"Uniform weights and measures? I wonder what criteria Your Majesty intends to use to start? Xu Guangqi obviously had some doubts, so he asked cautiously.

After Zhu Youzhen ascended the throne, in order to understand the technical level of the Ming craftsmen, he went to inspect the palace workshop many times. Then he found out that the measuring tools used by the craftsmen in the workshop actually had a set for each master craftsman, and except for the craftsmen in the father-son and master-apprentice relationship, there were no two craftsmen who used a standard measuring tool.

Zhu Youzhen only thought about this phenomenon for a while, and then he understood. The craftsmen of this era were called craftsmen, and their crafts were just like the farmer's plough and the merchant's shop.

Artisans regard their craft as heirlooms, so they do not learn from their masters, and they do not reveal their skills to outsiders at all.

Under this old-style master-apprentice system, every word taught by the master was enshrined as a golden rule, and if the apprentice dared to change the procedures and standards without permission, he would be beaten and scolded at the least, and expelled from the master at the worst.

Most of the craftsmen were illiterate and uneducated, they had not gone to school, and they did not have basic knowledge of mathematical theory. These craftsmen completely relied on rote memorization when they were apprentices, memorized every number told by the master, and then digested it bit by bit in their future lives, and summarized the experience told by the master.

In this way, the measuring tools handed down from the master have become the top priority, because without this set of measuring tools, even if you learn a little fur, you can't make exactly the same thing. In Zhu Youzhen's view, these craftsmen are using their measuring tools as technical barriers to isolate others from prying on their skills.

After learning about the weights and measures in the workshop, Zhu Youzhen immediately became interested in the weights and measures on the market, and he asked Jinyiwei to start collecting about the standard situation of weights and measures in various parts of the Ming Dynasty.

He soon found that the current Ming Dynasty has a great discrepancy in actual tax revenue and account income every year because of the difference in weights and measures between the north and south, between the government and merchants, and between landlords and tenants.

As far as the accounts are concerned, all the taxes due by the state have been put into the treasury, but when it comes time to spend, the officials find that the inventory is not as large as in the accounts. Although it cannot be ruled out that some officials have taken advantage of it, this kind of corruption should have been settled in the accounts long ago.

Officials who couldn't find the reason, in order to fill this inexplicable shortfall, finally came up with such a wonderful way to float away. Since there is a shortage of state taxes receivable, wouldn't it be better for me to reduce the part of my expenditure? Not only can it make up for the shortfall, write off the loss of food and material handling, but also leave yourself with a hard-earned money.

Although officials like Xu Guangqi, who prefer science, after repeatedly hearing about the disputes caused by the inaccuracy of such weights and measures, have a vague feeling that the Ming standard of weights and measures should be adjusted. However, on the one hand, there is the imminent threat of the Ming Dynasty such as the Donglu Rebellion outside, and it seems that the problem of weights and measures is not so critical, and it can be put aside for the time being.

On the other hand, behind this chaotic weights and measures, it involves the huge interests of the gentry and officials in the Ming Dynasty, and these gentry and officials rely on different weights and measures to collect several times the national tax from the peasants.

Although Xu Guangqi was a little surprised that Chongzhen wanted to unify weights and measures, because he felt that this matter might not be implemented. But this is a good thing for the study of the natural sciences based on mathematics.

However, the Yellow Emperor set five quantities, Shao Hao with the same measure, and adjusted Lu. The cloth knows the ruler, and the cloth knows the inch. The prosperity of one hand is overflowing, and the two hands are overflowing. All this shows that in the past, the units of weights and measures were set by people, so they were very different. If you want to fix the unit of weights and measures scientifically and accurately, and be accepted by the people of the Ming Dynasty, you can't be too detached from reality.

If the emperor just came up with a set of weights and measures standards that could not be accepted by the people on a whim, then it would only make the weights and measures of the Ming Dynasty more chaotic and hinder the national economy and people's livelihood, and Xu Guangqi would definitely oppose it.

Therefore, Xu Guangqi wanted to confirm Zhu Youzhen's idea first, and then decide whether to persuade or support to reformulate the standard of weights and measures.

Zhu Youzhen sorted out his thoughts, and then said to the three people in front of him: "Although the original weights and measures have different standards, they have been used for hundreds of years after all, and some are even units left over from the Song and Yuan dynasties. If it is completely abandoned all of a sudden, it will definitely cause confusion among the people, so I want to call the weights and measures that were commonly used in the Ming Dynasty the city system, which means that the people can still use the old weights and measures.

I intend to establish a uniform standard of weights and measures for the imperial court, which I call the metric system. According to the principle of geometry, we all know that the volume of a cube is the cubic of the side length, which means that the length and volume can be converted, as long as we determine a standard length, we can determine the volume of a standard cube, that is, the capacity. Then we fill this standard cube with some kind of object, such as water, and then we can get a standard weight.

Next, what we need to do is to divide these three standard units in detail, and then link them to the original municipal units. In this way, when we unify the weights and measures of the public system, the weights and measures of the municipal system will also be unified. Do you think this idea is feasible? ”

"Dare to ask Your Majesty, what is the standard?" Deng Yuhan couldn't wait to be the first to ask, as a fanatic of scientific research, he was always curious about anything new and new.

Zhu Youzhen was a little stunned, hesitated for a while, and then hesitantly explained: "The so-called standards are things that meet the standards themselves and can be compared and checked by similar things. For example, if we take a grain of rice as the standard, any grain of rice that is larger or smaller than it is a non-standard grain of rice. Or if we take one corona as the standard corona, then the other coronas at the same time are not the same as the time it shows, then we can think that the coronas at different times are not standard and problematic. ”

Deng Yuhan thought carefully about Zhu Youzhen's explanation, nodded again and again, and said, "Your Majesty, you really have supreme wisdom. As long as we set a standard, then whether it is in Daming or in Europe, we can make the same utensils, which is a very important thing for the exchange between Daming and Europe. ”

Only then did Zhu Youzhen remember that Europeans also have no standard concept now. The emergence of the European public system of weights and measures was a matter of the French Revolution. The subsequent Napoleonic Wars brought the metric standards formulated by the French to the whole of Europe, which objectively promoted the rapid development of the industrial revolution in Europe.

Zhu Youzhen was thinking about it, and Xu Guangqi also praised it with a smile: "Your Majesty's way of using geometric principles to link length and volume is really too subtle, and it is easier to operate than Liu Xin's way of formulating weights and measures with millet and law, and the minister thinks that it is feasible to re-emphasize the system of weights and measures." ”

Deng Yuhan and Jinnige were very interested in what Xu Guangqi said, and they couldn't help but ask Xu Guangqi about the way they formulated weights and measures.

Xu Guangqi saw that Zhu Youzhen was also ignorant, and looked at himself with a vague expression. simply told the story of Wang Mang ordering Liu Xin to formulate weights and measures.

To put it simply, in the system of weights and measures constructed by Liu Xin, for the first time, the three units of weights and measures of length, volume and weight were linked, which was a great progress for China's natural sciences.

He took a certain variety of millet as the standard, with 1 grain as 1 point, 10 grains as 1 inch, 90 grains as 9 inches long, and 100 grains as 1 foot; The volume of a yellow bell palace tube is 1,200 grains of millet rice, which is recorded as 1 grain; The weight of 1,200 grains of millet is 12 baht.

However, this theoretically ingenious system of weights and measures is limited by the non-repeatability of millet in real use, and you cannot guarantee that your standard millet is exactly the same as the millet in Liu Xin's hand. Therefore, this set of weights and measures has become full of errors and omissions in actual use.

But in any case, this set of standards is the first time that this set of standards has been separated from the measurement of human body parts, and it is the first time that the Chinese have tried to fix weights and measures in a stable way. More than 1,800 years before the French formulated the standard of weights and measures for the public system.

After listening to Xu Guangqi's introduction, Deng Yuhan and Jinnige were all amazed by the weights and measures system designed by Liu Xin.

After listening to Xu Guangqi's story, the three of them immediately turned to the discussion of how to formulate a standard length, in the system of weights and measures proposed by Chongzhen, everything is based on the standard length.

As long as this standard length can be convincing, then the entire system of weights and measures of the public system can be established. For the discussion of this kind of scientific issue, the three of them were obviously very involved, and they forgot about Emperor Chongzhen, who was still on the side, after only a while.

The trio first denied the measurement of the standard length of human body parts, because later generations could not correct the standard length, so this system would eventually fall into the same chaos as the system of weights and measures built by Liu Xin.

The three of them discussed quietly and fiercely, and time passed quickly. When the prisoner Liu Yourong walked in with a few officials holding the articles prepared by the prisoners, Zhu Youzhen finally couldn't help but interject and said to the three of them: "Why don't you take 1/40 million of the circumference of the earth's equator as a standard unit?" ”

"Why the circumference of the equator?" Deng Yuhan asked a little strangely.

"Why 1 in 40 million?" Xu Guangqi and Jinnige asked in unison.

Zhu Youzhen blinked his eyes and hated himself for talking too much, how could he forget that the three people in front of him were all scientists, and they would not be submissive to him in scientific research just because they were emperors.