For the people of Jiangnan, there is a cold wind blowing outside the gate, which will immediately make people feel what is the cold wind and what is the steel knife for scraping bones. However, compared to Jiangnan, because every household outside this gate has a warm kang, this house is warmer than Jiangnan.

But since this is the case, every time he comes out of the house, Zhu Mingzhong will wear a thick woolen coat, although the coat looks no different from an ordinary woolen coat, but the inner lining of the coat is made of mink. Wearing a locomotive hat made of wolf skin, that is, the "liberation hat" of later generations, I don't feel cold.

In the Shanhaiguan City at night, there is no movement on the quiet, not spacious street, compared with the past, because the government ordered an order to issue an order requiring the businesses along the street to hang lamps and lanterns outside, so the city is no longer as dark as in the past, and only a few yamen or large households hang lanterns outside the door. These lanterns hung by the government's orders have different appearances, most of them are bamboo lanterns, and they are also dark and bright, and many places can only reflect a little light under the lamp. But even so, it makes the street somewhat brighter.

As he walked along the street, Zhu Mingzhong occasionally encountered some patrolling guards, and when he passed in front of a temporary government office, the sentry outside the gate stood under the door, watching vigilantly ahead.

This is the quartermaster office, thinking of what he heard a few days ago, Zhu Mingzhong walked straight over, and the sentry outside the door immediately stopped him.

"What do you guys do?"

The sentry looked at the people in front of him, although they were wearing coats, but there was snow on their coats, why did these people come here in the middle of the night? Just as the attendant was about to answer, Zhu Mingzhong spoke.

"Oh, we and Colonel Xu are old friends of Jiangnan. I heard that he was sick and came to see him. ”

Colonel Xu in Zhu Mingzhong's mouth is Xu Yousen, the younger brother of Xu Youzheng, the director of the Ministry of Engineering, when he just captured Changzhou, Xu Youzheng was a talent he personally recruited, perhaps in terms of technology such as cannon casting, although Xu Youzheng, who has a family tradition, can not be compared with Zhu Mingzhong standing on the shoulders of giants, but the artillery of the Loyal and Righteous Army has become the most professional artillery in East Asia in this era under its one-handed training, and has compiled a large number of artillery teaching materials, it can be said that artillery is the most professional unit in the Loyal and Righteous Army.

Although when Xu Youzheng was invited, he was rejected by the Xu family, but later with the stability of the situation, the children of the Xu family left the village one after another, some of them were civil officials, some were in the Ministry of Industry, and some were also in the army, Xu Yousen was one of them. However, Xu Yousen is not very conspicuous among the children of the Xu family, he is just in charge of logistics in the army, if it weren't for the fact that when he was at a meeting a few days ago, he learned that he was ill, Zhu Mingzhong couldn't even remember him, he would just pass by here, thinking that he was Xu Youzheng's younger brother, and it was also a matter of course to go to see him.

"Oh, the chief is very sick, and he may not be able to see the outsiders! Please wait, sir, and go to the next ceremony. ”

So saying, the sentry went in, but the sentry on the side still stinged him. After a while, a sergeant came out of the door and saluted Zhu Mingzhong.

"Please forgive me, Chief Xu is sick in bed, and I really can't greet him in person, please move into the inner ......"

Several people followed the sergeant into the courtyard. Turning over the house in the front yard, the group came to the door of the study. Listening to Xu Yousen in the study, he coughed lightly and said to the window.

"Which brother arrived? Please come in. ”

As soon as Zhu Mingzhong stepped into the door, he smelled a strong smell of medicine, and then he only saw a young man with a thin face, he was sitting behind the desk, and when he raised his head, Zhu Mingzhong didn't even notice his appearance, but only saw a pair of very dark eyes, and a pair of eyes. At first glance, Zhu Mingzhong almost didn't believe his eyes, and he had already lost weight like this after only a few days of not seeing him.

A cold wind hit the study. Zhu Mingzhong couldn't help but shudder. Xu Yousen, who raised his head, couldn't help but be startled when he saw the king, and hurriedly exclaimed.

"Ah, yes—the king!"

He stood up and said with a long shudder.

"I don't know if the king is coming to the cold evil, this ...... That's ......."

Zhu Mingzhong leaned over and grabbed him, and said with a smile.

"What's this? I had nothing to do tonight, and I heard that you were sick, so I came to see you—what the hell is going on? You sit back and it's ...... cold."

Xu Yousen thanked him, got up with difficulty and sat back, then picked up his coat and put it on. Zhu Mingzhong didn't speak for a while, and walked around the room with his hands behind his back and watched. Seeing a stack of drawings on the desk, he picked up a random one and glanced at it, this look was not tight, he was suddenly startled, and looked at Xu Yousen, who was buttoning his coat, and said.

"Oh, Kong Ming lantern? There is still ...... under this Kong Ming lantern Hanging baskets? ”

Almost instantaneously, Zhu Mingzhong realized that this was not a Kong Ming lantern, or rather, this was an enlarged Kong Ming lantern, and an ordinary Kong Ming lantern would never have any hanging basket.

It's a hot air balloon!

However, with just a slight glance, Zhu Mingzhong can be sure that this hot air balloon can't fly, at least with people. Because it's a little too small.

"What? Do you want to carry people with it? ”

Seeing that the king saw it, Xu Yousen leaned over and said.

"Back to the king's words. When he was a child, he liked to make Kong Ming lanterns to play, and when he was young, he used to use large Kong Ming lanterns to bring mice and other things to the sky......"

mentioned the stubbornness of his youth, but Xu Yousen didn't speak,

"Earlier, when I was talking to Wutang, the king had said that the victory of the battle depended on whether the commander could grasp the overall situation of the battlefield and the right time to attack. However, when it comes to combat, the problem of visibility on the battlefield can further complicate the situation. After the first few shots, the smoke from the gunpowder, mixed with the dust kicked up by thousands of cavalry and infantry, formed the "fog of war", and the entire battlefield would be enveloped in smoke, and in many cases, even the flash of the muzzle could not be seen......"

As an officer, Xu Yousen is a student of Zhu Mingzhong, and the so-called "fog of war" is exactly what Zhu Mingzhong emphasized when he taught them. Xu Yousen naturally remembers this vividly.

"Therefore, on the battlefield, the commander needs to stand on the commanding heights......"

From the 19th century to the early days of World War I, the school balloon played an extremely important role on the battlefield, and the main task of the condescending school balloon was to carry out battlefield reconnaissance. It's just that the balloons of that era were hydrogen balloons, and now ...... Is it possible to make a hydrogen balloon now?

Because of Xu Yousen's enlightenment, Zhu Mingzhong's mind immediately came up with several methods for producing hydrogen, from electrolysis to hydrocarbon cracking, and finally there is only one method that is the most realistic, that is, to use zinc and hydrochloric acid and dilute sulfuric acid to react to produce hydrogen, but the cost of this method is too high, after all, the price of zinc is relatively expensive, and there must be a problem in the cost of using it to make hydrogen, and the compression of hydrogen is also a problem, and the possibility of compressing hydrogen under the current technical conditions is almost zero.

Balloon!

After thinking about it for a while, Zhu Mingzhong put his eyes on the paper again, looked at the large Kong Ming lantern, and then looked at Xu Yousen and said with a smile.

"However, there are always high and low points in this commanding height, sometimes it may be on the enemy's side, and many times, it is not high enough, so you want to use Kong Ming lanterns, don't you?"

"King, that's exactly the case, the minister has always thought that since Kong Minglan has become bigger, since it can bring mice to the sky, if it is bigger, it will definitely be able to bring people up, so the minister has been planning this thing these days, but it's just ......"

Looking at the pattern, Xu Yousen said helplessly.

"It's just that this big hole lantern is always not durable, and it is tied with a rope, although it can be raised by a hundred feet, and it does not drift, but the time is very short every time......

Hearing him say this, Zhu Mingzhong, who almost understood the reason, just nodded, and when he saw the waiter bringing tea, he pulled the tea and held it in his hand to warm it, and then asked.

"Do you know why the Kong Ming lantern is raised?"

"This ......"

The king's rhetorical question made Xu Yousen stunned, and then he replied tentatively.

"Is it burning heat?"

Although he had never seriously thought about this question, Xu Yousen still vaguely guessed that it must be the heat generated by the butter burning under the Kong Ming lantern that allowed it to rise into the air.

"Since it's burning heat, then ......"

Picking up the pen, Zhu Mingzhong drew the appearance of a hot air balloon in his memory on the paper.

"We have to find a way to keep the hot air inside, the opening of the Kong Ming lantern will not only let the heat leak out, but also not big enough, we will make this opening a little smaller, and then make it bigger, well, you can calculate it first, calculate the relationship between the airbag and the weight, how big the airbag can drive multiple things, a little bit of experiment, and finally we can always get a scientific formula, and then, we can make a working hot air balloon accordingly ......"

Science is summed up from countless experiments and experiences, and it is precisely this process of summary that is lacking in Chinese history, so that it will always stay in the stage of experience and fail to form science.

Looking at the spherical hot air balloon drawn by the king, in addition to being surprised, Xu Yousen put forward his suggestion again.

"King, if this is the case, then it will definitely not be able to catch up with this battle, and the minister thinks that if it is possible, he can make a big one first......"

"Don't be in a hurry, don't be in a hurry, this battle can't catch up, in the future, you will definitely be able to catch up with other battles in the future, after all, ......"

Glancing into the distance, Zhu Mingzhong said with a smile.

"Don't forget, the Qing captives are still stealing from the northwest and occupying Shaanxi, and when Li Ziyuan is finished, he will definitely use troops in Shaanxi, and when we fight Tongguan, the hot air balloon will definitely come in handy......"