Glossary
A
The Age of the Moon refers to the time elapsed between successive New Moons. It is typically displayed on a watch Dial as a cycle of 1 to 29½ Days, which corresponds to the period of the moon’s Revolution around the Earth. This Complication helps track the moon’s phases and is commonly found in Lunar Watches.
An Altimeter is a Complication on a tool watch that measures and displays Altitude above sea level. Essential for Aviators, it tracks ascent and descent, making it useful for Climbers, Walkers, and Mountaineers. This feature provides crucial information for activities where knowing the altitude is important.
Anglage, or Chamfering, is a traditional watchmaking technique involving the careful filing of the sharp edges of watch components to create a smooth 45° Angle. This meticulous process, often done by hand, removes burrs and machining marks, enhancing both the aesthetics and functionality of the movement by reducing the risk of corrosion. Anglage is mainly applied to the Bridges, Plates, and other visible parts of the movement, showcasing the craftsmanship and adding value to high-end timepieces. This technique is especially prominent in Swiss watchmaking, particularly in the cantons of Vaud and Geneva.
An Annual Calendar is a Watch Complication that displays the Date, Day, and Month, adjusting automatically for months of varying lengths. Unlike a Perpetual Calendar, it requires manual correction once a year in February due to its inability to account for leap years. This mechanism switches the date back to the 1st after reaching the 30th or 31st, depending on the month. First introduced by Patek Philippe in 1996 with the Ref. 5035, the annual calendar remains a sophisticated feature that simplifies the maintenance of wearing a complex watch.
An Anti-Magnetic Watch is designed to resist the effects of magnetism, which can disrupt its movement. The first anti-magnetic watch was developed by Vacheron Constantin in 1915. To achieve this resistance, critical parts of the movement, such as the Escapement and Balance Wheel, are made from anti-magnetic alloys. This design helps maintain accuracy even when exposed to magnetic fields encountered in daily life.
An Aperture is a small opening on the watch Dial that displays various indications, such as the Date. Common in models like the Rolex Datejust, it offers a clear view of essential information through a discrete window, enhancing both functionality and design without overwhelming the dial’s aesthetic.
Arabic Numerals, ranging from 1 to 12, are commonly used on watch dials to indicate Hours. These numerals are the standard numerical symbols used globally today and are easily recognizable, making them a popular choice for clear and precise time indication on watch faces.
An Asthmometer is a feature found on some chronographs, designed to measure the rate of Respiration. The dial includes a scale calibrated to indicate the number of respirations per minute. Typically set for 15 Respirations, the chronograph hand is started at the beginning of the measurement and stopped after the 15th breath. The scale then provides the respiration rate per minute, making it a useful tool for medical professionals to monitor a patient’s breathing.
ATM, or “Atmosphere,” is a unit of pressure used to indicate a watch’s Water Resistance. 1 ATM equals 10 Meters of water pressure. However, a watch rated at 3 ATM (30 meters) is only splash-resistant and not suitable for swimming. Watches suitable for swimming typically have at least 5 ATM (50 meters) resistance, while diving watches should have 20 ATM (200 meters) or more. The higher the ATM rating, the greater the water resistance, with specific uses ranging from showering to professional diving.
B
The Balance Spring, or Hairspring, is a crucial component in a mechanical watch, functioning much like the heart of the watch. It is a fine, coiled spring that controls the movement of the Balance Wheel, facilitating the wheel’s oscillating motion which divides time into equal segments. This spring helps regulate timekeeping by adjustments in its length. Its precise operation is essential for the accuracy of the watch, making any changes to its geometry or length critical for maintaining optimal performance.
The Balance Wheel in a mechanical watch is comparable to a pendulum in grandfather clocks. It is a weighted wheel that oscillates, splitting time into consistent intervals, essential for the watch’s accuracy. Modern balance wheels are often made of materials like Glucydur to enhance their precision and reliability. This component, together with the balance spring, regulates the timing through its rhythmic oscillations.
Barrettes are small metal bars used to attach the bracelet to the watch’s lugs. These bars come in different types, depending on the lug design. They are essential for securing the watch strap or bracelet, ensuring the timepiece stays comfortably on the wrist.
The Barrel in a mechanical watch is a cylindrical component that houses the mainspring, the device responsible for storing energy when the watch is wound. It is characterized by a toothed rim that drives the watch’s gear train, influencing the power reserve—the duration the watch can run without being wound again. This component is crucial for the distribution of power within the watch’s mechanism, ensuring consistent operation.
The Bezel is a ring on the top of a watch case, surrounding the crystal. It serves both decorative and functional purposes, securing the watch glass. Bezels vary in functionality: they can be fixed, unidirectional for tracking elapsed time (common in divers’ watches), or bidirectional, allowing the wearer to mark time from a reference point by aligning the bezel’s 12 o’clock position with a chosen moment on the dial.
A Bridge is a metal plate with embedded jewels that supports the gears of a timepiece. It is a stable metal component used as a base for other parts like pivots, and it is secured to the base plate on both sides. Unlike a bar or cock, which are fastened on one side, a bridge provides greater stability. This essential part holds at least one bearing of a rotating component, ensuring the smooth operation of the watch movement.
C
A Calendar feature on a watch displays the Date and often the Day of the week. There are several types of calendar watches. Most show the information Digitally through an aperture on the watch face, while some Chronograph watches display it on Sub-Dials.
A Caliber, or Movement, is the term for a watch movement, defining its Origin, Type, and Manufacturer. It refers to the entire set of main organs and mechanisms inside the case that allow the watch to function. Originally, it denoted the layout and dimensions of movement parts, such as wheels and barrels. Today, it encompasses the specific layout, shape, and components of a movement. Brands that produce their own movements call them “Calibres Manufacture,” though many use movements from major manufacturers like ETA, Sellita, or Miyota.
The watch Case is the outer body of a timepiece that houses and protects the movement from Dust, Moisture, and Shocks. It consists of the Case Middle, Case Back, and Bezel. The case also defines the watch’s shape and overall appearance. Common materials include Steel, Bronze, Gold, Carbon, Ceramic, Titanium, Platinum, Sapphire, and Tantalum. Shapes can be Round, Oval, Rectangular, Square, Cushion, Barrel, or Triangular.
The Caseback is the cover on the back of the watch case, opposite the dial. It can be clipped or screwed down for better Water Resistance, especially in diving watches. Casebacks come in two types: Solid, which hides the movement, and Display, which shows the movement through a crystal. Casebacks often include Inscriptions with important information such as the Brand Name, Serial Number, Origin, Hallmarks, Water Resistance Rating, and Case Material.
Ceramic is a high-tech material used in watchmaking for its Stainless and Scratch-Resistant properties. Its hardness is just below that of diamond, scoring a 9 on the Mohs Scale, compared to diamond at 10. Ceramic is known for its durability and aesthetic appeal, offering a high level of scratch resistance that surpasses steel and gold.
A Chronograph is a watch that tells the time and also functions as a Stopwatch to measure elapsed time intervals. It features additional hands and sub-dials, activated by Push Buttons, to start, stop, and reset the timer. Originating from the Greek words “Chronos” (time) and “Graphein” (to write), modern chronographs display elapsed time without inscribing it. This complication typically includes Hour, Minute, and Second Indicators and can sometimes feature Tachymeter Scales for measuring speed. Unlike a Chronometer, a chronograph is not certified for high-precision timekeeping.
A Chronometer is a watch that meets high precision standards, deviating no more than 5 seconds per day for mechanical movements. These watches receive an official certificate from organizations like the COSC (Contrôle Officiel Suisse des Chronomètres). To earn this designation, the watch must pass rigorous tests under various conditions, such as Temperature and Position Changes. Unlike chronographs, which measure elapsed time, chronometers are recognized for their superior timekeeping accuracy and reliability.
The Clous de Paris is a decorative Guilloché Pattern often found on watch dials. This intricate design features hollowed lines that intersect to form tiny, pyramid-like shapes. The pattern adds a refined texture and visual interest to the dial, enhancing the overall elegance of the timepiece.
A Complete Calendar complication displays the Day, Date, and Month. It requires Manual Adjustment at the end of each month that does not have 31 days. This type of calendar does not account for shorter months automatically, so the wearer must reset the date at the end of each month with fewer than 31 days.
A Complication is a mechanism added to a basic watch movement. Complications can be divided into three groups: displaying additional hands (like a chronograph), sounding mechanisms (like alarms), or providing Astronomical Indications (like moon phases). They refer to any function beyond displaying hours, minutes, and seconds, including date displays, chronographs, and perpetual calendars. Complications enhance a watch’s functionality and complexity, with some examples being Power Reserve Indicators, Tourbillons, and Dual Time Zones.
A Corrector is a button, usually flush or inset into the watch case, used to adjust internal complications such as a calendar. Unlike pushers, which stand out from the case and control functions like chronographs, correctors are often discreet and require a special tool to press. Some correctors, like those on the A. Lange & Söhne Lange 1, resemble pushers but are designed for specific adjustments. These buttons help maintain the accuracy of complications without disrupting the watch’s aesthetics.
The COSC (Contrôle Officiel Suisse des Chronomètres) is the Swiss institute responsible for certifying the accuracy and precision of chronometers. Established in 1973, COSC tests watch movements over 15 days in various positions and temperatures. Only movements that meet strict criteria, with an average daily rate deviation of -4 to +6 seconds, receive certification. This certification is essential for a watch to be labeled a chronometer. COSC operates three testing centers in Switzerland and certifies around 6% of Swiss watches annually.
Also known as Geneva Waves or Stripes, this traditional finishing technique is applied to movement plates and bridges, creating evenly spaced, parallel lines. The decoration gives the watch a highly aesthetic appearance and is typically done on semi-automatic or CNC machines for precision. The name originates from Geneva, renowned for its watchmaking. In the Glashütte region, a similar technique called Glashütter Streifen is applied at a different angle, also enhancing the watch’s visual appeal.
The Crown, often fluted for grip, is a knob on the case exterior used for Winding the watch and setting the time and date. In some models, it can also start the chronograph mechanism. Diving watches often feature a Screw-Down Crown for enhanced water resistance. Historically, pilot watches had oversized crowns for easier handling with gloves.
The Crystal is the transparent cover over the watch dial, sometimes also placed on the case back to view the movement. There are three main types: Acrylic Crystal, an inexpensive plastic that can be buffed to remove scratches; Mineral Crystal, heat-treated for scratch resistance; and Sapphire Crystal, the most durable and scratch-resistant, made from synthetic sapphire. Some crystals have an Anti-Reflective Coating to reduce glare.
D
A Complication that indicates whether the time displayed is AM or PM. This can be shown through a small Dial with a single hand rotating every 24 hours or a Sun-Moon Indication. Often found in GMT/Dual Time or World Time Watches, it helps distinguish between day and night in different Time Zones.
Dead Seconds, also known as Dead-Beat Seconds or True Beat Seconds, is a complication in Mechanical Watches where the Second Hand jumps forward in distinct one-second intervals rather than sweeping smoothly. This function, also referred to as Seconde Morte in French and Ruhende Sekunde in German, mimics the ticking motion commonly associated with Quartz Watches. Breguet described this feature as “Seconde d’un Coup” or “Sudden Second.” Achieving this precise jump in mechanical watchmaking is considered a technical accomplishment.
A Deployment Buckle is a three-part Folding Clasp that secures the two ends of a watch bracelet. When fully deployed, it provides enough room to place the watch on the wrist. When closed, the buckle covers the folding mechanism, providing a secure and streamlined fit.
The Dial is the face of the watch, displaying Hours, Minutes, and Seconds. It may also show the Date, Day, and Moon Phases depending on the complication. Made from metal or other materials, dials feature Markings, Numerals, Symbols, and additional information. They can be Engraved, Guillochéd, Lacquered, Set, Luminous, or Enameled, and may include Sub-Dials for extra functions. The dial often only displays the Manufacturer’s Name but can come in various colors and finishes. The process of adding inscriptions is called Pad Printing or Transfer Printing.
A Dual Time-Zone timepiece allows the simultaneous display of time in two different time zones. This is typically shown with an additional Hour Hand that tracks time in a 24-hour mode. Some watches feature a separate Sub-Dial for the second time zone. This feature is useful for travelers and those who need to keep track of time in multiple locations.
E
Enamel is a vitreous substance, primarily composed of Silica mixed with various Oxides to produce a range of colors. It is used to decorate metal surfaces such as Gold, Silver, and Copper. The process involves applying enamel paste to a metal base and firing it in a Kiln at temperatures between 650°C and 950°C. “Grand Feu” is a traditional enameling technique requiring high heat to achieve bright, long-lasting colors. This technique results in vibrant, durable watch Dials with a unique luster.
The Equation of Time complication displays the difference between “Mean” time (average solar time) and “Solar” time (true solar time). Due to Earth’s elliptical orbit and axial tilt, this variance fluctuates throughout the year. An Equation of Time watch shows this difference, often through a Sub-Dial or additional indicator. This complication reflects the difference in minutes between the actual solar time and the 24-hour day, corrected by a Cam Mechanism inside the watch.
The Escapement regulates the release of energy from the Mainspring, releasing it in controlled bursts to drive the Balance Wheel. It generally includes components like the Escape Wheel, Pallets, and Pallet Fork. The Swiss Lever Escapement is the most common type used today. It ensures the balance wheel’s oscillations are maintained, allowing for accurate timekeeping. The escapement is crucial in controlling the movement’s energy, thereby governing the rate at which the wheels and hands of the watch revolve.
F
A Flyback Chronograph features a mechanism that allows the Stopwatch to be reset to zero and restarted with a single button press, without the need to first stop and reset. This is especially useful for Pilots who need to measure successive time intervals quickly. The term “Flyback” refers to the reset and restart action, which is executed swiftly to ensure minimal time loss, crucial in rapid sequence timing.
A Flying Tourbillon is a type of tourbillon where the mechanism is supported only from the bottom, without an upper bridge, giving the appearance that it is floating. This design allows for an unobstructed view of the tourbillon, enhancing its aesthetic appeal. Unlike a traditional tourbillon, which has both upper and lower supports, the flying tourbillon is held in place solely by the lower pivot, providing a more intricate and visually striking complication.
A Folding Buckle, also known as a Deployant Clasp, features a mechanism that unfolds when opened. It is designed to not fully open, ensuring that if it accidentally unlatches, the watch remains secured around the wrist. This design minimizes the risk of the watch slipping off, providing both convenience and safety.
G
GMT refers to Greenwich Mean Time, a global time standard set at the Prime Meridian in Greenwich, England. It represents the mean solar time at the Royal Observatory in Greenwich, London. In watches, GMT indicates a feature that allows them to display a second time zone. This is particularly useful for tracking local and another time zone simultaneously, often shown in a 24-hour format to distinguish between AM and PM hours in the second zone. GMT watches are invaluable for travelers and those who engage with global schedules.
A Grande Sonnerie is a sophisticated watch complication that audibly strikes the time. It automatically chimes the Hours and Quarters at each quarter-hour, indicating the number of quarters elapsed during the respective hour. Additionally, it can repeat the entire sequence of chimes with the push of a button. This intricate mechanism allows the wearer to know the time without looking at the watch, showcasing the pinnacle of watchmaking craftsmanship.
Guilloché is an intricate engraving technique creating decorative patterns on metal surfaces, mainly used on watch dials. It involves engraving lines or curves using a Guilloché Machine or by hand with a burin. This technique, dating back to the 16th century, adds a sophisticated, aesthetic appeal. Common patterns include Clou de Paris, Sunray, and Wave. Originally mechanized in the 18th century, it enhances both beauty and functionality, improving readability through its interplay with light.
H
Hands are thin, rigid metal pieces on a watch dial that indicate time. Most watches have three hands: Hour, Minute, and Second, with some models featuring a fourth for a second time zone. Initially, only hour hands were used until the balance spring enabled minute and second hands. Hands consist of a Body, Head, Neck, Counterweight, and Point. Types include Baton, Stick, Dauphine, Leaf, and more, each contributing to the watch’s aesthetics and functionality.
A feature for Diving Watches, the Helium Escape Valve allows helium molecules to exit the watch case during a diver’s ascent. This prevents the watch from breaking under pressure changes. Found on professional dive watches, the valve is crucial for divers using mixed gases with helium at great depths. Without it, trapped helium could cause the watch crystal to pop out during decompression. The valve is a one-way mechanism, ensuring safe helium release and maintaining the watch’s integrity.
I
J
Jewels in watchmaking, often referred to as “Rubies,” are synthetic ruby jewel bearings utilized to reduce Friction within the Movement. They are synthetic Corundum, chosen for its Purity and absence of Inclusions, enhancing Durability and Cost-Efficiency. These jewels serve crucial roles in minimizing Wear and maintaining the Precision of the Timepiece’s mechanical operations. Typically found in parts of the movement subject to high friction, these bearings help ensure long-lasting, accurate performance in Mechanical Watches.
A Jumping Hour complication displays the time through a Numeral in a small window on the Watch Face. The numeral jumps forward at the start of each new hour, offering a Digital Readout in an analog setting. This mechanism enhances Readability and adds a unique feature to the Timepiece, setting it apart from traditional watches where the hour hand moves continuously. The Minutes and Seconds are read as normal from the Analog Hands and Dial, while the hour is indicated by the jumping numeral.
K
L
A Leap Year indicator on a watch shows whether the current year is a Leap Year. Leap years, divisible by four, except for Secular Years not divisible by 400, have 366 days, with an extra day added on February 29th. The concept, introduced by Julius Caesar in 45 BC as part of the Julian Calendar, was used to account for the Earth’s 365.2422-Day Solar Orbit. Leap years generally occur every four years, aligning the calendar year with the Astronomical Year.
The Lever is a crucial component of a watch’s Escapement Mechanism, acting as a two-armed connection between the Escapement Wheel and the Balance Wheel. It transmits power from the escapement wheel to the balance wheel, maintaining the Oscillations necessary for Timekeeping. Additionally, it regulates the flow of Energy, ensuring the Gear Train moves at regular intervals. Due to its shape, the lever is sometimes referred to as the Anchor. The lever experiences both sliding friction and impact, making it one of the most stressed parts of a Mechanical Watch.
Lugs are projections on a Watch Case that attach to the Strap or Bracelet via Spring Bars. Typically, a watch has four lugs. The distance between the lugs, known as Lug Width, is crucial for determining the appropriate strap size. Common lug widths include 16 mm, 18 mm, 20 mm, 22 mm, and 24 mm, allowing for various strap options to match personal style and comfort.
Luminous Colors on watches enable readability in the Dark. Historically, Radioactive Materials like Radium and Tritium were used, but these posed Health Risks. Modern watches use non-radioactive substances like Superluminova and LumiNova®. Superluminova, a Phosphorescent Material, is safe and long-lasting. Tritium H3, used for higher legibility (e.g., military watches), utilizes tiny tritium gas light sources for continuous illumination without external charging. These advancements have replaced older phosphorescent and radioactive dials, ensuring Safety and effective Illumination.
M
The Mainspring is a coiled strip of metal housed inside the Barrel of a watch. It delivers the power needed for the Balance Spring to maintain its Oscillations, thus driving the watch Movement. Made from a special alloy of iron, nickel, and chromium, the mainspring stores energy when wound and releases it gradually as it unwinds, powering the Gear Train. Modern mainsprings are generally stainless with a high elastic limit, providing at least 36 hours of running time. They are wound using a tool before being inserted into the barrel.
A Manual Movement is one that is wound by hand using the Winding Crown. This type of mechanism requires regular winding to keep the watch running. The term “Manual” also refers to tasks performed by hand, highlighting the skill and craftsmanship of early watchmakers known for their manual dexterity.
A Manufacture is a watchmaking factory that produces its products almost entirely by hand, symbolizing quality. Modern definitions vary, but experts agree it should refer to a company that manufactures at least one Watch Movement in-house. Historically, few companies in Switzerland and Germany met this standard, but competitive markets now demand proprietary movements. The term, preferred in its French variation, originates from Latin meaning “Made By Hand.” A manufacture is a watchmaking company that crafts every part of their timepieces internally.
Markers indicate the hours on a Watch Dial and can come in various shapes such as batons, circles, lines, or diamonds, depending on the timepiece’s design. They generally replace traditional Roman or Arabic Numerals and run from 1 to 12, but 24-hour watches are also available. Markers can be inscribed, applied, or painted on the dial. They have evolved to allow more creative and varied dial designs, sometimes combining numerals and markers.
A Mechanical Watch is driven by a mechanical movement, which can be manually wound or automatically wound through the wearer’s wrist movements, unlike electronic Quartz Watches. These watches feature intricate machinery that powers the timekeeping functions without the need for batteries. After the quartz crisis of the late 20th century, mechanical watches have become synonymous with Luxury and Craftsmanship, dominating the high-end watch market. They are prized for their artistry, engineering, and traditional watchmaking techniques.
A Minute Repeater is a complex watch complication that chimes the time on demand when activated by a slider on the case. It sounds Hours (low tone), Quarter Hours (high and low tones), and Minutes Past the quarter (high tone). For instance, 3:22 would chime as 3 hours, 1 quarter, and 7 minutes. Invented in the early 18th century, it is one of the most sophisticated and costly features in mechanical watchmaking.
A Moon Phase indication displays the current phase of the moon. This complication tracks the Lunar Cycle, which lasts 29 days, 12 hours, 44 minutes, and 2.8 seconds. The cycle consists of four main phases: New Moon, First Quarter, Full Moon, and Last Quarter. The moon phase is often represented by a rotating disc showing two moons, advancing by a notch every 24 hours. More precise mechanisms, like the “Astronomical Moon,” use a 135-tooth wheel, resulting in a one-day error only every 122 years.
A smooth, iridescent material found inside the shells of Mollusks, often used on Watch Dials for its aesthetic appeal. It commonly appears in milky white but can also be found in colors like silvery gray, gray-blue, pink, and salmon. Known for its shimmering effect, Mother of Pearl adds a unique, luxurious touch to timepieces.
N
O
An Open-Worked Dial is a timepiece dial where part or all of the inner workings are visible from the front. This design allows a view of the intricate Mechanisms inside the watch, showcasing the craftsmanship and complexity of the Movement.
P
Perlage, or circular graining, is a decorative technique used on watch components like Bridges, Movement Plates, and Dials. It involves creating a pattern of small, overlapping circles or beads using a rotating tool. Originally intended to trap Dust and reduce light reflection, it now serves primarily as an aesthetic feature. This intricate finish can be applied manually with a Beading Machine or through automated methods for mass production, reflecting the craftsmanship and attention to detail in high-quality watchmaking.
A Perpetual Calendar displays the Day, Date, and Month, accounting for leap years, with no manual adjustment needed until the year 2100, when a leap year is skipped. It automatically adjusts for months with varying days, including February in leap years. This complication, often found in high-end watches, ensures the date transitions accurately through the year. The only manual correction required will be in 2100, as secular years divisible by 100 are not leap years.
A Pin Buckle is a classic watch clasp consisting of a small, flexible metal pin that fits into a hole on the Watch Band, similar to a belt buckle. This mechanism allows for easy size adjustment and secure fastening on the wrist. The pin is hinged to the clasp, which closes the bracelet, making it a widely used and traditional option for securing a watch.
The Poinçon de Genève, also known as the Geneva Seal, is an independent Swiss certification awarded to timepieces with impeccable finishing and detail, guaranteeing their horological excellence. Established in 1886, this certification is issued by an official body of the Geneva Watchmaking School. To earn this prestigious mark, a Movement must meet stringent criteria regarding origin, quality, and reliability, including 12 specific standards for machining and fine-tuning. Only watches assembled and adjusted in the Canton of Geneva are eligible for this seal, which is a symbol of exceptional craftsmanship.
A Power Reserve Indicator shows how much time a watch can run before needing to be wound. Found in mechanical watches, it displays the remaining energy stored in the Mainspring, often indicated in hours or days. This complication, also known as Reserve de Marche, is especially useful in mechanical watches, helping users know when the watch requires winding. Typically, it features a hand that moves between “Zero Power Reserve” and “Maximum Power Reserve” positions.
A Pulsometer is a scale on a Chronograph used for measuring pulse rate. It allows wearers to calculate their Heart Rate by timing the seconds it takes for a set number of heartbeats, then reading the corresponding rate off the scale.
A Pusher is a component on the side of a watch, functioning like a button to activate specific features, such as the Chronograph. Commonly referred to as a ‘Push-Button’ it allows the wearer to start, stop, or reset functions.
PVD, short for Physical Vapor Deposition, is a vacuum process used to apply thin coatings onto surfaces. In watchmaking, it commonly refers to adding colored coatings to Cases and Bracelets or applying anti-reflective coatings to Crystals.
Q
A Quartz timepiece is battery-powered and does not require manual or automatic winding. It uses a quartz crystal to maintain accurate timing, vibrating at a high frequency (32Khz) when exposed to an electrical current from the battery. This movement type, highly precise and virtually drift-free, powers the watch mechanism. Modern advancements include self-recharging quartz movements through body motion or solar cells. Quartz Watches can be Analog, Digital, or a combination of both (Ana-Digi.)
The Quartz Crisis refers to the period in the 1970s and 1980s when affordable Quartz Watches revolutionized the industry, severely impacting traditional mechanical watchmaking. This era saw many Swiss watchmakers struggle to compete with the precision and low cost of quartz timepieces from Japan, leading to significant industry changes.
R
A Regulator is a device in a wristwatch movement that adjusts the Balance Spring’s Length to control the watch’s rate, speeding it up or slowing it down. Moving the pointer towards “+” or “-” (or “A” or “R”) adjusts the spring. Historically, precision clocks known as regulators were used by watchmakers to observe timepieces, featuring a Pendulum with a precise length and often including Mercury Temperature Compensation. These clocks have low amplitude and fine adjustment mechanisms, often displaying Minutes, Hours, and Seconds on separate dials.
A Retrograde indication is a display where a hand moves along an arc and quickly returns to the start rather than completing a full 360-degree rotation. This mechanism is commonly used for Power Reserve Indicators, Date Displays, and sometimes for Hours, Minutes, or Seconds. Retrograde hands move backward instantly to reset after reaching the end of their scale, creating a visually engaging and technically complex feature. Some mechanisms simulate this effect using Multi-End Pointers, especially for Moon Phase indicators.
Roman Numerals are numbers displayed in Roman convention on Watch Dials from I to XII. For example: I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII. These numerals are often used for a classic and elegant appearance.
The Rotor, also known as the Oscillating Weight, is a semi-circular component in Automatic Watches that winds the Mainspring as it moves with the wearer’s motions. Made from heavy materials like gold or tungsten, it enhances the oscillation. Often visible through a Transparent Case Back, the rotor is frequently decorated and sometimes engraved with the Brand Logo. It rotates freely in both directions to keep the watch running as long as it is worn on the wrist.
S
Sapphire Crystal is an artificially produced glass made from monocrystalline aluminum oxide (Al2O3). It has a hardness of 9 on the Mohs Scale, making it highly scratch-resistant and only surpassed by diamond in hardness. Sapphire crystals can be Flat, Arched, or Domed, with production methods varying in complexity and cost. Anti-Reflective Coatings are often applied to enhance clarity. Used in high-quality watch glasses, sapphire’s durability and resistance to scratches make it ideal for protecting watch dials and showcasing movements.
A Secular Perpetual Calendar is a rare and advanced variant of the Perpetual Calendar, designed to account for long-term calendar irregularities, including the exclusion rules for leap years. It automatically adjusts not only for the varying lengths of months and leap years but also for centuries that are not leap years (e.g., 1900, 2100) according to the Gregorian Calendar. This feature ensures the calendar remains accurate over centuries, handling the 100-year and 400-year rules without manual adjustment, making it a pinnacle of horological complexity.
An Automatic, or Self-Winding, timepiece has a movement powered by the wearer’s wrist motions via an Oscillating Rotor. Originating from a 1778 document by Hubert Sarton, this mechanism winds the mainspring with every wrist movement, ensuring continuous energy. If not worn regularly, the watch can be manually wound or placed in a Watch Winder to maintain its power reserve. The rotor’s bidirectional movement effectively transfers energy to the mainspring, keeping the watch running smoothly without the need for manual winding.
A Skeleton watch features a dial that reveals the inner workings of the timepiece, often visible from both the front and back. This involves hollowing out movement parts like plates and bridges to expose as many components as possible. Traditionally done by hand, this art form includes cutting, sawing, and filing away unnecessary material. Modern methods also use machines to achieve skeletonization. The movement is usually sandwiched between Sapphire Crystals, allowing an unobstructed view of the intricate mechanism.
In a Repeater Watch, the Slide is a component made from the same metal as the case, which moves along the case middle to wind the spring of the striking mechanism. The slide is used to activate the repeater mechanism, allowing the watch to chime the time. Some slides feature a Silent-Slide Function that prevents the mechanism from striking, offering the user the option to silence the chime.
A Split Seconds Chronograph, also known as a “Rattrapante” or Double Chronograph, includes a flyback hand that allows for the measurement of split-second times or timing simultaneous events of unequal duration. The chronograph starts with two superimposed hands. Pressing a button stops one hand for an intermediate time reading, while the other continues. Pressing the button again makes the stopped hand catch up with the moving one. This function is useful for timing multiple events that start together but end at different times.
A Spring Bar is a thin metal rod used to attach a Watch Strap to the Case Lugs. It features a compression spring inside, which pushes the two ends outward, securing the strap between the lugs. This mechanism allows for easy strap changes and ensures the strap remains firmly in place.
T
A Tachymeter is a scale on the Bezel or edge of a Watch Dial used to calculate speed over a set distance, typically kilometers or miles per hour. To use, start the Chronograph at a starting point and stop it at the endpoint; the scale indicates the average speed. The scale is most often associated with chronograph watches and is essential for timing activities like racing.
A Telemeter scale is used to measure distances based on the speed of sound, commonly found on Chronographs. By starting the chronograph when seeing a flash (like lightning) and stopping it when hearing the sound (like thunder), the distance to the event can be read off the scale. This is because sound travels at approximately 340 meters per second. For instance, if the chronograph stops at 18 seconds, the telemeter scale would indicate a distance of about 6 kilometers. This function is particularly useful in activities such as mountaineering.
The world is divided into 24 Time Zones to ensure that each region’s average Solar Time aligns with the true solar time. Watches often include functionality to display time across these zones. When traveling east, clocks are set forward, and when traveling west, they are set back, usually by one hour, although exceptions exist with differences of 30 or 45 minutes. The Prime Meridian, at Greenwich, England, marks the starting point. Each zone follows the same legal time, with adjustments sometimes made by countries to better fit their needs.
The Tourbillon is a device invented by Abraham-Louis Breguet in 1801 to counteract the effects of gravity on a watch’s accuracy. It places the Escapement in a rotating cage, making one full rotation per minute. This helps to even out positional errors in vertical positions, improving precision. While initially practical for pocket watches, it now serves mainly as a testament to a watchmaker’s skill and craftsmanship in modern wristwatches.
The Trotteuse is the second hand of a watch. It can be “Central,” located at the center of the dial, or appear as “Small Seconds” on a sub-dial. In chronographs, it is often integrated into smaller dials. The central trotteuse is fixed at the dial’s center, while the small trotteuse is placed on a specific sub-dial. The trotteuse advances in jumps, following the Oscillations of the watch’s Balance Wheel.
U
Universal Time (UT) is a time standard based on the Earth’s rotation, initially aligned with mean solar time at the Greenwich Meridian. It accounts for Earth’s irregular rotational speed due to tidal forces from the Sun and Moon. To maintain synchronization with atomic time, Leap Seconds are occasionally added, forming Coordinated Universal Time (UTC). UTC serves as the global standard for civil timekeeping, ensuring accuracy by balancing atomic time precision with Earth’s natural cycles. Watches with a World Time feature can display multiple time zones simultaneously.
V
Vibration in a watch movement refers to the oscillation of the Balance Wheel between two extreme positions, creating the ticking sound. The frequency is measured in Hertz (Hz) or vibrations per hour (vph), with common frequencies being 18,000 vph (2.5 Hz), 21,600 vph (3 Hz), 28,800 vph (4 Hz), and 36,000 vph (5 Hz). Higher vibrations enhance accuracy but consume more energy. Quartz Watches, vibrating at 32 kHz, are more precise than mechanical watches due to their higher frequency.
W
A Wheel in watchmaking is a circular component that rotates around an axis to transmit power or motion within the movement. The Wheel Train includes all the geared wheels that drive the hands and complications, transferring torque from the Barrel to the Escapement Wheel. These wheels are typically held in place by Bridges or Cocks connected to a Plate, with high-torque wheels often anchored with Jewels. The Balance Wheel, essential for regulating time, usually has an Anti-Shock Device to secure its staff.
A World Time complication displays the time in up to 24 different time zones around the world. The outer edge of the dial usually features the names of cities representing each time zone. The current hour in a particular time zone is read by looking at the scale next to the city name that aligns with the hour hand. The minutes are read as usual. Watches with this feature, known as “World Timers,” allow the wearer to quickly see the time in various global locations.
