<P> Note also Peter Lightfoot's Wells Cathedral clock, constructed c. 1390 . The dial represents a geocentric view of the universe, with the Sun and Moon revolving around a central fixed Earth . It is unique in having its original medieval face, showing a philosophical model of the pre-Copernican universe . Above the clock is a set of figures, which hit the bells, and a set of jousting knights who revolve around a track every 15 minutes . The clock was converted to pendulum - and - anchor escapement in the 17th century, and was installed in London's Science Museum in 1884, where it continues to operate . Similar astronomical clocks, or horologes, survive at Exeter, Ottery St Mary, and Wimborne Minster . </P> <P> One clock that has not survived is that of the Abbey of St Albans, built by the 14th - century abbot Richard of Wallingford . It may have been destroyed during Henry VIII's Dissolution of the Monasteries, but the abbot's notes on its design have allowed a full - scale reconstruction . As well as keeping time, the astronomical clock could accurately predict lunar eclipses, and may have shown the Sun, Moon (age, phase, and node), stars and planets, as well as a wheel of fortune, and an indicator of the state of the tide at London Bridge . According to Thomas Woods, "a clock that equaled it in technological sophistication did not appear for at least two centuries". Giovanni de Dondi was another early mechanical clockmaker whose clock did not survive, but his work has been replicated based on the designs . De Dondi's clock was a seven - faced construction with 107 moving parts, showing the positions of the Sun, Moon, and five planets, as well as religious feast days . Around this period, mechanical clocks were introduced into abbeys and monasteries to mark important events and times, gradually replacing water clocks which had served the same purpose . </P> <P> During the Middle Ages, clocks primarily served religious purposes; the first employed for secular timekeeping emerged around the 15th century . In Dublin, the official measurement of time became a local custom, and by 1466 a public clock stood on top of the Tholsel (the city court and council chamber). It was the first of its kind to be clearly recorded in Ireland, and would only have had an hour hand . The increasing lavishness of castles led to the introduction of turret clocks . A 1435 example survives from Leeds castle; its face is decorated with the images of the Crucifixion of Jesus, Mary and St George . </P> <P> Early clock dials showed hours: the display of minutes and seconds evolved later . A clock with a minutes dial is mentioned in a 1475 manuscript, and clocks indicating minutes and seconds existed in Germany in the 15th century . Timepieces which indicated minutes and seconds were occasionally made from this time on, but this was not common until the increase in accuracy made possible by the pendulum clock and, in watches, by the spiral balance spring . The 16th - century astronomer Tycho Brahe used clocks with minutes and seconds to observe stellar positions . </P>

How did they keep time in the middle ages
find me the text answering this question