History of stone mill

1. Who can tell us about the origin and history of "stone mill", or the creation related to stone mill, which shows that circular stone mill is a great invention of working people in ancient China in grain processing machinery?

But for a long time, its origin and history have not been recognized by people. Many experts who study the development history of agricultural machinery in China avoid talking about this issue.

So far, no one has published an article about the origin history of circular stone mill in academic circles. In order to reveal this invention and creation of China ancient working people in science and technology, the author discussed this issue according to the materials and documents provided by archaeology. The upper limit of time for grinding a round stone, originally called? The Han dynasty was called grinding.

When was it born? Few people can answer this question at present. According to "Shiben" and other documents, "If lost?" It is inferred that the use of circular stone mills in China began in the early Warring States period.

Because Gongbo means Luban, and Luban and Mozi are contemporaries (475-376 BC). But for a long time, people have been skeptical about the correctness of the records in Shiben.

Professor Liu Xianzhou, a famous expert in the history of construction machinery in China, only cautiously concluded that the stone mill should have been used at least two thousand years ago? (1) before the demonstration, we must first understand the production technical conditions needed before the birth of the round stone mill. That is to say, before the birth of the round stone mill, what level of production technology could be reached at that time, and what were the social factors that prompted its birth? As we all know, the so-called circular stone mill is divided into upper and lower fans, both of which are carved into flat cylinders with large stones of a certain thickness. There is a short vertical shaft in the middle of the lower fan, which is made of iron, and a corresponding hollow sleeve in the middle of the upper fan. The two fans are combined, and the lower fan is fixed, so that the upper fan can rotate around the shaft.

At the same time, there is a cavity on the contact surface of the two fans, which is called "grinding chamber". There are grinding teeth around the inner hole and grinding eyes on the upper hole.

It can be seen that there are many processes to make a stone mill and it is difficult to carve. In the era when iron tools have not yet appeared, it is impossible to have a stone mill. According to the research of relevant experts, the invention of iron smelting technology in China was at the end of the Spring and Autumn Period.

An iron block unearthed from Chengqiao Bridge in Liuhe, Jiangsu Province in the late Spring and Autumn Period, after scientific analysis, is white iron. This is the earliest pig iron unearthed in China and scientifically analyzed, and it is also the earliest pig iron in the world.

Casting tools with pig iron began in the early Warring States period, and by the middle and late Warring States period, iron tools were widely used in China. At present, there are as many as 16 kinds of ironware unearthed in this period. ② However, does this mean that "World Book" records "public works?" Must it be correct? Judging from the time of the invention of iron smelting technology, there will be no problem in the era of stone grinding.

But the problem is not that simple. It was not invented by Lu Ban, or it may not have been invented in Lu Ban's time. It should be created by the working people collectively. It may have been invented by Lu Ban before or after. Below we can look at the information provided by archaeology in this regard. As far as I know, the archaeological discovery of stone mill belongs to the Warring States period, and there is only one case in Handan City, Hebei Province. And the report is too simple, with no pictures and no dimensions. Just behind the unearthed relic stone tools, it reads: "There are large and small stone mills, stone mortar, stone hammer, slate, column base, etc." ? (3) can't provide reliable materials for us to study this problem.

Now it can be recognized as the archaeological discovery of stone mill, and the earliest age should be the stone mill unearthed from the site of Qin stone processing factory in Lintong, Shaanxi Province. The mill is a square with a diameter of 54 cm and a thickness of 7 cm, with a shaft hole of 5*5 cm in the middle, a plane with a diameter of 20 cm near the inner ring, and four grinding grooves separated by spiral grooves from the outside? ④。

This is the next fan. Followed by the * * * stone mill unearthed from the Han tomb in Hebei.

The mill is divided into upper and lower fans. The center of the surface of the upper fan is a circular groove with a protruding periphery, and there is a beam in it. There are rectangular holes on both sides. The bottom is covered with round nested grinding teeth, and the center is slightly concave. The grinding teeth of the lower fan are also round and nested, and the surface is slightly convex. The center has a cylindrical iron shaft with a grinding height of 18 and a diameter of 54 cm. The upper part of the copper funnel has a big mouth and lower abdomen, and a wide band pattern is applied outside the waist. The upper caliber is 94? 5. The lower caliber is 29, and the height is 34 cm.

From the upper mouth down to 16 cm, the inner wall of the funnel extends horizontally outward, facing each other, and its span exceeds the diameter of the stone mill, indicating that the four claws were originally equipped with wooden devices to support the stone mill. ⑤ In addition, there is a stone mill unearthed in Liyang, Qin Dou, which was identified as a relic of Qin Dynasty in the original report.

In fact, judging from the size and shape of the mill (only the upper fan), it is very similar to the stone mill in Mancheng. Especially grinding teeth, round and nest, some people think it may be Han Mo? ⑥。

Now let's not talk about whether the stone mill of Qin Dynasty unearthed in Lintong, Zheng Zhuang and the stone mill unearthed in Mancheng Han Tomb are in the same strain. Only from the above materials, the use time of circular stone mill in China can be traced back to the Qin Dynasty at the earliest. Considering that the Qin Dynasty existed for a very short time in the history of China, it is still valid to set the time when China's circular stone mill began to be used in the late Warring States period.

Of course, the book World Book says, "Like losing?" It is legendary, and it is not enough to rely on it. So why was the round stone mill born in the middle of the Warring States period when iron farm tools were widely cast? Engels once said, "Once there is a demand for technology in society, this demand will push science forward more than ten universities"? ⑦。

The author thinks that the birth of circular stone mill in China is the need of soybean and wheat in grain processing technology. As early as before the Warring States Period, although soybeans and wheat had been planted in northern China, these two crops did not occupy the primary position in the whole crop.

By the Warring States period, soybean, in particular, had become the main food crop in northern China. In the literature of this period, it is often mentioned that "rice and millet are not enough, and people will be hungry."

⑧ "Sages rule the city, fleas can't get out, and millet gathers, so there are many millet, and the people take food as security." ? Pet-name ruby "sages rule the world, making millet like fire and water, adding fire and water to millet, how can people be unkind?" ? 10 "Xiaomi is hidden deep"? 1 1, "plant trees to gather millet"? 12, "People who embroider clothes and eat millet"? 13。

So is soybean. It can be seen that soybean has surpassed any kind of food crops in the Warring States period, and soybean is convenient.

2. The discovery history of graphite dilution In fact, graphene originally exists in nature, but the single-layer structure is difficult to peel off.

Graphene is stacked layer by layer to form graphite, and the graphite with a thickness of 1 mm contains about 3 million layers of graphene. Pencil gently across the paper, leaving traces may be several layers or even just a layer of graphene.

Graphene was in the laboratory in 2004. At that time, Andrei Cem and Kostya Novoselov, two scientists from Manchester University in England, found that they could get thinner and thinner graphite flakes in a very simple way. They stripped the graphite sheet from the highly oriented pyrolytic graphite, then stuck both sides of the sheet on a special tape, and tore the tape to split the graphite sheet in two.

Keep going like this, the sheets are getting thinner and thinner. Finally, they got a thin sheet consisting of only one layer of carbon atoms, which is graphene. Since then, new methods for preparing graphene have emerged one after another. After five years of development, it has been found that it is not far away to bring graphene into industrial production.

Therefore, in the following three years, Andre Geim and Konstantin Novoselov discovered integer quantum Hall effect and room temperature quantum Hall effect in single-layer and double-layer graphene systems respectively, and they won the 20 10 Nobel Prize in physics. Before the discovery of graphene, most physicists thought that thermodynamic fluctuations did not allow any two-dimensional crystal to exist at a finite temperature.

Therefore, its discovery immediately shocked the condensed matter physics community. Although both theoretical and experimental circles believe that the perfect two-dimensional structure can not exist stably at non-absolute zero, single-layer graphene was prepared in the experiment.

3. The historical evolution of the mill

Mill, originally called Wei, was called Mill in Han Dynasty.

The development of China stone mill can be divided into three periods: early, middle and late.

From the Warring States to the Western Han Dynasty, the grinding teeth in this period were mainly pits, including rectangles, circles, triangles and jujube pits. Their shapes are varied and extremely irregular. From the Eastern Han Dynasty to the Three Kingdoms, it was a period of diversified development of grinding teeth, and the shape of grinding teeth was radial and diagonal, with four, six and eight belts. The later period is from the Western Jin Dynasty to the Sui and Tang Dynasties (up to now). This period is the mature stage of stone grinding, and the mainstream of grinding teeth is eight-zone oblique line type and ten-zone oblique line type.

heavy burden

It is people, animals and water that grind. The mill driven by water was invented in the Jin Dynasty. The power part of the waterwheel is a horizontal waterwheel. The upper fan of the mill is installed on the vertical shaft of the wheel, and the running water drives the mill to rotate. This kind of mill is suitable to be installed in the place where the water impact force is relatively large. If the impact of water is relatively small, but the amount of water is relatively large, another form of water mill can be installed: the power machine is a vertical wheel, and a gear is installed on the axle, which is connected with the gear installed at the lower part of the grinding shaft. The rotation of the water wheel turns the mill through gears. These two kinds of water mills are relatively simple in structure and widely used.

When history developed to 1970s, people skillfully combined ancient technology with modern elements to create motor-driven stone mills, including two kinds of stone mills, chip stone mills and roller stone mills. The grinding part of the chip mill is divided into a fixed part and a rotating part, forming a horizontal structure. The fixed part is a semi-cylindrical groove matched with the rotating part on the long side of the rectangular stone. The rotating part is made into a cylinder, and the middle hole penetrates into the transmission shaft. The surface of the contact area between the semicircular stone trough and the rotating cylinder is engraved with a pattern similar to that of the ancient stone mill, and the corresponding shielding transmission part forms a product of the combination of the old and the new. The grinding part of the roller stone mill is roller cylindrical rock, which looks like the grinding roller of a steel mill, and the surface is engraved with patterns similar to those of ancient stone mills.

creator

Luban, the Inventor of Stone Mill

Lu Ban was an outstanding inventor in ancient China. He lived in the late Spring and Autumn Period and was called a disaster. Because he is from Lu, he is also called Lu Ban. It is said that he invented saws, planers and rulers for carpenters. He also used his wisdom to solve many problems in people's lives. When Luban lived, people wanted to eat rice flour and wheat flour. They put rice and wheat in a stone mortar and pounded them with a thick stone stick. This method is very laborious, and the powder is coarse and fine, and it is rare at a time. Luban wants to find a way to get twice the result with half the effort. Just use two flat cylindrical stones with a certain thickness to make a grinding fan. There is a short vertical shaft made of iron in the middle of the lower fan, and a corresponding empty sleeve in the middle of the upper fan. After the two fans are combined, the lower fan is fixed and the upper fan can rotate around the shaft. On the opposite sides of the two fans, there is an empty chamber called grinding chamber, and the periphery of the chamber is made into falling grinding teeth. There are grinding eyes on the upper fan. When grinding, the grains flow into the grinding chamber through the grinding eyes, are evenly distributed around, are ground into powder, flow from the cracks to the grinding disc, and are removed by a Luo sieve to obtain flour. Many rural areas are still grinding their faces with stone mills.

kind

Traditional stone mill

1968, a stone mill about 2 100 years ago was unearthed from Mancheng Han Tomb in Baoding City, Hebei Province. It is a copper-stone compound mill consisting of a stone mill and a copper funnel. This is the earliest stone mill discovered in China so far.

Modern stone mill

The modern chip stone mill retains the grinding part of the traditional stone mill, that is, two cylindrical rocks, and changes the traditional power generation device, from the original donkey to the motor, and adds a conveying device and a cleaning device. Compared with the traditional stone mill, the modern stone mill saves labor, reduces the amount of labor and improves the output of the stone mill.

The conveying device consists of a large hopper, a fan, an air door, a funnel and a pipeline. The cleaning device consists of a screen, a brush and a round roller.

4. What is the saying of stone mill in Feng Shui? What's the saying of millstone geomantic omen?

In geomantic omen, the millstone means "Qinglong", and in folk geomantic omen, the roller is called the white tiger.

Qinglong White Tiger is the God of the East and the God of the West in Han mythology. Star worship originated from ancient Han people. Among many door gods, there is a special door god, which is specially used to guard the Taoist temple gate. They are what Taoism often says: "Left green dragon, right white tiger". For example, in the Taoist resort Qingcheng Mountain Ancient Road View (Shi Tian Cave), in front of the towering mountain gate, there are two temples. The left temple is a powerful dragon statue named Meng Zhang Shen Jun, and the right temple is a brave white tiger statue.

There's a saying that there are no bones left. A millstone is something with a heavy shade. It is best to put it in the northeast corner or northwest corner of the house. Deciphering the geomantic function of stone mill: stone mill is a white tiger, which is generally used for porch geomantic omen. There are evil spirits in Castle Peak or evil spirits in Duan Long, but they can only be placed after surveying the actual terrain and the situation of Jiugong, otherwise it will be harmful to people's health.

The mention of the stone mill reminds people of the little donkey who has been grinding things blindfolded. It is also reminiscent of the landlord bullying the long-term workers hired at home and letting them grind them for him. It also reminds people of the mill in grinding bean curd. With the progress of society, the stone mill, a daily appliance, has been gradually replaced by various modern and convenient scientific and technological products, but he has a new identity, that is, feng shui supplies.

On the stone mill, it has left indelible vicissitudes and witnessed thousands of years of historical changes.

Stone mill is a kind of household appliance, but with the invention of electricity, it is gradually replaced by various modern scientific and technological products and gradually comes out of people's sight.

However, in ancient geomantic omen, whether before or after, the stone mill will still occupy a place and play its role in geomantic omen.

Stone mill is a geomantic tool. Now let me briefly talk about the role and characteristics of stone mill in geomantic omen:

Characteristics of stone mill:

First, the shape of the pole;

Second, the shape of the millstone ditch is distributed in a rotating pattern;

Third, the number of stone ditches in the millstone divination can be divided into single-sided and double-sided, with yin and yang distribution, corresponding to the two devices;

Fourthly, the flow holes on the stone mill turntable are strikingly similar to what scientists call black holes at present;

Fifth, the most primitive divinatory symbols.

The role of the stone mill:

First, the stone mill acts as a white tiger;

Second, the role of exorcism;

Third, the role of reversing the magnetic field;

Fourth, and cooperation;

Fifth, pursue function;

How to place a stone mill in a house

The stone mill of the town house should be placed on the right side of the gate.

Stone mill was a grain processing tool more than 7000 years ago. Yellow sandstone, cut. The grinding disc is sole-shaped, with a flat front end and four short legs chiseled at the bottom. The grinding rod is nearly cylindrical, slightly thinner in the middle and slightly thicker at both ends, which is caused by long-term grinding of the cover.

The stone mill is shaped like a long slate, and its two ends are curved like soles. The stone mill is made of a whole piece of sand with a slightly concave front, which may be caused by long-term use. Most stone mills have four cylindrical grinding legs at the bottom, which are 3 to 6 cm high. Generally, the stone mill is about 70 cm long, with a maximum length of 1 m and a width of 20 cm to 30 cm.

Matching it is a stone roller, which is generally about 30 cm to 40 cm long and about 6 cm in diameter. It is hard to imagine that 7000 years ago, in such a distant era, human beings could figure out a processing tool for hulling grain with a whole slate. What is even more difficult to understand is that this production tool embodies the high wisdom of primitive human beings.

Unscramble the geomantic function of stone mill;

The millstone is a white tiger, which is generally used for porch feng shui. Used by the Castle Peak Evil Spirit or the Duan Long Yin Evil Spirit. However, it must be placed after surveying the actual terrain and the situation of Jiugong, otherwise it will be harmful to people's health.

There's a saying that there are no bones left. A millstone is something with a heavy shade. It is best to put it in the northeast corner or northwest corner of the house.

The millstone is a white tiger, which is generally used for porch feng shui. Used by the Castle Peak Evil Spirit or the Duan Long Yin Evil Spirit. However, it must be placed after surveying the actual terrain and the situation of Jiugong, otherwise it will be harmful to people's health. This thing will suppress the earth's atmosphere and affect Feng Shui. Unless this place is shady, use a millstone to suppress evil spirits. Otherwise it will be fierce.

Put a stick of incense on the millstone on a regular basis, and put something to eat on the millstone during the Chinese New Year holidays (honoring ghosts and gods). If nothing happens, don't let the children sit on the millstone. As the saying goes, money makes the mare go, but no money can make you rich, have a wallet and have a smooth career. China has a saying of raising ghosts since ancient times.

5. "Historical Records of Shengsong Yuanbao" Regarding the silver money in the Northern Song Dynasty, according to Fang Ziyu's "Records of Words and Money", "The silver money has been said by Li Yin Zhenghe, and the same party has a silver name, and the name of the silver name is unbreakable."

However, Baozi has many questions about this kind of money. Fang went on to write: "I think Song Zhisheng, Daguan, Xuanhe and Jingkang were really pure silver, which was different from Bao Tong in Yuan Dynasty, Bao Tong in Dade and Wanli in Ming Dynasty.

It can be seen that at the beginning of the last century, Mr. Fang, a famous minter in China, had seen the silver coins of the sage Song Yuanbao Xiaoping, but unfortunately he did not see the rubbings handed down from generation to generation, nor did he see the real thing again. 20 11June1day, an ancient well containing 4 tons of ancient coins from the northern song dynasty was dug at a construction site in the Lule Bridge section of Ganjiang Road, Suzhou, including an ingot of Song Shengyin. It is recorded in Notes on the East China Sea: Tools: paper (cicadas, flowers or other thin materials are also acceptable).

Ink (all kinds of ink can be too strong, water can be added, and solid ink will do). Extension bag (according to the size of the extension bag to be made, take a sponge, make it into a circle and wrap it with household plastic wrap, then wrap it with face cloth and finally wrap it with fine silk cloth and rubber band, and adjust the tightness of the extension bag).

Water (Fan Mingdou size can prevent ink smudge, a few drops of glue can increase ink adhesion, 250g of water and 30g of salt can prevent fiber shrinkage and paper deformation after long-term storage, stir evenly, put a piece of paper on the water surface to play a filtering role, and use the water oozing from the paper surface). Brown brush (used for pressing and spreading paper).

Press plate (screwed into different diameters with paper clips and plastic plates). Cushion (to prevent money from moving and acting and reacting.

Use a soft rubber pad and a book). Scale (paper pressing) writing brush (dipped in water) making: 1.

Put a small dollar on the mat, and it won't move when it is wet. 2. Dip the adjusted amount of water into the paper with a brush and draw it on the coin. Choose a piece of paper with the right size, even and free of impurities, and cover it on the coin.

Press the pressure plate. 3. Cover the rubbing paper with raw rice paper to absorb excess water, then cover the rubbing paper with raw rice paper and flatten it with a brown brush. Gently punch out from the middle of the coin, and finally cover the coin with plastic wrap before punching (the effect is that the plastic wrap is thinner and the characters can be clearly punched out).

At this time, the voltage ballast is fixed. Why not press the ballast from the beginning? Because the rubbing paper will be straightened when it is first pressed, and it is easy to break with a brown brush. 4. Don't put the ink in the inkstone too thick, dip it evenly with the extension bag, and hammer it with the extension bag to suck out the excess ink in the lifetime publicity. This depends on the drying of rubbing paper until it turns slightly white (the key step of a rubbing), and gently hammer it down from the money with rubbing bag to make the ink clear and even (the first pass is the most important).

Then you can ink it many times until you are satisfied, but in the end, you must beat the inner buying wheel of the coin again, so that the outline is clear and three-dimensional. According to "Oriental Insights", in addition to pyrometallurgy, there is also the "water smelting copper method".

This method of copper smelting is to replace copper from the solution containing copper compounds with metallic iron, then scrape it off and cook it to obtain copper ingots. The so-called "bile water" refers to the natural spring water containing copper sulfate (commonly known as bile and bile alum in China).

It is formed because some natural copper sulfide ores will generate soluble copper sulfate after weathering and oxidation, which will be soaked and leached by groundwater and rainwater and then dissolved in spring water. As long as the concentration of copper is large enough, this bile water can be used as raw material for copper hydrometallurgy.

As early as the Han Dynasty, our ancestors had noticed that metallic iron could replace copper. For example, it is recorded in the ancient book Huainan Wanbi Book of the Western Han Dynasty that "Zeng Qing (a mineral of copper carbonate) got iron and then [iron] turned into copper".

Shen Nong's Classic of Materia Medica, written in the Eastern Han Dynasty, says that "stone gall can turn iron into copper". Ge Hong, an alchemist in the Eastern Jin Dynasty, said more clearly in his Inner Chapter of Bao Puzi: "Painting iron with Zeng Qing, iron is as red as copper, ... and it is all a change from the outside to the inside."

But at that time, most people didn't know this phenomenon exactly, and mistakenly thought that iron would be transformed into copper when it came into contact with Zeng Qing and stone gall. As late as the Tang Dynasty, some alchemists who were engaged in alchemy took advantage of this chemical change, heating and refining stone gall water and mercury in a large iron pot, and the replaced copper and mercury formed amalgam.

Then, they heated the copper amalgam that looked like sand and evaporated the mercury, so they got red copper powder. They are euphemistically called "Red Silver" and are very proud, thinking that they have really realized the transformation from iron to copper.

This "stunt" was recorded in "Dragon and Tiger Return to Dan" written by alchemist Jin Lingzi in the late Tang Dynasty. About the Five Dynasties, "smelting copper with danshui" officially became a practical method to produce copper.

By the Song Dynasty, this craft had developed to a considerable scale. According to the conference and food articles in Song Dynasty, Shui Ye copper was used in 1 1 in Huizong period of Northern Song Dynasty, and there were three major areas: Censhui in Shaozhou (Guangdong), Lead Mountain in Xinzhou (Jiangxi) and Dexing in Raozhou (also in Jiangxi).

In the second year of Chongning (A.D. 1 103), the total output of bile copper in China reached 1874427 Jin, accounting for 12% of the copper output at that time. However, after Zhao and Song Dynasties moved to the south of the Yangtze River, the copper production in Jiangnan 14 States dropped sharply, while the bile copper production in the main road was still 2 10000 Jin, accounting for 80% of the total copper production in the Southern Song Dynasty.

Therefore, Song people attached great importance to the production of bile copper. Zhang Jia, a native of the Southern Song Dynasty, wrote a book "A Brief Introduction to Copper Immersion", which recorded the production of bile copper at that time. As for the specific operation of leaching bile copper, it is recorded in the History of Song Dynasty that pig iron is sliced, put into a tank filled with bile water, soaked for several days, and then the precipitated mud copper (called "red coal") is scraped off and put into a smelting furnace for smelting.

At that time, the benefit was probably to exchange two Jin of iron for one Jin of copper, and the technical level was quite high. In addition, at that time, there was a "copper leaching method" for frying copper with bile soil, and its basic principle was the same as that of "bile water method". This method is "less workload", but "its soil is endless and its benefit is thicker than copper mining", so it is also widely used.

Master Zhu Ying's decameron in Bamboo records: 1. Look at this copper. Most of the coins in ancient China were cast in the form of copper alloy, so the coins showed different colors with different alloy compositions. The copper quality of coins in different times is different, and because of the different ancient smelting techniques, the ancient coins cast in different regions are also different, and each dynasty has its own characteristics.

Generally speaking, coins cast by copper-zinc alloy are yellow, and coins cast by copper-tin alloy are blue. During the Qing Dynasty and the Republic of China, Xinjiang, * * * and other places cast money with copper and a little zinc and lead, and the money was red after casting.

Currency in the pre-Qin period.

6. What about the stone mill? The people regard the stone mill as a "dragon", and the stone mill on the grain field is absolutely not allowed to sit. Sitting on a stone table is a "green dragon head", which will definitely offend the gods and be detrimental to the summer harvest. There is also a saying that "sit on a stone, rot your crotch and eat less food." "rotten crotch" is a punishment for people sitting on stones; "Less grains" is a punishment for those who use this kind of stone.

Stone mill introduction:

Stone mill is a machine used to process rice, wheat, beans and other grains into powder and pulp. It began to use human or animal power, and in the Jin Dynasty, the working people in China invented the waterwheel powered by water. Usually made of two round stones. The grinding surface is two layers flat, and the junction of the two layers is textured. Particles enter the middle of the two layers from the upper hole, move outward along the grain, and are ground to form powder when rolling through the two layers.

Extended data:

Mill, originally called Wei, was called Mill in Han Dynasty.

The development of China stone mill can be divided into three periods: early, middle and late.

1. From the Warring States to the Western Han Dynasty, the grinding teeth in this period were mainly pits, such as rectangles, circles, triangles and jujube pits. Their shapes are diverse and very irregular;

2. The period from the Eastern Han Dynasty to the Three Kingdoms is the middle period, which is a period of diversified development of bruxism. The shape of grinding teeth is radial and oblique, with four, six and eight belts;

3. The later period is from the Western Jin Dynasty to the Sui and Tang Dynasties (up to now). This period is the mature stage of stone grinding, and the mainstream of grinding teeth is eight-zone oblique line type and ten-zone oblique line type.

It is people, animals and water that grind.

The mill driven by water was invented in the Jin Dynasty. The power part of the waterwheel is a horizontal waterwheel. The upper fan of the mill is installed on the vertical shaft of the wheel, and the running water drives the mill to rotate. This kind of mill is suitable to be installed in the place where the water impact force is relatively large.

If the impact of water is relatively small, but the amount of water is relatively large, another form of water mill can be installed: the power machine is a vertical wheel, and a gear is installed on the axle, which is connected with the gear installed at the lower part of the grinding shaft. The rotation of the water wheel turns the mill through gears. These two kinds of water mills are relatively simple in structure and widely used.

When history developed to 1970s, people skillfully combined ancient technology with modern elements to create motor-driven stone mills, including two kinds of stone mills, chip stone mills and roller stone mills.

The grinding part of the chip mill is divided into a fixed part and a rotating part, forming a horizontal structure. The fixed part is a semi-cylindrical groove matched with the rotating part on the long side of the rectangular stone. The rotating part is made into a cylinder, and the middle hole penetrates into the transmission shaft. The surface of the contact area between the semicircular stone trough and the rotating cylinder is engraved with a pattern similar to that of the ancient stone mill, and the corresponding shielding transmission part forms a product of the combination of the old and the new.

The grinding part of the roller stone mill is roller cylindrical rock, which looks like the grinding roller of a steel mill, and the surface is engraved with patterns similar to those of ancient stone mills.