who invented the first mechanical clock in 1300
History of timekeeping devices 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,[4][83] 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.[83] Al-Muradi's clock also employed the use of mercury in its hydraulic linkages,[84][85] which could function mechanical automata.[85] Al-Muradi's work was known to scholars working under Alfonso X of Castile,[86] hence the mechanism may have played a role in the development of the European mechanical clocks.[83] Other monumental water clocks constructed by medieval Muslim engineers also employed complex gear trains and arrays of automata.[87] Like the earlier Greeks and Chinese, Arab engineers at the time also developed a liquid-driven escapement mechanism which they employed in some of their water clocks. Heavy floats were used as weights and a constant-head system was used as an escapement mechanism,[4] which was present in the hydraulic controls they used to make heavy floats descend at a slow and steady rate.[87]
Time zone The first adoption of a standard time was on December 1, 1847, in Great Britain by railway companies using GMT kept by portable chronometers. The first of these companies to adopt standard time was the Great Western Railway (GWR) in November 1840. This quickly became known as Railway Time. About August 23, 1852, time signals were first transmitted by telegraph from the Royal Observatory, Greenwich. Even though 98% of Great Britain's public clocks were using GMT by 1855, it was not made Britain's legal time until August 2, 1880. Some British clocks from this period have two minute handsâ€”one for the local time, one for GMT.[3]