The hanging basket of the hot air balloon is very huge and adopts a two-story structure. The upper floor is a variety of equipment used to operate the hot air balloons, and the lower floor is a living area, which is like a two-story building hanging.

Can this thing fly? Today we will see the news. Many people watching the fun gathered together, including craftsmen and craftsmen's families, as well as free royal relatives, and even Li Shimin came here specially. After all, if they take off successfully this time, mortals can conquer the sky, which is of great significance.

This thing can also be used in military affairs. Maybe in the future, the Tang Dynasty can directly use airdrop method to send troops.

Of course, Li Shimin did not allow Yunyao to take risks, so the first batch of users of the hot air balloon were selected craftsmen. Yunyao told them that they could be kept in history after success, and if they failed, they would be given pensions to their family, so the five craftsmen also began to operate the hot air balloon without hesitation.

When everyone saw the hot air balloon getting bigger and bigger and bigger, they stared in surprise, and when they saw the balloon floating up with the second-story building, they were even more shocked.

Huang Bixia also grabbed Yunyao's hand nervously. Although she knew the princess' plan three years ago, she always thought that there was no possibility of taking off. She never expected that it was right in front of her. Just today, it turned out that the hot air balloon could really take off with heavy objects.

But the cable has not been released yet, so the hot air balloon did not fly directly to the high altitude, but just tightened the cable and floated in the low altitude. But this was shocking. It was as if it was three feet high and was almost caught up with the walls of Chang'an City. If you fly a little higher, you can overlook Chang'an. Li Shimin could only sigh that his daughter had really surprised him. He didn't understand the principle. He only heard from the students of the Imperial College that hot air went up and cold air went down and so on.

Li Shimin also asked at the time: "Why is the mountain colder than the foot of the mountain? If the heat is going up and the cold is going down, then the top of the mountain should be hotter than the foot of the mountain?"

But science is unfamiliar. Although the high altitude is indeed colder and the ground is warmer, the hot and cold air are just opposite to human cognition. The students of the Imperial College explained that the warmth of the mountain is because they are close to the ground and the temperature on the ground is warmer. The top of the mountain is far away from the ground, so it is colder. Simply put, the temperature obtained by the earth is mainly from the storage of the ground, rather than the direct exposure of the sun.

At that time, Li Shimin also seemed to understand, but now it is indeed proved that hot air is going upward, so as long as the hot air is wrapped, the heat can hold the weight to the sky. At this time, a little scientific spirit suddenly popped up in Li Shimin's mind, and he couldn't help but say to himself: "When Guanyin Bodhisattva left on the clouds that day, was the clouds also hot?"

If it is hot, it will not support the soles of the Bodhisattva's feet, but hold up the bottom of the skirt.

The students of the Imperial College were also very excited. This is science and amazing. They are also responsible for explaining to Li Shimin how the hot air balloon works, how to fly, and how to fall.

Falling down means letting away hot air. There is an outlet on the top of the hot air balloon. As long as the hot air is released, the height can be reduced.

In short, today the people of Chang'an saw a huge monster outside the city surpassing the city wall, just like a huge round head, which is really novel and fun.

Several generals also said that with the hot air balloon and a telescope, they could see thousands of miles away.

Li Shimin could no longer hold back and decided to go up in person. Although there was danger, the ministers all knew that Li Shimin was not afraid of danger, so they were also rushing to the forefront and expressed that they would follow the emperor to bravely enter the sky.

Yunyao thought to himself that this is not a toy, and he also had to travel to the west on a hot air balloon. However, such a fresh thing is too attractive to mortals. Yunyao had been able to fly before, so he no longer had any curiosity about the altitude. However, this is the first time that mortals have stepped on such a high altitude. How can they not be excited or curious?

The cables were still not loosened, but Li Shimin was already very happy and stood in the fence on the second floor with several ministers and looked into the distance.

"Hot air balloon." Li Shimin even waved his hand on the hot air balloon and wrote three words, which was considered to be a formal recognition of the greatness of the hot air balloon. Then Shi Xingdao wrote a poem: "Chang'an is surrounded by mountains, flowing in Qujiang City, and he wants to see thousands of miles away, climb the hot air balloon."

Everyone said it was okay, isn’t it just that I just want to go to the hot air balloon? It’s really a good idea. The emperor is really both civil and military, and he is full of flowers in his writing.

Li Shimin was also very happy and rewarded the craftsman who controlled the hot air balloons for him. Then he wanted to put the hot air balloons in the palace and climb up to overlook Chang'an when he had time. So he came down and said to Yunyao: "Good daughter, my father is very fond of the hot air balloons. This hot air balloon was sent to the palace, allowing me to overlook Chang'an in my spare time, which also helps me care about my people and the country."

It’s obviously for the sake of playing for yourself, but it has a half-dollar relationship with the country?

Yunyao could only say: "Father, this is the first hot air balloon, and there are many shortcomings. If the father needs hot air balloons, then I will definitely develop the second generation of safer and more comfortable hot air balloons for the father to use."

When Li Shimin heard this, he felt that it made sense. The first generation must be improved, and the second generation must be better than the first generation. So he accepted this statement and said, "Then I will wait for you to develop the second generation hot air balloon, but don't let me wait for a long time."

Yun Yao immediately said: "In order to develop the second-generation hot air balloon as soon as possible, I think the first-generation hot air balloon needs to be used to accumulate experience. So I decided to bring my son-in-law and take the hot air balloon back to Jiannan Road to visit relatives, and ask my father to be kind."

Li Shimin knew that Yunyao liked the prince-consort very much. If there were no hot air balloons, it would be difficult to climb back to Jiannan Road. But now that the sky has passed, he should go back to the prince-consort’s hometown. So he considered it and nodded in agreement and said, "Okay, but be careful, and you are not allowed to run around. After returning to Jiannan Road, you will come back after visiting the marriage. Don’t be nostalgic with the prince-consort among the people, do you know?"

"Daughter knows." Yunyao said that she would not accept anything from the outside king's order. She not only wanted to run away, but also to Tianzhu.

"When are you going to set off?" Li Shimin asked.

"Five days later, the use of hot air balloons attaches great importance to the weather. I have invited Yuan Shoucheng, a famous hexagram master in Chang'an, to walk with me. Divination of the weather along the way can ensure safety." Yun Yao did not lie. The weather for Yuan Shoucheng's divination was exactly the same as the arrangements of the Heavenly Court, and it was more accurate than the weather forecast.

Seeing that his daughter was considerate, Li Shimin felt at ease to let her go. When the child grew up, he had his own plans, and parents could not tie the child to him forever.

Soon everyone knew that Princess Li Zhuyun of Dancheng was going to take her first hot air balloon journey, and newspapers reported the news of flying to Jiannan Road this time. Since ancient times, there have been records of the difficulty of Shu Road. It has not been easy to enter Shu since ancient times. Now with hot air balloons, everything is simple. If it goes well, it is to open up a new route to enter Shu. Maybe in and out of Shu, there will be hot air balloons all around.

If it succeeds, the princess will have great merits. Many Chang'an residents think that the princess is willing to take risks, which is really amazing. Other royal members are envious of Yunyao's real names when they see that Yunyao is so popular, and they wish they can't get a share of the pie.
Chapter completed!