Alarms
If you want to write about a rooster crowing in the distance in the mornings, then you are more than welcome to. But...what about those times when you just need a good old timer? It is not quite known when they were first used though according to Historyplex “The earliest known reference is found in a poem by the Chinese poet and thinker You Jiangu (520 CE).”
To use the clock candle, a candle was either marked directly or it’s case was marked at certain intervals to mark a certain amount of time.
A nail would then be driven into the candle at the desired mark; when the wax melted to the point the nail was driven to, the nail would fall and clang in the metal plate below the candle successfully alerting the user to the time that had passed.
So there you have it. A historically accurate alarm clock to write about.