I was engaged in infrastructure construction in the Han Dynasty [Transmigration Book]

Liu Tan asked, "Have you never seen these three dikes?"

Xu Lin shook his head: "Master taught me everything, and I have never seen it before."

Liu Tan asked again: "Then what do you think?"

Xu Lin said honestly: "Master has been digging canals and diverting water according to the terrain all his life. He has studied dikes and dams but has never put them into practice. Although I have learned a lot, I have limited experience."

Liu Tan let out a long sigh: "That can't be helped, now you are the most experienced here, and we can only discuss it."

Xu Lin asked with some doubts: "Although I don't have much experience, I can see that these types of dikes are eclectic, and there are three types of dikes. Why don't you recruit such talents?"

Liu Tan looked at Xu Lin with a serious expression: "This...can't be recruited."

Xu Lin was a little surprised. There are very few people in the world who can pay as much attention to water conservancy as the king of the north. Although the emperor also pays attention to it, he can give far less than the king of the north.

People who can study water conservancy these days are certainly concerned about the world and running for their ideals, but people have to live, and they can realize their ideals and make their lives better. Even the king of the north can solve the problem of succession. How could it be impossible to recruit them?

Not to mention that the northern border country is located in the middle and upper reaches of the Yellow River, and most of the problems in the lower reaches come from this. If the problems here can be solved, then most of the problems in the Yellow River can be solved.

From the perspective of emotion and reason, the northern border country is the best choice, how could it not be able to attract them?

Xu Lin thought for a while and said: "The reputation of the master in this line of minister is still there. Although the minister has grown up in the past few years, he has traveled a lot of places. Your Highness may wish to inform the minister of this person's situation, and the minister will try to persuade him. "

Liu Tan's expression was suddenly very difficult to say, and he thought to himself: It's useless for me to tell you, if I don't tell you, I don't know who it is at all, even if I know who it is, you can't travel through time and space to bring him back.

He didn't get a response from Liu Tan after he finished speaking. Even if he couldn't see Liu Tan's expression, he knew that there must be something unspeakable.

For a moment, Xueba's brain started to think of many rumors he had heard before. He remembered hearing people say that the current Shuofang City was supposed to be the city where the gods lived in the sky. When Shuofang City was destroyed, he was very sad, so he moved the city from the sky to the ground.

Xu Lin didn't believe this kind of statement. There are traces of the step-by-step construction of the new king from scratch, so there are many people who refute this kind of statement, so there is another legend.

It is said that in order to conceal his identity, the King of the North led people to find materials that could build the Heavenly City, and then led the people to build the current King's Capital. Everything in the King's Capital was modeled after the Heavenly City.

This statement... Xu Lin remained skeptical, but felt it was possible.

Xu Lin turned his head to Liu Tan and asked cautiously, "This... Could it be that His Highness made it himself?"

Liu Tan coughed lightly: "Don't worry about this, let's take a look at the drawings first."

Xu Lin immediately knew that they were the only ones to come.

However, Xu Lin was in high spirits. He had doubts about the existence of the fairy world, but the things from the hands of the king of the northern realm were indeed good things.

He touched it carefully and asked a little strangely: "Why do these three seem to be so different?"

Through groping, these types of dams formed images in his mind, one of which was the largest and was in the shape of a right triangle; the other was in the shape of a circular arc;

Liu Tan explained: "The biggest one is the gravity dam, which consumes the most materials. It should be relatively commonly used to block water through its own stability. The arc-shaped one is an arch dam, and the arc faces the upstream. The materials needed are not too much. When a large amount of water hits it, it can carry the force to both sides. And this is the buttress dam, which is the smallest of the three types of dams, but this one relies on the foundation to unload the force. So it needs to be built on a rock foundation."

After listening to it, Xu Lin pondered for a while and slowly removed the wooden board with the buttress dam and said: "This is not the first choice. The rock foundation means the ground is hard, and it is more difficult to dig a canal. Now the northern border country has a large area of ​​land. It’s empty, you can choose a more suitable place to open the canal, there is no need to waste manpower on it.”

Liu Tan nodded, and took the wooden planks of the pier dam aside. Although this thing is temporarily useless in the northern border country, it is still quite useful if you encounter that kind of naturally formed mountain waterway.

Xu Lin carefully explored the gravity dam and the arch dam again, and after thinking twice, he still said: "If it is the minister, the minister will choose the gravity dam."

Liu Tan said: "The gravity dam is indeed the most suitable."

There is no other reason, but the main reason is that the construction is simple and the calculation should be relatively simple. Arch dams have relatively high requirements for mechanical calculations.

Now that the mechanics have not yet formed a system, some people may have already touched the door, but it takes too much time. The disadvantage of the gravity dam is that it requires more materials, and the latter is easier in comparison.

Just as Xu Lin wanted to ask about the specific situation of the gravity dam, he saw His Royal Highness the King of the Northern Realm pull out two more pieces of paper as if by magic, on which were written a bunch of things that he couldn't even understand.

Liu Tan said: "According to our current situation, one of the dams is to prevent the river from backflowing, and the other is to discharge floods. Try to stabilize the current river course and don't allow the Yellow River to change its course at will."

Xu Lin nodded and said, "So what is needed is an overflow dam."

Liu Tan patted Xu Lin on the shoulder and said, "That's right, so the remaining work is very difficult. Just tell me what manpower you need. If it doesn't work, I'll write to the emperor!"

Xu Lin suddenly became Alexander. He knew a little bit about dams. He didn't mean to design the structure and build it directly. The most important thing was to make the dam body able to withstand the impact of the water flow.

He said cautiously: "This matter... please give me some time, Your Highness. I remember that Master once recorded it. I will wait for you to go back and have a look."

Liu Tan encouraged him: "Go ahead, you need people to give, and you need materials to give materials. Once the first building is built, the rest will be much easier."

It was the first time for Xu Lin to take the lead, and he was so excited that he immediately resigned and wanted to go back to his master's old books.

When he left, Liu Tan looked at Xu Lin's back, stroked his chin and said, "It's inconvenient to always be carried around."

Miao Rui also knew a little about Xu Lin's situation, sighed and said, "It's really a pity for Xu Lin."

Xu Lin was named the messenger of Hechuan by Liu Tan before, so Miao Rui called him the messenger.

Bi Gao asked: "I heard from the doctor that it seems that there is no cure?"

Liu Tan shook his head: "It's a disease he suffered from since he was a child. How easy is it to get a cure after so many years?"

The disability caused by malnutrition is a bit miserable to think about, unless he is amputated and fitted with artificial limbs.

But considering the level of medical care these days, the high probability of amputation is tantamount to letting him die, so this is not feasible.

Liu Tan took the case and said, "It's not that there are other ways."

Miao Rui and Bi Gao turned their heads to look at Liu Tan, and Liu Tan drew a wheelchair on the white paper.

Miao Rui and Bi Gao looked at the wheelchair with blank faces: "This is... a car?"

This shape is somewhat similar to the previous ice cart, except that there are skates under the ice cart, and this cart...has two big wheels and two small wheels, so this is more like a cart in their traditional sense, but what's wrong with this cart? Not even a cover?

Liu Tan said casually, "It's a wheelchair. You'll know when it's made. It's a birthday present for Xu Lin."

When he said this, he felt a little guilty. In fact, he should have thought of the wheelchair a long time ago. It's just that he was either busy with other things before, or he was tired of being with Lu Xuan, so he didn't think about it at all. If he thought about it earlier It might as well be a New Years gift.

Fortunately, Xu Lin's birthday was at the end of February, so there was still an excuse for a birthday gift.

You can go to Gongshu for this kind of thing, and you don't need Gongshucan to do it.

When Gongshu also saw the blueprint, his first reaction was a little puzzled, but after Liu Tan explained to him that it was for Xu Lin, he asked, "Then why are the wheels different in size?"

Liu Tan said: "This is for the convenience of his own movement. The big wheel can be pushed by hand, so a push rod needs to be added around the outer circle of the wheel, and the small wheel controls the steering."

Gongshu also frowned: "Control the steering? This... how to control it?"

"Universal wheels." Liu Tan knew that he was talking fast after finishing speaking.

Universal wheels support circular rotation, including fixed casters and movable casters. Although this thing looks inconspicuous, it is the epitome of industrial development everywhere. It can be said that it cannot be made without a certain industrial foundation.

So after meeting Gongshuyi's blank gaze, Liu Tan sighed and said melancholy: "Be a steering handle, turn around and I..."

Gongshu also said immediately: "Your Highness, don't worry, I will try my best to make...the wheelchair. If there is something wrong, I will come and ask Your Highness for advice."

Liu Tan originally wanted to draw a diagram of the steering system directly. This is very simple. Anyone who has driven a car or even played a four-wheel drive can know how to control the front wheel steering.

In the end, he was interrupted by Gongshu before he finished speaking.

After Gongshu finished speaking, he secretly glanced at Liu Tan, and he couldn't help it. After his father got here and found out everything, he scolded him savagely, which probably meant to order everything, so what do they want to eat?

Then his father used himself as an example to demonstrate the ability to add several mechanisms to the drawings provided by His Royal Highness the King of the North.

Gongshu also felt that he couldn't go on like this. The correct procedure should be ordered by the King of the Northern Realm, and they had to figure out how to do it. Every time, the King of the Northern Realm figured out what to do and let them do their best. It was indeed too easy to be replaced. .

Liu Tanruo smiled and said, "Alright, let's go, but you must hurry up, I will use it at the end of the month."

Gongshu also took the blueprint and left, while Liu Tan took out the letter he had written to Chang'an, and after thinking about it, he had someone send it to Chang'an.

At this time, Liu Che was looking at the winter jasmine outside the window, calculating how long it had been since Liu Tan wrote a letter.

The previous New Year's greetings are not counted in his eyes. If he counts this way, Liu Tan hasn't written to him since he returned to Chang'an!

As soon as I cursed the little bastard in my heart, I received a letter from Liu Tan.

While opening the letter, Liu Che thought about whether his son had encountered any difficulties recently. The spring plowing was about to start, and there should be a lot of things missing in the northern border country. In this letter, Liu Tan might be begging him for something.

Liu Che glanced at the newly delivered documents next to him. The farm tools and seeds were all ready, and they were about to be sent to the northern border country.

Thinking of this, the corners of his lips raised unconsciously, and then he fixed his eyes on the first sentence on the letter: Father, my son has made a better new plow!

Liu Che:? ? ?