Bringing the Railway to Daming

Chapter 184 Zhu Biao's son's scientific education, the Mirror Bureau and the Glass Factory [Please subscribe]

Liu Kuan said, "We've been preparing for this experiment for a long time. Taking off should be no problem. This time, the main thing is to see how long the hot air balloon can last once it's airborne."

Upon hearing this, Zhu Biao couldn't help but look at the busy crowd.

I saw that the hot air balloon basket under the crowd was about nine feet in diameter, and about five or six feet high from the outside, which was quite large.

Although it is made of bamboo, it is so large and has to be filled with fuel and a stove, so it must be very heavy.

"Can this thing really fly?"

Even though Zhu Biao trusted Liu Kuan very much, he was still a little skeptical about the hot air balloon launch.

Seeing that Zhu Biao had nothing else to ask, Liu Kuan went to work with the students.

However, he and his students were mainly responsible for directing, measuring, recording, calculating and the like, while the skilled craftsmen of the experimental group were actually responsible for assembling the hot air balloon.

Because of sufficient preparation in advance and a large number of people, the experimental team completed the assembly, inspection and other pre-launch work of the hot air balloon in less than half an hour.

At this time, the hot air balloon's balloon had been pulled up and erected on top of the basket.

It was also at this time that Zhu Biao realized that the balloon was incredibly large - its widest diameter was almost five times that of the hanging basket!
It’s several feet high!

Standing on the large parade ground, it looks like a strange "small building".

However, because the bottom has not yet been ignited and burning, although it is called a sac, it does not actually have the shape of a ball.

Zhu Xiongying, who was already ten years old, was the class leader of the main hall and the actual person in charge of the experimental group for quite a period of time. After confirming some things with the craftsmen, he came to report to Liu Kuan.

"Teacher, all preparations for the first hot air balloon launch experiment are complete. May I ask if we can ignite it?"

Liu Kuan nodded, "Light the fire!"

A foreman of the experimental group personally climbed onto the hanging basket, lit the special coal in the furnace, and added alcohol, rosin and other fuels in turn. When he saw the flames rise several feet high, he came down carefully.

Everyone began to wait.

Zhu Biao had only a vague understanding of the principles of hot air balloon launch, so he couldn't help but ask, "How long do we need to wait?"

Liu Kuan said, "Theoretically, the balloon should be airborne within half a quarter of an hour. However, since this is the first test, I am not sure how long it will take."

It would only take half a minute or a quarter of an hour, so Zhu Biao also waited patiently.

Under the gaze of the crowd, the balloon that was tied to the surrounding scaffolding swelled up at a speed visible to the naked eye and automatically detached from the scaffolding.

The craftsmen gradually removed the scaffolding according to the steps they had practiced.

About half a minute later, the balloon was fully inflated and became a full balloon, and the scaffolding was completely removed.

"Great! The balloon is floating in the air!" Zhu Quan, who is only five years old and just started school this year, clapped his hands and shouted happily.

The other students in the main hall, the older ones like Zhu Ying and the younger ones like Zhu Yunwen, Zhu Zhi, and Zhu Zan, also showed excitement and excitement, but also nervousness.

Because the balloon floating in the air is just the beginning of the experiment, the experiment will only be considered successful if the balloon and the basket are lifted to a certain height and stay in the air for a certain period of time.

Then, under the gaze of everyone, the balloon slowly rose, straightening the rope connecting to the hanging basket.

"The basket has left the ground!" This time it was Zhu Yunwen who shouted excitedly.

"Great!"

"This experiment will definitely succeed!"

"Yes, we have been preparing for so long and have solved so many problems. We will definitely succeed!"

At this moment, the princes and grandsons of the Grand Hall ignored the minor conflicts they usually had with each other and were all looking forward to the successful launch of the hot air balloon.

Zhu Biao pulled Zhu Xiongying and Zhu Yunwen to his side. Seeing the hot air balloon take off from the ground, he couldn't help but tighten his grip on the two children's shoulders.

Even Liu Kuan was excited and nervous. After all, it was his first time to participate in the hot air balloon manufacturing and launch experiment.

Under the excited and nervous gaze of the crowd, the huge and full balloon carried the hanging basket up little by little.

One zhang, three zhang, five zhang...

A special rope is connected to the bottom of the basket. It is thin, light, but strong. As the hot air balloon climbs, it is pulled up in coils.

After about half a quarter of an hour, the hot air balloon pulled up and straightened all the prepared ropes, and finally stopped in the "altitude".

Zhu Biao shielded the sun with one hand and looked up at the hot air balloon in the sky. His face was filled with shock and he couldn't help muttering, "It actually rose up, and it's so high..."

After coming to his senses, he couldn't help but ask Liu Kuan, "Brother-in-law, how high is the hot air balloon from the ground now?"

Before Liu Kuan could reply, Zhu Xiongying said, "Father, the rope under the basket is one hundred meters long, which is more than thirty-three feet. Therefore, the hot air balloon is also more than thirty feet above the ground right now."

"More than thirty feet?!" Although Zhu Biao had expected it, he was still shocked by the answer in the living room.

Then his eyes lit up and he said, "It's so high. If someone stood there with a telescope, wouldn't they be able to overlook the entire capital?"

Liu Kuan smiled and said, "The capital is so big, I'm afraid I can't see it all with a telescope. The telescope I brought is more suitable."

Zhu Biao said, "The latest telescope developed by the Mirror Manufacturing Bureau has a much higher magnification than before. From such a high position, if we were in the city center, we could almost overlook the entire capital."

The Mirror Manufacturing Bureau was one of the palace's internal manufacturing agencies separated from the Silver Manufacturing Bureau last year, and was specifically responsible for the production of telescopes and silver mirrors.

As for the glass factory reorganized from Liulichang, it was divided into two, one under the Silver Bureau and the other under the Industrial Production Department of the Ministry of Industry.

However, even if the Zhu family only controlled the production of silver mirrors, they could make a lot of money, not to mention that they also controlled a small part of the glass production.

As for the production of telescopes, Zhu Yuanzhang kept them a secret within the imperial court, keeping them secret. Naturally, they were not sold to the public, and were usually given as treasures to meritorious generals. The barriers between glass production technology and the Ming dynasty's original colored glaze production technology were relatively thin. With the rise of transparent glass and silver mirrors among the common people, Liu Kuan estimated that it wouldn't be long before someone would secretly develop glass production technology.

As for telescopes, if any of them were to fall into the hands of the public, they would probably be copied even faster.

At that time, it will depend on how Zhu Yuanzhang and Zhu Biao respond - Liu Kuan has no control over this matter.

The hot air balloon began to sink just a few minutes after it took off.

Seeing this, Zhu Biao couldn't help but say nervously, "Brother-in-law, this hot air balloon seems to be broken. Is it going to fall? Should we stand further away?"

In fact, Liu Kuan and others were more than a hundred steps away from the hot air balloon's launch site, but Zhu Biao still couldn't feel at ease.

Liu Kuan smiled and said, "Xiong Ying, you explain."

Zhu Xiongying nodded and said to Zhu Biao, "Father, the hot air balloon can take off because it is filled with hot air, and hot air is lighter than cold air."

"So, even if the fuel below burns out, the hot air balloon won't fall. Instead, it will slowly descend as the air inside cools down. As long as the balloon isn't damaged, there's no need to worry about it crashing."

After listening to Zhu Xiongying's popular science explanation, Zhu Biao suddenly understood and felt a little embarrassed at the same time.

Although he would take time to study mathematics and natural sciences, he spent most of his time dealing with state affairs, so his understanding of these areas was naturally not as good as Zhu Xiongying's.

It can be said that if Zhu Biao were to return to the university today, he would probably be okay in Confucianism and mathematics, but would probably be a poor student in natural sciences.

In less than half a minute, the hot air balloon landed on the ground.

Liu Kuan immediately led students including Zhu Xiongying and a group of craftsmen to inspect and record, and then discussed with the students.

"If we count from the time the hot air balloon was hovering at an altitude of 100 meters, its time in the air was only a little over four minutes, less than five minutes."

"However, if we count from the time it takes the basket to ascend to the ground, the entire ascent takes nearly twenty minutes."

"From this, it seems that we are on the right track in using specially made honeycomb briquettes as the main fuel and rosin and alcohol as combustion aids."

During the experiment, Liu Kuan asked Zhu Huilan to use a tablet computer to record the time of each stage. When she summed it up at this time, she was in a good mood.

The fuel for hot air balloons in later generations was mainly liquefied petroleum gas. At that time, Liu Kuan couldn't even produce liquefied petroleum gas, let alone liquefied coal gas.

Afterwards, he asked his students to conduct experiments on various fuels that the Ming Dynasty could collect, and finally found that coal had the highest calorific value.

So he asked his students to start experimenting with coal, such as how to further process coal to make it have a higher unit calorific value and burn longer.

Because the coal flame was not big enough, Liu Kuan and his students later came up with the idea of ​​adding combustion aids.

As for the balloon, the experimental group naturally went through many experiments before developing the current practical version.

Later hot air balloon money bags were mainly made of nylon and fiber, which were not only light in weight but also waterproof, fireproof and resistant to high pressure.

At that time, the Ming Dynasty could not find materials with such good performance.

Fortunately, if Liu Kuan was only making a basic hot air balloon (some book friends said the name of pseudo hot air balloon was unpleasant, so he changed it), it would not rise to a really high altitude, so the requirements for the material's high-pressure resistance would be very low.

Therefore, the balloon of this primary hot air balloon is actually made of silk, cotton, linen and other materials, and is brushed with tung oil and other materials to trap the hot air.

If you do this, it will definitely not be fire-resistant and may even be quite flammable.

But there is no other choice but to do this right now.

Liu Kuan was satisfied with the results of the hot air balloon launch experiment, but a few students were not satisfied.

Zhu Tan said, "It's only been in the air for four or five minutes. If it were allowed to float, it would probably only be able to fly a few miles."

Zhu Ying continued, "We probably won't be able to get out of the outer city of the capital for more than a few miles. Besides, there are no people or weapons in the basket right now. If we carry them, it will be even heavier. The hot air balloon will probably hover even lower in the air, and someone standing on the roof might be able to shoot it with a bow and arrow or a musket."

The experiment was successful and the other students were originally very happy, but after hearing what Zhu Tan and Zhu Ying said, they suddenly felt a little depressed.

Liu Kuan said with a smile, "This is just the first hot air balloon launch experiment. It's good enough that it succeeded. If we want the hot air balloon to rise higher and stay in the air longer, we just need to continue researching and improving it."

Although he said this, Liu Kuan knew in his heart that if the Ming Dynasty did not make significant breakthroughs in materials and fuels, it would be difficult to significantly improve the performance of hot air balloons.

Next, Liu Kuan summarized the experimental experience with the students and discussed the next direction for improving the hot air balloon.

Just as he finished speaking, he saw a group of people running towards him from the direction of the imperial city.

The leader was a eunuch. After dismounting, he saluted Zhu Biao and said, "The emperor has ordered His Royal Highness the Crown Prince and Prince Consort Liu to enter the palace immediately."

Zhu Biao didn't ask the eunuch anything, but said directly to Liu Kuan: "Brother-in-law, shall we go together?"

"Please allow me to give a few words to the students."

After Liu Kuan finished speaking, he went to explain a few things about the finalization of the experiment to Zhu Xiongying and others, and then he mounted his horse and headed to the imperial city with Zhu Biao.

After entering the Fengxian Hall, Zhu Biao and Liu Kuan successively saluted Zhu Yuanzhang.

When Liu Kuan raised his head, he noticed that Old Zhu had a happy look on his face.

'It seems like a good thing,' he thought.

As expected, Old Zhu smiled and said, "There's a battle report from the north: a great victory in Qingzhou. Guolai and Bulanxi were captured alive, and more than 30,000 of his men were taken prisoner. According to Feng Sheng's battle report, the Shenwei and Hudun cannons played a significant role in this battle."

　First update.

　　Correct the typo later

　　
　
(End of this chapter)