Door nails have a long history. In ancient China, in order to resist the invasion of foreign enemies, the gate was made very thick, wrapped with iron plates and nailed with doornails with caps. This method has been used for thousands of years.
The doornails of the Forbidden City in Beijing are all made of copper and plated with a layer of distilled gold, which is dazzling and even more splendid. There are eighty-one doornails at the entrance and exit of the emperor. Taking the number "nine" means that the emperor is supreme. The number of doornails of other emperors, county kings, princes and other officials decreased in turn, such as vertical nine horizontal seven, vertical seven horizontal five and so on. The doornails of low-ranking people are made of iron. Interestingly, why is there only 72 doornails at the Donghua Gate of the Forbidden City in Beijing, 9 fewer than the Xihua Gate and the Wumen Gate? Here is a story: Li Baicheng, the leader of the peasant uprising in the late Ming Dynasty, captured Beijing, and Ming Sizong fled from Donghuamen and hanged himself in Jingshan Park. Therefore, the royal family of Qing Dynasty considered Donghua Gate unlucky, and decided to enter and leave the royal spiritual material through this gate, and at the same time reduced its doornails to 72, while the doornails of other palace gates were still 8 1 door.
Door nail, in short, is the decoration of the circular protrusion nailed on the outside of the door leaf, which is a unique decoration on the doors of ancient buildings in China. With the development of social economy, iron nails have been installed on the doors of rural single-family houses in Guanzhong area of China. The door is welded with angle steel, and the wooden board is cored to form a steel wooden door, which mainly plays the role of connecting angle steel and wooden board, and also plays a certain decorative role, but it is much inferior to the doornail of the ancient gate. Whether it is solid wooden doors with rich ancient buildings or modern steel wooden doors, nailing rows of huge golden doornails is not only more forbidden, but also gives people a beautiful enjoyment, which also contains the unique cultural connotation of China.
The doornail is not called doornail in the earliest records, but called "Zhuo Yi". It is related to guarding the city and defending against fire attack. This is a military defensive measure. Mud the door in wartime to prevent fire; Usually this neat row spacing becomes an ornament on the door leaf. Therefore, the doornail may be a relic of ancient Zhuo Yi. According to the previous research of architectural archaeologists, it is considered that the generation of door nails is the structural need of the door itself. As a kind of door decoration, the door nail is to avoid the unsightly nail marks exposed.
In the feudal society of China, the rulers attached great importance to the doornail, which was a symbol of feudal rank. Zhu Yuanzhang, the emperor of the Ming Dynasty, once brought doornails into the legal system, and ordered Zhang Chou, the minister of rites, to study the types of ancient doornails. Because the doornails were not inspected, the Ming Dynasty only stipulated that the main entrance of the city should be painted with red, gold and copper nails, but there was no quantitative regulation and no doornails were mentioned to officials at all levels. After entering the customs in Qing Dynasty, the number and materials of doornails became an important form to reflect the feudal hierarchy. The use of doornails at the gate of the Qing Dynasty is also stipulated in the Qing Code. The system of Wang Mi is: "The doornails are vertical and horizontal." There is a saying in Example of Congregation that "there are three golden nails in every door". Prince's Mansion and County's Mansion: "Gold nails and roofs are reduced by two-seventh of the prince." Baylor House, Zhen Guogong and Fu Guogong: "There are seven nails in the public gate." Four more than the forty-five doornails in the county palace. However, the material has changed, from gold nails to iron nails. So it is lower than the gold nail used in the county palace. The following government brothers: "Gongmen has seven nails. The following is reduced to five. "
What about the doornail clause of the feudal supreme ruler? It is clearly recorded in the Hall of Qinghui that "all the doors of the palace worship the base, covered with yellow colored glass, and the doornails are gold nails, while the four doors of the altar temple and mound are left outside, all painted with red gold nails and nine nails vertically and horizontally". The palace is a first-class building, and the doornails are "nine vertical and nine horizontal", 8 1 gold nail. In the Code of Engineering of the Ministry of Industry in Qing Dynasty, there are three regulations on the number of doornails used at the palace gate: vertical nine horizontal nine, vertical seven horizontal seven, vertical five horizontal five, all of which are positive numbers, because nine is the pole of positive numbers, and vertical nine horizontal nine is the highest. Take the existing doornails in the Forbidden City as an example, most of them are vertical nine and horizontal nine, and a few are vertical seven, horizontal seven, vertical five and horizontal five. But Donghuamen is a special case, because after the emperor shunzhi's death, the coffin went out of Huamen to Jingshan. The altar temple in Kyoto or Muji is the first-class temple where the emperor personally attended the sacrifice. Although it is convenient for the emperor to sacrifice, on the other hand, because ordinary people can't participate in such activities, there is no other place. Its doornails are also "nine vertical and nine horizontal", with eighty-one for each door. Second-class temples are temples where emperors offer sacrifices or send ministers to offer sacrifices on their behalf. Xiyue Temple at the foot of Huashan Mountain belongs to this kind of temple. From the existing ancient doornails in Xiyue Temple, it is not difficult to see the doornail system of secondary temples. Xiyue Temple was built in Han Dynasty and perfected in Ming and Qing Dynasties. There are three tunnels and five gates along the central axis, namely: Haolingmen (also known as Liansanmen), Wufenglou (also known as Wumen), Lingxingmen, Jinchengmen (also known as Jintianmen) and Houzaimen. Among these five gates, the well-preserved one belongs to Lingxingmen. There are doornails in the middle of Xing Xing Gate, which are vertical and vertical, and doornails in the left and right doors, which are vertical and horizontal. The door leaf of Lianshan Gate has been destroyed. Although it was repaired by later generations, it is the same as Lingxing Gate. The other three doors were also damaged, but it can also be judged that this is the case. Third-class temples, located in government offices and county offices, are sacrificial temples presided over by local officials. For example, the "doornails" of city god temples in various places should be vertical and horizontal, or vertical and horizontal.
To sum up, it is not difficult for us to see that the "doornail" of Loumen as a sacrificial temple also has a strict system, and it is not allowed to violate the ceremony. The reason why the "doornail" was strictly regulated later was the product of the hierarchical system after human beings entered the class society.