Verge escapement

Verge escapement and balance wheel from an early pocketwatch
Verge and foliot escapement from De Vick tower clock, built in Paris, 1379, by Henri de Vick

The verge (or crown wheel) escapement is the earliest known type of mechanical escapement, the mechanism in a mechanical clock that controls its rate by allowing the gear train to advance at regular intervals or 'ticks'. Verge escapements were used from the late 13th century until the mid 19th century in clocks and pocketwatches. The name verge comes from the Latin virga, meaning stick or rod.[1]

Its invention is important in the history of technology, because it made possible the development of all-mechanical clocks. This caused a shift from measuring time by continuous processes, such as the flow of liquid in water clocks, to repetitive, oscillatory processes, such as the swing of pendulums, which had the potential to be more accurate.[2][3] Oscillating timekeepers keep time for all modern clocks.[4][2][5][6][7]

  1. ^ Harper, Douglas (2001). "Verge". Online Etymology Dictionary. Retrieved 2008-06-22.
  2. ^ a b Marrison, Warren (1948). "The Evolution of the Quartz Crystal Clock". Bell System Technical Journal. 27 (3): 510–588. doi:10.1002/j.1538-7305.1948.tb01343.x. Archived from the original on 2007-05-13. Retrieved 2007-06-06.
  3. ^ Cipolla, Carlo M. (2004). Clocks and Culture, 1300 to 1700. W.W. Norton & Co. ISBN 0-393-32443-5., p.31
  4. ^ Jespersen, James; Fitz-Randolph, Jane; Robb, John (1999). From Sundials to Atomic Clocks: Understanding Time and Frequency. New York: Courier Dover. p. 39. ISBN 978-0-486-40913-9. Archived from the original on July 3, 2023. Retrieved October 30, 2020.
  5. ^ Stehle, Philip (1971). Physics: the Behavior of Particles. Harper and Row. p. 59. ISBN 9780060464110.
  6. ^ Bloomfield, Louis (2007). How Everything Works: Making Physics Out of the Ordinary. Wiley. p. 296. ISBN 9780470170663. Archived from the original on April 4, 2023. Retrieved March 19, 2023.
  7. ^ "Clock". Glossary, Time and Frequency Division. US National Inst. of Science and Technology. Retrieved 13 August 2024.