The cattle in Seoul were slaughtered, and the soldiers of the Song Kingdom who were not skilled in their skills were good at killing, but they were raw when they peeled cowhides, destroying the integrity of many cowhides, and Su Jinqi scolded.

By noon the next day, more than 30 huge cowhide balloons had been sewn up, and the giant bamboo baskets hanging below were still being made. Speaking of manipulation, there is actually nothing to maneuver, because except for controlling the rise or fall of the balloon by controlling the size of the brazier's burning, the rest can only be helped by the wind, because there is no way to control the course of the balloon.

There is only one condition for selecting soldiers, not to be brave and fierce, but to look at their weight; The thin soldier was discriminated against in the army, but unexpectedly, the salted fish turned into a fragrant dumpling, and the thin soldier like a monkey became a sought-after commodity, and was selected by the marshal to enter the balloon air team in the envious eyes of everyone.

Ma Han, Zhao Hu and others were directly ignored by Su Jin because of their overly strong physique, which made them depressed, seeing that these guys who were selected were smiling, Ma Han angrily slapped the most powerful thin monkeys in the face, and scolded: "If things are not done well, Lao Tzu will skin you." ”

In the early afternoon, the balloon production was finally completed, Su Jin used a bamboo pole tied with cloth strips to plug it into the roof to test the wind direction, the northeast wind was slightly stronger, and the wind might be stronger when it rose into the air, but the wind was very stable; It is not easy to find a good weather in such a season, and time waits for no one, because the scouts sent out have already discovered the figure of the pathfinder scouts of Yelu Chongyuan's army who returned to Shangjing, that is to say, Yelu Chongyuan's army is already two hundred miles away in the territory west of Taizhou, and at the speed of cavalry, even if it snows heavily, it can be reached in four or five days at most, and the imperial city must be captured by then.

"Load up and get out of town." Su Jin commanded.

Pan Jiang led 5,000 soldiers to escort Su Jin and hundreds of others out of the city, and they had to rush to the open space north of the imperial city to let the hot air balloon rise into the air and fly over the imperial city with the help of the wind; The configuration in each bamboo basket is three soldiers, 50 water bladders converted into fire oil bags, and a barrel of fire oil used as fuel, with a total weight of less than 500 catties.

After everything was ready, the first hot air balloon that Su Jin rode began to ignite, and the soldiers held the opening at the lower end of the cowhide ball, so that the hot gas produced by the burning of the fire oil was poured into the cowhide ball, and the cowhide quickly expanded and stood upright, driving the hanging basket to rise slowly, Su Jin shouted: "Cut the rope." ”

The four pulled ropes were cut at the same time, and the balloon staggered into the gray sky, higher and higher.

Su Jin stretched out his thumb and made a nice gesture, and the soldiers below were thunderous with joy, and they began to ignite and rise into the air, and for a while, more than 30 giant wind lanterns slowly rose in the sky north of Shangjing, and with the wind of the north wind, they flew towards the imperial city in a fluttering manner.

The balloon flew not smoothly, the wind speed in the air was very fast, making it difficult to control the balloon, and the flames of the brazier burning below also swayed to the side, Su Jin regretted not adding a fireproof cover around the brazier, it would be much better; Just as he was regretting, he saw a balloon behind him suddenly catch fire and burn, and a ball of fire crashed down on the ice field, igniting the billowing smoke of the fire.

Su Jin scolded angrily: "Stupid, stupid." While ordering the guards around him, he took out the flag and waved the flag to signal to lower the height.

The airflow at the low altitude stabilized a lot, and the balloon gradually stabilized, but this kind of height of only twenty zhang high was very easy to be shot by the archers on the head of the city, but the bed crossbow could not be in the air, and the power of the bow and arrow was limited, so this risk was worth taking.

The sky gradually darkened, more than thirty red monsters flew up to the head of the imperial city, the soldiers guarding the city had already seen the monsters floating in the air, they first felt strange, and then felt frightened, these guys with flames are not birds or clouds, it is difficult to predict whether it is a curse or a blessing.

The news soon spread throughout the imperial city, and everyone walked out of the house and looked up at these visitors from outside the sky, and some people even thought that the gods had descended, kneeling in the snow and kowtowing.

The west building of the palace also got the news, the queen mother and the prince Yelu Hongji were talking, and when they heard the news, they also came out to watch the vision with the support of the palace maid, but saw that more than 30 monsters came from the north, slowly floated to the sky above the palace, and suddenly slowly fell down, from more than 20 zhang high to more than 10 zhang high, Yelu Hongji looked at it more and more wrong, because he had seen that it was not a god descending, but a huge balloon hanging under the bamboo basket, and someone in the bamboo basket was looking down with a probe to look down.

"Not good! It's Song Jun. Yelu Hongji suddenly realized that the armor was the standard of the Song army, and it was the Song army that came down from the sky to attack.

"Protect the Queen Mother into the palace! Guarding the Queen Mother, he quickly ordered General Yelu to bring troops to help. Yelu Hongji gave a series of orders, his immature face turned white with fright, and he reached out and pulled out the scimitar on his waist.

He thought that the Song army was going to fall to the ground to attack, but what happened next made him unexpected, the Song army in the sky above blew a sharp whistle, and the whistles reverberated in the night sky one after another, and the next moment dozens of fireballs fell from the sky, and the skin that was lit with fire burst in the air, and a rain of flames suddenly fell in the sky, falling on the top of the temple, the treetops, and the grass, and everything that was combustible was burned; The palace maids and attendants screamed and ran away in a panic, and the rain of flames fell on them, turning them into burning men, rushing around the palace and igniting more places.

Su Jin held the bamboo flute in his mouth, every time he blew it, more than 30 fire oil bags were ignited and thrown into the palace below, after dozens of fire oil bags were all dropped, the palace below was already a sea of fire, the palace people on fire ran and shouted, the guards were busy and futile to fight the fire, and the pigs of the harem concubines and princesses and queen mothers were all in sight.

At the same time, the Liao soldiers on the ground also came from all directions, and Su Jin hurriedly ordered: "Evacuate in the air." "It is extremely dangerous at an altitude of more than ten feet, and once you are shot at the cowhide ball, you will crash here.

The soldiers increased the fire of the brazier, and the hot air balloon quickly rose into the air, taking advantage of the wind to slowly cross the entire imperial city and reach the sky over Seoul; The Liao army below raised their heads and rode their horses and ran with the balloon, until the balloon crossed the high wall and entered the sky over Seoul, and then they could only look at it and sigh; The Liao army stationed on the city wall and the enemy tower shot arrows into the air in vain, but the height was too high, and it could only be a show.

When landing, three hot air balloons accidentally crashed, causing a fire in a residential area of Seoul, which made Su Jin depressed, but he also knew that these things were inevitable, and this kind of simple device would only dare to take risks if he was forced to be helpless, if it was in the future life, he would definitely be scolded as a madman; But with this successful air raid and personal operation, Su Jin had many ways to improve, such as adding a windshield to the brazier, adding a foldable wind shield to the edge of the bamboo basket to increase or slow down the speed, and so on.

What makes Su Jin even more proud is that the fire oil he worked so hard to refine finally appeared in this era for the first time as a power fuel, Su Jin has tried many times to recall the structure of the steam engine or diesel engine in later generations, but he knows that with his own ability and the technology of this era, I am afraid it will be difficult to complete this dream, he can only write down his thoughts and ideas and tell the people around him, maybe there will be a genius who will be able to understand this idea and build a power machine soon.

The hot air balloon as a product of the super era that can soar in the sky is shocking, but at the time of life and death, Su Jin really can't take care of much, after the arrival of Yelu Chongyuan, more than 80,000 people will face the desperate situation of the annihilation of the whole army, at this time, let alone a hot air balloon, as long as the conditions allow, Su Jin even dared to drop an atomic bomb.

Su Jin has no doubt what kind of impact this air raid will have in this era, no one has ever attacked the enemy from the air, and he is not worried that it will change the course of this era, because in the final analysis, this simple hot air balloon still needs a lot of technology and materials to support, the refining of oil is a big problem, and the lack of power to rely entirely on wind power will also make this thing have great limitations, it can change the situation of the battle, but it cannot change the pattern, which is why Su Jin dares to use it.

And another thing that Su Jin has secretly developed, but Su Jin does not show it, that is the steel pipe firearm equipped with Su Ji's ocean-going fleet, which is the prototype of the musket, even if he understands that this thing will become popular in the world one day, Su Jin is only limited to the equipment of a small number of cronies in the ocean-going fleet or his own personal guard, Su Jin does not want to be the initiator of this kind of murderous weapon.

After this successful air raid, the imperial palace of Shangjing of the Liao State in the imperial city was burned to rubble, but this was only the beginning, and in the next two days, the hot air balloons were frequently dispatched, and the targets of the attack were all over the imperial city, and the fire in the imperial city was never extinguished in these two days, and a large number of houses were burned down, and there was almost no place to live.