The piezoelectric properties of crystalline quartz were discovered by Jacques and Pierre Curie in 1880. The first quartz crystal oscillator was built by Walter G. Cady in 1921, and in 1927 the first quartz clock was built by Warren Marrison and J. W. Horton at Bell Telephone Laboratories in Canada
A chronometer is a portable timekeeper that meets certain precision standards. Initially, the term was used to refer to the marine chronometer, a timepiece used to determine longitude by means of celestial navigation. More recently, the term has also been applied to the chronometer watch, a wristwatch that meets certain precision standards set by the Swiss agency COSC.
The first professional clockmakers came from the guilds of locksmiths & jewellers. Clockmaking developed from a specialized craft into a mass production industry over many years. Paris & Blois were the early centers of clockmaking in France. French clockmakers such as Julien Le Roy, clockmaker of Versailles, were leaders in case design & ornamental clocks. Le Roy belonged to the 5th generation of a family of clockmakers, and was described by his contemporaries as "the most skillful in…
Prague Astronomical Clock 1462: The Ottoman engineer Taqi al-Din described a weight-driven clock with a verge & foliot escapement, a striking train of gears, an alarm & a representation of the moon's phases in his book The Brightest Stars for the Construction of Mechanical Clocks, written around 1556. Similarly to earlier 15th-century European mechanical alarm clocks, the alarm was set by placing a peg on the dial wheel at the appropriate time.
History of timekeeping devices - Wikipedia, the free encyclopedia
The earliest medieval European clockmakers were Christian monks. Medieval religious institutions required clocks because daily prayer & work schedules were strictly regulated. This was done by various types of time-telling & recording devices, such as water clocks, sundials & marked candles, probably used in combination. When mechanical clocks were used, they were often wound at least twice a day to ensure accuracy.
Water Clock: The first geared clock was invented in the 11th century by the Arab engineer Ibn Khalaf al-Muradi in Islamic Iberia; it was a water clock that employed a complex gear train mechanism, including both segmental and epicyclic gearing, capable of transmitting high torque. The clock was unrivalled in its use of sophisticated complex gearing, until the mechanical clocks of the mid-14th century
The clock towers built by Zhang Sixun and Su Song, in the 10th and 11th centuries, respectively, also incorporated a striking clock mechanism, the use of clock jacks to sound the hours. A striking clock outside of China was the Jayrun Water Clock, at the Umayyad Mosque in Damascus, Syria, which struck once every hour.