver is +1 (for example, silver nitrate, AgNO3); a few +2 (for example, silver(II) fluoride; AgF2) and +3 compounds (for example, Silver sulfate ; Ag2(SO4)3 are also known.


Watch to measure short periods of time, such as races. The stop watch is an instrument purely for time measurement. It does not show the time. Normal watches which also have a stop function are called chronographs.


Second display not from the centre, but by a hand in a subsidiary small dial. This type of second implies a different construction of the movement.




A movement whose plate and bridges have been cut away to expose the wheels, leaving only the substance which the watch needs to function. The movement is placed between two sapphire crystals to highlight this transparency.


A material commonly used in both the front and back casings of wristwatches, especially in skeleton watches and watches made to be highly resistant to damage such as those used by divers or by the military. Inex of scandinavia uses sapphire crystal in some of their watches, for an example. The sapphire crystal used in the watch industry is a transparent material made of crystallizing aluminum oxide at very high temperatures. Chemically, synthetic sapphire is the same as the natural sapphire used in jewelry, but without the coloring agents that give the gemstone its various hues. When it is heated, the synthetic sapphire forms round masses that are sliced into pieces with diamond-coated saws. These disks are then ground and polished into watch crystals. (One reason sapphire crystals are relatively expensive is that the tools required to make them are costly.) Sapphire (whether natural or synthetic) is one of the hardest substances on earth. It measures 9 on the Mohs scale, which is a system for rating the relative hardness of various materials. (Diamond measures 10, the highest rating.) Watch crystals made of synthetic sapphire are often marketed as scratch resistant, meaning they are very difficult – but not impossible – to scratch. Diamond can scratch them; so can man-made materials that incorporate silicon carbide, with a Mohs rating of between 9 and 10 it is, like diamond, harder than sapphire. These materials are sometimes used to make simulated-stone surfaces for furniture or walls. The watch wearer should note that accidentally scraping a sapphire crystal against such a surface could cause a scratch.


Is a non-radioactive pigment that can shine for a long time. This phosphorescent pigment works like a light-battery. Through daylight or other sources of light the material gains energy. In the darkness it can be luminous for several hours, depending on the quantity of the material. This effect can be reproduced all the time, irrespective of the age of the material. Superluminova pigments do not contain any radioactive substances.


Watch in which the plates, bridges and cocks are cut away until the limit of functional stability so that the individual movement components become visible. Skeleton Skeleton watch: watch in which the case and various parts of the movement are of transparent material, enabling the main parts of the watch to be seen.


Many watch cases or pieces of jewellery are given a matt finish by using a very fine, mostly crosswise pattern. This procedure is called satin finish.


The power reserve indicator is one of the most important features of a mechanical watch. The latter has either automatic or manual winding. In order to run at a regular rate a mechanical timepiece needs to have at least 30 per cent of its mainspring wound. An automatic timepiece needs to be worn for about 10-15 hours until it is fully wound. The power reserve indicator displayed at the watch with automatic movement shows how much time a watch will function when not worn. The one displayed at a watch with the manual winding mechanism shows the time left for its next winding.


The Gregorian Calendar is a revision of the Julian Calendar which was instituted in a papal bull by Pope Gregory XIII in 1582. The reason for the calendar change was to correct for drift in the dates of signifigant religious observations (primarily Easter) and to prevent further drift in the dates. The important effects of the change were:

Drop 10 days from October 1582, to realign the Vernal Equinox with 21 March
Change leap year selection so that not all years ending in 00 are leap years.
Change the beginning of the year to 1 January from 25 March Despite a frequently repeated factoid these days, there is no special treatment of years which are divisible by 4000. The main aspect that gets any attention these days is the leap year rule. The change in the number frequency of leap years (by dropping 3 every 400 years) slightly changes the average year length to something closer to reality. Adoption of the new calendar was essentially immediate within Catholic countries. In the Protestant countries, where papal authority was neither recognized not appreciated, adoption came more slowly. England finally adopted the new calendar in 1752, with eleven days removed from September. The additional day came because the old and new calendars disagreed on whether 1700 was a leap year, so the Julian calendar had to be adjusted by one more day. The Gregorian year length gives an error of one day in approximately 3,225 years.