An escapement is a mechanical linkage inside watches and clocks that regulates timekeeping by controlling how the gear train advances, giving small pushes to an oscillating element such as a pendulum or balance wheel while periodically releasing a tooth of the escape wheel to let the gear train move forward at a steady rate. This dual action both restores energy lost to friction and produces the ticking sound characteristic of mechanical clocks. The first mechanical escapement, the verge escapement, appeared in thirteenth century medieval Europe and marked a major advance, allowing clocks to move away from continuous flow devices like water clocks toward oscillatory timekeeping. Earlier liquid driven escapements existed in ancient Greece and China but depended on the rate of fluid flow and were far less precise, and after the pendulum was introduced around 1657 escapement design advanced rapidly, with more than 300 variants developed by the nineteenth century even though only about ten of them ever saw widespread commercial use.
Facts
Patent or First-Use DateNo patent exists for a medieval escapement; recorded as the earliest firmly dated written description, in a Spanish document prepared for Alfonso X. The world's first known escapement, in Tang China, is more than five centuries earlier but only approximately dated (723 or 725 AD) and is recorded on the year fact instead. SignificanceThe escapement let clockmakers trade a continuous process, like the steady flow of water, for a repeating, countable tick, making the mechanical clock possible and giving every later timepiece its regulated beat. 1 Disputed
YearThe earliest known clockwork escapement was built in Tang dynasty China by the Buddhist monk Yi Xing and government official Liang Lingzan in 723 or 725 AD, for a water-powered armillary sphere. It did not lead directly to the European mechanical clock; the escapement usually credited with that development, the verge escapement, was invented independently in medieval Europe during the 13th century, with the earliest firmly dated written description a Spanish document for Alfonso X in 1277. Connections
In Field
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1. Escapement (Wikipedia)
Wikipedia contributors, Wikimedia FoundationHistory, Liquid-driven escapements subsection
In China, the Tang dynasty Buddhist monk Yi Xing, along with government official Liang Lingzan, made in 723 (or 725) AD the escapement for the workings of a water-powered armillary sphere and clock drive, which was the world's first clockwork escapement.
History section, first paragraph
The invention of the escapement was an important step in the history of technology, as it made the all-mechanical clock possible.
History, Liquid-driven escapements subsection, Yi Xing sentence
In China, the Tang dynasty Buddhist monk Yi Xing, along with government official Liang Lingzan, made in 723 (or 725) AD the escapement for the workings of a water-powered armillary sphere and clock drive, which was the world's first clockwork escapement.
History, Liquid-driven escapements subsection, Alfonso X sentence
According to Ahmad Y. Hassan, a mercury escapement described in a Spanish document for Alfonso X in 1277 can be traced to earlier Arabic sources.
In Field: Mechanical Engineering, Categories
Mechanical power control
View the Source Frequently Asked Questions
Did the escapement begin with mechanical clocks?
No; the earliest escapements drove water-powered and mercury devices.
No. Escapements first appeared in liquid-driven devices. In China the Tang dynasty Buddhist monk Yi Xing, with the official Liang Lingzan, made an escapement in 723 (or 725) AD for a water-powered armillary. A mercury escapement described in a Spanish document for Alfonso X in 1277 can be traced to earlier Arabic sources. The mechanical escapement later made the all-mechanical clock possible.
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