After Emperor Zhu Yuanzhang of the Ming Dynasty ceded the throne to Emperor Zhu Yunwen of Wen Jian, Judy launched a mutiny and decided to move the capital to Beijing. In the fourth year of Yongle (1406), the construction of the Forbidden City in Beijing was based on the Nanjing Forbidden City, which took 14 years and was completed in the eighteenth year of Yongle (1420). According to China's ancient astrology theory, Ziweiyuan (i.e. Polaris) is located at the zenith where the Emperor of Heaven lives, and heaven corresponds to human beings, so it is also called the Forbidden City. Since it is the place where the emperor lived, the materials used in the Forbidden City must be extremely luxurious, and the architecture is exquisite and gorgeous, which not only applies astronomical geomantic omen, but also brings together the wisdom of craftsmen.
Therefore, although the Forbidden City is all made of wood, it can withstand lightning strikes and stand firm in the earthquake because of its peculiar design art, but the floor tiles of the Forbidden City are inlaid, so they can't resist earthquakes. Therefore, after many earthquakes, the floor tiles of the Forbidden City have long cracked, and the layers are uneven, losing their original luster and wettability. When mending the floor tile, the staff also discovered the secret of the floor tile, and could not help but sigh: "Judy's heart is really vicious."
As the king of a country, Judy still usurped the position of his nephew Zhu Yunwen. Although he doesn't think so in his heart, he is still worried that someone will retaliate against his nephew, so he is most worried about his own safety. He was afraid that someone would dig a tunnel underground to take his own life, so he asked that the floor tiles must be put together and the foundation should be high, so as to overlook Beijing. The craftsmen dare not neglect at all. They fired the blue bricks at once. The clay of blue bricks was specially shipped from Suzhou and made in the suburbs of Beijing. Every production process is supervised.
In order to meet Judy's requirements, craftsmen arranged the floor tiles of 15 layer neatly, reaching the point of "knocking with metal and breaking without holes". Bricks with this characteristic need a lot of manpower and material resources from soil selection to brick making, smoking, transportation and polishing, and the cost is very expensive, so these floor tiles are also called "bricks".
That's not all. These floor tiles are also burned with the year number and the name of the craftsman, so that the person in charge knows which batch of floor tiles are, and it is convenient to blame if there is a problem. In terms of security, it can be said that it is very fine. When laying floor tiles, the process is more complicated. Before bricklaying, the bricks that meet the bricklaying requirements should be soaked in tung oil to increase the luster, and then passed the official inspection.
According to the official book of the Qing Dynasty "Project Record", "Two feet of gold bricks can only grind three pieces per work. In the field, a bricklayer and two laborers can only build five bricks a day. For example, laying bricks in the Hall of Supreme Harmony requires 1, 273 grinders, 944 bricklayers and 1, 888 laborers. " And this is just a project of the Hall of Supreme Harmony. If the whole palace of the Forbidden City is paved, how much manpower and material resources will be needed. It can be seen that the production of this kind of floor tile in Chengdu is a huge project.
According to historical records, after the completion of the Forbidden City, Judy ordered all the craftsmen who participated in the renovation of the Forbidden City to be poisoned, probably because they were afraid that the secret of the construction of the Forbidden City would be leaked, which also showed Judy's cruelty.