If Heaven hadn't given birth to me, I would be arrogant.

After much persuasion, Zong Ze finally made Zong Xiaozhang understand that the walls of the Divine Machine Camp were irreplaceable unless a second Iron Sand Mountain could be found on the Holy Word Continent. Even if an Iron Sand Mountain were found, it would be barely enough to build a wall the size of the Divine Machine Camp; to encircle a city with walls, even several more Iron Sand Mountains wouldn't be sufficient!

After all, the entire Shenji Camp is much smaller than a city. Running around the walls of the Shenji Camp is only ten kilometers. This amount of earth is probably not even enough for one wall of a city!

However, under Zong Ze's persuasion, Zong Xiaozhang still kept the matter of the city wall a secret for his grandson. When reporting to Lan Qizhan, Zong Xiaozhang simply mentioned it briefly, saying that the city wall was much stronger after being tempered by fire!

After all, besides Zong Xiaozhang, the empire couldn't find another martial god openly displayed, and no one would bother testing the city walls' sturdiness. Plus, Zong announced the official commencement of hot air balloon manufacturing. So, the matter was simply covered up!

No one could have imagined that so many people would suffer greatly on this very steel wall. Even Zong Xiaozhang hadn't anticipated that this steel wall was not only sturdy, but that Zong Ze had also tampered with it, leading later generations to call this city wall the "death wall that could never be breached!"

A few days later, all the soldiers of the Divine Machine Battalion returned and resumed their normal training and life. It must be said that Zong Ze was incredibly lucky; he had designed several sets of crossbows that were far superior to the original crossbows on the Holy Word Continent in both stability and range!

However, what troubled Zongze was that these crossbows needed to be forged by a blacksmith. But if they were forged by a blacksmith, Zongze believed that the forging techniques and processes would soon be leaked. Of course, even more crucial was the forging of the hot air balloon components!

However, after Zong Ze discussed this issue with the generals of the Shenji Battalion, all the generals laughed!

It turns out that in this war-torn continent of Holy Word, ordinary civilians, in order to survive, would generally choose to farm or weave, while men would usually choose to blacksmith as their source of income!

In other words, apart from Zong Ze, all the 50,000 soldiers in the Shenji Battalion could wield a sledgehammer and work as blacksmiths. Some of them even learned blacksmithing from a young age because their families had been blacksmiths for generations, and they could forge advanced weapons!

Well, that's great! With a single order from Zong Ze, the original training time for the Shenji Battalion soldiers to run through the Iron Sand Mountain was changed to blacksmithing time. For a period of time, the people outside the city walls could hear the clanging and banging of blacksmithing every day!

Finally, under Zong Ze's command, the first hot air balloon on the Holy Word Continent was born! The entire hot air balloon was made of twenty buffalo hides, and a large basket that could accommodate thirty people was suspended below the balloon. The fuel used to ignite the balloon was the most abundant kerosene on the continent!

The ascent and descent of a hot air balloon are determined by the size of the flame jet! Zong Ze doesn't have the ability to build a flamethrower, but that doesn't mean he can't build a blower!

The hot air balloon had a human-powered blower attached to its exhaust nozzle, powered by four pedals modeled after those used for exercise on Earth. With all four soldiers pedaling together, the balloon ascended quite quickly!

A hot air balloon can hold thirty soldiers, which makes up a squad. The soldiers in the squad take turns powering the blower, allowing the balloon to keep flying in the sky until the fuel runs out!

On September 28, 15601, the calendar of the Holy Word Continent, it was an exciting day for the entire imperial nobility, because it was the day that the Imperial Air Force's Divine Machine Battalion would take to the skies. The first passengers on this hot air balloon were General Zong Ze, the Marquis of the Divine Machine Battalion, and the commanders of the five divisions of the Divine Machine Battalion!

Originally, including Lan Qizhan, everyone from the imperial nobles to the Zong family and all the soldiers of the Shenji Battalion advised Zong Ze not to be the first to try riding it, since this thing was still very risky, and one wrong move could cost you your life!

However, Zong Ze ignored all advice and insisted on being the first to ride it. He said, "I was in charge of designing and building this hot air balloon. If there are any risks, I must be the first to take them. I don't have the habit of letting my soldiers take risks for me. This is my responsibility as the supreme commander of the Shenji Battalion!"

Naturally, Zong Ze's words deepened the soldiers' personal respect and admiration for him. But no one knew that Zong Ze had no choice; he really had to be the first to try something new!

Because, although two years ago in the main hall, when Flor asked him how to control the direction of the hot air balloon, Zong Ze confidently and mysteriously said that it was a secret!

However, Zong Ze actually didn't know how to control the direction of the hot air balloon! He only remembered that people who had used hot air balloons on Earth had said that the direction of the hot air balloon was determined by its altitude!

After all, at that time, Zong Ze was a unique super immortal on Earth. Not to mention hot air balloons, even supersonic fighter jets could not keep up with Zong Ze's speed of flying on his sword. Therefore, Zong Ze had only heard about it at the time and had never tried it!

Therefore, Zong Ze had to personally take charge this time. As a former wandering immortal, Zong Ze had a much higher sensitivity to air flow. Only after personally practicing this could he gain a concrete understanding of how to control the flight direction of the hot air balloon and then teach it to the soldiers of the Divine Machine Battalion when he returned!

Under the eager gazes of Lan Qizhan and all the nobles, Zong Ze led five division commanders onto the hot air balloon. Shi Mo, who had become the commander of the fifth division, took out the fire rope that he had prepared in advance and ignited the oil in the flamethrower with a whoosh!

After the other four division and battalion commanders lit the flare, they sat on the four foot pedals and began to pedal rapidly and forcefully. Before long, amidst the expectant gazes and exclamations of the crowd, the hot air balloon carrying Zong Ze and the others slowly took off and flew into the distance!

The hot air balloon moved at a moderate speed, neither too fast nor too slow! Before long, it disappeared from sight! At this moment, the most excited person was none other than Emperor Lan Qizhan of the Rune Empire!

Although the hot air balloons were no longer in sight, Lan Qizhan's gaze remained fixed on the sky, muttering to himself, "This is my Divine Machine Battalion, this is my air force! I... have an air force now!"

Fox, standing to the side, hurriedly offered his flattery: "Congratulations, Your Majesty! The Rune Empire has acquired its first air force since the advent of gods and demons. Your Majesty will surely become an emperor for all ages!"

At this moment, Lan Qizhan seemed to have thought of something, and turned his gaze to Zong Xiaozhang: "Old Marshal, did Zong Ze say before he left when they would be back?..."