[Third Update.] 】

As soon as I entered the foundry building, it immediately heated up.

Today was a cloudy day, but it was much cooler because of the two rains the day before.

But the heat wave in the factory is rolling, making people feel as if they have entered the hot summer.

"It's hot." Zhang Dian turned his head and said to Han Gang, just when he came in, he was already sweating on his head.

"Where is it cast, there is nothing that is not hot."

Zhang Dian looked at the black ground under his feet, and said with a little disgust: "That is, Yukun, you, are willing to run here." ”

The last time I tested the pine gun, but it was outside. This time it was changed indoors, fortunately it was just to see, and it was not a test launch, otherwise the momentum would not have lifted the roof of the shed.

Han Gang smiled: "There are some things that are more reassuring to see with your own eyes." ”

When it was really casting, Han Gang would not come to visit. During serious working hours, he, the minister of Xuanhui, rushed over and asked the craftsmen below to do something? That is, he will come over.

The last time the pine cannon was test-fired, Cai Jing and Zhang Dian were invited by Han Gang to witness one after another. This time, the artillery was cast, and it was two at a time, and Zhang Dian was in a hurry, so he came over first. And Cai Qu and Guo Kui are still waiting for the experiment to let them watch.

The group was guided by Fang Xing to the place where the cannon was newly cast.

Two bronze guns sat side by side.

Fang Xing deliberately put the two cannons together, and at a glance, they were almost identical, and there was no difference at all.

Both cannons were cast in bronze. Copper is not cheap, but artillery has the advantage that if it breaks, it can be melted down and reforged. Not much is wasted of the materials inside.

It's just that not only copper coins need a proper ratio, but also the copper ratio in bronze artillery needs an accurate and valid number. The current two cannons are just for people to see. Zhilu said that this is a promising weapon. After that, it was necessary to experiment with different shapes of artillery, the front-loaded breech-loading gun, and the rear-loaded breech gun, all of which had to be designed and manufactured. The materials used in artillery, including copper, tin, and lead, are also tested. Although Han Gang brought Zhang Dian to show off, but after listening to Han Gang's explanation, Zhang Gang didn't understand it even more. Even in the first place, there was not so much trouble in making the god arm bow.

But a pair of eyes, he still brought it.

These two bronze cannons have completely changed their appearance compared to the pine cannons that Zhang Dian saw the previous time. The texture is different, and the size is much smaller. The dark and deep metallic color looks like it has great power, so the color is deep and restrained.

The size of the cannon was far less than that of the Thunderbolt and the Eight Bull Crossbow, and it was already small when it was a pine cannon before, and now it is even smaller. In addition, the two sides of the cannon body were named by Han Gang as cannon lugs and short rods used to support, which was not much bigger. If its power is comparable to the two, the Thunderbolt Cannon and the Eight Bull Crossbow...... No, it's the artillery cart and the bed crossbow that will be eliminated.

"This is artillery?"

When he saw the pine cannon before, Zhang Dian asked Han Gang like this. Now that he finally saw the finished product, he asked Han Gang again.

"Of course, where would there be a fake?" Han Gang replied with a smile.

Fang Xing then explained: "It is driven by gunpowder and sends the shells to the enemy, so it is called artillery." ”

Listening to Fang Xing's introduction, Zhang Dian suddenly approached, squinting at the surface of the cannon body.

"What's wrong?" Han Gang asked.

"Let's see if there's trachoma." Zhang Dian smiled and raised his head.

Trachoma is very difficult to appear, and the most feared thing is trachoma. As soon as there is a slightly larger one, the tone of the whole bell is immediately destroyed. On the subject of how to prevent trachoma, but the group of clocksmiths in the group is the best expert.

The caliber of four inches is actually not as big as a man's fist. Zhang Dian compared the muzzles of the two guns with his fist, and the inner diameters of the bores of the two guns looked exactly the same.

"No need to compare, it's definitely the same. If it's different, just hit it back. Han Gang said with a smile, "The cannonball is to be fired in the barrel, and the caliber of the bore and the cannonball must be matched, otherwise it will not be able to exert the maximum power." At present, every gun produced under the supervision of the Firearms Bureau is of the same type, and every gun must be the same. The length, radius, and weight of the barrel, as well as the diameter and depth inside the chamber, must be the same. ”

"Can you do it?" Zhang Dian looked the artillery up and down, and did not forget to talk to Han Gang.

"The shells made next door, as well as the medicine packs, are all made according to the size, and if the size of the artillery made here is out of shape, either the shells can't fit in, or they just put it in but it's too spacious. So what's the use? Think about a crossbow, if the crossbow machine and the crossbow body do not match, and the arrows do not fit into the arrow slot, what use can such a crossbow come in? ”

At the beginning of the establishment of the Ordnance Prison, it was to find a balance between fine work and mass production, at least when Lu Huiqing and Han Gang advocated the rules and regulations of the prison, the size and craftsmanship were placed in an extremely important position. And the craftsmen have adapted to the demands of the craft.

"Brother Zihou, what do you think of this artillery?"

Instead of replying immediately, he said, "Let's try first." ”

"I'm just waiting for Brother Zihou to speak." Han Gang smiled and asked Fang Xing to solve the problem.

The craftsmen quickly set up a pulley set and hoisted one of the guns onto the rail trolley in the factory. Led by two horses, the crowd followed, also walking slowly.

It was Han Gang's plan. It is to start with light infantry guns, so that it is easy to cast. If you can have a little eyebrows, you can then allocate manpower to design a heavy city defense gun. It is also more reassuring to defend the city.

The caliber is four inches, the weight is about 1,000 catties, and it can be mounted on a two-wheeled gun carriage, which should be installed on the wheels, and the wheels should be wide enough, so as to adapt to the passage of the wilderness. But the gun carriage had to be moderately heavy, so that it could suppress the reaction force of the artillery, but not too heavy, so that it could be dragged with the army with a minimum of horses.

Now this kind of bronze cannon is worried that it will explode, so he ordered the craftsmen to make the first and second cannons thicker. After the demonstration, the real development begins, and that's when we try to reduce the weight. Even the wrought iron cannon must be studied at the end.

How to find the right balance in a series of requirements is a problem that designers have to think hard. Han Gang estimates that this will take almost a year. Find the most suitable size so that it is easy to set. After the finalization is completed, the mass production plan is designed.

It would be nice to have a boring machine. Han Gang thought so more than once in the workshop. A knife directly bores the solid barrel out of the barrel, and by the way, the fire door is repaired. The artillery produced in this way must be as smooth as a mirror inside, and it must be one of the most suitable barrels for shooting.

But in reality, it can't be that simple. Stable knives alone are the biggest problems, and the precise and powerful rotation of the blade is not the answer that can be given in this era.

The result of taking a step back is that we can only try to carry out precision casting, and there are still many problems left, and the flexibility is to expand the range of error permission a little, but it is still necessary to be as fine as possible, so as to live up to the name of Han Seiko.

The artillery was quickly erected, in an empty field in the ordnance prison. Gunpowder and shells were brought, and the targets were erected in front of the muzzles, a distance of a hundred paces. The next step is how to go about launching.

"Let's get started." Zhang Dian waited anxiously, he hoped to meet a real surprise.

The craftsmen immediately got busy, loading the medicine bag, loading the shells, connecting the leads, and everything was ready after the final, Fang Xing saluted Zhang Dian and Han Gang, and said, "Please also invite the Privy Council and Xuanhui to preside." ”

Zhang Dian looked at Han Gang, Han Gang gestured, and asked Zhang Dian to take care of himself.

Again humbling, he picked up a small torch and carefully lit the fuse.

The lead made a sizzling sound, and in an instant it sank into the barrel of the cannon, and before Zhang Dian could flash back to the evasion position, the cannon roared loudly, and Zhang Dian was so shocked that he toe, and the whole person was more than two inches taller.

When I looked back, I saw that the muzzle of the cannon was shrouded in a puff of white smoke. The privy envoy was a little disappointed not to see the condition of the cannon being discharged, and when he looked at Han Gang again, he found that his expression was different.

"What's wrong?" Zhang Dian asked anxiously.

"I hit the target, but I flew out." Fang Xing pointed out for Han Gang.

Zhang Duan looked closely, and sure enough, there was a small gap at the top of the wooden target.

"Where's the cannonball, how far did it go?" He looked in the direction of the gun, and his face changed suddenly. It's cheaper over there and the walls of the Imperial City!

"At least three hundred and sixty steps." Han Gang's voice was no longer as quiet as before.

He felt terrified now, this cannonball just now was so rash that he almost ran to the imperial city. Fortunately, the terrain here is not convenient to aim at the walls of the imperial city, so it is just right to go over. And the craftsmen did not dare to aim their artillery at the imperial city.

"Isn't that more than a mile?!" Zhang Dian looked at it again, and his face became even more ugly. It's lucky that you didn't hit the imperial city, but what if you hit someone?

Send someone to take a look. Han Gang said a word to Zhang Dan, and then ordered his cronies to go to the point of the artillery muzzle to look for it.

"How? Yukun, what do you think? "Zhang Dian was nervous for a while, but now he let go. As long as you don't hit the Imperial City, other crimes are easy to say.

"After all, gunpowder won't work." Han Gang shook his head.

Han Gang clearly saw how much gunpowder residue had been brought out by the mop that cleaned the barrel of the cannon.

It seems that the biggest problem of artillery gunpowder is the purification of raw materials.

The source of saltpeter is soil on the walls and floors of latrines, as well as near places where livestock manure is accumulated. That's where saltpeter is produced. In addition to this, there are other types of nitrate, which have similar names, but cannot be used to make gunpowder.

Nitrate is not the same as nitrate. The nomenclature of this era is completely uncoherent. A medicinal herb has more than a dozen names. What is needed to make gunpowder is nitrate, and Han Gang remembers that it is potassium nitrate. The other one, called miscanthus salt, is useless at all.

It's just that the separation and purification of the elements has not been carried out until now. Han Gang's superficial academic skills were not enough for him to complete such a task.

He also sometimes thought about using spectroscopic analysis to identify new elements. Gaslamps, prisms, microscopes, any of them, the technical reserves of the Armament Supervisor and the General Supervisor can fulfill his requirements. But the problem is Han Gang himself, he only knows the term Ludao spectral analysis, he doesn't know anything else, and he doesn't have any specific details, so he is completely useless now.

It's really hard!