The Incense Clock (Simplified Chinese: chino 钟, Traditional Chinese: 香 钟; Pinyin: Xiangzhong; Wade-Giles: Chung-Hsiang, literally, "Fragrance Clock") is a Chinese timing device that appeared during the Song dynasty (960-1279) and spread to neighboring countries such as Japan. Watches' bodies are effectively specialized incense burners that hold incense sticks or powdered incense that have been manufactured and calibrated at a known burn rate, which is used to measure minutes, hours or days. The watch may also contain bells and gongs, which act as forwards. Although the water clock and astronomical clock were known in China (for example: His song), incense clocks were commonly used in homes and temples in dynastic times.
wiki
