First indoor clock

Markings on the stem indicated the passing of set periods of time as the candle burned down. It is said that in the late 9th century, King Alfred the Great of England created an elaborate 24-hour clock made from six large candles, each of which was 30 cm (1 ft) tall, marked with 20-minute intervals and designed to burn for four hours. It was used to help the King divide his day into periods of study, prayer, royal duties and rest.