Candle Clocks and Other Early Alarms

At My Modern Met, Madeline Muzdakis describes clocks, with and without alarms, from millennia ago. A common one, first described in China in about 520 AD, uses candles that burn evenly. By marking the drop in the wick, users could note the passage of time.

To make this candle clock into an alarm clock, place nails into the candle. When the wax around a nail melts, the nail falls into a metal tray, clattering noisily, and hopefully getting the attention of the user.

Read about other ingenious early clocks, most notably those that could keep track of time on seagoing vessels, at My Modern Met.

Photo: Benutzer:Flyout