From Greek HOROLOGION, clock, solar quadrant, TIME, time period, duration, hour, day and LEGO, say, express . From this also derives our watch and Italian lobology. Sun clock in which the time is determined by the length of the shadow of the body itself located back to the sun, widely used in medieval monasteries. Such a clock can be inscribed in one of the ashlars of the Visigothic church of San Pedro de la Nave (seventh century) in Zamora, moved stone by stone, when the esla reservoir was built, in 1930 32.