After seeing Chu Chen's glance, Princess Xin Yue nodded repeatedly, "Yes, yes, it's related to me, it's indeed related to me."
The Empress sighed imperceptibly, "What is it exactly?"
"I heard that Your Highness's birthday is approaching, and I have a gift I wish to present to Your Highness."
Princess Xin Yue suddenly turned her head, a flicker of surprise in her eyes, "How did you know it was my birthday?"
Chu Chen smiled without answering.
This information, of course, came from the simulator, but it could not be revealed.
Chu Chen took out a Kongming lantern from his怀中, "May I ask Your Majesty to allow me to demonstrate?"
Upon receiving permission, Chu Chen lit the Kongming lantern.
Watching the Kongming lantern slowly ascend under the scorching flame, the Empress nodded with great interest, "This thing of yours is quite interesting."
"But is this all you want to show me?"
Chu Chen slowly said, "I originally wanted to amuse the Princess, but the Princess thought that if this thing were larger, could it carry people into the sky? That's what gave me inspiration."
"You mean, making a larger version of this thing can fly into the sky?" The Empress scoffed, "Are you talking nonsense?"
"If I'm not mistaken, this thing is made of paper, isn't it?"
"If it really flies into the sky, won't a gust of wind blow it apart? Wouldn't the people on it have no chance of survival?"
"If it is to carry people, it naturally cannot be made of paper. It must be sewn with cowhide, and have a sturdy basket woven from rattan vines underneath."
"I have carefully calculated, and this method is feasible."
"It's just that the initial sample is quite costly, and the project is enormous. I implore Your Majesty to allocate funds and personnel, and I will surely give Your Majesty a surprise."
Princess Xin Yue looked at Chu Chen in astonishment.
She never imagined that Chu Chen would dare to ask the Empress for money and people.
At first, she even thought this matter had to be kept from the Empress, otherwise, she would surely be punished.
Chu Chen's actions completely refreshed her understanding.
The Empress pondered for a moment, "If it were before, I would certainly not agree."
"But now the palace finances are much more abundant, I can make an exception."
Saying this, the Empress chuckled, "You are quite clever, using my wealth to please my daughter."
"Let me see what tricks you can come up with."
Stepping outside, Princess Xin Yue bit her lower lip, "Is this truly a birthday gift prepared for me?"
"And how did you know my birthday?"
Chu Chen smiled slightly, "If one pays more attention to Your Highness on a daily basis, one will naturally know your birthday."
"However, Your Highness, you can give this gift to Her Majesty."
"Why give it to Mother?" Princess Xin Yue said with some displeasure, "This is clearly my birthday gift."
"You can give the technology and blueprints to Her Majesty," Chu Chen said helplessly. "The first one made will naturally be yours."
"But what use does Mother have for these blueprints?"
"The uses are vast," Chu Chen smiled slightly.
"Let's not mention anything else. If this hot air balloon can fly to a height of a thousand zhang, who can touch it? If it's used in military campaigns, wouldn't it be invincible?"
"Think about it, if Her Majesty is happy, won't she stop caring about you doing nothing for so many days?"
"It can actually be like this!"
The more he mentioned it, the more excited Princess Xin Yue became, and she quickly urged Chu Chen to produce the finished product.
In reality, the military application of hot air balloons was very limited.
This thing had no power, and to move, it could only rely on the wind.
And wind, being uncontrollable, depended entirely on fate. Such an uncertain thing naturally had little initiative in military affairs.
It could only play a very limited role in reconnaissance.
If one really wanted the hot air balloon to move, there were ways. For example, using specially made oars to glide in the air, or equipping the hot air balloon with horizontal propellers and driving it by human power.
However, the enormous size of the hot air balloon dictated that its speed was very limited.
Therefore, in his previous life, with the development of the aviation industry, hot air balloons were quickly phased out.
But here, Chu Chen felt that hot air balloons still had great potential.
First and foremost, cultivators existed in this world.
Even if one used specially made oars to paddle in the air, a cultivator with sufficient attainment could achieve far more than a dozen ordinary people.
As long as two or three martial artists were placed on board, the power problem of the hot air balloon could be solved.
Once it could move freely, in the sky thousands or tens of thousands of meters high, where no one could reach, the hot air balloon could play a huge role.
From such a high altitude, even just throwing down some rocks could cause immense damage to an army.
Not to mention the reconnaissance role it could play.
With hot air balloons, other countries would essentially be defenseless against Yunyue Kingdom. They could come and go as they pleased.
The Empress had clearly realized the potential of hot air balloons, which was why she agreed to let Chu Chen expend so much manpower and resources to manufacture them.
Although she wasn't particularly hopeful.
A few pieces of cowhide and a pile of fire could go into the sky? Wasn't this a fantasy?
Her agreement to such an outrageous request was more out of appreciation for Chu Chen's ingenious ideas.
Since Chu Chen had earned so much money for Yunyue Kingdom, a little waste was insignificant.
But the Empress never expected that after only two days, Chu Chen would invite her to witness the ascent of the hot air balloon.
Looking at the enormous hot air balloon on the ground, the Empress was completely bewildered.
"Can it really go into the sky?"
"It truly can," Chu Chen smiled slightly. "I have already tested it."
"Oh? You have flown up once already?" The Empress frowned slightly.
"Not yet, we just conducted a fire test to ensure that this hot air balloon is indeed usable," Chu Chen replied with his head lowered. "For the first ascent, it is only proper that Your Majesty witnesses it personally."
The Empress smiled slightly, "Then show me what this thing you spent so much manpower and resources on is capable of."
Chu Chen bowed his head in assent.
With a command, various eunuchs and laborers busied themselves, some lighting fires, others holding up the balloon.
Before long, the balloon's envelope was inflated and slowly began to float upwards.
The basket below also gradually lifted off the ground.
Chu Chen had people place two bound sheep inside, then increased the heat, and the hot air balloon slowly ascended.
Of course, thick hemp ropes were tied to the bottom of the basket to prevent the hot air balloon from losing control and flying out of the palace.
"It actually... can fly up?" the Empress murmured in shock, watching everything before her.
"This thing weighing several hundred jin can fly into the sky with just a ball of fire? This is too miraculous!"
"It's flying up, it's flying up, it's actually flying up!" Princess Xin Yue also exclaimed excitedly.
Chu Chen smiled without speaking, but inwardly he scoffed.
In his opinion, the cultivators in this world were even more miraculous. Just by meditating, they could increase their lifespan and strength. A mere hot air balloon was less than one ten-thousandth as miraculous as a cultivator!
"If it can carry sheep into the sky, then people should have no problem, right?" the Empress asked anxiously.
Chu Chen nodded slightly, "A hot air balloon of this size can carry five people. The fuel inside can sustain flight for a quarter of an hour."
"If it carries only three people, with sufficient fuel, it can fly for an hour."