The training of the recruits has been put on the agenda, and Payne, as their instructor, has shown great rigor and dedication, and he knows that if he sweats a little more during training, he may save his life on the battlefield, and he must be responsible for such soldiers.

And Rand also took the time to review the progress of the veterans learning the ballista, after the first ballista was assembled, in less than ten days, ten ballistas have been successfully launched, the soldiers showed great interest in this weapon, no one wanted to hold a spear and fight with the monsters in close combat, after hearing the news that there would be no reinforcements this year, a considerable number of soldiers were retreating, no one had the confidence to defeat the barbarians, and the advent of the ballista was alive and the soldiers' low fighting spirit was forcibly raised to a high level.

The power of the ballista is undeniable, but it is also very simple to operate, and it is more labor-saving and powerful than a traditional longbow.

Over the years, many of the relatives and friends of the barbarians have lost their lives in the barbarian raids on the air-crossing territory, and their resentment towards the barbarians has reached the point of wanting to skin and gnaw their bones, but they have no choice but to bury their anger in their hearts because they have been unable to defeat the barbarians in the past, but this year the situation is different.

Everyone is holding back their strength, and they want to fight a turnaround battle, and it is better to annihilate all those brutal barbarians and let them all go to hell!

"Oak, fuse these two steel pipes together, and make sure that the joints are tightly fitted and there are no leaks!" Rand sat in the smelting chamber and handed Oak two cut steel pipes.

Oak's mood has been a little low recently, Rand has asked him, but he just said that he is a little tired, seeing that he doesn't want to say more, Rand did not ask further, but quietly asked the mentor who is responsible for teaching Orke, and after getting Oak's recent diligent reply, Rand also put his heart back in his stomach.

Oak pressed the smooth profiles of the two steel pipes together, the flames spilled into the cracks like flowing water, the steel softened and melted at a speed visible to the naked eye, and gradually fused together, Oak's control over the flames was really strong, and he didn't waste any power.

"The material of this steel pipe is close to perfect, even if I want to refine such a material, it will take a lot of work, my lord, what do you want to do with it?" Oak was a little curious, and after placing the steel pipe in the coolant to cool down, he asked his own doubts curiously.

Rand took the steel pipe from Oak's hand, and found that the original seam had become a whole at this time, but the color was slightly dull, and as long as it was slightly polished, there was no trace of it anymore.

"Oak, did you let off the fireworks?" Rand looked at the inside of the steel pipe, which was fairly smooth and would not show any resistance.

There will not be a big gap with the steel pipe forged at one time.

"When I was a child, my father used to show me, it was very beautiful, it looked like stars in the sky. Oak nodded, fireworks were a luxury that only the aristocracy could afford, like he had only seen once when he was a child at a jazz's birthday party with his father.

"Do you know what the light that flies into the sky is made of?"

"Incendiary, wood, or coal, or something?" said Oak, shrugging, "I remember that thing had a lot of smoke and a pungent smell of choking. ”

No one paid attention to these things, and to Oak they were just a gadget, and the nobles were just playing with the festivities, and they were not as gorgeous as magically created illusions, but no one knew what a huge power was hidden in the body of this gadget.

"No, a mixture, charcoal, sulfur, and a scientific name for potassium nitrate," Rand said, sobbing at the pile of black powder on the table, "this is it." ”

After learning about the low price of saltpeter in this world, Rand was extremely excited, and he exchanged iron ore with people to buy a large batch of saltpeter.

On this continent, the power of * has not yet been discovered, and saltpeter is only a material used by nobles to make iced red wine, but as a modern person, Rand is well aware of the destructive power of *, in order to refine high-purity potassium nitrate, he ordered people to crush the purchased saltpeter, pour it into hot water, and wait for the water temperature to drop, the impurities that are insoluble in water are removed, and the crystallization after drying is the purified potassium nitrate.

This is a very old and rudimentary method of purification, but due to the difficult conditions, Rand can only do this.

Charcoal and sulfur can be purchased, and Rand has studied that the flame used in pyrotechnics is less powerful, mainly because of the ratio of the three mixtures, the most lethal ratio should be 15:2:3, and the crystallization of potassium nitrate accounts for a large part of the ratio.

"I don't quite understand, what are you doing with these things, if you want to see the fireworks, I can do ten times more beautiful than that. Oak didn't know what Rand meant's meant.

"No, no, no, it does more than that, if you put it in a sealed space, when ignited, it can burst out with amazing potential, propulsion and explosiveness. "Rand poured some of his own powder into the steel pipe with only one outlet, and then compacted it with a wooden rod with a stopper, which is extremely important, and if there is a leak or the filling is not satisfactory, it is likely that the combustion rate of the impact * will lead to insufficient propulsion, or more serious consequences, such as backfire.

"Are you, are you going to use it to make weapons?" Oak finally understood the meaning of Lante's words, "This kind of thing doesn't have any real lethality other than being able to burn the hair of enemies, you think too much!"

"In a distant country, they used this kind of * to make weapons, and the lethality caused by them was several times or even dozens of times greater than that of cold weapons of the same volume!" Randt pouted and said: "If it weren't for the fact that the cold weapon tactics had lasted for thousands of years and were too mature, that country would have unified the world with rudimentary firearms. ”

* This kind of thing, it is really a must-have artifact for traversers, it is simple to make and powerful, and it is very convenient to use, leaving only one exit in a sealed space, and then filling it with lead bullet or thistle terrestris, * The gas generated at the moment of explosion will have a huge propulsion, it can be called the first generation of shotguns, but the steel pipe used as the barrel is difficult to make, and with the help of Oak, there are few steel pipes that meet the standards of production landing.

This rudimentary firearm is not called a firearm, it can only be regarded as a lead bullet launcher in the strict sense of the word, and in the memory of Rand's previous life, this firearm is collectively known as a firearm, which was researched and equipped into his army hundreds of years ago, and Rand remembers the name of that army.

Camp Divine Machine.

Da Ming Shen Machine Battalion.