Horology

Science dealing with contrivances for marking the hours. The earliest of these was the sun-dial IMG:content-0655.jpg:[graphic] IMG:content-0656.jpg:[graphic] (see DIALS). Another method was the emptying of a ve el of sand or water (see CLEPSYDRA, HOUR-GLASS). Alfred the Great measured time by the consuming of candles. Pope Sylvester II. is said to have invented the scapement 996, in a clock he made for Magdeburg, and many European monasteries had wheel - and weight clocks in the 11th century. Richard de Walling ford made a famous astronomical clock at St. Alban's 1320, and the great one at Stra burg was constructed 1352-70 and remodeled 1571-74. Portable clocks with mainsprings were already known in 1320 and repeaters ab. 1676.