|Clapper and Gong / Han nationality / Period : 20th century|
Clapper / Material : timber / L : 18.4 cm , W : 6.4 cm , H : 4 cm
Gong / Material : copper / L : 24.2 cm , H : 1.5 cm
The system of timekeeping during nighttime began from the 2nd century BC, where drums were used at the first place, then it was changed to clappers and gongs around the 11th century.
The role of night watchmen during ancient times was in charge by the dedicated government office runners; not only were they responsible for reporting time at night, but also patrolling the streets and alleys. Such system can still be found in Taiwan before 1895.