As long as you don't take the sun into consideration, this 18th century contraption could very well be the world's first alarm clock that uses light as a wake up trigger, instead of sound.
A spring-loaded mechanism triggered by its built-in clock releases a flint-lock that lights a pop-up candle. So if you needed to rise before the sun was up, you didn't have to fumble your way out of bed in the dark looking for a way to light a candle. Brilliant! [The British Museum via Neatorama via Wunderkammer]