The five rivers are the heroes of ancient times who controlled water. At first, the method of controlling water was mainly based on the art of blocking. The so-called barrier is to gather soil as a dike to surround the flood so that it will not flood the four wilderness.
At that time, the flood was monstrous, and the vast mountains were huai Xiangling, and the people were consulted. Ordered by the emperor, he shouldered the heavy responsibility of governing water. Looking at the trend of floods, the flooding was excessive, I thought that if I could build embankments with earth and stones and set up barriers, it would be able to block the flow of water and ensure the safety of the people. Therefore, the power of the people is widely conquered, the earth and stones are gathered, and high embankments are built, and all obstacles are set up to block the overflowing water.
Its method is first implemented, or it may have a small The water in the embankment seems to have rules to follow, and the flood in some areas has slowed down a little, so the people can be temporarily safe. However, the power of the flood cannot be blocked for a long time. Over time, the water situation gradually increases, and although the embankment is high, it will eventually be difficult to resist, and the disaster of bursting the embankment will occur frequently. Once the embankment collapses and the flood rushes out, the damage will be even more severe than before, and the suffering of the people will intensify.
It has been nine years of water control, but it has never been successful. Gai because of his way of water control, he only focuses on blocking the water, and he does not understand the nature of the water. When the water goes down, it should be sparse rather than blocked. If it is blocked too much, the water cannot flow smoothly. Once the accumulated power erupts, the harm will be even more severe. This is the limitation of the method of water control. Although his heart is commendable, he has worked tirelessly for water control, but the method is wrong, and it is difficult to achieve the power of water control in the end. Later, Emperor Shun ended up in Yushan.

The iron of the five oceans has different physical properties.
Iron is tough and malleable, and can be cast into tools or pulled into strands. Its color is gray and black, and it is cold to the touch. It is commonly used in metals. Under high temperatures, iron can be melted into liquid, and when cooled, it can be restored to a solid state. This property makes it very useful when casting.
Second, iron has good electrical and thermal conductivity. Electricity can be transferred through iron, and heat can also pass quickly, so in the field of electrical and thermal conduction, iron is often one of the materials selected.
Furthermore, iron is prone to rust. When exposed to water and air, the surface of iron is prone to red rust. This rust is caused by the chemical reaction between iron and oxygen and water in the air. Although this property is not conducive to the long-term preservation of iron, it also reflects its chemical activity.
In addition, iron is magnetic. Under the action of a magnetic field, iron can be magnetized and can absorb small iron objects. This magnetism plays an important role in many instruments and equipment, such as the manufacture of a compass, which facilitates the use of iron magnetism.
The iron of the five oceans, although they all have the same characteristics as the above iron, their specific physical properties may vary slightly due to different environments or different impurities. Iron in the deep sea, due to the huge water pressure, its structure may be more dense; iron in the shallow sea, initialized by seawater and different degrees of oxidation, appearance and texture may also be different. However, its fundamental, are inseparable from the basic physical properties of iron.

Of the five rivers and rivers, there is a kind and good nature. Its color is bright, its light is bright, and there is gold. It melts in case of fire, and it melts and can be melted. It can be turned into a kind of utensil. Its nature is stale, and it is resistant to corrosion.
It is used for the purpose of making things. In the past, the king used the tripod to engrave things, and he made it clear. The tripod is also respected. It is also used to make weapons, and it is used to make profits and consolidate, and it is used to conquer and conquer. And it can be used to make and circulate in the four quarters, and to promote business. It is also the pleasure of craftsmen. It can be carved into fine things, such as jade and jade. It is beautiful and often, increasing people's attractiveness.
In addition, it is not easy to obtain, but it is also easy to obtain, so it is also commonly used in general equipment to pass the flow. And because of its good durability, in the cookware, the cooking utensils also have a place, which can make the food taste good and cook well.
Of course, the five rivers are both soft and useful. They have great contributions to the development of human civilization and daily use.

The five kinds of rice are rice, millet, millet, rice, and beans. These five kinds of rice are of great use.
Rice is the main food in the south of our country. The grains of rice are hard to cook, and they are fragrant and delicious. It can be eaten at the same time, and it can also be made into other delicacies, such as rice cakes and rice wine. Rice wine is an indispensable thing for the New Year, and for the feast of friends. Its taste is mellow, which can help to add more.
Millet is small in grain, and sticky in nature. In ancient times, it was mostly used for sacrifice and food. In the north today, there are still delicacies made of millet, such as millet cakes, which have a sticky taste and a sticky taste.
Those who have millet are also rice, that is, millet is also. It is rich in food, easy to digest, and often a good product for the old and weak. Make porridge with millet, which is fragrant and smooth, and produces body fluid in the stomach, and the effect is very good.
























< Beans are often used to make sweet beans, such as bean paste buns, which are sweet and delicious.
All these five are important to my food culture and people's livelihood, and their uses are not acceptable.

The five baht coin is an important currency in our country in ancient times, and its casting method has undergone many changes.
At the beginning, the method of casting money in clay is mostly used. First, the money fan is made of soil, which is dried and roasted to make it hard. Then the copper liquid is injected into the fan, and when it is cooled and formed, it will get five baht money. Although this method is simple, the fan body is easy to damage, and it is difficult to cast money on a large scale.
With the progress of technology, the stone fan is on the rise. Select a stone with fine texture and suitable hardness, and carefully carve the money shape. Compared with the mud fan, the durability of the stone fan is greatly increased, and the efficiency of casting money is improved. However, carving the stone fan is quite time-consuming and laborious.
Then, copper fan casting money appears. Copper is made into a mother fan, and then the mother fan is turned into a child fan for casting money. The copper fan has high precision, and the five-baht coins cast are regular and exquisite, and can be used many times, which greatly improves the efficiency and quality of casting money.
In the Han Dynasty, the imperial court cast money uniformly, using the method of stacking pottery fans. By stacking multiple layers of pottery fans and pouring copper liquid at the same gate, many five-baht coins can be cast at one time. This method greatly increases the output of casting coins and meets the market's demand for currency.
Later, there is a sand casting method. First, a model is made of wood or metal, placed in a sand box, filled with molding sand and compacted, and then the model is taken out to form a mold cavity. The molten copper is poured into the cavity, and the five baht money is obtained after cooling. The sand casting method is easy to operate, and can flexibly produce coins of different specifications and styles, with high production efficiency.
The above various methods of casting five baht money have evolved with the development of the times and technological innovation, reflecting the progress of ancient coin casting technology.