Great Tang princess

Chapter 822 Minor Industrial Progress
In the conference room of the Academy of Engineering, Li Yuechen stood on the podium and gave a class to a group of craftsmen below.

At this moment, both the old craftsman and the young apprentice are listening carefully.

The only difference is that most of the elderly craftsmen are illiterate, so they need to let their apprentices take notes instead of themselves.

And Pei Bishu was also sitting on the side, typing on the typewriter with both hands, recording what Li Yuechen said.

After all, it is impossible to fully understand many things only once.

But it is not possible to let the princess come to give them lectures every day, so detailed records must be made, and the craftsmen will discuss with each other to solve some difficult points.

Only those that cannot be solved will be reported to the princess and asked her to come and explain in person.

While writing on the blackboard with chalk, Li Yuechen said: "First of all, we must make it clear that the proportion of oxygen in the air is the same whether it is on the ground or at a height of [-] meters!"

Having said that, she wrote down the number [20.9%] on the blackboard.

"It's just that as the altitude increases, the air density will decrease by about [-]%, which is [-]%, so the absolute amount of oxygen will change!"

Today's engineering academy craftsmen can understand words such as air or oxygen, so they can basically understand what she said.

And Li Yuechen never put on airs, so some people dared to ask questions during her lecture.

A young female apprentice raised her hand and asked, "Dare to ask Your Highness, why don't airships now have to consider such issues?"

"Well, that's a good question!"

Li Yuechen waved his hand with a smile, let her sit down first, and then explained: "The speed of today's airships is not fast, and the height is not too high, so there is no need to consider the issue of cabin pressurization. But the aircraft to be made in the future, the flight The altitude cannot be lower than 3000 meters, and the speed will be faster. Especially when transporting soldiers, breathing problems must be considered, otherwise they will all suffocate in the cabin!"

These are two completely different things in themselves, so it doesn't matter that airships don't consider pressurization, but airplanes don't.

"By the way, you guys have tried it recently and made an altimeter. Let me explain the principle..."

The airship is fine, the plane must have an altimeter and a spirit level.

Because the pilot of the aircraft must know what altitude he is at and whether the aircraft is level, this is an essential safety measure.

Don't even think about the electronic level nowadays, just use a larger glass ball to fill the water.

Similarly, the altimeter can also be made mechanical instead of electronic.

The principle is actually very simple. Use elastic metal to make two saucer-shaped discs. The bottom should not be too flat, but should be wavy.

Then put the two discs together to make a good seal.

In this way, it becomes a hollow structure in the shape of a flying saucer.

Because it is sealed, its shape will change accordingly as the atmospheric pressure changes.

As long as it is connected to the pointer of a dial through a steel rod, the pointer will rotate as the height changes.

Then write the number on the dial, so that the pilot can intuitively know what altitude the aircraft is currently at.

This thing is actually an obsolete product in the future. When Li Yuechen was learning how to fly a small plane abroad, he basically replaced it with an electronic altimeter, and it was the same when he was skydiving.

It's just that this era doesn't have that condition, so we can only rely on this old antique.

But this is also a relative term. For this era, this kind of old antique should be regarded as a kind of black technology.

While explaining, don't forget to draw a simple schematic diagram to let them understand more intuitively.

The craftsmen also keep it firmly in mind, and will actively ask questions when they encounter something they don't understand.

But really speaking, compared to the compressor, the altimeter is much simpler.

They decided to make this simple thing first. As for the compressor, it may take a long time.

……

During the few days from working on the eighth day to the fourteenth day of the first lunar month, Li Yuechen explained to them about airplanes in the Engineering Academy almost every day.

On the fourteenth day of the first lunar month, I finally finished the first part.

They just need to make these things first, and after they are done, they will consider the problem of the aircraft itself.

And to be honest, making an airplane in this era is simple and easy, but it is really difficult to say difficult.

Just talking about the flight itself is actually very easy, as long as you have an engine and know the mechanism of the aircraft, it is very simple to do it.

The difficulty is that there is no radio today to guide the pilot.

This requires the pilot to have extremely superb driving skills and courage.

The flying speed of the plane is very fast, so it also requires high physical and psychological quality.

Many people may not know that in the 30s, the level flight speed of the aircraft could already exceed [-] kilometers.

The dive speed was already close to the speed of sound, but due to the technical limitations of that era, it was impossible to break through the sound barrier.

And the aircraft of that era, most of the material is wood!
So now the prerequisites for making aircraft are sufficient, it just depends on how far it can be achieved.

Li Yuechen chose many plans among the flight models he knew.

For example, Wright aircraft.

But the structure of the special type aircraft is too simple, and it should be able to do better now.

Then came Benoist, the world's first passenger aircraft and the world's first scheduled flight.

But the Benoist plane can only carry two people, the pilot and one passenger.

And the speed is not fast, and the flight distance is too short.

Taking into account the current level of craftsmanship, Li Yuechen finally decided to make the Bellanca aircraft.

The Bellanca aircraft completed the long-distance flight from Japan to the beautiful country in 1931.

He is the world's earliest record holder for a long-distance voyage without a road.

Of course, having said that, it's better to start with the Wright model first.

After all, compared to flying far and high, the first goal is to fly first.

Just start playing the big game. If the experiment fails at that time, it will waste a lot of time and money.

So after handing over the blueprints of the special aircraft to them in the future, Li Yuechen announced that he would have a holiday, and he would talk about anything after the Lantern Festival.

Today is the fourteenth day of the first lunar month, Li Yuechen plans to go back early and go to the street to watch the lanterns at night.

There will be fireworks to watch tomorrow, and I don’t know what new tricks those fireworkers will be able to make this year after a year of dormancy.

But at this time, Pei Bishu came over: "Your Highness, don't rush away, there are new artifacts for His Highness to see today."

"Oh? What new object did you make?" Li Yuechen suddenly became interested.

Pei Bishu waved his hand, and a young man behind him came over pushing a machine with four small wheels.

Li Yuechen recognized it at a glance, it was indeed a lawn mower!
"It's ok, it's really done!" Li Yuechen praised, and then waved his hand directly, "Go, go and try!"

"Yes!" Pei Bishu quickly agreed.

A group of people came outside the engineering institute. Basically, there are a lot of weeds by the river, which can be used for experiments.

Under Li Yuechen's signal, Pei Bishu poured a bottle of diesel into the fuel tank.

Then he pulled the rope and yanked it violently, and the engine immediately let out a low roar.

Pei Bishu began to push the car forward, and wherever he passed, the grass of different lengths had turned into a thin layer.

Under the flat car body, the cut weeds were directly put into the towed burlap bag behind the car.

The running of the car is also very smooth, at least for now, there are no obvious problems.

Seeing Pei Bishu pushing the cart forward like a child who got a novelty toy, turning a corner from time to time, Li Yuechen nodded with a smile.

Then let him stop, and called him to the front: "Okay, since this thing can work, let's start researching mechanical farm tools."

"Yes, this subordinate will go back and form a project team!" Pei Bishu replied.

It has to be said that after getting along with Li Yuechen for a long time, he has also learned a lot of vocabulary for the future.

After seeing the power of industry, Pei Bishu, who is nearly [-] years old, is still full of energy every day.

Just thinking about how to research more useful things.

As the whimsical ideas put forward by the princess were realized one by one, Pei Bishu also wanted to see how many more magical things he could make.

……

After returning to the princess mansion, it was still early, so Li Yuechen wrote a letter to his mother lying on the table.

He explained that he had already manufactured a lawn mower, and at the same time he talked about his plan to manufacture an airplane.

In fact, it stands to reason that Li Yuechen intends to let his mother come back. After all, Li Chongrun is getting married soon and wants her to come back to attend the wedding.

However, Wu Zetian didn't have too much affection for his grandchildren, after all, he had never seen him a few times since he was a child.

Although they all have their own blood, but there is always no sense of intimacy.

So Wu Zetian didn't come back, thinking about celebrating the New Year in Zhenzhou, too lazy to bother.

And the fourth brother Li Dan stayed in Zhenzhou to take care of his mother, but sent someone to bring a gift.

It's not too expensive, it's just coral, but it's a bad intention anyway.

In short, it is impossible for the whole family to gather together for Li Chongrun's wedding this time.

And this is just the beginning. With the reform of the royal family in the future, I am afraid that it will only be in the student days when we can get together completely.

A little older, and being assigned to different military regions, I am afraid that there will be few opportunities to gather together in my life.

……

That night, Li Yuechen took Shangguan Wan'er and his two sisters and sisters-in-law to the street to watch the lanterns.

Because she herself is too famous among the people, in order to avoid being recognized by others, she wore women's clothing for the first time today.

Although the group of guards around him can definitely tell that he is not an ordinary person, at least if he is not dressed as usual, it is not easy to be seen as his true identity.

So today Li Yuechen wore a blue skirt with a brown cloak outside.

In terms of material, it should be made of chest leather, and the warmth retention is quite good.

Li Yuechen doesn't like makeup, so she still looks plain.

But fortunately, the skin is fair, and no makeup is needed to make the complexion look good.

The high ponytail that has remained unchanged for thousands of years on weekdays has also become the fairy-looking bun that most women in this era will wear.

This kind of hairstyle is generally worn by women after the age of 30, although she does not look like a woman over 30 from the outside.

But Li Yuechen also doesn't like to pretend to be young on purpose, after all, if he meets a younger generation, he will not look majestic if he looks too young.

But even though she doesn't wear makeup, as a princess, she wears a lot of expensive hair accessories on her head.

Going to the streets tonight, I don't plan to ride a horse or a carriage. It's good to take a walk.

The guards around him also took off their military uniforms and put on the clothes of ordinary maids, so they wouldn't be too conspicuous.

Except for Yiluoru, the other guards didn't carry guns, they just had an ax hanging on their thighs under their skirts.

As for Yiluoru, he hangs the shotgun on his shoulder to ensure that he can hold it in his hand at any time.

Nowadays, no one among the people knows this thing, so don't worry about it causing panic or something.

When you see it at most, you will feel that it is some kind of special cold weapon.

When they came to the street, Princess Xuancheng couldn't help but said: "In recent years, there have been more and more people here."

"The Household Department manages the household registration, sister should know how much the population has increased?" Li Yuechen asked.

Princess Xuancheng nodded slightly: "Actually speaking, the increase is almost all foreigners. Although the local population in Dongdu has also increased, but now most of them are children. In recent years, foreign businessmen have frequented a lot, and there are more How many people..."

"They're all here for business?" Princess Yiyang was curious.

"No, some of them came to settle here for various reasons." Pei Qingwan replied, "All businessmen are only Sogdians."

Li Yuechen, a Sogdian, knows that he has no fixed place to live and is good at management.

From the point of view of race, they should belong to the Central Asian side, and their skin is darker, but it is not the same as that of Africans.

The blackness in Africa is relatively deep, and the skin is also the most delicate to the touch among all races.

Central Asians are more like the kind of black that has been tanned, between bronze and black, and their facial features are closer to those of the yellow race.

Speaking of which, there are quite a few Sogdians who settled in the Tang Dynasty, and many of them have even been immigrants for several generations, and have completely become Han Chinese.

However, the gene that likes to do business is not so easy to change, and most people still do business for a living.

Princess Xuancheng looked at the lanterns on the street and said: "But speaking of it, there are indeed a lot of Hu people recently, and some people even ask the Ministry of Households through their connections to ask if they can get the household registration of the Tang Dynasty."

"Oh? How did sister reply?" Li Yuechen asked.

"After investigation, most of the people who asked about their household registrations escaped from crimes committed in their own country, so they did not agree." Princess Xuancheng replied.

Li Yuechen smiled: "Well, these people don't need to talk to them. But if there are people who are willing to join the Datang household registration, they can consider it at their own discretion."

After all, Datang's ethnic policy is indeed open and inclusive, but it cannot let everyone in.

Those who have committed crimes in their own country, even if they come to Datang, they cannot be good birds.

The few people just chatted and walked, looking at the lanterns with different shapes on the street, and asked the guards to bring the camera over from time to time to take a picture.

Li Yuechen thought in his heart that these photos should become archaeological materials after a thousand years.

(End of this chapter)