Incense clock

The Feueruhr (also: Luntenuhr ) were used in China and Japan mostly cultic acts. They are among the elementary clocks.

In narrow boat-shaped bronze bowls, which often took the form of an elongated dragon, an aromatic compound from the bark of Illicium was burned religiosum. Across these shells hung threads with attached metal balls that were severed from of the burning embers. The metal balls falling into a tray and indicated the elapsed time. Fire watches were not used for daily use, but served in temples cultic purposes.

Colloquially, candles, clocks and watches oil are referred to as fire watches occasionally.