The news that the saint personally welcomed the Persian envoy into the city was the biggest talk in the streets of Luoyang in September.

He was given enough face and courtesy, so that everyone in the world knew that the saint valued new learning.

At this moment, the business bookstore under the Ministry of Internal Affairs was booming, and all kinds of mathematics books were almost sold out. Some scholars who felt that they could not compete with others in the way of writing, their inner persistence was also shaken, and they considered trying agricultural science.

Maybe I want to study mathematics, but I only have a year and a half left, and I don’t know if it’s too late.

There are also some builders in Beijing who are paying attention to the arrival of Persian scholars.

The last time was the arrival of Master Mani thirty years ago. Later he compiled a book called "Geometry", which won the Xia King Award. After several revisions, it was finally finalized and became a compulsory textbook for mathematics students, and most of the test questions came from it.

Construction engineers should also study this book, and it is the key point.

After completing the study, combined with the knowledge of "Mechanics" - to be honest, the content of this book is still relatively crude - the builders have completely entered a new realm.

On September 30, at the request of the saint, the Persian Bardia gave a lecture at the Imperial Academy of Dongdu and mentioned the theory of "arc-triangular body potential" (spherical triangle).

In addition to mathematics students, there were also a large number of undergraduates in construction majors who came to attend the lecture.

The effect is quite sensational.

Mathematics students are intoxicated by newer and more systematic knowledge.

Construction students saw the possibility of applying it to architecture.

The biggest problem faced by arches and dome structures is the problem of lateral thrust.

If you just build a small arch or small tomb, you can rely on thick walls or the earth to offset the lateral thrust. For example, in the arch structure of the Zhaozhou Dasheng Bridge, the land on the river bank is used to offset the lateral thrust and prevent it from collapsing.

But the cost is too high. Is there a way to cleverly reduce or even offset the side thrust through mathematical and mechanical design?

Of course there is, and this involves advanced mathematical principles such as spherical triangles.

Overall, the lecture was very successful, but there were some hiccups.

Some of the workers who were building the Luoyang Palace City were overseers, and the young masters and old craftsmen came to listen. This Bardiya was also very polite. He believed that the huts designed and built through knowledge of mathematics and mechanics were, in essence,

They are all greater than the magnificent buildings piled up using a lot of manpower and material resources regardless of cost. He believes that the latter, no matter how beautiful and spectacular, is an existence without brains and thoughts.

Naturally, these words greatly offended people.

Since the Tang Dynasty, it has suppressed all parties and refused to conquer. How powerful is the Central Plains country? Chang'an and Luoyang are huge and magnificent. How can they be inferior to others?

As a result, someone came up with various design styles, material specifications, and construction details stipulated in the "Ying Repair Order" that dates back to the Tang Dynasty to refute.

Bardia glanced through it with the help of a translator.

Of course, in such a short period of time, it was impossible for him to read it carefully. He could only take a quick look and get a general idea.

Suddenly, he stopped translating, pointed to a certain page, and asked: "Why do you have to use wood of such specifications?"

It was the appendix of the "Ying Repair Order" that was common in both the Tang and Xia dynasties. It generally talked about the specifications of the materials to be prepared. For example, a certain paragraph stipulated that the cross-section of the dougong was "fifteen minutes high and ten minutes wide" and wood of this specification must be used.

When the craftsmen heard this, they found it difficult to answer. Because their ancestors had stipulated that this should be done, how could they change it?

"Trees vary in size and thickness. If they were all of this size -" Bardia said.

"The materials are divided." The translator said in Chinese from the side.

Bardia probably understood that "wood grade" means specifications, so he continued: "If you use this kind of wood, your range of material selection will be much smaller. You may need to go to distant forests to select. Isn't this a waste?

?”

"My Daxia land is rich in resources, so I just need to travel more places and choose from more. If it doesn't work, I will recruit slaves and spend more money. Even if I cut wood from central Guizhou or Jiangxi, I can transport it to you." A craftsman said with a little pride.

He said: "The pontoons in the three cities of Heyang are wooden boats that were cut down in Hongzhou, Jiangxi, and then transported to Heyang by boat on dry land. Have you never seen it?"

"Now Hongzhou can't build this ship, we have to go south to cut wood." Someone whispered.

No one paid attention to him, everyone looked at Bardia.

"Waste, there is no need to strictly specify the materials. We can use different specifications of materials through mathematical calculations during construction, which can reduce a lot of waste." Bardia repeated.

"The construction of all houses is based on materials. It is clearly stated in the "Ying Repair Order" on the first page." The craftsman shook his head and said: "How dare you use materials that do not comply with the regulations of the "Ying Repair Order"

With your talent, what should you do if something goes wrong?"

"I calculated through mathematics and nothing will happen." Bardia said confidently.

This is the difference in philosophy.

Chinese craftsmen believe that they can use materials of specific specifications to assemble and build buildings very quickly through regulations such as French style. This is because not only do various materials have "material differences", but even house regulations are certain, which is equivalent to

Later generations used prefabricated materials and modular housing construction, which was highly efficient and fast.

Bardia believes that this will cause huge waste.

Some materials may still be found nearby, but what about thick pillars? According to their plan, they have to search for them in the southern forests thousands of miles away, cut them down, and then transport them back.

What kind of transportation cost is this? Bardia couldn't imagine it.

To make matters worse, trees grow in cycles. Wood is easily damaged and even more susceptible to fire. At this rate of consumption, sooner or later, future generations will not be able to find enough wood to build the palace. To be more precise, future generations will not be able to find enough wood to build the palace.

No one can find wood that meets Miyagi's "wood classification" regulations.

What to do?

He believes that it is possible to build a house by changing the design, doing mathematical calculations on site, and using whatever materials are available.

As a column that supports weight, it is indeed impossible if it does not meet certain specifications, and there may be safety hazards. But I can reduce the weight it needs to bear through design.

In Constantinople, Baghdad, Bukhara and other places, when nobles built manors and castles, there was never any stipulation on the length, width, and thickness of materials that must be used. In fact, if you look around, you can often find materials of different lengths.

Mixed use.

In order to ensure safety, the nobles hired mathematicians to conduct a large number of mathematical calculations on-site and design while building. The general design was determined in advance, but the detailed design was not.

In short, it is similar to specifying the shape and structure of a house in advance, and then using the same strictly specified materials to modularize it.

The other method is to use local materials. If the materials do not meet the requirements, the designer will analyze the stress on site and perform mathematical calculations, and may redesign the design.

The former is very fast, and if the materials are sufficient and transported in place, it can be built for you in a short time.

The latter is slower, and it is normal for the construction period to drag on for decades. Some castles even require three generations of grandparents to build before they are finally completed.

"And here, why is it stipulated that the pillars must have one and half side legs?" Baldia turned the page and asked.

Side kick means inclination. A side kick, probably less than 1%, is stipulated in the construction method, but the reason is not stated.

"Laws are laws." someone said.

This answer is obviously a bit perfunctory.

"That's not the case. Houses built with mortise and tenon joints are prone to collapse." This answer is a bit sincere.

"Why did it collapse?" Bardia asked.

Unable to answer.

"I have never come across this kind of design, but I took a look and understood the reason." Bardia said: "This is actually using the roof to generate a thrust to stabilize the structure of the house. The person who wrote this book may understand

, because he proposed this design, which is very effective, but why don’t you understand?”

The craftsman was speechless.

Would our ancestors really understand this? Maybe.

He actually knows the use of the side kick. After all, he has been an old craftsman for half his life and has rich experience. However, he did not fight for this face just now because he suddenly remembered a question that has been bothering him for a long time: the ancestors prescribed a side kick, so why is it a

?Is half okay? How about two?

This question has been lingering in my mind.

He had never done anything so "deviant" and tilted one foot to the other in order to create French regulations. He did this strictly and never exceeded it in his life.

When I was young, I was curious and asked my master, but he couldn't answer it, and he never studied the question in detail. Generation after generation, they have passed on the experience of their ancestors and passed this way.

Sometimes, there will be a few amazing and talented people, and then due to chance, or they are appreciated by important people and have a higher status, they dare to delve into these details and then modify the construction method, but it seems that such people only scratch the surface.

"Finally, let me ask another question." Baldia closed the French style and said: "If I change the roof to a vault, how do you choose the materials?"

Everyone was silent.

This question is obviously beyond the scope. Because it is not written in the construction method, the shapes of the houses in the book are all prescribed, and even list dozens or hundreds of buildings with different functions, such as pavilions, bridges and towers, etc., each

Each type has corresponding construction methods and specifications for selecting materials. But if the shape of the building is not among the hundreds of types, they are not sure.

Perhaps, only a few people with official status in prison have such a certain degree of certainty. They have been immersed in this art all their lives and have a very deep understanding of the construction process. It is possible to break through the stereotypes and be original, but it is only

"Maybe". At least when they were designing and building the Hehuan Hall, they backed down.

"On the way to Luoyang, I heard a saying, 'Nothing can change without its origin.'" Bardia finally said: "Have you mastered the origin? If you don't master the origin, you won't change."

I have never been exposed to your architectural style, and I have never designed it, but give me a few months to understand. I can definitely design your traditional palace, but you cannot design our palace, because I

Once I master the 'Zong', I will 'change'."

****

If the construction of the Hehuan Palace back then had already made the group of architects who used mathematical knowledge to design buildings slightly surpass the traditional master craftsmen and craftsmen in status, which made them uncomfortable, then this time the Imperial College lectures were completely kicking

It's the nature of a hotel and it doesn't give any face at all.

Shao Shude burst out laughing after hearing this in the palace.
To be continued...