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]
History of measurement The earliest known uniform systems of weights and measures seem all to have been created at some time in the 4th and 3rd millennia BC among the ancient peoples of Egypt, Mesopotamia and the Indus Valley, and perhaps also Elam (in Iran) as well.