Why should copper coins be made into "outer circles and inner sides"?
China's copper coins are not all inside the outer circle, but have many shapes: knife-shaped, trousers-shaped and key-shaped. Square hole copper coins have been used for more than 2,000 years since Qin Shihuang unified the monetary system in 22 1 BC, and were abolished at the end of the Qing Dynasty in 1900. There is a square hole in the middle of a coin, no matter how different the copper is or how different the size is. In the Book of Foodstuffs of the Han Dynasty, it was said that "money is a square". Why do you want to make square holes instead of round holes? There are several reasons to blame.
The first is the need of casting technology.
In the past, copper coins were made by melting copper and casting money. First turn copper into "copper water", and then pour it into the money mold for casting. The copper coins cast in this way are irregular and unsightly, and they will scratch their hands when used. In order to make the cast copper coins neat around, it is necessary to file them neatly. But filing one by one is time-consuming and inconvenient. Coin minters cut a hole in the middle of copper coins, put a hundred copper coins on a stick, and file them down, so that the outer edges of hundreds of copper coins can be filed flat. If the hole in the middle of the money is round, the copper coins will turn back and forth when filing, some will file, and some will not file. So the money hole is made into a square, so that when the square stick is inserted, the money will not turn back and forth, and filing will be much more convenient. This method has been passed down from the outside to the inside for more than two thousand years. There is not only a square hole in the middle of copper coins in China, but also a square hole in the middle of ancient copper coins in Japan and South Korea.
Secondly, China culture determines the shape of coins.
Coins run through the long history of ancient China, reflecting the continuity, stages and inheritance of culture in its development, and bearing and covering the cultural information in the historical process of Chinese civilization in an all-round way. In the form of coins, it inherits the concept of jade cong, which is a round square hole. It contains China's cosmology and philosophy of ancient heaven and earth, and it is the concrete embodiment of the ancient theory of Yin and Yang gossip. This philosophy of "the outer circle is the inner side" and "the harmony between man and nature" is an important element of ancient culture in China, which has had a far-reaching impact on the principles and codes of conduct of ancient people in China, as well as the architectural structure and geomantic customs in ancient China.
Chinese ancient coins
Except for the shape of the inner side of the outer circle, ancient coins are all cast with face value, which are weighing currencies. The units are "one", "Zhu", "Ba" and "two", such as Qin Banliang and Han. When casting Kaiyuan Bao Tong coins in the Tang Dynasty, it was stipulated that every ten Kaiyuan coins weighed one or two, and each Kaiyuan coin was called one coin, so ten coins were one or two. This is the origin of the weight unit "money". At this point, the unit of weight is no longer called baht, but money and beam, which is the key to changing China's weighing method to decimal, and the commonly known "half a catty" has gradually lost its original meaning. In the Tang Dynasty, money was not named after weight, but the weight of China was named after money, which directly affected the implementation of units of measurement and decimals.
Words were cast on ancient coins. The characters on coins used to be the so-called big seal script before Qin dynasty and the small seal script after Qin dynasty. The "Mang Qian" cast in the period of Wang Mang used the vertical needle seal script, Liu Zao Qian used the leaf character, and Buquan in the Northern Zhou Dynasty used the jade tendon seal script. These are all variants of Xiao Zhuan. After the Six Dynasties, official script was widely used. The "white quality" in Shu and Han Dynasties was the official script, which was the earliest official script in China. In the Tang Dynasty, Bao Tongqian of Kaiyuan also used official script, the so-called eight-part essay, which is said to have been written by the great calligrapher Ou Yangxun. The literature and art in the Song Dynasty were unprecedentedly prosperous, which was manifested in Qian Wen's calligraphy, and it was even more colorful: there were seal script, official script, regular script, running script and cursive script, and all kinds of calligraphy styles were available. Generally, each coin has at least two or even three styles, which is called money matching. Qian Wen's calligraphy includes Su Dongpo's "Dongpo Style" and Song Huizong's "Shoujin Style". A history of coins is almost a history of ancient calligraphy in China. Besides Chinese characters, coins minted by ethnic minority regimes include Luwen, Qiuci, Sogdian, Uighur, Turkic, Qidan, Basiba, Chahetai and Manchu. The History of Coins is also a complete collection of ancient Chinese characters of ethnic minorities.