An example of a medieval candle clock. People would hear the nail hit the ground, letting them know a certain amount of time had passed. These were used mainly by the rich,
A photograph of a candle clock, a thin candle with consistently spaced markings, that when burned, indicate the passage of periods of time. Dated 20th century Stock Photo - Alamy
Before Electricity, People Used These Candle Clocks to Tell the Time and Wake Up
Candle Clock Drawing by Mary Evans Picture Library - Fine Art America
Ink sketch candle clock Royalty Free Vector Image
candle clocks : r/tumblr
Discover the Candle Clock, A Historic Way to Tell Time and Set Alarms