When it was ugly, the candles were still lit in the house on Xu Er Road.

He sat across from an old man, discussing something excitedly, and both of them were not tired.

On the table in front of them were the notes from Su Chengyu's lecture to Xu Erlu today.

After all the notes were reviewed, the old man was still unsatisfied, "This 'periodic table' is really mysterious, at first glance it is incredible, but when you think about it, it is the foundation of all things. His Royal Highness the King of Chenzhou actually understands such an esoteric technique, and the foolish brother admires it very much! ”

Xu Erlu nodded in agreement, "Although His Royal Highness the King of Chenzhou said that he learned it from elsewhere, as far as my brother knows, there is no such doctrine in the world. He looked west, "My ancestors have always believed that the Europa people are very good at engineering and style, and they strongly advocate learning from the West. But at the moment, it seems that the Ming Dynasty is even far superior to the Westerners in this regard. ”

The old man looked at the notes on the table and hesitated: "The foolish brother wants to compile the techniques taught by His Royal Highness into a register to teach the people of the Ming Dynasty, but I don't know if it is appropriate......

After more than ten days, the mud fan has basically been smoked dry. Su Chengyu instructed the craftsmen to start burning the fan.

A series of processes, from firing to casting molten iron, are all very familiar to the craftsmen. In just one day's work, a cast cannon iron fan was cast.

However, due to the accelerated drying, the other two clay models were scrapped due to cracking during the casting process.

Xu Erlu immediately commanded everyone to correct and polish the iron model, and by the end of the night, all the preparations were basically ready.

The next day, all the cannon craftsmen gathered to start the first casting.

According to the process of iron mold casting in his memory, Su Chengyu first had the iron fan burned with charcoal until it turned red, so as to prevent the molten copper on the surface from solidifying too quickly and affecting the casting.

Subsequently, under the personal command of Xu Erlu, the liquid bronze was poured slowly and accurately into the pouring mouth of Tie Fan by craftsmen.

The casting was done quickly. After another half an hour, the cannon body was solidified, and when the craftsman dismantled the iron fan, the gun field was suddenly thunderous.

The entire gun body is smooth and flat, without any flaws, and it is simply more beautiful than the previous polished guns.

The craftsmen gathered around for the finishing touches. Xu Erlu looked at the flat cannon chamber and was amazed.

You must know that if you use the clay fan casting method, it will only be half completed at this time, and it will take ten craftsmen to work for more than ten days just to polish the gun chamber. And at this time, the artillery in front of me can be regarded as cast!

When the barrel was completely cool, Anthony took a small mirror and reflected sunlight into the barrel. The light shines straight to the bottom of the barrel, indicating that the barrel is not bent or out of shape.

Here, Su Chengyu instructed the craftsmen to tie the iron fan tightly with iron hoops, heat it on charcoal fire, and prepare for the next casting.

On the other side, the craftsmen didn't even eat dinner, loaded the cannon that had just been drilled into the fire door on an ox cart, and dragged it to the barren beach on the west side of the Ordnance Bureau to test the cannon.

Anthony knocked and knocked on and looked along the way, nodding frequently, apparently quite satisfied with the quality of the artillery.

Once the cannon was erected on a wooden base, Anthony had six and a half pounds of gunpowder loaded directly into it—twice as much as the intended amount of propellant.

Seeing the hesitant expression of the craftsman of the charge, the experienced gunner smiled and asked the interpreter to tell them that he had confidence in the gun.

After the gunpowder and iron bullets had been loaded, Anthony measured the angle with a gun gauge and lit the ignition with an indestructible rope at the tip of an extremely long stick.

I heard a loud sound of a landslide and the ground cracked, and a large area of mud immediately splashed on the barren beach nearly two miles away.

Anthony immediately lay down on the gun to test, and after a moment he happily announced: the test shot was successful, and the gun was safe and sound!

Su Chengyu also breathed a sigh of relief.

Although he has learned a lot of knowledge about iron mold casting cannons, and he also has some understanding of modern casting technology, but he is also the first time that a big girl has been on a sedan chair to cast a heavy cannon. It was only at this point that he was truly relieved.

Then several more test firings were carried out, and the artillery showed great stability and was basically ready for use on the battlefield.

When Su Chengyu returned to the Ordnance Bureau, Tie Fan had already completed the preparations and was about to carry out the second casting.

Two heavy guns of nearly 2,000 catties were cast in a row in one day! This is a miracle compared to the previous speed of one cannon a month!

By the eighteenth day when Su Chengyu began to cast cannons, all seven twelve-pounder cannons had been cast, plus one cast by Xu Erlu before, a total of eight heavy cannons.

This was also caused by the running out of copper ingots for casting cannons during the period, which led to a half-day shutdown, otherwise it could have been completed one day earlier. Fortunately, Yang Tinglin immediately purchased 6,000 catties of copper ingots near Ganzhou at a high price, which allowed the cannon casting work to continue.

Southeast of Ganzhou Mansion, Yang Tinglin's camp.

Yang Tinglin watched the ox cart dragging heavy cannons from the camp gate, and his heart was simply happy.

Since he took over the military affairs of Ganzhou, he has never seen what heavy artillery looks like, let alone eight guns at a time. With these heavy artillery in hand, this attack on Ji'an Mansion will definitely be nine out of ten.

Not far away, Zhu Youshu saw Yang Tinglin looking at him with a smug smile, and couldn't help but snort heavily, and arched his hand at him, "I'll reorganize my troops and horses, and pull out the camp and go north on the same day." After saying that, he glared at Su Chengyu, pulled Zhu Youling up, turned around and left.

Yang Tinglin let Su Chengyu into the big tent and bowed deeply, "Your Highness, these cannons really saved the entire battle situation in Ganzhou!" Please accept the bows of the lower officials. ”

Su Chengyu waved his hand and said, "Yang Butang doesn't need to thank me. I am a member of the Ming clan, and I should do my best for the community. ”

Yang Tinglin asked again: "Oh, by the way, I heard Xu Erlu say that His Royal Highness wants to borrow craftsmen from the Ordnance Bureau?" ”

Su Chengyu worked hard for more than half a month, waiting for this sentence, and said busily: "I really need one hundred and sixty skilled craftsmen." ”

Yang Tinglin immediately nodded, "What's so difficult about this, the craftsman is at your Royal Highness's choice." ”

He had already received a report from Xu Erlu yesterday, saying that now the Ordnance Bureau has used the method of casting cannons by His Royal Highness King Chenzhou, and it is enough to use only sixty percent of the previous craftsmen, and it can cast a Hongyi heavy cannon every day. Therefore, even if King Chenzhou is allowed to take away more than 100 people, the Ganzhou Ordnance Bureau should not be short of manpower.

What's more, it costs a lot to cast these eight cannons, and the craftsmen of the Ordnance Bureau will have to take a holiday in a short time.

Ten days later.

Jin Shenghuan, the chief soldier of the Qing army in Jiangxi, and his deputy general Wang Deren stood at the head of Ji'an City, looking at the black soldiers and horses of the Ming army in the distance, but they did not appear to be panicked at all.

Jin Shenghuan knew very well that although Yang Tinglin brought tens of thousands of troops to come, there were only thousands of soldiers who were good at fighting, and the rest were old and weak recruits.

At present, his main force is led by Liu Yipeng, Wang Jincai, Gao Jinku and other subordinates, and there are only 4,000 men and horses in the city in the Ming Righteous Army in the northern hinterland of Jiangxi.

But as long as he can hold on for half a month, after the main force returns, these recruits of Yang Tinglin are not his opponents at all.

However, to Jin Shenghuan's great surprise, there were bursts of artillery outside the city. A look of panic immediately appeared on his face, he was very familiar with the cannon, this is heavy artillery! A heavy cannon bigger than the Hongyi cannon in his hand, and there are quite a few of them!

After the Ming army lost the two ordnance bureaus in Beijing and Nanjing, it should have lost the ability to cast Hongyi cannons. Jin Shenghuan pinched himself hard, it hurt very much, it was not a dream. Then he jumped to his feet and shouted to his officers to divide up and defend the city.

Only five days later, an unrepaired section of the southern part of Ji'an finally collapsed under the concentrated bombardment of eight artillery pieces. Jin Shenghuan and Wang Deren abandoned the city and fled, only to be spared.