The Great Wall is an important project built in many dynasties and has played an irreplaceable role in history. From the Western Zhou Dynasty to the middle of the Ming Dynasty, the Great Wall was built, but the most famous one was the Great Wall built during the Qin Shihuang period. How was such a great project built in the era when Qin Shihuang's ironware was just popularized?

As we know, the Great Wall brick has a feature: each brick is engraved with the name of the producer, which is convenient for tracing the first responsible person when the quality of the brick is unqualified. The inspection system is very simple and strict. If a brick falls from the air, it will be considered unqualified if it is broken, and the workers who make it will be severely punished. Under this strict accountability system, every brick is of high quality.

Because not every place can produce excellent bricks, the main materials are generally made from local materials. Where the mountain is high, dig stones and lay stones on the mountain; In the plain loess area, that is, take soil on the spot and tamp it with soil; In desert areas, reeds or red willow branches are also covered with sand layer by layer. Materials such as bricks and tiles are generally opened on site to reduce transportation costs.

Adhesives are also used to repair the Great Wall. Because there was no cement to bond bricks at that time, workers at that time used glutinous rice paste as adhesive. Glutinous rice paste is a strong adhesive made of hydrated lime, glutinous rice and crushed sand. This adhesive has many advantages, such as firmness and durability, but its cost is too high. Using glutinous rice as raw material when millions of able-bodied men are unable to engage in agricultural activities is a waste of food and has aroused public anger.

Fine materials were used to build the Great Wall, but Qin died of his own reasons, which is regrettable.