In ancient times, China was a big agricultural country. How did the ancients process food?

? We can't know why they did it in the first place, but we can infer that after the running-in of the Paleolithic, our ancestors became familiar with tools such as stones. After the grain is recovered, it is obviously uncomfortable to eat it directly, and the taste is too bad. So some people thought of crushing these grains, or laying them on stones and heating them to make cakes, or cooking them in clay pots. So processing tools will definitely appear. ? At that time, the grain processing tools were very simple. A simple stone must have a larger plane on which the grain can lie flat, and then a tool for crushing the grain is needed. This is a stone stick.

Stones and sticks were the main tools at that time. The main force of breaking grain is manpower. People spread grain on a stone, then crush it with a stone stick and crush it into powder. Of course, this kind of processing tool was not the only one at that time. At that time, stone tools could be mainly divided into three categories, namely, ploughing tools, harvesting tools and grain processing tools.

Archaeologists unearthed more than 200 stone tools, more than 80 stone millstones, stone grinding rods and so on at the Neolithic site in Peiligang. More than 1000 pieces of stone tools, such as stone millstones and stone rollers, have been unearthed at the Cishan site in Wu 'an. It will be smarter for future generations to sacrifice the interests of Chu Jiu. If you trample on it, it will be ten times more beneficial. Some people will say that these are all records of the Han Dynasty, which may not represent the existence before the Warring States Period, let alone Xia, Shang and Zhou Dynasties. Of course, there was at that time, when Chu Jiu was more than just a farm tool. According to legend, there is such a record in Jiang Ziya's art of war "Six Towers":

Therefore, more advanced ones have to appear, and the former will be replaced by the latter. This substitute must have the simplest function, that is, it can be operated by animal power without manpower. This is the circular stone mill that was used later, and it was used until the 1980 s and 1990 s.

About the birth of circular stone mill, it has been controversial in academic circles. Some people say that it can be earlier, and some people say that it can only be in the Warring States period at the earliest. Because it looks simple, but its manufacturing process is very complicated, and an important tool is needed to help make it, that is iron. As we all know, iron was smelted and used only in the Warring States period, so many people think that such advanced stone mills can only appear in the Warring States period.

This kind of thing is divided into upper and lower parts, both of which are carved with large stones with a certain thickness. A short vertical shaft is needed in the middle of the lower fan, which is made of iron. There should be an empty sleeve in the middle position of the upper grinding fan corresponding to the lower vertical shaft, which can just be inserted into the lower iron shaft and fastened. In this way, the lower fan is fixed and the upper fan can rotate around the shaft. There is a "grinding chamber" on the contact surface of the two fans. The periphery of the chamber is criss-crossed with grinding teeth, and grinding holes are left on the upper grinding for downward grain leakage.

Professor Liu Xianzhou, a famous mechanical historian in China, is also very cautious when quoting Shiben, which can also explain some problems from the side. Archaeologists in China discovered round stone mills in Qin tombs and Han tombs. So it should have appeared at the end of the Warring States and the beginning of the Qin Dynasty!

After the Qin Dynasty, Chu Jiu did not disappear. Many people still use it, but it is not the mainstream. The mainstream is a round stone mill. Because animal power can be used instead of human power, animal power has been utilized and developed. Du Yu invented the "hydraulic continuous rolling mill" in Jin Dynasty.