<P> Greek astronomer Andronicus of Cyrrhus supervised the construction of the Tower of the Winds in Athens in the 1st century B.C. The Greek and Roman civilizations are credited for initially advancing water clock design to include complex gearing, which was connected to fanciful automata and also resulted in improved accuracy . These advances were passed on through Byzantium and Islamic times, eventually making their way back to Europe . Independently, the Chinese developed their own advanced water clocks (水 鐘) in 725 A.D., passing their ideas on to Korea and Japan . </P> <P> Some water clock designs were developed independently and some knowledge was transferred through the spread of trade . Pre-modern societies do not have the same precise timekeeping requirements that exist in modern industrial societies, where every hour of work or rest is monitored, and work may start or finish at any time regardless of external conditions . Instead, water clocks in ancient societies were used mainly for astrological reasons . These early water clocks were calibrated with a sundial . While never reaching the level of accuracy of a modern timepiece, the water clock was the most accurate and commonly used timekeeping device for millennia, until it was replaced by the more accurate pendulum clock in 17th - century Europe . </P> <P> Islamic civilization is credited with further advancing the accuracy of clocks with elaborate engineering . In 797 (or possibly 801), the Abbasid caliph of Baghdad, Harun al - Rashid, presented Charlemagne with an Asian Elephant named Abul - Abbas together with a "particularly elaborate example" of a water clock . Pope Sylvester II introduced clocks to northern and western Europe around 1000AD </P> <P> In the 13th century, Al - Jazari, an engineer from Mesopotamia (lived 1136--1206) who worked for Artuqid king of Diyar - Bakr, Nasir al - Din, made numerous clocks of all shapes and sizes . A book on his work described 50 mechanical devices in 6 categories, including water clocks . The most reputed clocks included the Elephant, Scribe and Castle clocks, all of which have been successfully reconstructed . As well as telling the time, these grand clocks were symbols of status, grandeur and wealth of the Urtuq State . </P>

Who invented the mechanical clock during the renaissance