Composition of the Golden Brick in the Forbidden City

Yaogan Town, Jiashan County, Zhejiang Province is a famous "kiln town" in history. The Beijing brick produced by it is a kind of special brick in ancient China. The price of each brick is as high as one or two gold, which is called "BRIC". Historically, it laid the foundation stone for the Forbidden City and the Imperial Home Forest.

In the folk, people are willing to imagine the golden palace where the emperor handles government affairs, saying that the ground of the golden palace is paved with gold bricks. Literally and according to most people's understanding, it is obvious that this brick is made of gold. In fact, this brick is not made of gold, but the Beijing brick of the dry kiln. There is a special record in "Golden Brick Land": "Beijing brick is a fine-grained square brick specially fired for the court, with fine particles and dense texture. If you knock it, it's called' BRIC'. Because these bricks were transported to the Cang Jing in Beijing for the exclusive use of the palace, they were called' Beijing bricks' and gradually entered wealthy folk families. " There is another saying about the origin of the name "BRIC": bricks in Beijing in the Ming Dynasty were very expensive, and a brick cost 50 taels of silver, which was far beyond the affordability of ordinary wealthy families, so people used "BRIC" to refer to it. At that time, there was a saying of "one or two bricks" among the people, hence the name "bricks".

It takes eight months to make a gold brick.

The production of Beijing bricks needs to go through several processes, such as earth borrowing, blank making, firing, kiln discharge, grinding and soaking. Several processes don't sound particularly complicated, but in fact, there are many small processes under every big process. Together, these large and small processes make the production of Beijing bricks a luxury.

We can see the complexity and strict requirements of brick-making procedures in Beijing just by taking the soil. Choose soil first and then borrow it. Those experienced masters can see where the soil is not only sticky, but also has high aluminum content and can be ground into powder. After selecting soil, it has to go through seven processes, such as digging, transporting, drying, grinding, pulping, grinding and screening, which takes up to 8 months.

The second step is blank making. The prepared soil is made into bricks by semi-manual and semi-mechanical methods. Ordinary Beijing bricks can be made of clay according to the required size and thickness. More complicated are those tiles with special technological requirements, for example, some tiles need to be painted with patterns. In order to make the fired pattern vivid, it is necessary to properly grasp the description of the pattern when making blanks.

The third step is to fire. After the green body enters the kiln, the process of igniting the kiln fire is extremely complicated: pumping chaff for one month, burning firewood for one month, burning firewood for one month and burning pine branches for 40 days. It takes 1.30 days to burn these four different fuels out of the kiln. The so-called soaking water means that after a kiln brick is burned, it must be watered to cool down. The water poured into the kiln must be picked up by the kiln worker along the steep and high brick ladder outside the kiln pier, and then poured into the kiln from above.

The fourth step is out of the kiln. On the day of leaving the kiln, the dust in the belly of the small kiln was very choking. Before leaving the kiln, although the temperature in the kiln has cooled for four or five days, the temperature in the kiln is still very high, and the long-burned Beijing bricks are hotter. Pieces of hot and heavy Beijing bricks are quickly passed in the hands of workers. In order to urge their peers to speed up, but also to encourage themselves, workers will make strange hisses when moving and unloading Beijing bricks. "The cargo ship berthed at sunset, and the female companion moved bricks and laughed. A face of kiln coal is sticky and sweaty, and Anon looks more beautiful than flowers. " This poem "Zhuzhici" describes the scene when she came out of the kiln-working in a hot kiln, the female kiln worker will soon be full of sweat and flying dust will come to her face. A woman who was originally "full of flowers" will suddenly be as black as coal ash.

The fifth step is polishing. Beijing bricks that have just come out of the kiln can only be regarded as semi-finished products. If you want to make it a radiant jade, you need to polish it painstakingly. The polishing of Beijing bricks is carried out in a circular sink, and the tools are extremely simple. Washing with water while grinding not only makes the surface of Beijing brick smooth, but also makes it brighter and brighter, and can even be used as a mirror. Unfortunately, the polishing technology that makes Beijing bricks look like mirrors has been lost.

The last step is to soak the oil. Polished Beijing bricks should be soaked in tung oil piece by piece. Tung oil can not only make Beijing bricks bright, but also prolong their service life.

You can only make 5 thousand gold bricks a year

At this point, the whole process from soil to Beijing brick is completed. Together, the above processes have taken more than one year, and each kiln produces no more than 7,000 Beijing bricks at a time-there must be a certain proportion of defective products and waste products. Dozens of skilled workers have worked hard for more than a year, earning only five or six thousand bricks, and each brick sells for fifty taels of silver. Although it is a bit exaggerated, it is by no means impossible.

Nowadays, although people's requirements for Beijing bricks are no longer as harsh as those of the royal family in the past-when selecting Beijing bricks, the royal family needs officials at all levels to pick up heavy Beijing bricks and check them piece by piece-and the progress of machinery and equipment has greatly shortened the firing time, it still takes more than three months to fire a kiln of Beijing bricks due to the limitation of traditional technology of Beijing bricks. ...