Long ago in ancient China a clever alarm clock was created using a burning candle marked into equal sections to measure time, a method praised in a poem by You Jiangu in 520 CE. Later in Europe inventors embedded metal pins in candles so that as the wax melted the falling pins would clatter on a tray to rouse sleepers. Although these clocks were affected by wax quality, wick thickness and temperature changes, they represented remarkable ingenuity in using available technology to solve a common h