The leader of the transportation team was not a soldier because his military uniform was not marked, and Yang Xu knew this person.

"Sir Xu, why are you here?" Yang Xu was a little surprised. Xu Yunting's official title was not high, he was just a fifth-rank official, but his identity was different because he was a senior researcher at the Royal Academy of Sciences.

That's right, the Royal Academy of Sciences has been adjusted many times and is very similar to the research institutions in later generations, especially the positions of researchers are basically in line with those in later generations.

Senior researcher, this position is similar to that of a Hanlin bachelor's degree, but in actual rights, senior researcher is much older than the expensive Hanlin bachelor's degree.

Xu Yunting is very tall, but his figure is a bit thin. It looks a bit ridiculous when worn with a military uniform without a military rank. In addition, Xu Yunting is a myopic person and wearing a pair of tortoiseshell glasses, which is very easy to recognize among a group of officers and soldiers, so Yang Xu saw him at a glance.

"Yang Shuai, long time no see." Xu Yunting smiled and saluted Yang Xu.

"Long time no see, by the way, why are you here?" Yang Xu asked again.

"Of course I'm giving you these things." Xu Yunting reached out and pointed at the convoy and replied with a smile.

"What are these? Are they not cannons?" Yang Xu asked in surprise. After watching for a long time, the carts in the convoy did not look like cannons. The oil cloth on the carriage was covered tightly, but it looked like food and grass.

"Hahaha, of course it's not a cannon. How easy is this cannon to be pulled over?" Xu Yunting immediately laughed when he saw Yang Xu's expression.

"What is it if it's not a cannon?"

"Of course it's a good thing, you'll know after a while." Xu Yunting blinked at Yang Xu and kept it a secret. Then he turned around and asked the officers and soldiers who were escorting the convoy and the people he brought to pull the convoy to an open space outside the city to be careful to unload the goods.

Seeing them busy, Yang Xu was even more puzzled, but he did not ask again, just watched quietly.

There were eighteen large trucks in the transport convoy. Except for three of them loaded with accompanying supplies, the other fifteen cars did not know what they were loaded.

When Yang Xu opened the covered oil cloth and moved things from it one after another, he was even more puzzled because the things he moved were folded in rolls of folded silk products. What are these things for? Could it be that the court spent so much manpower and material resources to transport some silk from thousands of miles away?

Silk? Why are you transported? Make clothes for the soldiers or make quilts? This is too unreliable, right? Yang Xu's face looked a little ugly when he thought of this.

Although he was puzzled, Yang Xu still planned to continue to see the situation. After all, the silk in front of him made him wonder. Zhu Yicheng was the emperor and had already given Yang Xu information before. In his letter, he attached great importance to the shipped things.

If it were just ordinary silk, Zhu Yicheng would never take care of it so specifically. Maybe these silks are just surfaces, and perhaps they have any important uses?

The convoy arrived in the morning and took more than an hour to unload the items from the car. It was not until noon that it was unloaded.

After a simple lunch, Xu Yunting continued to command the personnel to assemble the unloaded silk and some other strange things. It was not until the afternoon that all of them were assembled.

After the assembly was completed, Yang Xu still did not understand what Xu Yunting brought. Now there was a large pile of silk products on the ground. In addition, there was a huge basket and a stove-like thing. In addition, ropes were covered everywhere, which connected the baskets and silk at one end, and the other end was firmly nailed to the ground with wooden stakes. After finishing these, Xu Yunting carefully checked them and nodded with satisfaction.

"Yang Shuai, do you want to go up and see the sky with me?" Xu Yunting asked Yang Xu with a smile.

"Go up? Look at the sky?" Yang Xu didn't understand what Xu Yunting meant and was a little stunned.

Xu Yunting didn't say much, smiled and asked Yang Xu to stand a little further. Then he led a few people directly to the huge basket. After entering the basket, Xu Yunting issued an order to the people around him. After everyone was ready, Xu Yunting made someone ignite the stove set up in the basket.

This stove is different from an ordinary stove. It emits extremely strong light and heat after burning at a moment. As the flames ignite, the flames emitted from the stove are directly sucked in the round mouth set above the basket.

Standing in the distance, Yang Xu still didn't understand what Xu Yunting was doing, but he had a hint of expectation in his doubts.

After a while, as the stove burned, the silks that had been laid on the open space gradually rose. The silks began to expand from the inside from a flat shape, as if someone was inflating it inside.

Xu Yunting kept staring at the stove, and at the same time paying attention to the change in the state of the silk. After about ten minutes, as the silk expanded more and more severely, the silk began to float slowly into the air. Only then did Yang Xu see clearly that the shape of the silk floating was a huge oval. The maximum diameter of the oval was 20 to 30 meters, and the height was about the same.

Next, a scene that shocked Yang Xu happened. As the oval silk expanded more and more, it gradually flew higher and higher, and the implicated ropes also extended under the action of this huge hot air balloon...

After more than ten minutes, as the hot air balloon reached a certain level, the suspended force rose upwards and brought the baskets carrying people down into the air. In the stunned eyes of Yang Xu, the huge hot air balloon flew higher and higher, and the people standing in the basket, including Xu Yunting, also flew into the sky.

“This…this….”

Yang Xu couldn't speak for a moment, his eyes were stunned. At this time, he suddenly remembered what Xu Yunting said to him in front, that was to go up and look at the sky.

The hot air balloon flew higher and higher, and finally reached a very high place. Yang Xu believed that if it weren't for the ropes on the ground, it would have probably flew directly to the Heavenly Palace long ago.

This scene not only made Yang Xu stunned, but also the others were stunned.

When the hot air balloon flew to a certain height, all the people in Ulanwude discovered this huge thing flying in the air. Even some veterans who were not afraid of life and death on the battlefield were a little frightened after seeing it. This kind of scene was something they could never imagine and they didn't know what it was.

For a moment, the hot air balloon actually caused some panic to Ulan Ude. Fortunately, the casual staff of the Academy of Sciences told the army that this was not a monster, but a kind of equipment. Otherwise, in panic, some soldiers would probably raise their guns to shoot at the hot air balloon in the air.

Not only were the Ming army extremely shocked by the appearance of hot air balloons, but the captured Russians who were still in front of labor were also scared. Where did these Russians have seen this? They knelt on the ground with horror, kept marking crosses on their chests, muttering about God and the Lord...

When the hot air balloon reached its maximum height, the huge hot air balloon seemed to have become a point below. Looking up, Yang Xu's surprise gradually faded. He suddenly understood the value of this thing in war. As a qualified military strategist, Yang Xu had guessed the purpose of the hot air balloon. Only then did he understand why Zhu Yicheng wanted to give him that letter, and why did he use such a powerful weapon to transport it over so much manpower and material resources.

The test flight time of the hot air balloon was not long. After staying at the highest altitude for some time, the hot air balloon began to slowly descend under Xu Yunting's control.

Half an hour later, the hot air balloon slowly landed on the ground. When the passenger basket landed directly, a group of people who had already prepared quickly surrounded him and helped fix it. After a while, Xu Yunting crawled out of the basket and returned to Yang Xu with a smile.

"Mr. Xu, this is a powerful weapon, a military weapon! By the way, how did you make it? How did you make it fly up?" Yang Xu grabbed Xu Yunting's hand and was so excited that he couldn't do it himself.

Xu Yunting seemed to have known Yang Xu's reaction for a long time. He smiled and explained the principle of the hot air balloon. In fact, it was very simple, because there had been Kongming lanterns in the folk long ago. The hot air balloon was just a Kongming lantern that was countless times larger. As for other principles about science, Xu Yunting did not explain much, because even if Yang Xu said it, he would not understand it.

"Sir Xu, can this hot air balloon fly freely in the sky? Move in the required direction?"

"This is not possible yet." Xu Yunting understood what Yang Xu wanted to ask, and shook his head with regret: "Now we can only make the hot air balloon rise, but we can't make it move in a fixed direction. However, Yang Shuai doesn't have to worry. Flying is the first step. The next step is to find a way to let it fly freely. When the terrain is no longer obstacles to us, maybe we can fly directly from here to the capital, and it will take only a short time."

"That's how..." Yang Xu felt a little regretful. No wonder there were so many ropes fixed. This was because he couldn't control the hot air balloons flying away by themselves.

Although he was a little regretful, Yang Xu quickly regained the excitement he had at the beginning. No matter what, with this thing, it still had a great effect on war. On the complex battlefield, standing on the hot air balloon can be said to be completely visible. The enemy's every move is under the gaze of his own side. As a commander-in-chief, with such convenience, victory is not a problem for him at all.

Irkutsk is a major Russian town. Before, Yang Xu had thought of many ways to conquer Irkutsk, but he was not very sure.
Chapter completed!