Hexagonal Bronze Weight Inscribed with “Zhiyuan”

What do you think this small bronze block was used for? It was known as bronze weight in ancient China, which was used in the same way as today's sliding weight. This bronze weight of Yuan presents a hexagonal shape. The top is designed with a square-holed ear. The center is engraved with "official ten-jin weight made by Tanzhou Circuit in the 18th year of Zhiyuan era of Kublai Khan（1681）", which explains to us that this is an official ten-jin weight of the Yuan Dynasty. This bronze weight is cast with the name of the prefecture, the year of production and serial number, which is clear in inscription, complete in vessel shape, regular in modeling and indeed rarely seen. The discovery of it provids precious physical materials for the study on the system of bronze weights and measures established by Tanzhou Circuit affiliated to Hunan Pacification Superintendency in the Yuan Dynasty.