#A clock series

The mechanism of a timepiece with a series of gears driven by a spring or weights is referred to as clockwork the term is used by extension for a similar mechanism not used in a timepiece. A major stimulus to improving the accuracy and reliability of clocks was the importance of precise time-keeping for navigation. The next development in accuracy occurred after 1656 with the invention of the pendulum clock by Christiaan Huygens. During the 15th and 16th centuries, clockmaking flourished. Spring-driven clocks appeared during the 15th century. Watches and other timepieces that can be carried on one's person are usually not referred to as clocks. This distinction is not generally made any longer. Traditionally, in horology (the study of timekeeping), the term clock was used for a striking clock, while a clock that did not strike the hours audibly was called a timepiece. A major advance occurred with the invention of the verge escapement, which made possible the first mechanical clocks around 1300 in Europe, which kept time with oscillating timekeepers like balance wheels. Water clocks, along with sundials, are possibly the oldest time-measuring instruments. There is a range of duration timers, a well-known example being the hourglass.

Some predecessors to the modern clock may be considered 'clocks' that are based on movement in nature: A sundial shows the time by displaying the position of a shadow on a flat surface. Devices operating on several physical processes have been used over the millennia. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month, and the year. The Shepherd Gate Clock at the Royal Observatory, Greenwich analog flip clock radio 24-hour clock face in FlorenceĪ clock or chronometer is a device used to measure and indicate time. For other uses, see Timepiece (disambiguation). For other uses, see Clock (disambiguation).

A clock