After Qin Shihuang unified the six countries in 221 BC, he unified the currency system, with gold as the upper currency and copper coins as the lower currency. The copper coin was named after "Banliang", and later generations called it "Qin Banliang". From then on, China's copper coins (and later iron coins, lead coins, etc.) took the fixed form of a circle on the outside and a square on the inside, which lasted until the early years of the Republic of China.
The Qin Banliang coins were round on the outside and square on the inside. Many studies Or people who collect ancient coins talk about it as symbolizing the round sky and the square place. Is this true?
In the past, some scholars who studied the history of Chinese currency believed that the Qin banliang symbolized the round sky and the square place. This was because of the limitations of research conditions. At that time, the archaeological excavation materials were insufficient, which led monetary history researchers to mistakenly believe that Qin Shihuang created a new kind of money by unifying the currency system. During the Warring States Period, the concept of a round sky and a square place was prevalent, so the two were connected. It was thought that Qin Shihuang created the half-liang coins with a round outer surface and a square inner place based on the concept of a round sky and a square place. However, later archeology proved that Qin Shihuang only promoted an old money from the Qin State to the whole country. He did not create new money, which naturally negated the theory that it symbolized the round sky and the square earth. It turns out that among the many coins minted during the Warring States Period, one type was round, which was called "circle money" or "ring money" by later generations. In the early days, round coins were round on the outside and round on the inside, and later developed into round on the outside and square on the inside. Qin banliang was originally a kind of round money. If Qin Banliang symbolizes a round sky and a square place, wouldn’t it mean that all the garden coins with square holes also symbolize a round sky and a square place? Obviously it doesn't make sense.
The first person to say that round coins with square holes symbolized a round sky and a round place was Lu Bao of the Western Jin Dynasty. When he talked about the origin of copper coins in "The Theory of Qian Shen", he said: "The wise and enlightened people dug the mountain of copper, looked down and looked up, and cast it into money. Therefore, the inner side is like the earth, the outer side (round) is like the sky, and the outer side is like the sky. "Exactly." But Lu Bao's "On the God of Money" is intended to ridicule the social phenomenon that money can communicate with gods. It uses an exaggerated writing style and is not really talking about the origin of currency. The symbol of a round sky and a square place is just an excuse, so it cannot be used in other words. words as basis.
So why did the round coin develop from a round hole to a square hole? This can be explained from technical needs. First, the square hole facilitates the positioning of the text on the money. The two-character money text is arranged to the left and right of the square hole. Second, after the money is cast, certain processing (such as filing the edges) is required. A thin square wooden stick is inserted into the square hole to fix the money and facilitate operation.
Ye Shichang
"International Finance News" (Fourth Edition, October 8, 2001)