Hugo van Groningen sat on a small stool in the arsenal foundry, silently sorting out his tools. François, a gunsmith from Lausanne, once made cannons for Bavaria, and he was quite experienced, and he was the well-deserved leader of their group, and this was also approved by the "Tatars".

François was rated as a third-class worker by the head of the factory of the "Tatars", with a monthly salary of 30 riyals; And he, Hugo, a young man from Groningen, is only a first-class worker, and his monthly salary is only 5 riyals, and after deducting the monthly vegetable payment, he can only get 4 riyals.

In addition to the two of them, there are more than 20 people in the cannon casting workshop. However, they are all rookies with no experience, and except for a few "Tatars" who are quite smart, the other handymen are clumsy, and they can only add to the chaos at any time.

To be honest, Hugo had a good impression of those "Tatars". At least they are polite, and they don't seem to be uneducated, and they are often able to ask some unthinkable questions and ideas.

The cannon foundry once successfully cast four long-barreled cannons, which were not bad in performance and much lighter in weight than cast iron cannons. Regrettably, they didn't just cast these four cannons, but eight cannons. Obviously, none of the other four guns qualified.

In fact, this yield rate is already acceptable for a group of gunsmiths, who are mostly novices, but the "Tatars" obviously do not see it that way. They were extremely disappointed by this result, and one of the leaders surnamed Ma decisively stopped the supply of steel to the cannon foundry, and threatened to stop the work of the cannon shop until the problem of low yield was solved.

In this way, Hugo had nothing to do for a while, and of course, such days would not be too long. Soon, the "Tatars" returned. During this time, they studied four unqualified guns, three of which were blown up or cracked in the barrel during the charge test, and one was bent due to a problem with the barrel when it cooled.

This curved barrel gave inspiration to the "Tatars". After discussion, they concluded that this was due to the uneven cooling of the inner and outer walls of the barrel, resulting in invisible cracks in the inner walls of the barrel.

In all fairness, Hugo thought this conclusion was justified. When the barrel is cooled by steel mold, the outer wall area of the barrel is larger than the inner wall, and the air circulation on the surface is faster than that of the barrel, which naturally causes the outer wall to cool faster than the inner wall, resulting in cracks in the inner wall of the barrel. A crack appeared in the inner wall of the barrel, and the cannon naturally exploded.

The larger the caliber, the more likely it is to have such a problem, because the larger the caliber, the greater the difference between the inner and outer walls of the barrel, and the greater the difference in cooling speed, the easier it is to cause cracks in the barrel. Thinking of this, Hugo simply had a feeling of enlightenment, no wonder the higher the caliber of the cannon, the lower the yield rate, and even some large-caliber artillery could not be cast successfully at all, it turned out that this was the reason for everything.

Today, there are 4 new people in the cannon casting workshop, and these are the new gunsmiths recruited by the "Tatars". Based on the rudimentary Chinese he had learned at the night language school, Hugo knew that they were Swedes.

Damn the Swedes! Hugo muttered to himself.

The 8 "Tatars" who usually participate in the casting of cannons in the workshop have all arrived, and in addition to them, there is also a "Tatartan Chief" who has been here several times before. After a few quiet deliberations, they decided to offer a reward of 500 riyals to ask everyone for a way to speed up the cooling of the inner wall of the barrel. They promise that as soon as the method proves to be effective and reliable, the prize will be paid out immediately and the title will be upgraded by one level.

This condition made Hugo a little excited, and he began to calm down and think about the method.

Wang Qinian was a little irritable. 568 people, why don't many people understand all kinds of industrial manufacturing, I used to read novels on the Internet and those protagonists seemed to be incarnated as encyclopedias after crossing one by one, and I couldn't wait to understand everything and be proficient in everything. It's nothing to make guns and artillery, and aircraft carrier missiles can be made for you. It's really more than goods to throw away, and people have to die more than people! The 8 traversers in the cannon casting workshop can be regarded as having cast a few cannons with these Europeans, and they discussed it for half a night last night, but they didn't come up with any good ideas.

Wang Qinian was irritable when he suddenly saw a red-haired tall and thin foreigner standing up in the workshop.

It's him! Hugo van Groningen, a gunsmith from the Netherlands. Wang Qinian remembered it all of a sudden, he couldn't remember it, this guy was one of the only two genuine gunsmiths on hand before.

Is there anything he can do? This thought crossed Wang Qinian's mind.

"Sir. I... I think I have... Way. Hugo stumbled in Chinese. When he realized that he couldn't express himself accurately in Chinese, he immediately spoke English. His mother was English, so he was fluent in English, and he knew that many of these "Tatars" spoke English.

"Sir. I guess we can use water or oil to cool the inside of the barrel. "As we all know, water cooling is far more efficient than air cooling. Since the inner wall of the barrel cools more slowly than the outer wall, can we use some kind of medium with high cooling efficiency to speed up this process? For example, water or oil. ”

"Huh?" Wang Qinian's eyes suddenly lit up: "This is a method." ”

"Pour water into the barrel?" Wu Jun asked, he was a gunsmith trained by the Executive Committee.

"No, it's not. This will cause the barrel to crack. The more Hugo said, the clearer his thinking became, "We can make the inner mold of the cannon hollow, simply put, leave a cavity for cooling in the inner mold." When the inner wall of the red-hot barrel is in full contact with the inner mold, the heat transmitted from it heats the inner mold. At this point, we fill the chamber with water, and the water flows out of the reserved other opening, taking away the heat. In this way, circulating cooling can be achieved by continuously filling and discharging water. What's even better is that this process is still controllable, and we can control this cooling process by controlling the flow of cooling water, after all, if the inner wall dissipates heat too quickly, there will still be problems with the barrel. ”

"That's a good way!" Wang Qinian slapped his thigh hard, stood up and said excitedly: "Xiao Wu, I think this method is reliable!" Why don't we give it a try? ”

"I think it's okay." Wu Jun nodded and said, "Without further ado, let's cast a cannon as soon as possible and try the effect." Moreover, we have to explore how appropriate the flow rate of this cooling water is. ”

"Okay, I'll go find the vest." Wang Qinian said, "Let's see when his crucible will open, and when it opens, hurry up and get us some molten steel." Grandma is a bear, this kid is really picky, and he has been cut off from our milk for a whole month. ”

***********************************

Three days later, the test site was crowded.

Many people came to see the effect after hearing about the new process of casting guns. Not only Wang Qinian and Ma Jia came, but even Peng Zhicheng from the army also rushed over, after all, he was also the master of the cannon.

The cannon casting workshop launched a 24-pounder gun test this time.

It was a 24-pounder long-barreled cannon with a magnification of 18. Due to the use of high-quality high-carbon steel in casting, the weight of the whole gun including the gun carriage was only about 1.5 tons. After the casting of the gun body, the inner wall is cooled by water cooling, and the efficiency is greatly increased.

In fact, not only did the traversers cast this cannon, but also an 18-pound cannon had to be scrapped because the cooling rate of the inner wall was not well controlled, resulting in cracks in the inner wall.

The eight members of the artillery crew were all selected from the garrison, and they had conducted many live-fire training before, and their business was quite proficient.

The gunners first loaded a 4-pound recharge pack into the barrel, and because it was a test gun, it was not loaded with projectiles.

After everything was ready, Wang Qinian calmed down a little and signaled that he could fire. The crew pulled the long lead outside the gun door to a safe distance and set the lead on fire.

There was a loud "boom", and the muzzle of the cannon was filled with smoke. Wang Qinian looked at it, and his hanging heart suddenly let go, at least he didn't blow up on the spot!

The gunners quickly surrounded the gun, cleaned the chamber of the gun, and checked the barrel for cracks.

All the best! The artillery commander gestured to Wang Qinian's side.

The standard charge for the 24-pounder gun was 6 pounds, and this was only the first hurdle. The gunners would then load the bore into a standard 6-pound pack to test the performance.

The crew members expertly cleaned the chamber, loaded the standard powder bag, and then retreated into the distance, lit the fuse, and fired!

The 24-pounder cannon let out another roar. Without waiting for Wang Qinian's signal, the members of the artillery crew rushed forward to inspect the cannon body in the thick smoke.

No problem! The gun commander made the same gesture as the first time.

There were already small cheers from the audience, and Wang Qinian and Peng Zhicheng had smiles on their faces.

"8 pounds of medicine!" Wang Qinian waved his hand heroically, "Try the performance under the strong charge." ”

The gunners did as they were told, repeating the previous action again, only this time the pack was replaced by an 8-pound strong charge.

"Boom!" The 24-pounder cannon was still standing on the spot.

The artillery commander rushed over and carefully examined it for ten minutes before he shouted, "There are no cracks!" ”

"Yay!" Wang Qinian and Peng Zhicheng high-fived and celebrated, and the vest was also smiling.

The results of the test perfectly proved that the water cooling method of the inner mold was successful and effective when casting the gun. The next thing that needs to be done is to cast more cannons to confirm whether the yield rate has really been reduced to the desired result.

Hugo van Groningen stood behind Wang Qinian with a smile, and François and the four new Swedish gunsmiths looked at him with envy.

"Huh." Hugo chuckled inwardly, knowing that his future would be bright.