Key watchmaking terms from the world of "A. Lange & Söhne" at a glance. A - D E - H I - L M - R S - Z Adjusted in five positions The watch is timed for accuracy in the positions in which it is most often worn: dial up and down, winding crown up and down, and horizontal. Adolph Lange (1815-1875). Founder of the German precision watchmaking industry in Glashütte. Assembly screws Reusable screws for the initial assembly of Lange movements. Augustus the Strong Elector of Saxony (1694 - 1733). Under his reign, Dresden evolved to become a world-famous cultural metropolis, a centre of baroque architecture, and a crucible of scientific exploration. Balance cock Small metal plate screwed to the visible side of the movement. It carries the balance wheel shaft bearing. Bezel Upper part of the case surrounding the glass. It contains a groove into which the glass and the sealing ring are pressed. Black polish Also: mirror polish, specular polish. A special polishing technique that makes a surface look black at a certain incident light angle. Blued steel, blued screws Steel parts are slowly and cautiously heated (annealed) to about 300°C. This process coats the metal with an extremely thin, shimmering film of cornflower-blue magnetite (Fe3O4). Chamfering Also: angling, bevelling. The breaking and polishing of sharp edges on bridges and levers. The inclined surface has the same width along its entire circumference or length. Chronograph A watch equipped with a separate measuring mechanism and a separate seconds hand (chrono hand) that allows the measurement of short time intervals (stopped times). Column wheel Also: ratchet wheel, sometimes pillar wheel. A steel switching wheel that has upright columns. It controls all important switching operations in a chronograph mechanism. Constant-force escapement A mechanism integrated between the mainspring barrel and the going train in the LANGE 31. It assures constant torque delivery for an entire month and thus enhances the movement’s rate accuracy. A pretensioned, so-called remontoir spring is retensioned by 60 degrees every ten seconds. During the next ten-second period, it transmits this always constant amount of energy to the going train. Crocodile leather A popular term for alligator skin. Lange uses only crocodile leather from breeding farms that comply with legislation governing species-compatible animal husbandry. Day/night indicator In this display, an arrow performs one full revolution every 24 hours and points either to the dark or bright segment of the day/night ring. The bright segment stands for daytime between 6 AM and 6 PM, the dark one for nighttime between 6 PM and 6 AM. Diamond endstone A balance wheel shaft held in place by means of a diamond counter-bearing, or endstone, was one of the hallmarks of "1A" quality pocket watches made by Lange. In Lange tourbillon watches of the new era, diamond endstones limit the axial "play" of the carriage on both sides. Disconnector mechanism Complex device within the rattrapante mechanism that prevents exposure of the still-running chronograph hands to extra friction when the rattrapante hands are stopped. Double rattrapante Beyond the simple "stop watch" function, a rattrapante chronograph also allows lap-time measurements, time comparisons, and the determination of the fastest or slowest of several laps. With conventional rattrapante chronographs, these measurements are confined to the seconds scale and thus limited to a duration of 60 seconds. The double rattrapante mechanism developed by Lange has an additional rattrapante hand for the minute counter. This makes it possible for the first time to meaningfully exploit the rattrapante functions - for events that last up to 30 minutes. A - D E - H I - L M - R S - Z Eccentric poising weights Small, screw-like masses attached to the balance wheel rim. Their centre of gravity lies outside the axis of rotation. When they are turned, the position of their centre of gravity will shift and thus change the moment of inertia of the entire balance wheel. This causes it to oscillate somewhat faster or slower. Escape wheel Together with the lever, it constitutes the escapement. It is the last wheel in the going train. Five-minute clock The famous digital clock (hours = Roman numerals; minutes = Arabic numerals; 5-minute time interval) in Dresden's Semper Opera. It was built in 1841 by Friedrich Gutkaes and Adolph Lange, and is conveniently legible from all seats in the house. Flyback This complicated mechanism in the movement of the DATOGRAPH allows the user to instantly set the chronograph seconds hand to zero during an ongoing measurement. When the push-piece is released again, a new measurement starts without delay. This transforms the conventional sequence of "stop", "set to zero", and "start" steps into one single step. Form movement Technical term for a movement that is not round but instead shaped in the form of the case. Form movements can be rectangular, tonneau-shaped, or arcade-shaped, for example. Function surfaces Also: sliding surfaces. All surfaces of a lever that, in a watch, are in contact with other surfaces to execute a mechanical function. The surfaces are oiled or greased to reduce mechanical friction. Fusee-and-chain transmission An original, early drive system in a spring-powered watch. It assures that the going train is driven with the same moment, or torque, regardless of the state of wind of the spring barrel. It improves the accuracy of the watch. German silver Special alloy composed of copper and zinc, with a nickel concentration of about 10%. German silver is stronger than brass and has been traditionally used by Lange for the manufacture of plates and bridges. The addition of nickel minimises the oxidation of German silver and thus eliminates the need to electroplate the alloy - it can remain "untreated". Glashütte ribbing A linear decoration. It is produced by a rotating grinding wheel that is slightly inclined and moved along the surface of the workpiece in parallel lines. Glashütte solarisation A curved, radial decoration for round surfaces. When the watch is orbited against incident light, the light reflected by the ground surface moves around in a circle. Gold chaton The gold setting of a bearing jewel - in Lange watches, chatons are often secured to the three-quarter plate with two or three screws. Guilloching Engraved ornaments and patterns composed of straight and curved intersecting lines. A - D E - H I - L M - R S - Z Key-winding mechanism A winding mechanism that allows a watch to be wound with a separate key from the dial side or caseback side. Key-winding was once most commonly used to wind pocket watches or clocks powered by springs. The LANGE 31 features a newly developed key-winding mechanism. Lange balance spring The Lange manufactory produces small quantities of balance springs to the most stringent horological quality standards, requiring that the rate of the watch changes by no more than 0.6 seconds per day per temperature difference of 1 Kelvin (equivalent to 1 degree Celsius). Lever Also: pallet lever, escape lever. Part of the escapement that looks like a ship's anchor. It prevents the going train from spinning freely and thereby causes the characteristic ticking of a mechanical watch. Luminous hands and markers Hands and markers that emit light in the dark for several hours after having been exposed to sunlight. In Lange watches, they are coated with "Superluminova", a phosphorescent substance. A - D E - H I - L M - R S - Z "Pour le Mérite" The hallmark "Pour le Mérite" relates to the highest German order of merit for exceptional scientific - and later also artistic - achievements. It was inspired by Alexander von Humboldt and instituted in 1842 by Frederick William IV. Lange uses it as an attestation and endorsement of its most eminent movements. Manufactory Also: manufacture. Production facility that manufactures most of the key parts of a watch, especially the movement parts, in-house. Marine chronometer Highly accurate mechanical clocks carried on board ships and used for open-water navigation to determine the vessel's position. Monats-Werk German for “one-month movement”, the name of the calibre L034.1 movement in the LANGE 31. It refers to the 31-day power reserve. Moon-phase display A disc that rotates under the dial and is visible through an aperture. It shows the moon phases from full to new, generally as seen from the Northern Hemisphere. Nivarox An alloy composed of iron and nickel with additions of chromium, titanium, and beryllium. It is very suitable for the manufacture of hairsprings, or balance springs, due to its antimagnetic and temperature-compensating properties. The addition of beryllium dates back to a patent awarded to Richard Lange. This chemical element enhances the hardness and elasticity of the alloy. Observation watch Precision timepiece with large case and large dial, characterised by high rate accuracy, enhanced legibility, and a certain degree of robustness. Used to time scientific observations, as a navigation instrument, and in military applications as a deck watch or aviator’s watch. The Richard Lange revives the tradition of scientific observation watches crafted by “A. Lange & Söhne”. Outsize date display Depending on the size of the watch, this useful function makes it possible to display the date up to five times larger than in a conventional watch of similar dimensions. It is based on the patented two-disc mechanism. Perlage Also: circular graining. Cloud-like decoration on plates and bridges. It is produced by stippling the surface with a small rotating grinding wheel. Perpetual calendar The calendar display of a mechanical watch is called "perpetual" if it automatically updates the date, the day of the week, the month, and the moon phase displays. It not only takes into account the different durations of the months in the course of a year but also "knows" which years are leap years. The complex mechanism is controlled by so-called cams. Pinion A usually extended gear wheel for power transmission having more than six but less than 20 teeth. Planetary gearing A type of transmission that allows very large step-down ratios in compact configurations. Planetary gearing A type of transmission that allows very large step-down ratios in compact configurations. Plate A metal plate that carries small and very small movement parts. The shafts of the gear wheels of the going train, for instance, are held between two plates. Power-reserve indicator The power-reserve indicator displays the state of wind of the mainspring. It reminds the owner that the movement must be rewound again before it stops. Often called "UP-and-DOWN display" by Lange. Precisely jumping minute counter This is a function in Lange's chronographs that makes it easy to read stopped times. During a measurement, the minute counter does not advance gradually but instead jumps to the next minute marker when precisely 60 seconds have elapsed. Rattrapante function A rattrapante hand is a second hand that can be stopped independently of the chrono sweep-seconds hand. After it has been stopped (to record a lap time, for instance), it can be restarted and then will instantly catch up and resynchronise with the chrono sweep-seconds hand. Rhodium This chemical element belongs to the platinum family. Other metals can be electrolytically coated with rhodium. This process gives the coated parts a particularly white metallic sheen. Richard Lange (1845 - 1932). Adolph Lange's first-born son. Was awarded 27 patents and utility model grants. Discovered beryllium and other elements as property-enhancing alloy components for watch springs and is therefore deemed the spiritual father of the Nivarox spring. A - D E - H I - L M - R S - Z SAX-0-MAT The name of Lange's self-winding movements. "SAX" stands for Saxony, the state of origin of Lange watches, "0" is the numeral zero and stands for the ZERO RESET time-setting mechanism, and "MAT" stands for automatic. Sapphire crystal Glass made of artificially produced sapphire. It is very hard (9 on the Mohs scale) and scratch-resistant. It ranks just below the diamond in these two respects. Screw balance A balance wheel that has adjustable screws and tiny washers along its rim. Secular year A (full-century) year that can be divided by 100 without a remainder. The next secular years are 2100, 2200, 2300, ... Semi-oscillation Also: vibration. Half of the path travelled by the balance wheel from end point to end point. Splashwater-protected Also: watertight, water-resistant. Pursuant to the DIN 8310 standard, a watch is splashwater-protected if it can be submerged at a depth of 30 metres (pressure: 3 bar) for one minute and resist the ingress of water. Spring barrel A small metal drum with teeth, which accommodates the coiled mainspring. The mainspring stores the energy that runs the watch. Spring barrel stopwork A device that prevents the mainspring not only from being fully wound but also from totally unwinding. The stopwork limits the working range of the mainspring to that interval in which the torque delivered is relatively constant. This improves the rate accuracy of the movement. Stop seconds Mechanism that stops the balance wheel and thus the movement of the seconds hand when the crown is pulled. This allows a watch to be precisely synchronised with an external time signal. Synodic lunation A synodic lunation of 29 days, 12 hours, 44 minutes, and 3 seconds is the average time between two full moons (or two new moons). Synthetic ruby All references to the term "ruby" mean friction-reducing, wear-resistant jewels made of synthetically produced ruby for bearings, switching elements, and certain clicks. Because the homogeneity of its crystalline structure is better than that of natural rubies without any trade-off in terms of physical and chemical properties, synthetic ruby now dominates virtually all applications where jewels are required. Tachometer scale Also: tachymetre. Circular scale for speed measurements. If a chronograph is used to measure the time it takes to travel exactly one kilometre, the chrono hand will indicate the average speed on the tachometer scale [km/h]. The History of Your Watch If you purchased your A. Lange & Söhne prior to 1 July 2004, you will not yet have a personal copy of the booklet "The History of Your Watch". In this case, please submit your warranty card. You will then receive a new "The History of Your Watch" booklet when your serviced watch is returned to you. Three-quarter plate The three-quarter plate was introduced in Glashütte by Adolph Lange in 1864. Since then, it has been a typical feature of Lange watches. It accommodates the counter-bearings of the going train and enhances the stability of the movement. Three-quarter rotor A special winding rotor in the LANGEMATIK. Its diameter is more than 25% smaller than that of the movement, so it does not conceal the balance wheel while its motion is being observed through the sapphire-crystal caseback. Tourbillon A watch equipped with an intricate rotating carriage containing the balance wheel in the middle adjacent to the escapement. The carriage rotates about its axis once a minute. It compensates for the effect of the earth's gravity and improves the accuracy of the watch. Twin mainspring barrels Two barrels in tandem. Lange's twin mainspring barrels allow the implementation of a progressive power-reserve indication and deliver a power reserve of at least three days. UP-and-DOWN display The UP-and-DOWN display indicates the state of wind of the mainspring. It reminds the owner that the movement must be rewound again before it stops. It is also called "power-reserve indicator". Wave bracelet Precious, hand-finished detachable bracelet made of 18-carat gold or platinum for the LANGEMATIK-PERPETUAL. Whiplash precision index adjuster An adjusting device composed of a steel spring in the shape of a swan's neck, a pointer, and a setscrew. The screw is used to adjust the beat, or the timing, of the watch in very small increments. Wire-EDM machine Also: spark erosion machine. Electrical discharge machines are used to produce a variety of different watch parts. A powerful current is sent through a thin metal wire that moves from spool to spool in a dielectric fluid. An arc is produced when the wire approaches a metal workpiece. This removes, or erodes, metal from the workpiece without physical contact. ZERO RESET Patented mechanism that simplifies the synchronisation of the watch with a time signal. When the crown is pulled, it automatically causes the seconds hand to jump to the 12 o'clock (zero) position.