Incense clock

Clock and censer: the burning incense cuts the strings hold the weights, which fall at regular intervals

The incense clock (simplified Chinese: 香钟; traditional Chinese: 香鐘; pinyin: xiāngzhōng; Wade–Giles: hsiang-chung; lit. 'fragrance clock') is a timekeeping device that originated from China during the Song dynasty (960–1279) and spread to neighboring East Asian countries such as Japan and Korea. The clocks' bodies are effectively specialized censers that hold incense sticks or powdered incense that have been manufactured and calibrated to a known rate of combustion, used to measure minutes, hours, or days.