When discussing "衡权" (balance and weight), the character "衡" means balance, while "权" refers to weight. The purpose of a balance is to support weight and achieve equilibrium, essentially measuring the lightness and heaviness of objects. Ancient balances had various names, including shu, lei, chui, zi, huan, jun, lue, and yi, with standards varying across dynasties. "Han Shu" records that the names and usage methods of the balances in the Han Dynasty were very complete, but over time, they underwent numerous changes, and the specifics of those changes remain unclear. During the Yuan Kang period, Pei Wei argued that the connection between medical prescriptions and human life was crucial, and the current measurement units differed significantly from ancient ones, leading to serious consequences; he therefore proposed that the standards for measurement be revised, but his suggestion was ultimately not adopted.
In July of the 18th year of Shile's reign, while constructing Jiande Hall, he unearthed a round stone resembling a water mill, inscribed with: "Luquan Stone, weighing four jun, the same as the legal measurement balance. Crafted by the Xin family." Subsequently, there was discussion among everyone, and they concluded that this artifact dated back to the Wang Mang era.
