The keel waterwheel is also called "rollover", "treadmill" and "waterwheel", and it is called "keel" in the province. Irrigation tools in the history of Han nationality are very popular in most areas of China. This kind of water lifting facility has a long history. Because it is shaped like a keel, it is named "keel waterwheel".

Its structure is that the wooden board is used as the groove, the tail is immersed in the water flow, and there is a small shaft 1. At the other end, there is a small shaft, which is fixed on the wooden frame of the embankment. When in use, step on the turnstile to make the big wheel shaft rotate, and drive the blades in the groove to wipe water upwards and pour it into the higher ground.

Later, there was a water-to-dragon-bone cart powered by running water, and the ox cart pulled the ox wheel and turned over. And a car turned over by the wind. In Guangdong and other places, it is called "hand shaking" when it is lightly applied to the ditch between fields.

Step 2 make paper

In the first year of Yuan Xing in the Eastern Han Dynasty (105), Cai Lun improved papermaking. He made paper from bark, hemp head, cloth, fishing net and other raw materials through crushing, mashing, frying and baking, which is the origin of modern paper. This kind of paper is easy to find, cheap and has improved its quality, so it is gradually widely used. In order to commemorate Cai Lun's achievements, later generations called this kind of paper "Cai Hou Paper".

3, gunpowder

Gunpowder was invented by China people, and it has been over 1000 years. The study of gunpowder began with ancient alchemy.

China was the first country to invent gunpowder. In Sui Dynasty, the ternary system of saltpeter, sulfur and charcoal was born. Black powder officially appeared in the Tang Dynasty (the end of the 9th century). Gunpowder was invented by ancient alchemists. From the Warring States Period to the early Han Dynasty, emperors and nobles indulged in the fantasy of immortality, which drove some alchemists and Taoists to refine the "elixir" and gradually invented the formula of gunpowder during the refining process.

In the first year of Yongchun, Tang Gaozong (682), an alchemist initiated the sulfur fire extinguishing method in the Tang Dynasty. Sulfur and saltpeter were ground into powder, and then Gleditsia sinensis (containing carbon) was added. In the third year of Yuanhe in Tang Xianzong (808), flint method was created to burn saltpeter, sulfur and Aristolochia (containing carbon) together. These two formulas are a mixture of three kinds of medicinal materials, which have initially possessed the ingredients contained in gunpowder.

4. China Chess

China Chess is a kind of chess game originated in China, which belongs to an antagonistic game between two people. It has a long history in China. Because of its simple tools and strong interest, it has become a very popular chess activity. ?

China chess is a cultural treasure of China chess culture and Chinese nation. It has a long history, strong interest, simple and easy to understand basic rules, and has been enduring for thousands of years. China chess is a simulation of ancient wars, straight-line wars, land wars and plane wars. In ancient China, chess was listed as the art of self-cultivation of literati.

5. orange peel

Oranges, commonly known as "suspenders" and "shoulder poles", were agricultural tools of ancient Han people. This is the original tool for pumping water. In Shang Dynasty, oranges were used for agricultural irrigation. It adds a slender lever to an upright shelf, with a fulcrum in the middle, a heavy object hanging at the end and a bucket hanging in front. When you fall together, pumping water saves effort.

The structure of orange peel is equivalent to an ordinary lever. It is supported or suspended by vertical wood in the middle of a long horizontal pole. One end of the horizontal rod is connected with the sucker by a straight rod, and the other end is tied with or hung with a heavy stone.

When no water is pumped, the stone position is low (the potential energy is also small); When pumping water, people press down the straight rod and the water absorption device, and at the same time, the position of the stone at the other end rises (the potential energy increases). When the drain pipe is full, let the stone at the other end fall, and the potential energy originally stored in the stone will be transformed: through leverage, it is possible to lift the drain pipe.

In this way, the main stress direction of pumping process is downward. Because the downward force can rely on the weight of people, it gives people a relaxed feeling and greatly reduces the fatigue of people carrying water. This kind of water lifting tool was the main irrigation machinery in ancient China.

Baidu encyclopedia-keel waterwheel

Baidu Encyclopedia-Papermaking (History of China)

Baidu Encyclopedia-gunpowder (an agent that can be ignited by sparks, flames, etc.). )

Baidu Encyclopedia-China Chess (Board Game)

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