Alarm (Alarum arch.) An alarm wristwatch with a striking mechanism that consists of a hammer and gong. The hammer strikes the gong continuously until the alarm power reserve is exhausted. These watches can usually be set to the nearest five minutes and up to 24 hours in advance. Breguet offers a fine selection of alarm wristwatches, such as Le Réveil du Tsar Classique, Marine Alarme Musicale and the Marine Royale Alarm, which will work underwater to an impressive depth of 30 bar (300m).
Annual calendar An annual calendar automatically adjusts for the right date each month except for February with its 28 or 29 days. This type of complication displays the month and date, the day and date (the Rolex Sky-Dweller being a famous example), or simply the date. In addition, it may also display the phases of the moon. The annual calendar first appeared in the 1980s and became a most useful tool that only had to be adjusted once every February, rather than five times a year for the most basic calendar function. For the ultimate calendar complication, see the Perpetual calendar.
Note: Never attempt to adjust the day or date on an annual calendar between the hours of 9pm – 3am as this is when the gears of the date jumper are engaged and damage can result. It is prudent to get into the habit of adjusting annual calendars only between the hours of 4pm – 8pm.
Anti-magnetic Magnetism, in all its forms, is one of the great enemies of watchmaking. Cell phones, computers, radios, tablets, handbags with magnets instead of locks or zips, can all affect mechanical movements and disturb the rate or accuracy of a watch. Most at risk is the balance, responsible for a watch’s precision. Movements are sometimes encased in anti-magnetic cores, called a Faraday cage, to protect the movement from strong magnetic fields. Amongst watchmakers, anti-magnetic and non-magnetic components are being developed on a continual basis to strengthen a mechanical movement’s resistance to magnetism or to prevent magnetisation altogether.
Note: Breguet continues to innovate in this area and in 2006 developed an escape-wheel, lever and flat balance spring in silicon. Silicon renders the movement impervious to magnetic attraction and influence and has the benefit of being highly resistant to corrosion and wear. It also requires no lubricant and can be fashioned to extreme precision.
Automatic winding Since automatic watches are powered by the wearer’s movement throughout the day, no mechanical watch can truly be described as ‘automatic’ or self-winding. A rotor or rotating weight, also known as the oscillating mass, is set in motion by body movement of the wearer which in turn winds the mainspring via the gear train. In most watches the axis for the rotor is found at the centre of the movement although a small number of models have micro-rotors. These are much smaller and recognisable as off-centre rotors lending great visual appeal to movements with transparent case-backs.
Note: Automatic winding was invented during the 1770s pocket watch era and significant contributions were made by Abraham-Louis Perrelet (1729-1826) and later Breguet. It was not until the advent of the wristwatch that self-winding movements entered mainstream watchmaking during and after World War I, eventually becoming widespread during the 1920s and 30s. It seems almost a historical anomaly that this innovative system was not patented until September 1924 by English watchmaker John Harwood (1893-1964).
Balance The balance is both the pulse and beating heart of the mechanical watch. It is a circular mass or rim that moves to-and-fro on its rotational axis and is coupled to, and made to oscillate by, the balance-spring. The resultant tick-tock, back and forth, is called an oscillation and each oscillation comprises two vibrations that divides the time into strictly equal portions called “alternations”. The energy generated by the balance-spring flows into the balance whose vibration frequency sets the rhythm for the escape wheel and pallets. In short, the balance is the controller of the speed of rotation of all the wheels in a mechanical timepiece. Also called the controller or governor of a watch escapement.
Bar or cock A metal plate or bracket fixed to the watch plate at one end and supporting a balance or gear wheel or pinion. Also called a balance cock. In high horology it is often engraved by hand and decorated with elaborate chasing, floral motifs, or other designs to match the theme of the watch. See Breguet’s collection of minute repeaters for superlative examples of such engraving visible through the transparent case back.
Beveling One of the hallmarks of fine watchmaking: the art of bevelling or chamfering is to uniformly file down the edges of bridges, cams, plates, screw heads etc., usually to a 45° angle. The process is called anglage and is performed by an angleur or experienced watchmaker. Chamfering is tedious and painstaking work that cannot be rushed and is therefore the reserve of high horology timepieces. It can be found in any watch but is often applied to timepieces with transparent case backs or open-worked movements. This is not to say that some watches with solid case backs are not well finished, quite the contrary. Many grand complications with solid case backs hide movements that are finished to the highest levels of horology.
The result of finishing interior angles and edges to such a high degree is extreme smoothness that gives those parts a mirror finish or polish devoid of any irregularities (also called “black polish” or poli noir in French). This level of polishing cannot be achieved by machine application. Chamfered edges add depth to the movement in watches that are open-worked or have transparent case backs for viewing by the owner. The chamfers reflect a play of light and make the inner architecture beautiful to look at.
Note: Open case backs and transparent watches began to appear more frequently as of the late 1980s. This has become a widespread trend which allows watchmakers to show off the quality of their work and it has also forced the watchmaking industry as a whole to deliver an improved finish to all parts of a watch that are visible to the naked eye.
Bezel (Bezil arch.) A ring or rim that secures the sapphire crystal or plexiglass of a clock, pocket watch or wristwatch. Watches with transparent case backs repeat this process on the reverse side. The bezel also ensures the timepiece is dust/humidity proof and water resistant, especially in tool watches. Tool watches that are round in diameter often utilise the ring or rim as either a functional unidirectional or bidirectional rotatable bezel particularly when applied to aviation or diving watches with the appropriate scales marked on the bezel. Watches that are not round will not be able to have a rotatable bezel but may display bezel markings for hours or minutes or a tachymetric scale etc. Bezels can be any colour or material and need not be the same as the rest of the timepiece.
Breguet balance-spring A thin, concentric wire spring that sits curled inside the balance, where the outer coil is curved up and over the volute (spiral). The inner end is attached to the axis of the balance and the outer end is attached to the plate via the cock. As the balance oscillates, the elasticity of the balance-spring controls the oscillation rate of the balance. This has the effect of the balance-spring appearing to expand and contract, or “breathe”, as it exerts its influence on the oscillation rate to overcome variations in the impulses the balance receives from the escapement. Also known as the mainspring, “Breguet Overcoil” or “Spiral Breguet”.
Note: Abraham-Louis Breguet invented the “Overcoil” method of fixing the balance stud to the index (regulator) on the balance cock in 1795 and this has been widely adopted since (English watchmaker John Arnold (1736-1799) had previously incurved the spring end some time around 1770-80; a vital precursor to Breguet’s modification). It was then and now a revolutionary invention that gives a timepiece its rhythm and sets its rate, which is key to maintaining precision. The invention of the balance spring is attributed to Robert Hooke (1635-1703), however, it was first successfully applied by Dutch mathematician Christiaan Huygens (1629-1695) in about 1675.
Breguet hands A distinctive style of heat-blued steel hour and minute hands – shimmering with Breguet’s iconic blue – and instantly recognisable by their hollow, crescent-style “moon” tips. Designed in 1783, Breguet’s slim, sleek hands are easy to read and commonly known as “Breguet hands”. This is achieved by a process known as ‘bluing’ whereby polished steel is heated until the surface turns to a blue colour. They are found on most Breguet timepieces with the exception of the Type Family, all of which have Mercedes-style hands.
Breguet key Around 1789, Breguet invented the “ratchet key”, with a ratchet in its shaft that prevents turning the winding arbor the wrong way. Also known as a “Tipsy Key”.
Breguet numerals Designed by Breguet around 1783, the hour numbers on the chapter ring, at one time, comprised four forms: Arabic, Roman, Russian and Turkish. The Russian numerals are called Esclavons, referring to the Slavic languages. Breguet’s Arabic Numerals are the most enduring and famous to this day, instantly recognisable no matter the maker.
Bridge A bar with two supports fastened on top of the movement and affixed to the base plate via screws. Essentially a “sandwich” holding the movement and its parts together. The use of a base plate and bridges is the most common construction in the anatomy of watchmaking although skeletonised or open-worked movements use bridges only. See Bar or cock for a key part that generally has only one support.
Note: At Breguet and a few other manufactures, such as A. Lange & Söhne and Glashütte Original, master guillochers and engravers finish bridges to a superlative degree. Look for the grand complications within the Breguet collections for examples of this type of work, such as the tourbillon wristwatches not to mention the breathtaking double tourbillon, perpetual calendars and open-worked movements.
Calibre The arrangement of the components in a watch or clock movement. A calibre is usually given a reference number such as Breguet’s famous calibre 533.3 shown here. Different manufactures have their own reference for each movement, making identification easier. The term originally described rounds of ammunition i.e. the size of bullets and cartridges.
Chapter ring Graduated circle or outer dial or track of a clock or watch that displays the hour numerals as well as minute and second strokes. Antique and vintage timepieces sometimes have chapter rings that are painted or engraved. At Breguet, chapter rings are often identifiable by their classically styled Roman numerals set within a handsomely guillochéd dial.
Note: The hour divisions on the dial are called ‘chapters’, which derives from the Latin caput (head). The chapter ring is also sometimes called ‘hour circle’ or ‘hour ring’.
Chronograph From Ancient Greek meaning chronos (time) and graphein (to write), or writer of time, a chronograph is a complication within a watch or clock able to measure elapsed time on demand by enabling the seconds hand to be returned to zero at will. A chronograph is not the same as a stopwatch which does not display the time of day, although it is capable of performing the same functions. A specific feature is to have two or three sub-registers, called totalisers, on the dial to show the set limit which the chronograph is capable of measuring: either counting up to 30 minutes, 60 minutes, 12 hours (most popular) and the classic Richard Mille RM011 24-hour flyback chronograph tribute to Le Mans. The most common dial arrangements are duo- or tri-register chronographs, although there are other variations. Countdown chronographs are known as Regatta chronographs with the Rolex Yacht-Master II the icon among countdown timers.
The chronograph was invented by Louis Moinet in 1816, followed by the first marketed chronograph developed by Nicolas Mathieu Rieussec for King Louis XVIII in 1821. The King loved horse racing and wanted to know how long each race lasted. Breitling subsequently invented the first independent chronograph push-piece located at 2 o’clock on the watch case in 1915 and soon exhibited one of the first wristwatch chronographs. However, the patent for the flyback chronograph rests with Longines who developed their first flyback chronograph in 1936.
Note: A mechanical chronograph is usually operated in sequence, with the start/stop button at two o’clock and the reset button at four o’clock. The user starts and stops the chronograph before pressing the reset button. Operating a traditional chronograph out of sequence can risk damaging the movement. A flyback chronograph (retour en vol) is an added complication whereby the user can reset the chronograph while it is running simply by pushing the reset button (to zero the chronograph back to the start you simply stop the action and press reset as with any normal chronograph).
Chronometre From Ancient Greek meaning chronos (time) and métron (measure). Any precise timekeeper can be called chronometre or chronometer, however, to the purist, only those pieces using the “detent” escapement can be called chronometers whose primary purpose is determining longitude at sea. Nonetheless, with the advent of highly accurate mechanical wristwatches, any timepiece adjusted to 5 or 6 positions may indeed be called a chronometer.
Note: The earliest dated example of a detent escapement by Breguet is pocket watch No. 12, dating from around 1809 or earlier. Fittingly, pocket watch No. 12 is also a regulator. See Regulator. Additionally, in Britain the term has a more specific meaning and refers to marine timekeepers with highly accurate spring detent escapements.
Column wheel A small component that, when viewed from the top or side, resembles a circular top with crenelations. The column wheel looks like a turret or rook (chess) and facilitates the smooth transmission of starting, stopping and resetting of a chronograph. The column wheel was first introduced to the broader market in the late 1960s and is often viewed as a hallmark of high-end chronographs. It is called roue à colonnes in French and forms part of the base calibre of a chronograph movement. The column wheel can be seen in Breguet’s famous calibre 533.3 at the six o’clock position in this photo.
Note: It is not precisely known who first invented and built the column wheel but it has been attributed to Longines in 1878 for “a simple chronograph movement, the 20H calibre, patented by the watchmaker Alfred Lugrin” (source: Longines). Patek Philippe are also known to have used a column wheel in pocket watches dating from the 1890s (source: Somlo Antiques).
Complication Any addition to a mechanical timepiece that is linked to timekeeping outside of the hours and minutes. A complication is an indication that is added to the hours and minutes function of a timepiece that is directly linked with measuring the passage of time. Examples include: an alarm, annual and perpetual calendars, chronographs (split-seconds, flyback and traditional), day, date, month and year display, dual time, equation of time, moon phases, repeaters, sweeping seconds, and super-complications that include sidereal time and astronomical features.
Note: a power reserve indicator does not qualify as a complication, surprisingly and neither does the tourbillon. The tourbillon is an instrument designed by Breguet to counteract the effects of gravity on a timepiece and is not directly linked with timekeeping.
Constant force mechanism Also known as a constant force escapement and sometimes referred to by its French name, the remontoir. This mechanism winds a small spring to supply constant force to the escapement. It does this by separating the variable forces of the mainspring so that the balance may oscillate evenly and precisely at all times.
COSC The Contrôle Officiel Suisse des Chronomètres (COSC), the Official Swiss Chronometer Testing Institute, is the testing centre for certifying the accuracy and precision of chronometers. COSC’s main focus is testing mechanical timepieces but some high-precision quartz movements are also tested.
Côtes de Genève See Perlage.
Crown The crown is the ‘winding button’ used to wind and set a watch, giving the user direct access to the functions of the movement. A screw-down crown further protects the watch or clock from dirt, dust, humidity and water (some chronographs, such as the modern Rolex Daytona, also have screw-down push-pieces for the chronograph functions). The crown acts as a kind of ‘control panel’ to set the time, wind the watch or ‘hack’ the movement by pulling the crown all the way out thus stopping the balance for synchronisation against a reference time.
Note: Grand complications such as perpetual calendars require a special stylus to depress the buttons for setting the perpetual calendar which are recessed into the side of the watch or clock case.
Dial The dial constitutes the ‘face’ of a watch or clock, usually with hour markers or Arab or Roman Numerals around the border. A minutes and seconds track also often adorns the dial. Sub-dials for seconds, minutes, hours, day, month, date, moon phase, equation of time and power reserve may be found on the main dial depending on the movement. Breguet is famous for its guilloché dials, hand engraved on a rose engine. Other luxurious applications include enamel dials and mother of pearl dials.
Dual-time watch See GMT or Greenwich Mean Time.
Equation of Time or Équation Marchante This complication displays true solar time, as opposed to mean time. Because the Earth’s rotation is not constant, solar days vary slightly in length. This means that the speed of true solar time is not constant. It is correct only four times a year, around 15th April, 14th June, 1st September and 25th December. Mean time is based on the length of a mean or average solar day, which is 24 hours long, moving at a constant speed and known as the 24-hour clock that is divided into equal hours, minutes and seconds. The equation of time shows the difference between mean time and solar time as dictated by the sun all year round. Mean time runs up to 16 minutes behind solar time, as on 3rd November, and 14 minutes ahead of solar time, as on 12th February. These two values are exactly matched on the four days mentioned previously. The equation of time is sometimes indicated by a golden sun-tipped hand called marchant. It is usually paired with a perpetual calendar and fascinating to those with a particular interest in astronomy and maritime history. Watches and clocks with an equation of time must be precisely set by the watchmaker depending on the owner’s exact location on earth.
See Breguet’s ref. 3477 (above) for a pocket watch inspired example of a classic dress watch with perpetual equation of time, power-reserve indicator and perpetual calendar showing the day, date, month and leap year.
Escapement The mechanism which regulates the beat rate of a mechanical watch or clock. The escapement is a subassembly of parts combining: the balance, escape wheel, mainspring, pallets and pallet lever. The escape wheel acts on the balance (or controller) to regulate the speed at which the timepiece runs, whereby each oscillation of the balance allows one tooth of the wheel to escape. The speed of these oscillations gives the frequency of the calibre and the higher it is, the more precise the timekeeper becomes. The Swiss lever escapement is commonly used in mechanical timekeepers although there are many other types of escapement.
Escape-wheel and lever in silicon The escape wheel is the last wheel in a clock or watch train, giving impulse to the controller i.e. a pendulum for a clock and balance for a watch. See Escapement.
Note: As of 2006, Breguet is able to create silicon versions of three essential components: the escape-wheel, the lever and the flat balance spring. The result of several years of R&D, silicon has since been adopted by many leading watch manufactures to successfully combat magnetism and temperature changes. See Silicium/silicon.
First wristwatch Breguet is often credited with creating the first wristwatch or ‘wristlet’, as they were affectionately known during World War I and World War II. (Indeed, the endearing term was still in use in the 1950s although wristwatches were increasingly called ‘watches’ on both sides of the Atlantic.) The Queen of Naples, Caroline Murat, placed an order on 8th June 1810 for two timepieces: a Grande Complication carriage watch for the sum of 100 Louis, “in addition to a repeater watch for bracelet for which we shall charge 5,000 Francs” which became the first wristwatch ever known, the Breguet watch No. 2639. The firm’s archives further describe the order as: “oblong-shaped minute repeater watch (…), the said watch being fitted with a wristlet made of hair intertwined with gold thread” and, finally: “Oblong-shaped repeater for wristlet sold to the Queen of Naples on 5th December 1811.”
The watch was brought back twice for repairs, first on 8th March 1849 by Countess Rasponi and again in 1855. That was the last time it was seen, as no sketches survive and no public or private collection lists the Queen of Naples’ watch in its inventory.
Note: In 1868, Patek Philippe created a key-wound wristwatch, made for Countess Koscowicz of Hungary, although this watch was not delivered on a bracelet but rather affixed to a solid gold bangle. It is noteworthy that early documented evidence of small watches on bracelets were known as montres-bracelets.
Flyback chronograph or Retour en vol A flyback chronograph (retour en vol) is an added complication whereby the user can reset the chronograph while it is running simply by pushing the reset button (to zero the chronograph back to the start you simply stop the action and press reset as with any normal chronograph). Breguet also refers to this complication by the French retour en vol (retour – to return; en – on; vol – flight), a fitting description found on the dial side of the Type XXI and XXII. The flyback chronograph is useful for pilots as it allows for instant resetting as well as synchronisation. Breguet is forever associated with aviation history thanks to its Type 20 flyback chronograph wristwatch commissioned by the French Ministry of Defense in the early 1950s. The Type 20 dating back to 1954 remains an iconoclastic achievement among all pilot’s watches.
Note: Breitling led the way in the development of the flyback chronograph when it optimised the chronograph by separating the “start/stop” functions from “zero resetting” in a wristwatch in 1923. The stop and reset functions were previously controlled by the winding crown, so Breitling’s latest innovation made it possible to add up several successive times with ease. However, it was Longines which patented the flyback chronograph in 1936 and the company is sometimes erroneously credited with the invention of the flyback chronograph. It should be pointed out that the modern chronograph form was also thanks to Breitling, in particular Willy Breitling, grandson of the founder Léon Breitling, who invented the second independent chronograph push-piece in 1934.
Fusée (pronounced fewzee) From the Latin fūsus, meaning a “spindle” full of thread, the fusée is a device that equalises the pull of the balance-spring and thereby prevents the clock or watch from gaining time when first wound or losing time thereafter. Its highlight is the fusée chain, linking a spirally-grooved conical barrel and centre pinion, a tiny chain similar to a bike chain except that the individual links can be manufactured to sizes of less than 2mm! In 2007, Breguet launched the Tradition 7047 Grande Complication Fusée Tourbillon which is a superb example of this craft (see below).
Note: The origin of the fusée is not known but earliest theory of this mechanism can be attributed to Leonardo da Vinci’s sketches, c. 1490. An early fusée clock was made by Jacob Zech of Prague around 1525 but the idea actually originated with engineers who developed the windlass, designed for moving weights. Archimedes may be described as the founding father of all engineering pulley systems.
Photos © Montres Breguet SA. Fair use
Glossary © BreguetBlog.com 2019. All rights reserved