On the night of March 12, the Zheng family army camped.

Zheng Chenggong circled around the hot air balloon, looked at the hot air balloon and jumped a few times in the hanging basket, and found that there was no hole, proving that the bearing capacity is still there.

"Can this thing really carry people in the sky?" Yao Qisheng looked at this behemoth, asked in surprise and confusion.

Chen Yonghua replied excitedly: "Mr. Yao, you can really take off, Xia Guan promises!" I've tested it with a few horses before, and it's really flying into the sky. It's just that the load capacity is a little smaller! ”

Chen Yonghua was full of confidence, but Zheng Chenggong was uncertain.

Today's hot air balloons are made of high-toughness plastic, which has good resistance to compression.

This hot air balloon made in the late Ming Dynasty was put together by cowhide, sheepskin, and patchwork, and if it was put on it like this, there would be an accident, Zheng Chenggong really didn't dare to guarantee it.

However, in order to capture the city of Nanjing, he had to take a risk.

In the middle of the night, under the gaze of countless Zheng family soldiers and Chen Yonghua's order, three brave soldiers stood up, lit the coal, and desperately pulled the blower to send the hot air into the cowhide balloon.

Air is a mass substance.

The same volume of air, with different temperatures, has different densities and masses.

It's like water and ice, the density of water becomes less when it freezes. If you press the ice to the bottom of the water, it will always float up because the ice is less dense than the water.

The principle of balloon lift-off is simply as follows: the air inside the balloon becomes less dense when heated, and the mass is lighter than the same volume of cold air outside the balloon, so the balloon generates buoyancy and lifts off.

The heat was sent into the large ball made of cowhide, and the shriveled ball slowly expanded.

After heating for almost half an hour, the cowhide balloon was filled with hot gas, and in Yao Qisheng, He Wenxing and others opened their mouths wide and were stunned, the balloon slowly rose into the air.

Yao Qisheng couldn't believe it, and when he just wanted to scream, he suddenly thought of banning his mouth, and hurriedly covered his mouth with his hands, for fear that his voice would attract the attention of Nanjing City.

When the hot air balloon slowly rose, the warriors who had always been bold and had rolled on the battlefield more than a dozen times.

When they were sent to the sky, they clung to the siderail of the bamboo basket, their feet were a little weak, and their faces were pale.

Even so, they did not forget the general's advice, even if they were worried, even if they were afraid, they did not forget to add coal and pull the blower.

Seeing the hot air balloon rising between twenty-five and thirty meters, three thick ropes with pitch black tied under the hot air balloon hanging basket were pulled by more than a dozen big men on land to prevent it from drifting away with the wind.

Seeing the hot air balloon stop steadily in mid-air, Zheng Chenggong breathed a sigh of relief, and finally succeeded.

Seeing that the hot air balloon was successfully lifted into the air, Zheng Chenggong signaled that the remaining two hot air balloons could also be lifted off.

When the hot air balloon was lifted off, Chen Yonghua and He Wenxing were left here to carry out the follow-up plan, and Zheng Chenggong returned to the army camp with other soldiers.

In the handsome camp, Zheng Chenggong inspected his soldiers once, and drank sternly: "This battle will lay the foundation for the rise and fall of our army, only victory, not defeat!" ”

Wan Li, Huang Ting and others shouted in unison: "Yes! ”

At two o'clock in the morning on March 13, the Zheng family's army set off in unison.

Under the leadership of Wang Qibang, Yao Guotai and others, Tieqi Town took the lead in attacking, and the Zheng cavalry galloped around Nanjing City with a proud horse.

The Ironclad soldiers were fully armored and marched forward in unison to the beat of drums.

The artillery was also pushed to the front line, and the muzzle of the gun was aimed at the city, ready to open fire at any moment.

This time, Zheng Chenggong did not prepare for a night attack, and lit torches in front of the battle, shining on the whole army.

The vigorous action of the Zheng family army woke up all the Qing troops.

Marseille, Guan Xiaozhong and the others didn't even wear their clothes neatly, so they hurriedly ran to the south city wall, hid behind the female wall to observe, and looked at the Zheng Jiajun who was waiting outside the city, and couldn't help but swallow a mouthful of water.

Marsai looked at Guan Allegiance and said angrily: "Didn't you say that Zheng Chenggong was hypocritical and would not care about the lives of these untouchables? ”

Zheng Jiajun is in a desperate position, and Guan Zhongzhong really can't guarantee that Zheng Chenggong will not attack the city.

Guan Allegiance was speechless for a moment, not knowing how to answer.

Marseille snorted, turned back to the general and shouted, "Go, gather all the soldiers, and get ready for battle!" ”

When the co-leader Fei Yazhu Baturu heard this, he hesitated for a while and shouted, "My lord, what about these people? ”

Marseille's eyes widened and he shouted: "Let them consume some pirate shells here, our soldiers will wait under the city first, and as soon as there is an order, immediately give Lao Tzu up!" ”

"Yes!" After Ferya stopped Baturu and gave up, he turned around and went to gather the soldiers.

Zheng's army lined up in front of the city of Nanjing, and waited all the time, without attacking the city.

An hour passed slowly in the panic of the Qing army, and Marsai saw that Zheng Jiajun had not moved, and couldn't help but scold: "Attack and not attack, retreat and not retreat, what are these pirates trying to do?" ”

No one answered, because the Qing army was also confused.

Zheng Chenggong rode on horseback and sighed.

After working hard all day long, he was also very sleepy.

Just to attract the idea of Qing soldiers, Zheng Chenggong had to wait here.

Just as Zheng Chenggong was about to fall asleep on horseback, Chen Yonghua rode over.

"General, you've been ready to move on to the next step!"

When Zheng Chenggong heard this, he hurriedly patted his cheek to sober himself up, and then shouted: "Let the soldiers move and prepare to attack the city!" ”

"Yes!"

As soon as the military order was given, Zheng Jiajun, who had been quiet, made a move.

The sword and shield soldiers struck their shields with their broadswords, and the ironclad slammed their swords on the ground......

Zheng Jiajun shouted in unison: "Kill, kill, kill......"

With the shouting, the war drums of the Zheng family army also sounded earth-shattering.

The shouts, beatings, and drums of the 100,000-strong army rang out in one piece, and the momentum of the mountains and seas frightened the Qing soldiers!

The Qing army was keeping an eye on the Zheng family's army, for fear that if they were not careful, they would let the Zheng family's army enter the city.

When the Qing army focused their attention on the Zheng family army in front of the South Gate City, three black shadows quietly floated in the air.

In the early morning, the sky was dark, and the sky was just covered with dark clouds, covering the moonlight and starry sky, and the city of Nanjing was pitch black.

The balloons and baskets of the hot air balloons are painted black, and the stove is also surrounded by iron sheets, so that no fire is exposed.

Three hot air balloons were scattered in three places, one over the city of Nanjing, one at the foot of a hill not far from the east gate of the city, and one in the middle of them.

Under the small hill, He Wenxing was whispering: "Go up quickly, move quickly, you must not waste the opportunity this time!" (To be continued.) )