After Lin Yanyu left Xinzhou, he went to Wu Yueguo.

As Huang Fuhui guessed, although Qian Hongyu met with him, he mentioned the threat of Wu in the north, and hoped that Han would mediate between the two countries.

In fact, Qian Hongyu only wants to recapture Fuzhou now, and he has long wanted to continue to fight with Wu.

But he had just been taken Hangzhou, and if he took the initiative to make peace with the other party, it would inevitably make people laugh, so he did not send an envoy for a long time. Now the arrival of the envoy of the Han Kingdom is exactly what he wants.

Seeing this, Lin Yanyu had no choice but to go to Wu again.

Going around in April, when Lin Yanyu came to Hangzhou with the envoy group, he found that the city of Hangzhou was in a lively scene.

He was feeling a little curious, when he suddenly noticed that the carriage had stopped, and there was a sound of gongs and drums beating outside.

Lifting the curtain of the car, three young men in red robes rode on tall horses and waved to the people on both sides of the street, and the surrounding crowd responded enthusiastically.

Lin Yanyu sent his subordinates to inquire and learned that these three people were the champion of the new department, Bangyan and Tanhua, Lin Yanyu wrote down the name of the champion Du Hongzhang, and made a detour to the palace.

……

Imperial Palace, Engineer Academy, Ironmaking Department.

Lu Yuan sat on a chair in the kiln room, holding a drawing in his hand, his brows sometimes furrowed, sometimes relaxed.

When he asked Qi Guangzi to cast the barrel before, Qi Guangzi asked him if he wanted a bigger one or a smaller one.

In line with the principle that caliber is justice, Lu Yuan did not hesitate to choose the big one, so Qi Guangzi began to develop the cannon barrel using the casting method.

Lu Yuan also recently learned that there were two main methods of iron-making in this era: one was called the forging method, which directly made the iron plate into a tile, rolled it into an iron cylinder, and then joined it to create a round iron pipe.

However, this method can only produce smaller iron pipes.

The other is called casting, where molds are made first and then put into a kiln for refining.

Back then, if Lu Yuan had chosen the building method, he might have been able to build a small-caliber gun very early.

In order to make large-caliber iron pipes, Qi Guangzi could only use the casting method to study, and finally, after more than a year of trial and error, he finally created the first cannon pipe.

What Lu Yuan held in his hand was the casting drawings drawn by Qi Guangzi, and he finally knew how difficult it was to develop the cannon barrel, no wonder Qi Guangzi wasted it for so long.

In general, by the drawing method, it takes five steps to make a barrel:

The first step is to make a cannon mold with dry nan wood.

The second step is to install other molds such as ear and hoop on the gun mold, and then evenly paint the gun mold with coal ash.

In the third step, mud is mixed with glue yellow mud, fine sand, wool and other materials, pasted on the gun mold, and then thick iron wire is used to wrap it from the head to the tail of the gun mold.

The fourth step is to use a finger-sized iron bar to compare the length of the gun mold and place it on the gun mold as a skeleton. Then, an iron hoop one inch wide and five minutes thick was used to wrap it from the head to the tail of the gun mold.

The fifth step is to take out the wooden core, put the charcoal fire into the mud mold, burn the mud mold dry, and burn the gun lug, cannon hoop and other molds into ashes. After cooling, the ash is swept out and finally cast in the kiln.

At this point, the barrel is considered to be done.

These five steps are still Lu Yuan's simplified statement, specifically, far more than these five steps, such as the mud has to be repeated several times, and the kiln casting is extremely complex and complicated, which can be subdivided into more than a dozen steps, and it takes nearly ten days.

But no matter how difficult it was, the first barrel was finally built.

The round barrel was lying quietly in the kiln room at the moment, the barrel was narrow at the top and wide at the bottom, in order to be safe and prevent the chamber from exploding, Lu Yuan specially instructed Qi Guangzi to thicken one side of the medicine room, so this barrel looked a little bloated.

However, Lu Yuan didn't care if it was beautiful or not, what he cared about was the meaning behind this gray-black metal barrel.

The king of war, artillery, will be born in this era in advance, and with the casting method, the first caliber will reach about one foot three inches (twenty centimeters), and the power can be compared to the artillery of the late Ming Dynasty.

But then again, at present, this barrel is not completely from the artillery, the bore has not been polished and clean, the muzzle is not even, and there is no fire door or light door in the medicine room.

But this is not a problem, the hardest part is over, and the next thing is to use the knife to cut into the muzzle of the gun and smooth the inside of the gun. Then use a pure steel rough drill, dip it in oil to drill the fire door, and the artillery can enter the test firing stage.

Thinking of this, Lu Yuan was a little excited.

"Qi signed the order, thank you for your hard work." He said from the bottom of his heart.

"If I can help the king, I will be satisfied." As a result of many days of refining in the kiln, Qi Guangzi's face became darker and wrinkled.

"Your Majesty, the minister doesn't understand, what role can such a bulky iron pipe play?" Li Muyi was puzzled.

Lu Yuan laughed, Li Muyi used cold weapon thinking to think about the role of this cannon barrel, naturally confused, he swept his eyes, and found that only Lu Yun'er showed a thoughtful expression, and everyone else was a little confused.

"Envoy Lu, do you know?" He asked.

Lu Yun'er gently poked her chin with her fingers and was silent.

"This kind of iron pipe is used with iron balls." Lu Yuan reminded.

Lu Yun'er's eyes lit up, and he exclaimed: "I know, this is a long-range weapon, using the power of gunpowder explosion to shoot iron balls out!" ”

"That's it, and then you'll realize how terrifying the power of a gunpowder explosion really is." Lu Yuan was full of smiles.

Li Muyi recalled in his mind the scene of the explosion of the Divine Fire Thunder, the gunpowder was indeed very powerful, it could blow up the iron, and maybe it could really push the iron ball out.

Lu Yuan instructed Lu Yun'er: "Envoy Lu, this kind of artillery is relatively heavy, I will draw a drawing of a gun carriage later, and I hope you can make a gun carriage according to the drawings." ”

"Okay." The female envoy replied softly.

Lu Yuan turned to Qi Guangzi again: "Qi ordered, you immediately follow what I said before, polish the inside of the barrel smooth, and the muzzle must also be smoothed, I hope to conduct an artillery test as soon as possible." ”

"Obey."

"Signing Li, you immediately make some solid iron balls according to the caliber of the artillery."

Li Mu bowed down to receive the order.

……

The north gate of the Imperial City.

Lin Yanyu was asking to see him outside the city gate, he came to Hangzhou temporarily, and he did not report it in advance, otherwise, as an envoy of the Han Kingdom, he could directly live in the post house and wait for the meeting.

The guards of the Imperial City carried the news to the Ministry of Rites, and Qian Yu dragged his fat body through a long corridor and entered the room where Yu Bo worked in Langzhong of the Ministry of Rites.

When I entered the door, I saw that in addition to Yu Bo, there was also an acquaintance standing in the room.

"Zhu Yuanwailang, you're here again." Qian Yu greeted with a smile.

Now that he has lost his status as a relative of the emperor, he has to support himself with his own hands every day, and in order to save expenses, he even sold the Anle Palace, and currently lives in a three-acre mansion.

"Yes, come over today and hand over the imperial examination with Yu Langzhong, Zhang Shangshu hopes to let those examinees take up official positions as soon as possible." Zhu Anming replied with a smile.

Yu Bo looked at Qian Yu and asked, "Is there something Inspector Qian is looking for me?" ”

Qian Yu hurriedly said: "The envoy of the Han Kingdom has come and asks to see the king. ”

Yu Bo immediately stood up and said to Zhu Anming: "Zhu Yuanwailang, please wait for a while, I will tell you about this first, and then come back to discuss with you." ”

"Please be in the waiting."

Soon, only Qian Yu and Zhu Anming were left in the room, and the smiles on their faces disappeared, as if they didn't know each other, and they didn't say a word, and the atmosphere in the room was a little awkward.

After a long time, Yu Bo finally returned.

"Your Excellency is not in Wende Palace, so I came back a little late." Yu Bo apologized.

"Didn't you go to the Engineer Academy again?" Zhu Anming asked.

"Yes, the king seems to be fascinated there, and he didn't even pay much attention to the imperial examination, let alone the envoys of the Han State, so he let the Ministry of Rites receive him." Yu Bo said in a deep voice, showing a little worry in his tone.

"Since Yu Langzhong is going to receive the envoys, then the lower officials will retire first, and they will come back tomorrow to discuss the imperial examination with you." Zhu Anming retired very interestingly.

"Zhu Yuanwailang walks slowly."

Returning to his own public house in the ministry, Zhu Anming continued to work.

During this period of time, the Wu Yue officials in Hangzhou began to find him again, because he was the only one among all the demoted officials who served in the ministry.

Zhu Anming completely ignored these people, not because he didn't want to cultivate power, but because he knew that above his head, Zhang Dezhong, the secretary of the ministry, had been staring at him, so that he didn't dare to act rashly.

At the beginning of the work (5 o'clock), the bell rang, Zhu Anming packed up his things and returned to the house. As soon as he entered the lobby, Zhu Zuo, who got the news, rushed over.

"Father, has the matter of the imperial examination been decided?" His hurried voice rang out.

He also went to participate in the imperial examination this time, and took the forty-three places.

"It has been decided, and the top ten will be awarded the seventh rank to the eighth grade official position, and then go down in turn, and the worst can also get an official." Zhu Anming said as he drank tea.

"Who will be a clerk! Then you might as well retake the exam! ”

Zhu Anming shook his head: "Now it is because there are too many national official shortages, so there will be so many officials in the imperial examination, and when the officials are saturated in the future, I suspect that all the moves will start from the officials." ”

"Won't it?" Zhu Zuo was surprised.

"It shouldn't be wrong, I heard that the king has been working on lowering the boundary between officials and officials before, and recently he is preparing to increase the salary of officials and lower the salary of officials."

Zhu Zuo asked nervously: "Then with my rank, can I get an official this time?" ”

"It should be able to divide the nine-rank official."

Zhu Zuo breathed a sigh of relief and said with a smile: "By the way, Fan Yuping was taken away by the people of the Spiegel Academy today. ”

"What's going on?" Zhu Anming was taken aback.

Fan Yuping was the second place in the imperial examination of Hui'an Prefecture last year, and now he is the official of Zhu Anming.

After Zhu Anming became a foreigner, in order to be promoted as soon as possible, he began to investigate the personalities and preferences of other officials in the ministry, among which Fan Yuping was the focus of his investigation.

This investigation made him discover some strange things, Fan Yu's parallel affairs were extremely mysterious, and it seemed that there was something unsightly hidden.

Zhu Anming became more interested in him, sent more people to investigate and follow him, and with the strength of operating in Hangzhou for many years, he finally discovered Fan Yuping's secret - he turned out to be a spy planted by the enemy country in the officialdom of Wu State.

As long as his identity is revealed, it will be a huge credit, and Zhu Anming immediately realized this.

But he still has a suspicion, this matter may expose his hidden power, maybe it will make King Wu have a grudge against him.

It was such a delay that Fan Yuping was preempted by the Spiegel Academy.