History dating platform clock escapement
Between 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.
Existing clock mechanisms that used water power were being adapted to take their driving power from falling weights.
Candle clocks and sticks of incense that burn down at approximately predictable speeds have also been used to estimate the passing of time.
In an hourglass, fine sand pours through a tiny hole at a constant rate and indicates a predetermined passage of an arbitrary period of time.
However, it has practical limitations - it requires the sun to shine and does not work at all during the night - encouraged the use of other techniques for measuring time.
In India, the King of Jaipur the Pink City, Jai Singh II constructed many instruments and sundials in the observatories in cities Jaipur, Varanasi, Ujjain, Mathura between 1724-1730 A. He had a good interest in astronomy and town planning.
Independently, the Chinese developed their own advanced water clocks, passing their ideas on to Korea and Japan.Outside of Europe, the escapement mechanism had been known and used in medieval China, as the Song Dynasty horologist and engineer Su Song (1020 - 1101) incorporated it into his astronomical clock-tower of Kaifeng in 1088.However, his astronomical clock and rotating armillary sphere still relied on the use of flowing water (ie.While never reaching the level of accuracy based on today's standards of timekeeping, 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...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.
The sundial, which measures the time of day by the direction of shadows cast by the sun, was widely used in ancient times.