The principle of hot air balloon liftoff is actually very simple, that is, the balloon that uses hot air to float gas and then converts it into a load balloon.

But this thing is the same as the joke in later generations:

Eyes, I will.

Brain, I will too.

Hands, you two fart......

This includes the selection of balloon materials, combustion temperature control, load gravity testing and many other standard things.

Just like the tuning of a car, even if you have all the hardware facilities and first-class, you can still be a spicy chicken without good software tuning.

At this time, the first generation of hot air balloons developed by Zhang Dagong and Li Zhu had already been the result of hundreds of thousands of continuous experiments, and had basically reached the limit of what they could do at this time.

That's why Xu Changqing has to try it himself!

'On paper, I finally feel shallow, and I never know that I have to do it. ’

Zhang Dagong If they want to break through the bottleneck at this time, they don't know how much time it will take, if it is ordinary, it is nothing, Xu Changqing is also willing to let them toss more, but at this time, the arrow is already on the string, and it has to be sent!

Xu Changqing can only take shortcuts by himself!

Soon, Zhang Dagong and Li Zhu had finished explaining to Xu Changqing, and many craftsmen had already assembled the hot air balloon.

Xu Changqing smiled and said to the red lady: "Sister Hong, are you ready?" ”

The red lady couldn't help but gasp.

She had long known that Xu Changqing was bold, but she didn't expect that Xu Changqing's courage could be so big, this is really going to heaven......

But at this time, Xu Changqing was ready, and all the sons and craftsmen around him were watching, even if the red lady was scared, how could she retreat?

Thinking about it, she gritted her silver teeth and nodded emphatically.

However, she still wanted to say something, to show her bravery, but her body had already stopped listening to her call, and she couldn't speak at all......

Fortunately, Xu Changqing reacted quickly, pulled her with a smile, turned around this way, looked over there, she was like a marionette, turned around a few times, and was finally pulled into the basket by Xu Changqing.

After all, it is a military and has to undertake the task of bomb dropping, so this hot air balloon is very large, and the diameter of the basket is more than one meter five.

The hot air balloon has not yet been rolled out at this time, and it is only placed on the ground, which already occupies a huge space.

"Alright, let's get started."

Before the red lady could react, Xu Changqing had already finished inspecting the perimeter of the hot air balloon and made a gesture to Zhang Dagong and the others.

Soon, the surrounding people quickly spread out the hot air balloon, and Xu Changqing also lit the flame of the furnace and added fuel to it.

This fuel is carefully prepared, not coal at first, but charcoal, and only after liftoff, the best coke with stronger combustion efficiency will be used.

Including the material of the hot air balloon, it is also made of silk, numbness, oilcloth, and even fine animal skins, etc., many materials are mixed, and there are as many as five layers.

As the flames in the furnace continued to rise, the hot air balloon quickly inflated as if by magic, and turned into a cloud that obscured the sky.

Feeling the steaming heat from the stove, the red lady came back to her senses, but her legs were already weak, and she didn't dare to stand up at all, so she could only subconsciously hug Xu Changqing's thighs.

Xu Changqing couldn't help but smile: "Sister Hong, relax, everything is with me, it's okay." ”

But at this time, Xu Changqing didn't have time to take care of the red lady, and began to constantly pull the rope to adjust the hot air balloon.

In order for a hot air balloon to take off smoothly, in addition to these built-in hardware and software facilities, another key core element is wind!

If it is in the storm season of summer and autumn, let alone Xu Changqing, the first generation of hot air balloons at this time, even if it is advanced in later generations, he will not dare to rashly take off.

However, it is the end of winter, and the sea breeze is softer and less varied at this time of the evening, which is the most suitable time to take to the skies.

Seeing Xu Changqing constantly controlling the hot air balloon like a mountain, the red lady wanted to say something, especially wanted to help Xu Changqing, but her body didn't obey the call, so she couldn't do anything.

"Oh-"

"Mighty and mighty!"

"Lifted, lifted......"

At this time, there was a sudden earth-shattering cheer around her, the red lady's pupils dilated violently, and she saw that the huge hot air balloon was like a miracle, and it was gradually rising into the sky with them, and the cheering crowd around them soon became invisible, and even the sound became small after a while.

As far as the eye can see, there is only the vast sea, and the splendid waves that roll from time to time, and the sound of the wind seems to have begun to get louder.

In a short time, the hot air balloon has risen to a height of more than 100 meters, and you can see the mountains at a glance!

Xu Changqing's mind couldn't help but open up, and he felt that there was not a single cell in his body that was uncomfortable, and while adjusting the hot air balloon to keep it stable, he smiled and said, "Sister Hong, get up, it's already stable." ”

The red lady really came back to her senses, tried a few times, and sure enough, the hot air balloon seemed to be fixed, very stable, and then she got up carefully.

"Oh Mom......"

But as soon as she saw the suffocating scene around her, she almost fainted, and subconsciously threw herself into Xu Changqing's arms, as if only there could she feel a little sense of security.

Neither of them was wearing armor at this time, although the clothes on their bodies were a little thick, the feeling of warm nephrite in his arms still made Xu Changqing's heart flutter.

Secretly laughed: "Why aren't you arrogant now?" ”

However, the hot air balloon is the top priority, and after enjoying the delicate nature of the red lady for a while, Xu Changqing also began to encourage her constantly and let her stand up on her own.

After a while, feeling that there was really no danger, the red lady relaxed a little, and began to bear and enjoy this indescribable feeling independently.

Seeing that she was adapting, Xu Changqing also began to teach her how to operate the hot air balloon, including some of its principles.

At this time, the afterglow of the sunset gradually ended, the hot air balloon has drifted away from the small islands, to the vast sea, looking at the past, countless people on the island are looking at this side excitedly and nervously, but as small as ants.

"Changqing, I, I'm not dreaming, am I? This, this is really beautiful! Ahh

The red lady finally got used to it at this time, and began to really enjoy this feeling, and couldn't help but open her arms and let out a coquettish voice.

She has never had such a happy time in her life as at this time, especially with Xu Changqing by her side.

The smile on the corner of Xu Changqing's mouth couldn't be concealed, this is just like a painting, the goal is successful, the beauty is on the side, the scenery is picturesque, and he is free!

However, after only feeling this kind of unrestrainedness for a short while, Xu Changqing's mind returned to the topic.

Zhang Dagong and Li Zhu tested that the highest altitude of the hot air balloon was about 150 steps.

Of course, this is only their estimate based on their eyesight, and it is far from accurate.

This is also a big embarrassment at this time, there is no real metric.

It can also be seen from this that the first emperor's 'unified weights and measures' was such a proud achievement!

There are no standard weights and measures, and it is undoubtedly more difficult to accurately manufacture a measuring instrument for altitude, and Xu Changqing can only rely on his eyesight to roughly estimate the altitude at this time.

From a purely military point of view, in fact, it doesn't take 150 steps, and a height of 100 meters is enough.

Even if the Manchu Qing Dynasty had a marksman, shooting arrows into the sky and shooting flat are completely two concepts, and the height of 100 meters is enough for them to reach the dust.

However, for the sake of safety, 150 meters, or even 200 meters, can be regarded as the safest area.

After all, a hot air balloon must not only succeed, but also become a miracle, a cloud that hangs over the Manchu Qing forever, and there must be no failure!

The weights and measures of the Ming Dynasty at this time, one hundred and fifty steps, are almost about two hundred and twenty meters, and the height of about two hundred meters is already a bit close to the limit.

This makes it difficult to guarantee that there will be no problems in materials, controls and other aspects, and there are still many areas that need to be improved and enhanced.

Especially due to the weight of the weight, it is impossible to carry too much fuel, and it is extremely windy, which means that if you want to make good use of the hot air balloon, an air weapon that is ahead of the times, you must make accurate and accurate calculations before the war!

This is indeed difficult, but at this time, this kind of effect, this kind of deterrence, is absolutely immediate, and the results are immediate!

"Changqing, what do you want? Look, look over there, what a school of fish! ”

At this time, the red lady's coquettish call interrupted Xu Changqing's thoughts, obviously had a little temper, and pinched Xu Changqing's arm angrily.

Xu Changqing hurriedly looked in the direction of the red lady's finger, and saw dozens of dolphins, just like the elves of the sea, playing mischievously on the sea, and sometimes jumping out of the water, shouting arrogantly one by one.

Xu Changqing couldn't help but smile with relief.

Despite the dangers of the sea, they have always been the spirits of the sea!

Xu Changqing hesitated for a moment, but still hugged the graceful waist of the red lady, and said with a smile: "Sister Hong, are you happy today?" ”

Looking at Xu Changqing's slightly hot eyes, the red lady's pretty face turned red all of a sudden, how could she not understand what Xu Changqing meant?

I couldn't help biting my red lip hard.

However, after a while, her tears couldn't stop like a gushing spring, bubbling outward, but there was no sound, she clenched her silver teeth and turned her head, not looking at Xu Changqing.

How could Xu Changqing not understand the red lady's thoughts?

That's a bit of a sin to you......

However, the matter has to be solved after all, and escaping is definitely not the way, Xu Changqing thought for a while, and said solemnly: "Sister Hong, if you are not happy, the military advisor, I will talk about it." Hehe, my Xu Changqing's reputation is not good, and I don't care about this. However, you can rest assured, I can assure you that I will never hurt the military advisor. ”

Seeing that the red lady still didn't turn back, Xu Changqing wanted to say something more, the red lady suddenly turned around and hugged Xu Changqing hard: "Changqing, don't talk about it, forget it, so be it." I, I'm not worthy of your ......"

As she spoke, she lay on Xu Changqing's chest, crying incessantly, and soon made the placket on Xu Changqing's chest wet and transparent.

"Sister Hong, you, why are you suffering? I, Xu Changqing, can swear that as long as I handle things well, I will marry you immediately and enter the door, and I will definitely carry a sedan chair! ”

"Changqing, you, don't say it again. I'm just a willow, and I'm already a broken willow, how can I be worthy of you? I...... Ahh

"Smack!"

As he was talking, a sudden gust of turbulent air flow passed, Xu Changqing was holding the red lady, did not control the hot air balloon, the hot air balloon suddenly shook violently, and the stove in the basket immediately tilted, and many charcoal fires fell out at once.

The hot air balloon suddenly lost control and shook violently, Xu Changqing and the red lady were defenseless at all, and they staggered all of a sudden.

But that's not all!

The overflowing charcoal, one of which was bigger than a palm, was like having eyes, and when it was blown down by the wind, the red one was simply terrifying, like a devil, and flew directly towards the pretty face of the red lady.

The red lady's pupils dilated violently, and her ruddy little mouth also opened violently, wanting to exhale, but found that her voice didn't listen to the call at all, and she could only watch that the fiery red charcoal was about to fly to her delicate face.

But at this time, the corners of the red lady's delicate mouth suddenly showed a smile of relief.

Is her legendary but turbulent and tragic life finally coming to an end?

But it's okay this way, finally I don't have to worry about it anymore, and I don't have to be limited by the shackles of the world......

However, at the moment when the red lady was about to close her eyes and wait for the judgment of fate, a familiar big hand, like a heavenly soldier sent by God to save her, was fearless and extremely decisive and grabbed directly towards the fiery coal.

"Whew-"

In a moment, the red lady clearly heard the sound of the charcoal fire almost roasting the meat, and the smell permeated her ears and eyes.