According to research, the history of cement can be traced back to 5,000 years ago, when China used materials similar to modern cement to lay the ground. In addition, ancient Rome also used a mixture of lime and volcanic ash in construction, and its quality is not much different from that of modern cement.

However, these examples have a certain amount of chance, and the real invention of cement was after the 18th century. They use limestone and clay as raw materials, which are crushed, batched and ground to make raw meal, and then sent to cement kilns for calcination and maturation. After clinker is added with an appropriate amount of gypsum or other additives, and then grinded, cement can be obtained.

One of the most important and very difficult aspects of the cement production process is grinding. The raw meal must be ground to a very fine degree in order to have an adequate chemical reaction at high temperatures. The burned clinker must also be ground to a very fine degree in order to fully absorb water and turn into a cement slurry when used.

As a person who has repeatedly searched for limestone mines for cement factories around the world, Su Hao has a relatively full understanding of the cement production process, but how to produce cement under the technical level of the Ming Dynasty, especially to solve this very difficult problem of raw material and clinker grinding, Su Hao is at a loss.

He handed over this problem to Xu Zong and asked Xu Zong to experiment repeatedly. Xu Zong tried to grind limestone with ordinary stone grinding at first, but found that the hardness of limestone was about the same as that of stone grinding, and it was impossible to achieve the grinding effect at all. Later, he switched to an iron mill, and although he was able to grind the limestone this time, the grinding disc was also very badly worn. According to Xu Zong's calculations, the cement burned in this way is probably more expensive than iron, and it cannot be applied in practice at all.

However, this thorny problem is about to be solved by the Hao family and his son. Since Hao Qing smelted high-manganese steel, Su Hao has been keenly aware that high-manganese steel can be used to make tools for grinding cement raw meal. Because an important feature of high manganese steel is that the surface hardness is extremely high and very wear-resistant, the steel balls of the cement ball mills of later generations are also made of high manganese steel.

Su Hao introduced the principle of cement ball mill to Hao's father and son, and Hao's father and son understood it as soon as they heard it, and immediately began to develop it. In order to make the drum of the ball mill, Hao Qing also built two larger crucibles for smelting molten steel. As for Hao Yizong, he plunged into his own room and pondered the principle of the entire mechanical transmission part.

The ball mill is crushed by continuous rotation, which requires a steady stream of power as a guarantee. For this problem, there was also a way to solve it, that is, to use water power. As a water town, it is not difficult to find a place with abundant water resources. Hao Yizong assured Su Hao that within a month, he would definitely manufacture the ball mill and would not delay Su Hao's great cause of firing cement.

Since Xu Zong has been using various methods to make cement, Zhao Luo, who went to the mining area a few times when Cheng Yao was fine, naturally heard about it. In fact, Xu Zong has already made some cement samples, although it cannot reach the quality of cement in later generations, but in Zhao Luo's opinion, it is already very surprising.

"If the cost of cement can be reduced, we can use this cement to build roads, bridges, and houses in the future." Su Hao explained, "However, we can't take care of these things now, so let's build a batch of cement first and use it to build this dam." ”

When Zhao Luo and Su Hao were talking about the cement issue, Ma Yu kept squatting on the ground, holding a charcoal pen and calculating the formula. At this time, he stood up and said to Su Hao:

"Brother change, I calculated, if the dam is built here, the dam is 10 zhang high, the bottom of the dam is also 10 zhang, and the top of the dam is 3 zhang, then a total of 8,000 cubic meters of earthwork should be used. If a strong person can pick 50 cubic feet of soil and rock, then a total of 160,000 will be used. Brother Gai, look at it, am I right? ”

Su Hao took the calculation paper handed over by Ma Yu, glanced at it, and said with a smile: "Brother Duwen, you are now a little bit of a water conservancy engineer, and after a while, you can calculate the earthwork and the work." I've seen it, and there's nothing wrong with this algorithm. If you can use some machinery to help, I'm afraid you can use less to get into work. ”

Ma Yu was immersed in excitement, he said: "Don't say anything about mechanical assistance, I just say that according to this algorithm, if 2,000 people are requisitioned, then it only takes 80 ri to build this dam, and it makes me feel excited to think about it." The engineering calculation methods that he was taught made the younger brother suddenly open, and now he realizes that the scriptures he read in the past are all in vain. ”

"Stop, stop!" Su Hao hurriedly stopped Ma Yu, "Brother Duwen must not say this, when I go back, Old Master Wu should settle accounts with me." I have thought about it, after this reservoir is repaired, you still have to go back to the academy to read your sage books, I don't dare to use such mundane things to delay your splendid future. ”

Ma Yu shook his head and said: "Brother Change, this repair of the reservoir for the benefit of the people is the way of the sages." You've shown me this world, where can I sit back in that academy? I have already thought about it, and I will not think about the imperial examination in this life, so I will build a few more reservoirs with my brother of reform. ”

"I don't plan to build a reservoir for the rest of my life." Su Hao said, "When this happens, I still plan to go back to the academy to study hard for a few years, and then go back to take the Jinshi exam or something." This has no job and no power, even if you want to do something, it's not convenient. ”

Ma Yu nodded and said, "Brother Gai has great ambitions, and the younger brother admires it." However, the younger brother has made up his mind, and he will do this one thing to repair the reservoir after ri. Thinking about this Ming Dynasty, I have read countless books, and I don't care if I am less and my horse is alone. However, this matter of repairing the reservoir has not yet been done, and I should bear it. ”

"Good!" Zhao Luo stroked his palms and laughed, "What Brother Duwen said won my heart. How about this matter of repairing the reservoir and adding a certain Zhao? ”

This Zhao Luo is actually also a scholar, but after he got a show, he stopped studying, but ran out to play, and "traveled" in the name of "travel". Even if he is famous, it is just for the sake of not being restricted when he travels. Hearing Ma Yu claim that he didn't want to study, Zhao Luo felt that he had found a soulmate.

"Don't make a mess." Su Hao said with a smile. He found more and more that Ma Yu's entry was really quite "axial", otherwise he would not be the head of Fengcheng County. In the past, when he was studying, he was able to become a good scholar with this "axis", but now he is obsessed with building reservoirs, and maybe he can really become a real water conservancy engineer.

However, Zhao Luo also wanted to get involved in the matter of repairing the reservoir, Su Hao was a little disdainful, he said half-jokingly and half-seriously: "Brother Zhao, Brother Ma knows how to survey, understands calculation, and is diligent and studious, if you concentrate on repairing the reservoir, you can also achieve great success." But Brother Zhao, what will you do? ”

"Su Gaizhi, you're wrong. It seems that I, Zhao Luo, am also a showman, why can't I know it? Zhao Luo retorted seriously.

Su Hao said: "Brother Duwen is 20 years old, and it is time to learn things. You seem to be in your 40s, right? At this time, I will teach you trigonometry, can you learn it? Repairing a reservoir is a technical job, what can you do if you don't understand technology? ”

Zhao Luo was choked by Su Hao and was speechless, and it took a long time before he said: "This reservoir is not just about what you want." Do you want to use the people, and you can't spend money? I, Zhao, can't do arithmetic, but I still have the ability to calculate money. Duwen and I are one counting, the other is in charge of money, is this a perfect match? ”

Su Hao smiled: "This is indeed Mr. Fengling's director, you are so poor that you only have money left." ”

"Awards, awards." Zhao Luo was not annoyed, and replied with a smile.

Su Hao said: "However, to build a reservoir, at worst, 50,000 taels of silver is the minimum, do you have it?" ”

Zhao Luo shook his head and said: "Zhao's uncle has always said that Zhao is a loser, and he has defeated the Zhao family. However, although Zhao is poor, he can still make up 50,000 taels of silver. But this silver is not spent like this, the matter of repairing the reservoir is not a matter of Zhao Mou's entry, how can it be Zhao's turn to come out of the silver? ”

Su Hao said: "This is a troublesome matter. Before I came out, I had talked to Han Zhixian about this matter, and Han Zhixian thought that the political secretary might approve of the construction of the reservoir, so he would come up with some silver. However, it is not realistic to ask the chief secretary to cover all the costs of this reservoir. Han Zhixian is now thinking about how to gather enough money to repair the reservoir. If this trouble is not solved, it will be in vain for us to wait for the survey to be detailed. ”

Zhao Luo asked: "Change, you have always prided yourself on being smart, but you can't think of any good way?" ”

Su Hao said: "When did I claim to be smart? I've been thinking about this for months, and I still can't find a perfect solution. If you want to collect donations from wealthy families in the county, I'm afraid it's not a long-term solution, right? After the completion of this reservoir, it can benefit the people of the county, but this benefit can't be collected from the people, right? ”

Zhao Luo laughed and said: "Change, if you want to say that what you said to me just now is nonsense, I can teach you how to raise money, how about it?" ”

"Do you really have a way?" Su Hao was skeptical, but looking at Zhao Luo's triumphant appearance, he had a little more confidence in his heart, and hurriedly said: "Mr. Fengling forgives his sins, and the younger brother is disrespectful, and I ask Mr. Fengling not to care." This matter of repairing the reservoir is naturally the most suitable for Mr. Fengling, and the others are the light of fireflies, how can they compete with Mr. Fengling's moon? ”

"That's it, I know it's mean, and I won't even apologize." Zhao Luo said with a smile, he said that, but he was still very happy to hear that Su Hao had changed his words. He pulled Su Hao and walked back a few steps, pointed to the river beach they had just walked through, and said, "Change, didn't you think that these river beaches can also be turned into money?" ”

"Little brother doesn't understand." The second monk Su Hao couldn't scratch his head, and he didn't know what Zhao Luo meant by this.

Zhao Luo said: "I was inspired by the fact that you exchanged the improved red soil land for my mountain land, and this barren mountain has become fertile land, which itself is silver." Look at this large stretch of river flats, there is only grass growing in the barrenness. If there is a way to open it up and turn it into fertile land, is it worth 50,000 taels of silver? ”