The word 'clock' (from the Latin word for "bell") which gradually supersedes 'horologe' suggests that it was the sound of bells which also characterized the prototype mechanical clocks that appeared during the 13th century.īetween 12 there is an increase in the number of references to clocks and horologes in church records, and this probably indicates that a new type of clock mechanism had been devised. These early clocks may not have used hands or dials but “told” the time with audible signals. In 1198, during a fire at the abbey of St Edmundsbury (now Bury St Edmunds) the monks 'ran to the clock' to fetch water, indicating that their water clock had a reservoir large enough to help extinguish the occasional fire. For example, there is a record that in 1176 Sens Cathedral installed a ‘horologe’ but the mechanism used is unknown. The word 'horologia' (from the Greek hora, hour, and legein, to tell) was used to describe all these devices but the use of this word (still used in several romance languages) for all timekeepers conceals from us the true nature of the mechanisms. Important times and durations were broadcast by bells, rung either by hand or by some mechanical device such as a falling weight or rotating beater. This was done by various types of time-telling and recording devices, such as water clocks, sundials and marked candles, probably used in combination. Medieval religious institutions required clocks to measure and indicate the passing of time because, for many centuries, daily prayer and work schedules had to be strictly regulated. No clocks survive from medieval Europe but various mentions in church records reveal some of the early history of the clock. Later years saw the rise of automated water clocks in Arabia, China, and Korea. By the 9th century AD a mechanical timekeeper had been developed that lacked only an escapement mechanism. Herodotus had mentioned an ancient Egyptian time-keeping device that was based on mercury. The historian Vitruvius reported that the ancient Egyptians used a clepsydra, a time mechanism using flowing water. The hour hand is 9 feet (2.7 m) long, and the minute hand is 14 feet (4.3 m) long. The 5 foot 4 inch (1.63 m) person "holding on" to the six-o'clock marking has been inserted into the picture at correct scale. The massive clock on Big Ben, London, England. A silent clock without a striking mechanism is traditionally known as a timepiece, a term sometimes used by horologists and other specialists to describe ordinary wrist watches and other timekeeping devices lacking a striking mechanism (see Baillie et al., p. True clocks also have an announcing or striking mechanism that sounds after each set interval of time, usually by ringing a bell (which, as previously indicated, originally gave the clock its name), chimes, or gong. A common portable timekeeping instrument for personal used is the pocket or wrist watch. The clock in its most common, modern form (in use since at least the 14th century) displays the time in hours, minutes, and often seconds during a 12- or 24-hour period.Ĭlocks used for technical purposes, of very high accuracy, are usually called chronometers. Related subjects: EngineeringĪ clock (from the Latin cloca, " bell") is an instrument for measuring time.
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