Sun Ran, together with his son and a few apprentices, carefully dragged the iron cable on the gallows and slowly lifted the mold core. During the whole process, Sun Ran held his breath and was cautious, and he didn't dare to come out.

This gallows is specially made by Du Zhongxiao to cooperate with the casting of bells, and has the function of anti-slipping, which is the oil hoist of later generations, and a small manual lifting machine. The core of this is the ratchet and iron chain to prevent accidents from slipping.

Due to the heavy mandrel of casting, once it falls off when the core is lifted, it will cause inevitable losses, which may lead to casting failure. With this gallows, Sun Ran dared to take such a few people to the core, otherwise he must be very careful and adopt other more complicated methods.

The mold core came out, and Sun Ran jumped into the bell impatiently, watching carefully, knocking and knocking, and listening to the sound that came out. After fighting for a long time, he pounced out of it and let out a sigh: "God is pitiful, a success, it is a fluke." ”

Du Zhongxiao stepped forward, looked at the big bell that was still wrapped in dirt, and said, "Look like this, it's not difficult to cast it, where is it as evil as you said before?" What mandrel will take months to prepare, and how many pieces can be cast in that year? ”

Sun Ran smiled bitterly: "Official, according to your instructions, it seems that the casting will be started without waiting for the core mold to dry thoroughly, and this mold will be scrapped after one use." You see, the mandrel is cracked everywhere, and it will break if you accidentally touch it. Moreover, the inside of the bell is uneven, and it takes more time to polish. ”

Du Zhongxiao said: "Ciyuan Temple only needs a bell, how many times do you have to use this core mold?" If it's a bit more troublesome to polish, just find more people. ”

Sun Ran shook his head: "Official, the bronze bell is no better than other bronze utensils, and it requires all of them to be sophisticated. If the thickness is uneven, there are protrusions, the sound is not crisp, how can the temple receive it? Now the thickness of this bell is roughly uniform, and it does not need to be overly decorated, which is rare. ”

Du Zhongxiao also knows this truth, but he will stay in Xiangzhou until the end of the year at most, and he will definitely leave in Layue, where is there time for Sun Ran to prepare slowly and methodically. After casting the bell, there is still a cannon cast, and there is not much time.

The most difficult thing to cast a bronze bell is to manufacture the core mold inside, which is mainly made of mud and wooden frames, and the ingredients are extremely complex. The process requirements are very high when manufacturing, and the final product is extremely critical. After the core mold is made, it should be dried in the shade for a long time, usually several months. Such a carefully manufactured mandrel can ensure the integrity of the finished product, and it can be used many times. The second is the proportion of copper used for casting, carefully grasp the hand heat when smelting, where to cast first, where to cast, the structure is not allowed, have to be cast in sections, but also a long time of experience accumulation.

Du Zhongxiao couldn't wait that long, so he forcibly asked Sun Ran to dry the core mold with a simmer, and it only took more than ten days to cast the bronze bell. Due to the short time, the mandrel was scrapped after one use, and the inside of the copper bell was obviously uneven and of poor quality. Fortunately, there are no defects such as cracks in the bell wall, and it is carefully polished in the later stage, and it can be handed over to Ciyuan Temple.

After a breath, Sun Ran led people to pick up the soil around the bronze bell, and the bronze bell was exposed. Seeing that the bell wall was uneven inside and out, and there were a lot of numbness, Sun Ran could only sigh. The mandrel did not dry thoroughly, not only did it go out after one use, but it also caused the clock wall to be unsmooth.

Du Zhongxiao looked around the huge bronze bell, nodded and said, "Yes, although it is not very good, it can be used roughly." ”

Sun Ran said: "Official, if you carefully cast according to the small one, you should produce a high-quality bronze." ”

Du Zhongxiao said with a smile: "As long as there are no cracks, no uneven thickness, and the back is slowly polished, what's the tightness?" In my opinion, you have made this bronze bell very well, not bad. I also have a bronze vessel here, and it also has hundreds of catties, and I want you to pay for it again. ”

Sun Ran was stunned for a moment: "What kind of bronze do officials want to cast?" Do you want to cast a bell too? ”

Du Zhongxiao said: "What do I do when I cast a bell?" There are not so many people in the family, so they want to sing and eat. I'm going to cast a big brass pipe, and there is a name in the army called artillery. I've got a figure here, and a small model carved out of wood, and you can just cast it. ”

Sun Ran arched his hand: "Don't hide it from the officials, the small one has only cast a bronze bell, and what artillery has not been cast." ”

Du Zhongxiao said: "It's okay, I've seen you cast the bell these days, and I have a good idea in my heart, as long as I do what I ask." ”

After speaking, let Tao Seventeen come over and show Sun Ran the model of the wooden cannon he had made a few days ago.

Sun Ran looked at it carefully and asked Du Zhongxiao: "How big is the official going to be with such a cannon?" ”

Du Zhongxiao said: "It doesn't have to be too big, just magnify it ten times." ”

Sun Ran listened to it: "Magnify ten times, official, this is bigger than the bronze bell." ”

"Bigger than a bronze bell, of course. However, the walls of the barrels of the guns are much thinner than those of the bells, so they should not be difficult to cast. ”

Sun Ran thought for a while before saying, "The small ones can be tried, but I don't dare to say that they will be successful." ”

Du Zhongxiao said: "It's okay, you can try a few more times." If you can make a bell, you can also make a cannon. It's just a waste cast, it's nothing more than a waste of recasting, wasting some labor. ”

Sun Ran looked back at the bronze bell on the side, and his face was embarrassed: "Official, the small one has to take someone to polish this bell——"

Du Zhongxiao said: "Don't worry, let's cast the copper cannon first!" If the monks in the temple are in a hurry, I can send some soldiers to help you polish it. This kind of rough work is not as fine as the bell casting, as long as it is polished and smooth, anyone can do it. ”

Sun Ran was silent for a while, and seeing Du Zhongxiao's unrefusable look, he could only nod.

The bell is not an ordinary bronze vessel, although the big bell in the temple is not a musical instrument, regardless of the pitch, it must also have a crisp sound with a long echo, and it can be heard clearly everywhere in the temple when you knock it. If the polishing is not good, the voice is dull, and the monks will not want it. Now that it has been cast, if it is not good in the end, it will become a waste product in the end, and Sun Ran will not be able to cry when he arrives.

Du Zhongxiao didn't care about this, the copper was already here, and he was sure that Sun Ran could cast it, even if it was scrapped, it was nothing more than smashing and recasting. The most important thing now is to come out of the bronze cannon and conduct a test firing before returning to the capital. If you miss this opportunity, you may not be able to do it again in a few years, and the time will be in vain.

Du Zhongxiao instructed Tao Seventeen to draw more than a dozen soldiers from his command to help Sun Ran's family polish the bronze bell and prepare to make artillery.

What Tao Qiqi is doing here is an official in charge of casting guns and cannons, with more than 50 troops under his command and more than 200 craftsmen, so it is nothing to transfer this amount of manpower. Moreover, when Tao Qiqi heard that Du Zhongxiao was going to cast a bronze cannon, he was also full of curiosity and eager to try.

Prior to this, Du Zhongxiao had already prepared 500 catties of copper, and if it was not enough, it could be urgently transferred from the Xiangzhou military treasury. Coming back from the capital this time, Du Zhongxiao's identity is already different from before, as long as he doesn't ask too much, Yang Zi will gladly obey. Although the official positions of the two are similar, Du Zhongxiao is still young, and the future is unlimited, and Yang Zi also leaves a way back for himself.

Du Zhongxiao took Sun Ran to make bronze cannons, and when the core mold was ready, it was already late November, and it was almost the winter solstice.

The winter solstice is a big festival, and for the official, it is heavier than the Spring Festival, and it is also a day in the southern suburbs of Beijing. Du Zhongxiao cooperated with Yang Zi and made all kinds of preparations, and the matter of casting cannons was temporarily stopped.