Chapter 404 Another Use for Slag

At this time, Li Shimin sighed again:

It's still easy to fight.

Seeing that Rome could divide the east and west and house four emperors, Li Shimin was just shocked, but in the end it was not incomprehensible.

After all, from ancient times to the present, there are very few people whose territory can be so vast, I understand.

The most direct problem brought about by the huge territory is the difficulty of governance, and the problems contained in it, if explained by the theory of centers spoken by younger generations, are that the centers are misaligned, which will inevitably cause problems.

How does the central government control and control the situation so that the people in the southeast who are receiving taxes are willing to support the soldiers in the western regions?

This is a difficult problem to solve.

If something goes wrong, the border guards will starve, the people who pay the taxes will be bullied, and the public will be resentful, and chaos will arise.

But at least for now, judging from the history of the Han and Tang Dynasties, the dual-capital system may be feasible.

Judging from the deeds of Rome, the hidden dangers of multiple empires are too great.

However, these problems are relatively far away after all, and Li Shimin still needs to think about them by himself and get a clue before they can be discussed with capable ministers. Therefore, Li Shimin finally turned his attention to the light screen.

Seeing the word "Guangshen" again, I couldn't help but sigh:

"Spending millions of lives and people to build such a great cause is really... a waste of money."

It is because of this Guangshen that countless people suffered chaos and death in the late Sui Dynasty, and their vitality has not been restored to this day.

Li Shimin didn't even dare to think that if the people of the Tang Dynasty could have as many as 50 million people during the Daye Year, why would he need to be so cautious when conquering the Western Regions?

But it was just a fantasy after all. After shaking his head, he focused on these few words about Pan Jixun.

"This method of regulating the Yellow River..."

Before he finished speaking, Li Shimin felt his sleeve being pulled by someone:

"Your Majesty, this method only takes three days for me to verify its effectiveness. If you can prevent and control floods in the Yellow River, please give me your orders!"

This paragraph was spoken quickly and urgently, and it was only then that Li Shimin saw clearly that it was Yan Lide who was grabbing his sleeve nearby.

In this case, there seems to be no other option but to promise.

After getting the promise, Yan Lide stepped back happily, feeling that his record in the history books would probably add two more lines.

If we say that the simplest way to leave a name in history and educate the people and build a temple is to manage the Yellow River.

But this simplicity is only compared to the long drive straight into Mobei like Champion Hou. If it is really simple, why are the Yellow River's big troubles occasionally and small troubles endless?

Yan Lide is good at architecture, so he has experience in water conservancy. He also knows that the biggest problem of the Yellow River is that the complex river course makes it very difficult to clean up the siltation in steep places.

But now that the light curtain has thrown the key to the method in his face, Yan Lide feels that it would be unjust for him not to seize this opportunity.

Yan Lide was very comfortable, Li Shimin was very satisfied, the monarch and his ministers smiled at each other, and the atmosphere was very harmonious.

Li Shimin will not comment on the so-called livelihood of millions of water workers.

After all, it seems obvious that there are probably other problems that led to Ming Dynasty's behavior that seemed to be due to choking.

As for the specific reason, I’m afraid we won’t know until later.

[First of all, we need to understand a concept. China’s urban planning system has been quite mature since the Western Zhou Dynasty.

As a negative example, it is Rome. Ancient Rome was a typical natural agglomeration city and lacked planning.

The innate environment could not meet later needs. When the population exploded, ancient Roman craftsmen discovered that the terrain was mountainous and the geology was mostly rocky. With the technology at the time, it was impossible to dig culverts on a large scale, so building elevated water diversions was a last resort.

At the same time, during the Qin and Han Dynasties, the ancestors were no longer satisfied with planning a single city and began to try to build a city agglomeration planning system.

Taking Chang'an of the Han Dynasty as an example, Chang'an was overwhelmed by the rapid increase in population after the peace of the world. Under official planning, some functions that could be centralized were quickly transferred to surrounding small towns.

At its peak, there were as many as 57 small towns in the Chang'an metropolitan area. Each of these small towns performed their own duties and guarded the entire Chang'an metropolitan area in an orderly manner.

For example, cities such as Zhengxian and Xiayang have dedicated iron officials to concentrate iron smelting, which is the prototype of today's industrial zones.

For example, cities such as Yueyang and Huixian were located near the river. They were in charge of water transportation and set up huge granaries to transfer to the cities in Chang'an.

There is a salt official in Lianshao County to supply the salt needed by the capital in Guanzhong; Chuansikong is a new city built directly on the vacant land by the capital's shipbuilding department, hence the name, and it is also a purely functional satellite city.

Such advanced and complete planning is naturally also planned for urban water diversion. The more well-known water conservancy projects are Ling Canal, Zheng Guo Canal, etc. These water conservancy projects are firstly diversion canals to meet residents' daily water use. Most people think of irrigated farmland instead. secondary functions.

The most typical one is Longshou Canal, which is 70 kilometers long and located 30 meters underground.

This canal was built during the reign of Emperor Wu of the Han Dynasty. It took nearly ten years to mobilize tens of thousands of people, and finally led the Luoshui River into Chang'an, completing the first underground water diversion canal in Chinese history.

If you compare the Longshou Canal with the ancient Roman elevated aqueduct, you can tell at a glance which one is more difficult and which is easier.

After all, most of the elevated aqueducts in ancient Rome were only a dozen kilometers long. Even including culverts, the length of a complete aqueduct would hardly exceed 100 kilometers.

The Longshou Canal, which is entirely underground, is a full 70 kilometers long. As we all know, underground canalization involves the determination of altitude differences, canal path planning, water source selection, geological environment assessment, water flow distribution calculations, etc. , the technical reserves required by both parties are not on the same level.

The construction technology of Longshou Canal is now called Jingqu. After the Han Dynasty conquered the Western Regions, this technology quickly spread to Central Asia, received widespread praise and has been used to this day. It is called Karez in the folk, and its content is also described in history textbooks.

In addition, after the Han Dynasty, the technology related to domestic water has been developing. Nowadays, film and television dramas shoot ancient water extraction, regardless of the dynasty, and the wheel-tied bucket is more or less a bit stereotyped.

For example, the pressurized well, many people think it was invented in the 20th century, but in fact, many wealthy families in the Song Dynasty had already used it.

However, some scholars believe that this simple and easy-to-use water extraction facility began in the Han Dynasty, but there is no definite archaeological data to support it, so we can only look forward to future discoveries.

Water conservancy projects also run through the entire Chinese civilization. For example, the Great Wall, which is familiar to many people, is not a purely military building, because the characteristic of rammed earth walls is that they are afraid of being soaked by water. The ancients also spent a lot of thought on this. The heights of the enemy towers and the walls are different. There are drainage ditches dug next to the trap ditch, and the culverts are connected to drain the water to one side of the slope. The culverts and drainage ditches also have automatic anti-clogging designs.

This is also one of the reasons why the Great Wall can stand to this day. After hundreds and thousands of years of buildings have lost their military functions, only the drainage function of the secondary function is still in perfect operation to this day, which shows its technical content.

The technical content of the ancient Roman elevated aqueduct is not even as good as the original concrete used to build this project. This is the real black technology that has created the ancient Roman architectural art.

The huge volcanic group on the Apennine Peninsula provided enough volcanic ash. The ancient Romans found that mixing it with slaked lime clay and condensing it had an amazing hardness, so they built many magnificent buildings.

Ancient China really couldn't envy this thing. After all, the nearest volcanic ash production site is in Hainan Island, and the labor cost is sky-high.

Although there is a downgraded version where volcanic ash is replaced with iron slag, its effect is also greatly reduced and is far less useful than volcanic ash. 】

The light screen picture rotates, and Liu Bei also sees the astonishingly high ancient Roman aqueduct. His first reaction is that this thing is so magnificent, how can it not have technical content?

But as the last words turned again and again, Liu Bei's mood was full of twists and turns.

After all, just looking at the magnificent appearance of this ancient Roman building, you can know how useful this concrete is, which directly makes Liu Bei feel itchy.

He even considered whether to write a letter to Shi Xie and trade some with ironware.

But when he heard the formula behind it, he fell into ecstasy:

Iron slag? We have it, and a lot of it!