From candles that drop metal nails to the knocker uppers of industrial Britain, people devised plenty of cunning ways to ensure a timely wake-up before alarm clocks came along.

Candle clocks were once an easy way to build a clock without using complex mechanical devices: just observe how quickly a thin candle burns down, mark an identical candle with periodic gradations, and ...

Candle clocks were once an easy way to build a clock without using complex mechanical devices: just observe how quickly a thin candle burns down, mark an identical candle with periodic gradations, and ...

Candle flames are designed to be as stable as possible, but if multiple candles are bundled together, they will naturally vibrate depending on gravity and the diameter of the flame. Hardware engineer ...

Educator Ruth Mork teaches kids about clocks — from sundials to cuckoo clocks to roosters. Ruth Mork introduces clocks of all kinds — sundials, candle clocks, hourglasses, cuckoos, even a rooster! She ...

In some Muslim communities during Ramadan, people traditionally woke others before dawn so they could pray and eat the pre-fast meal.