On the second day of the Lantern Festival, Wang Chengen rushed to the Shijingshan Cannon Foundry early in the morning with two carriages full of supplies. In order to facilitate the transportation of coal, iron and other raw materials and the transportation of cast cannons, the ordnance superintendent specially connected a short-distance railway of more than 1 mile.

Since the Ordnance Supervisor had not yet developed the technology of railroad intersection, the materials brought by Wang Chengenhe had to be transferred to the short-distance railway leading to the cannon foundry.

However, the gantry crane developed by the Ordnance Supervision Department greatly reduced the labor intensity and handling time of transferring materials, and let Wang Chengen rush to the cannon factory before noon.

Wang Chengen, who stepped out of the carriage, glanced at the officials who came to greet him, and couldn't help but ask in surprise, "Why didn't you see Director Sun?" Didn't he know that the miscellaneous family came to offer condolences on behalf of His Majesty? ”

Director Ge, who is in charge of material management in the foundry, immediately explained for Sun Yuanhua: "There is an artillery cannon being poured today, and Director Sun is leading people to supervise and observe, and now it is really impossible to separate.

However, Director Sun had already instructed the lower officials to ask his father-in-law to go to Xiaoxuan at the foot of the stone mountain to rest, and when he finished his business, he would immediately come over to meet his father-in-law. ”

Hearing that Sun Yuanhua was casting cannons, Wang Chengen couldn't help but be moved, although the emperor seemed to have not paid much attention to the development of artillery, but he never cut off the resources for Sun Yuanhua to develop artillery. Based on Wang Chengen's understanding of Chongzhen during these days, he felt that the emperor was still very interested in artillery.

Since Sun Yuanhua and the others were casting cannons, he immediately became interested, and he felt that instead of sitting in a daze with these petty officials, it was better to go to the cannon casting site to have a look. When he returned to the palace, he would also report to Chongzhen to show that he was still very diligent in his work.

Since the cabinet promulgated the secrecy system, the ordnance superintendent has been the most strictly enforced department, and the cannon foundry has a strict system. First, it is to control the raw materials from being stolen; Second, the artillery casting technique is a major event related to the lifeblood of the military state, and it is also the only artifact that the Ming army relies on to deal with the northern nomads, so it is naturally more closely defended.

From the outside of the factory to the artillery casting site inside the factory, there were three security posts, and a mile away from the artillery foundry, there was a military camp with 650 people stationed in it. The task of this army was twofold, to defend the cannon foundry and to defend the Beijing-West Railway.

Generally speaking, unless there is an order issued by the Cabinet, the General Staff, and the Ordnance Superintendent, ordinary people cannot enter the inside of the cannon foundry to see how the cannon is cast.

However, Wang Chengen is obviously outside this rule, even if he does not represent the emperor today, as Chongzhen's closest chamberlain, he has enough power to see what this cannon foundry is doing.

Therefore, he only mentioned it lightly, and Director Ge personally took him to the foundry of the inner factory. Wang Chengen was very aware of the general situation and left his entourage outside, but he entered the most heavily guarded cannon factory by himself.

The so-called inner factory of the casting cannon is actually a single factory of three joints. Each single plant has a width of 9 meters and a length of 24 meters. At the front of the building, where raw materials are received for re-refining, there are two reverberatory furnaces, one for refining pig iron and the other for smelting copper.

The second workshop was where the artillery was poured, and rails were laid on the ground between the two workshops to transport the melted metal solution.

When Wang Chengen walked into the cannon casting workshop under the leadership of Director Ge, he saw Sun Yuanhua personally holding a hammer to dismantle the outer iron mold of the suspended cannon casting, and several officials and craftsmen beside him were nervously watching him dismantle.

Wang Chengen stopped Director Ge's move to come forward to report, he quietly stepped forward, and a group of artillery casters were staring intently at Sun Yuanhua's movements, and no one noticed Wang Chengen's arrival.

After walking to the edge of the crowd, Wang Chengen realized that the heat emitted from the iron model was still quite amazing, and it was still about freezing temperature outside, but standing here made him feel as if it had reached the scorching heat.

He felt that the heat was pressing when he stood here, and Sun Yuanhua, who was dismantling the mold, was not equivalent to taking a steam bath, and he admired these Sun Yuanhua a little. Obviously, he was born as a scholar and lived as a scholar with priority, but he was willing to do the work done by these craftsmen, which can be regarded as loyal to the king.

While Wang Chengen was still thinking about it in a mess, Sun Yuanhua finally carefully dismantled the four-piece eight-petal iron mold completely. After the iron mold was removed, the cast iron cannon body still maintained a dark red color, indicating that the temperature of the cannon body was at least hundreds of degrees at this time.

While he was still looking at the barrel of the cannon, the Portuguese gunsmith Peter King, who assisted him in dismantling the iron mold, had quickly finished inspecting the barrel of the cannon, and then congratulated him very happily: "Lord Sun, this cannon has no cracks, and the appearance is also very smooth, it should be regarded as a success."

After it has cooled down completely, and then check the condition of the lower chamber, we can report the good news to His Majesty the Emperor. This method of casting cannons is much faster than clay molds, and the cost is also greatly saved. I can assure you that even the iron cannon cast by the Bogaro Cannon Foundry is not as polished as this one. ”

Peter's praise did not receive a positive response from Sun Yuanhua, and he frowned as he stared at the cannon. Sun Yuanhua's abnormality immediately attracted the attention of Zhang Tao and Zhao Zhong who were standing beside him.

In the past few days, he stopped celebrating and asked him cautiously: "Director Sun, is there anything wrong with this iron mold cannon?" Why is your face so ugly? ”

The questions raised by Zhang Tao, Zhao Zhong and others also heard Wang Chengen's ears, and he suddenly stopped and put down his right hand that was about to greet Sun Yuanhua. He stood solemnly in place, and also wanted to hear what was wrong with this iron cannon, so as not to go back and report the wrong good news to Chongzhen.

Sun Yuanhua looked straight at the hanging cannon, and subconsciously replied: "Didn't you notice? The speed of cooling down of the cannon body is too fast, if it is a clay mold cast cannon, it will take at least two to three days to dismantle, but Tie Fan can dismantle the iron mold in only half a day. ”

"Isn't that great? At this rate, a set of iron molds can cast 3 cannons a day, compared with disposable clay molds, reusable iron molds will greatly save costs. And it also meets the requirements of His Majesty, try to unify the specifications of the cast iron cannon and the requirements of the same performance. Zhang Tao replied with some confusion.

Peter and the others also nodded in agreement, believing that cooling down too quickly was not a defect, but a good thing that it could speed up the turnover of iron molds.

Only Jiao Miao, Tang Ruowang and a craftsman next to them fell into deep thought. Sun Yuanhua shook his head and replied: "No, cooling down too quickly is not a good thing for the artillery itself... Sun Tiezhong, it seems that you also seem to have thought of something, why don't you tell everyone why. ”

Sun Yuanhua, who originally wanted to say his speculation, but the craftsman who swept to Tang Ruowang's side seemed to agree with his words, so he was a little surprised and asked the craftsman to say his opinion to see if he really understood his thoughts.

After working with Sun Yuanhua for so long, Sun Tiezhong was familiar with the personality of the adult with the same surname as himself, so he didn't shirk it, so he stood up stunned and said: "Last year, the adults asked us to study whether this method of annealing cast iron will affect the properties of cast iron.

At that time, we did many experiments, and finally found that the method of annealing and the length of annealing time can indeed have a great impact on the properties of cast iron after cooling.

The villain thinks that what Lord Sun is worried about is that the annealing time is too fast, which causes the gun body to be brittle, lacks flexibility, and is easy to cause explosion? ”

Sun Tiezhong's statement immediately sparked a discussion among the crowd on the side, and this speculation quickly diluted everyone's joy just now because of the success of the iron mold casting.

Seeing that the faces of his colleagues began to darken, Sun Yuanhua immediately realized that what he seemed to say was too serious. After all, everyone present had been busy with him for nearly half a year before he fixed the process of making iron molds, and now they had just a little hope of success, but they were suppressed by his speculation, wouldn't it be too much to hit their confidence.

Although under the research and practice of the past year, Sun Yuanhua can now be called a real artillery expert, but these colleagues around him have also helped him a lot. It was with their assistance that his dream of making artillery could become a reality little by little.

If he scares them away, who will work for him in the future? After all, most people's knowledge here is not limited to the art of cannon casting. With the many projects of the Beijing Academy of Sciences, it is better for them to go there casually than to follow him to cast cannons.

Thinking of this, Sun Yuanhua hurriedly comforted: "Actually, it's not so bad, when we check the standards tomorrow and the day after tomorrow, we will know whether the iron mold is good or not... Princess, why are you here? ”

When Wang Chengen rushed back to the palace at night, he explained to Chongzhen what he had seen and heard in the cannon foundry. Zhu Youzhen thought for a long time before saying: "Sun Yuanhua is right, this is the difference between white iron and gray iron." The quality of the cast cannon or gray iron is better.

However, they don't need to be so entangled, the pig iron from the churning furnace will indeed degenerate into white iron, but most of the pig iron smelted by the blast furnace is gray iron itself, so they can use the blast furnace pig iron for refining and casting cannons, so that there will be no problem of exploding.

Also, inform the Ordnance Superintendent that all artillery that is determined to be white iron should be used for export as much as possible..."