Technologies
How watches came to work as they do, invention by invention; the specifications and types that armies and industries wrote; and the traditions and practices built on them.
Technologies
- Wadokei: Japanese clocks
The mechanical clocks of Edo-period Japan, built to keep temporal hours that changed length with the seasons by moving weights on a foliot, switching between two foliots or adjusting the dial, and made obsolete when Japan adopted equal hours in 1873.
- The balance spring
The fine spiral spring fixed to a watch’s balance, announced by Huygens in 1675 and claimed by Hooke, which gives the balance its own steady beat; later makers shaped it, compensated it for heat and changed its metal.
- The lever escapement
The escapement Thomas Mudge devised in the 1750s, which leaves the balance free for most of its swing; taken up slowly by London and Liverpool makers, it became the escapement of almost every mechanical watch.
- The tourbillon
A regulator that carries the balance and escapement in a turning cage to average out the errors of a watch held upright, patented by Abraham-Louis Breguet in 1801 and revived in the wristwatch since the 1980s.
- The wristwatch
A watch made to be worn on the wrist: for about a hundred years a piece of women’s jewellery called a bracelet watch or wristlet, made respectable for men by soldiers and sportsmen before and during the First World War, and the ordinary watch by the early 1930s.
- The electric watch
The battery-powered watch of the 1950s and 1960s, the step between the mechanical watch and quartz: at the start a balance wheel driven by a battery, as in Hamilton’s Electric 500 of 1957, then Bulova’s tuning-fork Accutron of 1960.
- The quartz watch
The watch that keeps time by counting the vibrations of a quartz crystal: from the room-sized quartz clocks of the 1920s to Seiko’s Astron of 1969 and the Swiss Beta 21, then digital displays, cheap chips and the watch most people wear.
- The co-axial escapement
A watch escapement devised by George Daniels and patented in 1980, which changes the lever escapement to reduce sliding friction and the need for oil, and which Omega has made in series since 1999.
- Silicon in the movement
Silicon parts in the mechanical watch: escape wheels from Ulysse Nardin’s Freak of 2001, the temperature-compensated silicon balance spring patented by CSEM in Neuchâtel in 2002 and made industrially by a consortium of Patek Philippe, Rolex and the Swatch Group, and, since the patent expired in 2022, a material open to every maker.
- Automatic winding
Winding a watch by the wearer’s movement: a weight that swings or turns inside the case winds the mainspring.
- Établissage
The Swiss way of making watches by outwork: parts made separately in homes and small workshops, gathered, assembled and adjusted by an établisseur, and sold abroad by merchants.
- Interchangeable parts
The method behind the American watch: parts made on special machines to a model and master gauges, so that any part fits any watch of the kind.
- The mainspring and fusee
How a coiled spring replaced the falling weight in the 15th century and made clocks small enough to carry, and how the fusee, a cone-shaped pulley, and the German stackfreed evened out its pull as it ran down.
- The marine chronometer
The precision timekeeper a ship carried to keep the time of a reference meridian, so that longitude could be found from the Sun and stars.
- The verge escapement
The escapement of European mechanical clocks from the late 13th century and of watches until the 18th and early 19th centuries: a crown-shaped wheel pushing in turn on two pallets on a swinging rod, its rate set by a foliot or a balance.
- Water resistance
Keeping water and dust out of a watch case at its back, glass and winding stem: screwed cases from the 1870s, sealed wristwatch cases and screw-down crowns in the 1920s, and international standards from the late twentieth century.
Specifications and types
- The A-11
The US Army Air Forces’ wartime wristwatch specification: a black-dialled watch whose seconds stopped when the crown was pulled, made by Elgin, Waltham and Bulova so that crews could set their watches together to the second.
- The B-Uhr
The German air force navigator’s watch of the Second World War: a 55 mm instrument built to specification Fl 23883 by A. Lange & Söhne, Wempe, Laco, Stowa and IWC, whose two dial patterns still shape the pilot’s watch.
- The trench watch
The soldier’s wristwatch of the First World War: usually a small pocket watch given wire lugs, a luminous dial and sometimes a shrapnel guard, bought by officers as kit and issued in small numbers from 1917.
Traditions and practices
- Chronometry and certification
How the accuracy of a watch is tested and certified: from the observatory competitions of the nineteenth and twentieth centuries to today’s chronometer certificates, the Swiss federal Master Chronometer test, the Geneva Seal and makers’ own standards such as Grand Seiko’s.
- Dive watches
Watches built to be worn underwater and to time a dive, defined since 1996 by the international standard ISO 6425.
- Independent watchmaking
Watchmaking by individual makers and small workshops outside the large groups, who design and make their own watches, often by hand; since 1985 many have belonged to the Académie Horlogère des Créateurs Indépendants (AHCI).
- Japanese watchmaking
How Japan went from importing Western clocks and watches in the 1880s to making its own, competing with Swiss chronometers in the 1960s and leading the turn to electronic watches from 1969.
- Origin labels
What the place names on a dial promise, and who decides.
- Pilot’s watches
Watches made as instruments for flying: large, legible and easy to set, made originally for navigating by time and later for timing manoeuvres.
- The Glashütte tradition
The way of building watch movements that grew up in Glashütte, Saxony, after 1845: a large upper plate covering three quarters of the movement, frames of German silver, jewels in screwed gold settings and hand-engraved balance cocks, taken up again by the town’s makers after 1990.
- Tool-watch engineering
How watchmakers protect a watch against the conditions it is used in (magnetism, water and pressure, scratching and shock) and the standards that test it.