![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, 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,](https://i.redd.it/y7pw3x8e0vea1.jpg)
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 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](https://c8.alamy.com/comp/RJK1E6/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-RJK1E6.jpg)
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
![6,600+ Candle Clock Stock Photos, Pictures & Royalty-Free Images - iStock | Hour glass, Candle watch 6,600+ Candle Clock Stock Photos, Pictures & Royalty-Free Images - iStock | Hour glass, Candle watch](https://media.istockphoto.com/id/1071739804/photo/antique-book.jpg?s=612x612&w=0&k=20&c=zh98lUmJ8q89jV_1IEgYfKChYQs8yLdwK6Sf1-difmo=)