Fang Zian said goodbye to Su Heng's home and rushed to Qian Kang's home to ask him for help. The two of them went to various markets in the city, searching for pine charcoal by the truckload. The price of charcoal in the Song Dynasty was very high. A load of firewood was expensive. Grain costs less than 30 cents, but after it is burned into charcoal, a scale of charcoal costs up to 400 cents in the severe winter. A scale is only fifteen kilograms. In the cold winter, burning charcoal for heating can only be spent by wealthy officials and wealthy families. The extravagant money one can afford. Ordinary people's homes can only use firewood to burn a furnace, or simply endure the cold and use their bodies to fight against it.

Fortunately, it is already the peak of spring, and the weather has already been very warm. There is no need to burn charcoal for heating, but some are needed for cooking food. So it is actually the off-season for charcoal sales. And the people who burn charcoal in the mountains obviously have no way to get rid of it. They stored charcoal from spring to autumn and sold it in winter. Because they relied on this to make a living, they had to sell it. Because of this, the market price of charcoal dropped to 300 cents per pound.

Fang Zian settled the accounts and found that purchasing two thousand kilograms of charcoal plus shipping would still cost forty or fifty taels of silver. Su Heng said that so much charcoal would be burned in a day and a night, and if it went on for a long time, it would be a huge expense. So Fang Zian and Qian Kang discussed that since there is a long-term need for charcoal smelting, why not simply sign a long-term supply contract with a few people who make charcoal, so that the people who sell charcoal will not worry about being unable to sell, and they can also lower the price. We convened four sellers of good-quality pine charcoal to discuss it, and finally reached an agreement to purchase all the charcoal they produced for 280 cents per scale.

Both parties are happy. Fang Zian saves money and does not need to go out to purchase charcoal from time to time. This ensures the supply of subsequent blast furnace charcoal. As for the people who sell charcoal, they are actually very happy. The price is lower, but they no longer need it. Pulling a charcoal cart to sell or wait for buyers in the city can free up more time to burn charcoal. Producing more charcoal can make up for the loss. And the other party promises that no matter how much charcoal they burn, they will take it. This is a big deal that will last for a long time.

In fact, what Fang Zian hopes more is to use pebbles instead of charcoal. The price of pebbles is very low because most people are not used to this new type of fuel. Because there are too many impurities, there is not enough heat when burning, and the smoke is too thick. It would cause the whole family to be poisoned. Originally, in Bianliang City, the original capital of the Song Dynasty, many people used charcoal for heating in winter, and the court was ready to vigorously promote it. However, after more than a dozen mass murders occurred in succession, people were scared to death. I don't dare to use it anymore. The court's vigorous promotion has also been put on hold. The common people don't recognize it at all, and the rich and powerful people don't buy it at all.

Fang Zian originally wanted to use pebbles, but he had to admit that the current quality of pebbles is difficult to use in blast furnace smelting. Unless procedures such as crushing, cleaning and purification are carried out, the cost becomes extremely high. And it is completely done manually. It is impossible to crush coal and wash coal like this. Machinery must be designed, and the machine needs to be driven by a steam engine that has not yet been successfully used. So this actually becomes a paradox.

If steam engines want to be applied on a large scale, they must find a way to cheaply transform charcoal, which was everywhere in the Song Dynasty and has not yet been put into popular use, so as to facilitate the operation of steam engines. The cost of charcoal is too high and it is bulky. It is not resistant to burning. It is necessary to make fuel that is small in size but can continue to burn for a long time, such as charcoal balls, to ensure the safety of the steam engine.

The continuous operation of the system does not require someone to add fuel to the fire every moment. Therefore, every innovative thing launched must have a series of supporting updates. Only at this level, it is a kind of pulling the whole The significance of scientific and technological innovation and progress. Of course, the first one to eat the crab will obviously have to pay a greater price and put in more effort and energy.

That night, the gourd-shaped blast furnace in the Su family's backyard was officially ignited. A large amount of charcoal was shoveled into the upper and lower furnaces, and soon after it was ignited, the fire was raging. The huge chimney mouth actually sprouted dark red in the dark night sky. The flame, a circle of air inlets below, sucked air in to support combustion without wind. Fang Zian didn't understand the operating principle of this gourd-shaped blast furnace at all. At first, he had doubts about it, but now he realized that it was his own I don’t know enough. In addition to meeting the needs of what he calls secondary smelting, Su Heng’s blast furnace also seems to have some kind of air circulation function, which can fully burn fuel without the need for bellows. It even has to be adjusted according to the size of the charcoal fire during the process. Perform temporary sealing and opening of air inlets to regulate fire intensity.

When the fire burned until midnight, a miracle appeared. The entire blast furnace seemed to be burned through, and the whole blast furnace was pink in color. It was like the translucent red color seen when shining a flashlight on the palm of the hand. Fang Zian was shocked. He was afraid that an accident would happen, but Su Heng didn't take it seriously and instead looked surprised.

"Successful, this furnace is successful. After burning to this level, after cooling, the entire smelting furnace will be able to withstand extremely high furnace temperatures in the future. A refractory layer will be formed in the inner tank, and it will be as smooth as a mirror and will not be afraid of sticking. Molten iron and carbon slag. It can be said that the furnace is the key to smelting. If the furnace is successful, the subsequent things will not be difficult."

Fang Zian seemed to understand, but he didn't need to understand. As long as Su Heng thought it was successful, he would naturally be happy and happy.

After the fire remained in this state for an hour, Su Heng began to close the air inlets one by one. The fire gradually dimmed, and the entire furnace showed a dark red color. After that, charcoal was added every quarter of an hour, and then only one hole was opened for ventilation. , to maintain the temperature in the furnace. The dark red flame coming out of the chimney mouth has long since disappeared, and the blue-black smoke billows out, which is quite exciting for the great industrial development in the steam age.

From night to day, and then to the evening of the next day, the charcoal fire in the gourd blast furnace never went out. Two thousand kilograms of charcoal burned only a small pile of less than two hundred kilograms. Su Heng never left the scene. Fang Zian and Qian Kang did not leave even half a step. Sister-in-law Su and Su Zheng brought food and water to the stove. The three of them became more and more cooperative, with Su Heng in charge of controlling the heat, and Fang Zian and Qian Kang in charge. When carrying charcoal and adding charcoal, the three people's heads and faces were covered with black ash, and their eyes were blood red.

"It's almost done. You can turn off the flame. Open the furnace door and rake out the remaining charcoal fire." Su Heng finally said.

Fang Zian and Qian Kang jumped up, hooked the furnace door with an iron hook, and used an iron rake to rake out all the remaining charcoal fire. The upper and lower furnace doors were all opened, and dozens of air inlets in a circle were also opened. It began to dissipate heat naturally. By the early morning of the next day, the furnace finally cooled down from being scorching hot. Under Su Heng's lead, the three of them got into the still hot furnace through the furnace door. Under the light of the light, Fang Zian They were all dumbfounded. The interior of the furnace was indeed as smooth and smooth as a mirror as Su Heng said, as if a layer of glaze had been burned out.

The same thing. He reached out and struck it, and there was a roaring and echoing sound as a whole. It was hard and smooth, which was amazing. After inspecting the upper and lower layers, Su Heng expressed that he was extremely satisfied. The entire gourd blast furnace was evenly sintered without any damage, which reached his level. requirements.

"Okay, the furnace has basically taken shape. The smelting crucible and other facilities I have sent from Wuxi tomorrow will also arrive by ship. Once those things arrive, we can officially smelt the required refined iron. Mr. Fang , I have to discuss a few things with you." Su Heng said with red eyes and dark gray face.

"Brother Su, it's okay to say so." Fang Zian said.

"Okay, this iron smelting is a delicate job and cannot be done casually. The subsequent casting of parts is also a technical job. Not just anyone can do it. So this time I called a dozen brothers from my hometown in Wuxi to help me. They They all worked with me in the past. Later, when I moved to the capital, they opened an iron shop in Wuxi and made a living by blacksmithing. But this time, I had to invite them all. I gave them ten taels of silver a month. There are sixteen people in total. I’m afraid you will have to pay for this money. It costs one hundred and sixty taels a month. They also have to support their families." Su Hengdao.

Fang Zian was overjoyed. Su Heng brought his own team, which was really what he wished for. I like this kind of thing. Professional people work with professional people to get twice the result with half the effort. This is the case for veteran leaders and Wan Dalongtou. This is the fastest way to do things. Method. As for the salary, the salary of ten taels of silver for a craftsman like this who is favored by Su Heng is not high.

"Brother Su, although you and I are in a cooperative relationship, you can completely make the decision in this matter. Not only their salary, but also their living and food expenses must be dealt with. As long as it is beneficial to the whole matter, I will completely abide by your decision. Do it as you wish. Brother Qian, listen carefully, I may not have much free time here in the future. You are responsible for contacting Brother Su on these matters, and you must also remember this rule. Do not be stingy with all necessary expenditures, and follow Su's complete instructions. Do as Big Brother asks." Fang Zian said.

Qian Kang wholeheartedly agreed, and Su Heng was very happy in his heart, and continued: "What's more, now that everyone has arrived and everything has arrived, it's time to start smelting iron. In the next few days, we are going to purchase iron ingots, etc. I'm afraid it will cost a lot of money. As long as you believe me, I will build this steam engine. But as for how much money it will cost, I have no control over it. Don't feel bad about it then."

Fang Zian said: "I don't hesitate to throw away the pot and sell the iron. As I said before, you make the decision. But I'm afraid I don't have time to stay here with you every day. Brother Qian Kang represents me. If you have anything to do in the future, just tell him."

Only then did Su Heng remember to ask: "I heard that you took the Spring Examination. Have you released the results? Did you win?"

Fang Zian smiled and said: "I barely succeeded, so I don't have time to come here every day. I'm afraid I won't be able to help myself from now on."

Su Heng did not comment or even say congratulations. He nodded and said: "So that's the case. There's nothing you can do about it. Once you become an official, you have to be restrained by others. It's okay. Since Brother Qian represents you, I'll just discuss it with him."

Fang Zian smiled and said: "I will also make time to come. I hope to see the steam engine built soon. That is the moment I am most looking forward to."
Chapter completed!