- Amplitude (Vibration)
- Analog or Analogue
- Antimagnetic watches
- Antireflection, Antireflective
- Automat, Automatic
Vibrations of the balance per hour. Two vibrations make the well-known tick-tock sound of the mechanical watch, known as one oscillation.
Watch fitted with a ringing mechanism that is automatically released at the required time.
Angle of oscillation for the balance.
Analog or Analogue
A watch displaying time indications by means of hands.
Watches designed to be especially resistant to magnetic fields. Non-magnetic nickel alloys are used for the balance springs and a soft iron core may surround the movement.
Superficial glass treatment assuring the dispersion of reflected light. Better results are obtained if both sides are treated, but in order to avoid scratches on the upper layer, the treatment of the inner surface is preferred.
Synonym for a watch with automatic winding. The movement of your wrist makes the rotor (oscillating weight) turn, thereby winding the mainspring of the watch movement.
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 (s) strikes. The moving parts are linked, through an aperture on the dial or caseback, with the sonnerie hammers (s) striking a gong.
The hairspring or balance spring expands and contracts with the oscillation of the balance wheel forming together the oscillating system. The balance spring of a watch consists of a thin, flat wire often made of Nivarox
Part of the escapement of a mechanical watch. Oscillating device which divides the time into equal sections. This serves the same function as does a pendulum in a clock.
The barrel contains the wound-up mainspring, hooked to it at its outer end and which stores the energy, assuring a power reserve of 36 to 45 hours for the watch. The mainspring is wound up manually by means of the crown (handwinding watch) or through the movement of the oscillating weight (Rotor) in an automatic watch. There may be more than one barrel for longer power reserve.
Chamfering of edges of levers, bridges and other elements of a movement by 45 degrees; a treatment typically found in high-grade movements.
Top ring for the crystal and/or decorative ring on the upper side of the watch case.
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.
Brass plate fixed on the main plate by two or more pins and screws. The wheels and staffs turn between the bridge and main plate
- Calendar, ANNUAL
- Calendar, FULL
- Calendar, PERPETUAL
- Carriage or Tourbillon Carriage
- Centre Second Hand
- Clous de Paris
- Column Wheel
- Côtes Circulaires
- Côtes de Genève
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 (s) or certain elements of the case.
An intermediate complication between a simple calendar and a perpetual calendar. This feature displays all the months with 30 or 31 days correctly, but needs a manual correction at the end of February. Generally date, day of the week and month, or only day and month are displayed on the dial.
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 moonphases.
This is the most complex of the calendar horology complications 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.
Description for a watch movement according to construction, size and factory origin.
1 Carat = 1/24 fine gold of a gold alloy. An 18 carat gold alloy contains 18/24 fine gold = 75% fine gold content.
Carriage or Tourbillon Carriage
Rotating frame of a tourbillon device carrying the balance and escapement(s). 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 one rotation per minute, errors of rate in the vertical position are eliminated. This solution was originally designed to compensate for the wearing-position of pocket watches but has now become desirable for its aesthetics and technical sophistication in wristwatches.
Container housing and protecting the movement (s), usually made up of three parts: middle, bezel, and back.
Centre Second Hand
see Sweep second hand.
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.
A watch that includes a built-in stopwatch function, i.e. a timer that can be started and stopped to time an event. There are many variations of the chronograph.
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.
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.
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.
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 (s), power reserve (s), GMT (s), and full calendar (s). Further functions are performed by the so-called great complications, such as split-second (s) chronograph, perpetual calendar (s), tourbillon (s) and minute repeater (s).
Pusher (s) positioned on the case side that is normally actuated by a special tool for the quick setting of different indications, such as date, GMT (s), full or perpetual calendar (s).
Abbreviation of “Contrôle Officiel Suisse des Chronomètres,” the most important Swiss institution responsible for the functioning and precision tests of movements of chronometers (s). 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/+6 seconds per day is tolerated. Testing is performed on the movement only not the cased watch.
Decoration of rotors and bridges of movements, whose pattern consists of a series of concentric ribs.
Côtes de Genève
Decoration applied mainly to high-quality movements, appearing as a series of parallel ribs, effected by repeated application of a cutter leaving thin stripes.
Additional hand on a chronograph (s), 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 (s), also called subdials.
Button to wind up and set the watch to time.It is linked to the movement through the winding stem (s) passing through a hole in the case. For waterproofing purposes, simple gaskets are used in water-resistant watches, whilst diving watches adopt screwing systems (screw-down crowns).
Term used to denote the time deviation from a reference source after 24 hours. Differences may relate to the quality of the watch movement, the wearer's activities and other environmental factors.
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.
Face of a watch, on which time and further functions are displayed by markers (s), hands (s), discs or through windows (s). Normally it is made of a brass,sometimes silver or gold.
Depending on the type of movement used, the daily rate may vary between -5 to +20 seconds.
A watch displaying time indications by means of numbers rather than hands. There may be a mix of both analogue and digital displays on the same watch dial. Usually refers to quartz watches
Specially constructed wrist watch for deep sea diving. Divers watches are fitted with screw-in crowns, and they are guaranteed to withstand underwater pressures of 20 ATM (200 m).
Ebauche, Movement Blank
Incomplete watch movement in principle without mainspring and balance. The movement blanks are assembled, refined and completed with the missing parts.
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.
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.
Mechanism built in between the gear train and balance wheel. The escapement transfers the power from the gear train in regular and even time sequences to the balance, the oscillating system.
The escapement wheel and the lever build the escapement. It is the last train wheel.
ETA SA, leading manufacturer in Switzerland for movements. ETA movements are used for many renowned Swiss watch brands.
Fine Time Adjustment
Regulating lever to adjust the daily time accurately. The majority of Swiss watches are fitted with a regulating lever for particularly precise time adjustment.
Engraving on the dial or case of a watch, covered with an enamel layer.
Said of surfaces worked with thin parallel grooves, mostly on dials or case bezels.
Feature combined with chronograph (s) 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. 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.
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, s. Vibration
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).
The majority of water resistant watches are equipped with gaskets in the case back, the crystal and the crown.
The system of wheels and pinions which, from the barrel B, transmits the driving power to the escape wheel E, Z1 centre-wheel, Z3 third wheel, Z5 fourth wheel. E escape wheel. All these wheels are riveted to their respective pinions, Z2, Z4, Z6.
see Poinçon de Genève.
Bronze and beryllium alloy used for high-quality balances (s). This alloy assures high elasticity and hardness values; it is non-magnetic, rustproof and has a very reduced coefficient of expansion, which makes the balance very stable and assures high accuracy of the movement.
Abbreviation for Greenwich Mean Time. As a feature of watches, it means that two or more time zones are displayed. In this case, the second time may be read from a hand making a full rotation in a 24-hour ring (thereby also indicating whether it is a.m. or p.m. in that zone).
Electro deposited layer of gold, the thickness of which is given in microns.
Harmonic flattened bell in a steel alloy, generally positioned along the circumference of the movement and struck by hammers (s) to indicate time by sounds. Size and thickness determine the resulting note and tone. In watches provided with minute-repeaters (s), 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 (s) 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).
Decoration of dials, rotors or case parts consisting of patterns made by hand or engine-turned. By the thin pattern of the resulting engravings—consisting of crossing or interlaced lines—it is possible to realize even complex drawings. Dials and rotors decorated in this way are generally in gold or in solid silver.
- Handwinder, Hand winding
- Helium Valve
- Hertz Heinrich
- High Frequency Movement
Steel or brass element used in movements provided with a repeater or alarm sonnerie (s). It strikes a gong (s) or bell (s).
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.
Handwinder, Hand winding
A watch whose mainspring is wound up daily by means of the winding crown.
Heart-shaped cam (s) generally used to realign the hands of chronograph counters.
Valve inserted in the case of some professional diving watches to discharge the helium contained in the air mixture inhaled by divers.
German physicist (1857-1894). The word Hertz is now used as physical measurement for the frequencies (numbers of vibrations), indicated as oscillation per second.
An artificial glass made of a plastic resin.
High Frequency Movement
Watches which make a minimum of 28'800 vibrations.
New kind of alloy developed exclusively by Hublot that will be launched in 2008.
A hublot fan.
Trade mark of a Swiss shockabsorber (see Shock-absorber).
Instantaneous date means that the date changes instantaneously at midnight.
Precious stone used in movements as a bearing surface. Generally speaking, the steel pivots (s) of wheels in movements turn inside synthetic jewels (mostly rubies) lubricated with a drop of oil. The jewel’s hardness reduces wear to a minimum even over long periods of time (50 to 100 years). The quality of watches is determined mainly by the shape and finishing of jewels rather than by their number (the most refined jewels have rounded holes and walls to greatly reduce the contact between pivot and stone).
Jewelled Lever Escapement
Lever with pallet of synthetic ruby.
Feature concerning the digital display of time in a window. The indication changes almost instantaneously at every hour.
This tool is used in the production of bezels.
Ancient French measuring unit maintained in horology to indicate the diameter of a movement (s). A line (expressed by the symbol ""’) equals 2.255mm. Lines are not divided into decimals; therefore, to indicate measures inferior to the unit, fractions are used (e.g. movements of 13’’’3/4 or 10’’’1/2).
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 (s) turning inside jewels (s), the sliding areas between levers, and the spring inside the barrel (requiring a special grease), as well as numerous other parts of a movement.
Double extension of the case middle (s) by which a strap or bracelet is attached. Normally, straps and bracelets are attached with removable spring bars.
Said of materials applied on markers (s) and/or hands (s), emitting the luminous energy previously absorbed as electromagnetic light rays. Tritium is no longer used and was replaced by other substances having the same emitting powers, but with virtually zero radioactivity, such as Super-LumiNova and Lumibrite.
- Made in Switzerland
- Marine Chronometer
- Mechanical Watches
- Micrometer Screw
- Mineral Crystal
- Minute Repeater
Made in Switzerland
Produced and assembled in Switzerland.
Flat coiled spring that powers all mechanical watches. This and the barrel make up the driving element of a movement . It stores and transmits the power force needed for its functioning.
A mechanical movement (v) 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 (s), from this to the barrel (s) through a series of gears (s) and finally to the mainspring (s).
Highly accurate mechanical or electronic timekeeper enclosed in a box (hence the term box chronometer), used for determining the longitude on board ship. Marine chronometers with mechanical movements are mounted on gimbals so that they remain in the horizontal position necessary for their precision.
Elements printed or applied on the dial, sometimes luminous, used as reference points for the hands to indicate hours and fifteen- or five-minute intervals.
Watch that stores the running power by means of a mainspring. The mainspring is either wound up manually in a handwinding watch or in an automatic watch by the swinging weight (Rotor) through the movement of the arm.
Element positioned on the regulator, allowing to shift it by minimal and perfectly gauged ranges so as to obtain accurate regulations of the movement.
1/1000 mm or 0.00l millimetre used for instance to measure the thickness of gold plating.
Mineral, mostly flat watch crystals. Mineral crystals are hardened after polishing and therefore less sensitive to scratches than plexi crystals.
Self-contained mechanism, independent of the basic caliber (s), added to the movement (s) to make an additional function available: chronograph (s.), power reserve (s.), GMT (s), perpetual or full calendar (s).
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.
The entire mechanism of a watch. Movements are divided into two great families: quartz and mechanical; the latter are available with manual (s) or automatic (s) winding devices.
Trade name (from the producer’s name) of a steel alloy, resisting magnetization, used for modern self-compensating balance springs (s). The quality level of this material is indicated by the numeral following the name in decreasing value from 1 to 5.
- Pillar-Plate or Main Plate
- Plate (Bottom Plate)
- Plexiglas, Plexi Crystal
- Poinçon de Genève
- Pointer Calendar
- Power Reserve
- Pulsimeter Chronograph
- Push Pin
- Pusher, Push-Piece or Push-Button
Part of the lever escapement, shaped like a ship's anchor (see Escapement). Device of the escapement (s) transmitting part of the motive force to the balance (s.), 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
Supporting element of bridges (s) and other parts of a movement (s).
Combines with a wheel and an arbor (s) to form a gear (s). A pinion has fewer 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.
End of an arbor (s) turning on a jewel (s) 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 (s) system.
Plate (Bottom Plate)
The plate supports the bridges and the various parts of the movement. The movement plate and the bridges build the frame of the movement.
Said of a metal treated by a galvanizing procedure in order to apply a slight layer of gold or another precious metal (silver, chromium, rhodium or palladium). In a watch the base is likely to be brass or steel.
Plexiglas, Plexi Crystal
Watch crystal made of acrylic crystal. This material can be processed and polished easily. The advantage for the owner of the watch is the comparatively high resistance to shocks but scratch resistance is low.
Poinçon de Genève
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.
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.
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.
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.
Small metallic spring pin fixed between the horns of the case to hold the watch strap.
Pusher, Push-Piece or Push-Button
Mechanical element mounted on a case (s) for the control of specific functions. Generally, pushers are used in chronographs (s), but also with other functions.
An abbreviation which stands for Physical Vapour Deposition. The PVD technology used for watches and bracelets is one of the most up-to-date and non-polluting coating systems. Its quality can be compared to 10 micron gold plating. The PVD finish is highly scratchproof and long lasting. The authentic gilt colour tone is obtained by applying a 23 carat gold layer.
Watches with analogue or digital display, whose movement is regulated by a by high-frequency vibrationsinduced in a quartz crystal. The quartz watch requires an electrical power source from a battery, solar cell or generator similar to a mechanical rotor. The display may be analogue, digital or mixed. There are also a few combination mechanical/quartz watches.
Quick Change Corrector (Date)
Mechanism for the direct setting of the date, to avoid turning the hands over 24 hours.
With fine regulating the watchmaker adjusts a watch to run as accurately as possible (see Fine Time Adjustment).
Made up by balance (s) and balance spring (s), 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 (s 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.
Regulating the functioning of a movement by lengthening and shortening the active section of the balance spring (s). 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 (s) to micrometer screws (s)) to limit error margins to very few seconds per day.
"Watch that strikes the hours by means of a mechanism operated by a push-piece or bolt. There are various types of repeaters. Quarter-repeater : sounding a low note for the hours and a ""ding-dong"" for each of the quarters; Five-minute repeater: striking the hours, quarters and five-minute periods after the quarter; Minute-repeater: striking the hours, quarters and minutes; Grande sonnerie (grand strike): striking the hours and quarters automatically and repeating when a push-piece is pressed down; Chiming repeater: in which the quarters are struck on three or four gongs of different pitch. The mechanism of the striking work is among the most complex complications."
Said of a hand (s.) 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.
Alloy of gold, copper and silver. The rose gold tone is due to the copper content.
Rotating Top Ring
Rotating bezel on the top ring of a watch case, serving in most instances to record additional data.
In automatic-winding mechanical movements the rotor is the part that, by its complete or partial revolutions and the movements of human arm, allows winding of the mainspring (s). (see Swinging or Oscillating Weight).
Synthetically produced precious stone, used in the watch movement as pallet stones and bearings (jewel holes) to reduce friction and wear.
- Sapphire Crystal
- Screw Back
- Screw-in Crown
- Second Time-Zone Indicator
- Setting Mechanism
- Shockproof, Shock-Resistant / Absorber
- Skeleton, Skeletonized
- Small Second
- Sonnerie (En Passant)
- Split-Second Chronograph
- Stainless Steel
- Striking Work
- Super Luminova
- Sweep Second Hand
- Swinging Or Oscillating Weight (Rotor)
Watch crystal made of artificial sapphire. A sapphire crystal is highly scratch resistant due to its extreme hardness.
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 (s.) (indicating the average speed), telemeter (s.) (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..
Case back with thread so that it can be screwed on to the watch case.
Special crown which is screwed in for better security and used mainly for divers' and sports watches.
Second Time-Zone Indicator
see GMT and World Time.
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.
Shockproof, Shock-Resistant / Absorber
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.
Watches whose bridges and pillar-plates are cut out in a decorative manner, thus revealing all the parts of the movement.
Part of a mechanism moving with friction on a slide-bar or guide.
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.
Decoration with a spiral pattern, mainly used on the barrel wheel or on big-sized full wheels.
Sonnerie (En Passant)
Function consisting of an acoustic sound, obtained by a striking work made up of two hammers (s) 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 (s) or an additional pusher (s) it is possible to exclude the sonnerie device and to select a so-called grande sonnerie.
Chronographs with split-second mechanisms are particularly useful for timing simultaneous phenomena which begin at the same time, but end at different times, such as sporting events in which several competitors are taking part. In chronographs of this type, an additional hand is superimposed on the chronograph hand. Pressure on the pusher starts both hands, which remain superimposed as long as the split-second mechanism is not blocked. This is achieved when the split-second hand is stopped while the chronograph hand continues to move. After recording, the same pusher is pressed a second time, releasing the split-second hand, which instantly joins the still-moving chronograph hand, synchronizing with it, and is thus ready for another recording. Pressure on the return pusher brings the hands back to zero simultaneously, provided the split-second hand is not blocked. Pressure on the split pusher releases the split-second hand, which instantly joins the chronograph hand if the split-second hand happens to be blocked.
Steel which does not get rusty and is not affected by corrosion. It is extremely resilient.
see Sonnerie and Repeater.
Sweep Second Hand
"A second hand mounted on the centre of the main dial usually ""sweeping"" the entire circumference of the dial each minute"
Swinging Or Oscillating Weight (Rotor)
The natural movement of the arm makes the oscillating weight swing round, thus winding up the mainspring of the automatic watch.
Function measuring the speed at which the wearer runs over a given distance. The tachometer scale is calibrated to show the speed of a moving object, such as a vehicle, over a known distance. The standard length on which the calibration is based is always shown on the dial, e.g. 1,000, 200 or 100 meters, or in some cases one mile. As the moving vehicle, for instance, passes the starting-point of the measured course whose length corresponds to that used as the basis of calibration, the observer releases the chronograph hand and stops it as the vehicle passes the finishing point. The figure indicated by the hand on the tachometer scale represents the speed in kilometers or miles per hour.
By means of the telemeter scale, it is possible 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, viz. approximately 340 meters or 1,115 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 as distance from the storm.
Particular shape of a watchcase, imitating the profile of a barrel, i.e. with straight, shorter, horizontal sides and curved, longer, vertical sides.
Device invented in 1801 by A. L. Breguet. This function equalizes position errors due to changing positions of a watch and related effects of gravity. Balance, balance spring and escapement are housed inside a carriage (s), also called a cage, rotating by one revolution per minute, thus compensating for all the possible errors over 360. Although this device is not absolutely necessary for accuracy purposes today, it is still appreciated as a complication of high-quality watches.
Isotope of hydrogen, slightly radio-active, is used to activate the luminous dots on the dial. The emitted radiation is so low that there is no health risk.
Movement of a pendulum or other oscillating bodies, limited by two consecutive extreme positions. In an alternate (pendulum or balance) movement, a vibration is a half of an oscillation (s). The number of hourly vibrations corresponds to the frequency of a watch movement, determined by the mass and diameter of a balance (s) and the elastic force of the balance spring. The number of vibrations per hour (vph) determines the breaking up of time (the “steps” of a second hand). For instance, 18,000 vph equals a vibration duration of 1/5 second; in the same way 21,600 vph = 1/6 second; 28,800 vph = 1/8 second; 36,000 vph = 1/10 second. Until the 1950s, wristwatches worked mostly at a frequency of 18,000 vph; later, higher frequencies were adopted to produce a lower percentage of irregularities to the rate. Today, the most common frequency adopted is 28,800 vph, which assures a good precision standard and less lubrication problems than extremely high frequencies, such as 36,000 vph.
Watch case, crown, buttons (push-pieces) and crystal are water resistant and dustproof up to the underwater pressure or depth mentioned by the manufacturer (3 atmospheres, corresponding to a conventional depth of 30 meters; 5 atmospheres, corresponding to a conventional depth of 50 meters). The water resistance should be checked yearly.
English term for water resistant watches.
Circular element, mostly toothed, combines with an arbor and a pinion (s) to make up a gear (s). Wheels are normally made of brass, while arbors and pinions are made of steel. The wheels between barrel (s) and escapement (s) make up the train (s).
Element transmitting motion from the crown (s) to the gears governing manual winding and setting.
Shaft on which the crown is fixed at the outer end. The winding system is the connection between the crown outside the case and watch movement.
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.
Additional feature of watches provided with a GMT (s) 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.