I was so excited to do this candle tattoo with an eye in the flame for Matt last week! Candles have been used as a source of illumination for centuries, but have also been used as clocks. Because candles burn fairly consistently and burn measurably, in the past they were used as a way to tell time. The candle designed for this purpose might have time measurements, usually in hours, marked along the wax. The Song dynasty in China (960–1279) used candle-clocks. By the 18th century, candle-clocks were being made with weights set into the sides of the candle. As the candle melted, the weights fell off and made a noise as they fell into a bowl. A form of candle-clock was used in coal-mining until the 20th century as well. Candles also make for great tattoos! Thanks, Matt!