Shi Yiwen, who frowned, listened to Zhao Shizhen's question and asked rhetorically.

"Do you see what's the most expensive in the bird's guns?"

"What's the most expensive?"

Zhao Shizhen thought for a moment, and then said.

"It should be a gun pipe, a gun pipe from the beginning of the embryo grinding plate, reel, drill the core, grinding a total of 23 work, accounting for two-thirds of the work, its price is the most expensive."

While surprised by Zhao Shizhen's memory, Shi Yiwen nodded.

"Yes, the most expensive and time-consuming is the barrel, it doesn't matter if the price is four taels of silver, the most important thing is how to reduce the cost, this is the most important, and how to reduce the cost of the barrel is the key factor."

"Childe, I'm afraid this cost is not easy to reduce, after all, this barrel is the root of the flintlock pistol."

"That's right, if you want to cut work on this, I'm afraid you will gain or lose."

Listening to the persuasion of the two of them, Shi Yiwen shook his head and said,

"I'm not talking about cutting corners, in this way, let's rest first today, and when I figure it out, we'll continue tomorrow."

There are some things, just by thinking about it, it must be incomprehensible, and in the end, Shi Yiwen still went to Zhang Sixi to understand the whole process of making bird guns from his detailed understanding.

"So, the function of refining the embryo and beating the plate is to beat the pig iron to mature the iron plate?"

"Yes, Childe, the iron classes collected by this Ministry of Engineering are all pig iron, and mature iron must be made first and then beaten into plates before it can be rolled into a pipe."

"No wonder the labor costs are so high."

"Yes, Childe, even if it is smelted into wrought iron, it has to be hammered into a board by the big guy, people say that it is easy for craftsmen to make money, but it is also to earn hard money."

"Actually, it doesn't have to be so hard."

"Childe, what did you say?"

"It's nothing, let's keep talking."

Continuing to chat with Zhang Sixi, Shi Yiwen basically has an understanding of the manufacture of bird guns, and of course he also knows where to start.

Because it was almost the New Year, Shi Yiwen did not leave Zhang Sixi, and when he returned to Beijing, he specially asked him to rest assured that even if he used them, he would pay according to his work.

Taking advantage of things, Shi Yiwen never bothered to do.

"That day, you said that cutting corners, this kind of thing, must not be done, in fact, compared to cutting corners, you can completely rely on technology to reduce costs."

Facing Zhao Shizhen and Wu Cai, Shi Yiwen said with a smile.

"Technology?"

"Yes, it's technology, you see, it takes six jobs to make the board, and it takes almost two pieces of silver. The purpose of smelting the embryo and beating the plate is to make the pig iron into a mature iron plate, since we now have an iron factory, we can start from the iron smelting and directly make a mature iron plate. ”

Shi Yiwen explained.

"Just make a mature iron plate?"

"Yes, it is to smelt wrought iron directly."

Zhao Shizhen was surprised, he had only heard of the ancient millennium to get wrought iron, and he had heard of direct iron smelting.

"Actually, it's not that difficult, it's just a matter of building a new furnace."

Turning his eyes to the two iron-making furnaces with a daily output of 1,000 catties in the iron factory, Shi Yiwen had another thought in his heart, just with these earthen furnaces, they would break the sky in a year, that is, two or three hundred thousand catties of iron, and such a little iron would not be enough to make flintlock pistols.

"Shiji, didn't you say that day, I want to show off my skills, this is just right, since we want to do this well, let's start from scratch, first dismantle the two stoves, and directly replace them with new stoves!"

Just do it, in the surprise of everyone, the two iron-making furnaces in the factory stopped, and then Shi Yiwen took out a new blast furnace drawing, in fact, it is from the library found in the book "Soil Ironmaking" found in the blast furnace drawings, not the common 1.5 cubic earth blast furnace in the era of large iron and steel, but up to more than seven meters high, made of bricks and stones, it refers to the modern European blast furnace and modern air blast furnace furnace furnace general structure, can produce twenty tons of pig iron per day, it also needs to be connected to the hydraulic bellows.

Just do it, for a whole year, Shi Yiwen has been staying in the iron factory, busy building a new blast furnace. However, the construction of the furnace is not simple, and while the masons are using stone from the mountain to penetrate the furnace, the most critical refractory materials also need to be solved. Because it takes a temperature of about 1,500 degrees Celsius to smelt steel, and ordinary clay bricks begin to soften at about 1,400 degrees Celsius, it is necessary to fire refractory bricks.

In fact, it is not too difficult to fire refractory clay bricks, and ordinary land brick kilns can do it, but even so, in the next two months, Shi Yiwen has been "barred" with bricks.

Just when the sixth year of Wanli was about to end, the first batch of refractory bricks were burned for three days from the trough clay kiln with a length of 4 meters, a width of 2 meters and a height of 2 meters, and finally came out of the kiln after two days of cooling.

"Zhiyuan, are you talking about the refractory bricks laid in the hearth?"

Faced with his inquiry, Shi Yiwen said a little dullly.

"No, it's a brick kiln."

"Still want to build a brick kiln?"

"Yes!"

Shi Yiwen's tone was a little helpless, this batch of refractory bricks is fired with clay, the main components are aluminum oxide and silica, and although this refractory brick can withstand a high temperature of 1730 degrees, it is not suitable for use as a blast furnace, can only be used for hot blast furnaces. Because alumina and silica are acidic materials that react with reducing agents and slag during the smelting process, another brick kiln is needed to fire alkaline refractories.

Alkaline refractories in the 21st century are generally made of magnesium oxide, and electrolysis technology is required to produce magnesium oxide...... This is certainly unattainable material. In the book of earth-based ironmaking, the road to solving the problem is also pointed out - dolomite bricks. The written version is that it is tar dolomite bricks. Dolomite is one of the more common stones, and there are such stones in the mountains near the ironworks. Dolomite is a composite of calcium carbonate and magnesium carbonate, calcination can obtain heat-resistant alkaline materials calcium oxide and magnesium oxide, and tar bitumen is a binder.

However, because the calcination temperature of tar dolomite bricks is 1600~1650 degrees, which is much higher than the refractory degree of general clay bricks, he needs to realize the firing of refractory clay bricks and use it to build a brick kiln for firing dolomite refractory bricks.

It took almost two months, and it was not until February 20 of the seventh year of Wanli that Shi Yiwen finally got the tar dolomite refractory bricks he needed for the furnace. The asphalt in the raw material of tar dolomite bricks is a by-product obtained through coking.

Finally, when the first batch of refractory bricks were spread out in the furnace of the blast furnace, Shi Yiwen, who had been busy for this day for two months, finally realized what the industrial system was. But there is no such brick. There can be no blast furnace. Without blast furnaces, there would be no large-scale steel industry.

In fact, in many cases, it is these tiny and seemingly worthless things that restrict the development of industry.

When the craftsmen were laying the refractory bricks, as if they suddenly thought of something, looking at those craftsmen, Shi Yiwen said to Wu Cai beside him.

"Wu Cai, do you know? I dare to say that my iron factory, even in another ten years, others will not be able to imitate it! ”

Suddenly, before Wu Cai could react, he listened to Gongzi sigh again.

"You, a brick almost exhausted me, they, can they make a brick like this?"

They simply can't make it, after all, what seems like a simple stone is actually a manifestation of the industrial system. With the textbook in hand, they all struggled for two months. Others...... In less than ten years, they can't see the mystery at all.

The system may be the biggest difference between industrial civilization and agricultural civilization. And now, what Shi Yiwen needs is to establish this seemingly simple but incomparably complex system in this era of poverty and whiteness. This system cannot be replicated by people in the era of agricultural civilization.