It had been two days since Li Gengyun and Guo Feng had gathered these craftsmen, and on the third day, there was exciting news from the secret base, that is, the iron pipe that Li Gengyun said was finally completed. Similarly, in the development of explosives, every morning the four craftsmen sorted out the explosives that had been prepared in the previous ratio, and handed over all the untested explosives in their hands to the guards of the secret base. In the afternoon, the guards sent the explosives to the location designated by Li Gengyun, and a special person was responsible for testing.

According to Li Gengyun's requirements, each explosive tested was numbered, and each number corresponded to the distribution ratio of the explosives. Because the method used to wrap the explosives is made in the form of flower cannons, the packaging is the same, and the most important thing is to look at the ingredients inside.

After two consecutive days of testing, Li Gengyun received a reply from the test area, that the power of the No. 25 explosive package was "enough to crack the slate", while the power of the other numbered explosive packs varied, and the best one was only the "shaking flying slate". Although the power of this No. 25 explosive package was stronger than that of other explosive bags, it did not meet Li Gengyun's requirements. The size and thickness of the slate were specified by Li Gengyun himself, and he demanded that if the slate could be shattered with a flower cannon explosive package, then the dynamite test would be successful.

Regarding the iron pipe, Li Gengyun learned that the iron pipe was completed, and he also rushed to the secret base, but to his disappointment, although the iron pipe was completed, the quality of the iron pipe was not good. Although it has the appearance of an iron pipe, the thickness of this pipe wall is a little too exaggerated, it is as thick as a little finger, and the weight of a four-inch iron pipe is already quite load-bearing, and ordinary soldiers can only lift it when they use this iron pipe. If this kind of iron pipe is used to make an arquebus, not to mention the crosshairs of aiming, even the soldier will feel difficult to hold it in his hand, let alone aim?

So Li Gengyun overturned the conclusion of the three blacksmiths' iron pipe molding, and his request was to make the diameter of the iron pipe not more than one little finger, and the size of the inner tube was exactly the size of half a little finger according to the standard requirements. This made the three blacksmiths a little embarrassed, they didn't know what Li Gengyun wanted these iron pipes for, not to mention the troublesome process of making these iron pipes, especially when quenching iron pipes, they had to have a strong and accurate grasp, and they didn't know how to reduce the thickness. was at a loss, and finally Li Gengyun gave them a suggestion, that is, to use abrasives to use stone molds for the first improvement, then use sand grinding for the second separation, and finally use iron molds for the third casting.

After hearing this, the three of them also suddenly realized, so they hurriedly started to start the production of iron pipes, and in terms of molds, Li Gengyun arranged several guards to help them make them together.

"Mr. Li, this is the latest batch of test explosives, do you want to go and see the test situation for yourself?"

At this time, the head of the guards pointed to the flower cannon of a flatbed truck and asked Li Gengyun, and it happened that the test site was not far from the secret base, so he thought that since Li Gengyun was here, he could also go and observe. After all, Li Gengyun is well-informed, and in their hearts, he is simply a god-like existence, maybe in the process of experimenting, Li Gengyun can find out the problem and find out how to make the elements of explosives.

"It's good!"

Li Gengyun nodded, these days he is basically recuperating at home, and his apprentice Mu Bai went to Jiangzhou with his father Mu Yang and went to Liu's house to pay New Year's greetings. Of course, Li Gengyun also secretly arranged many masters to protect the safety of their family, and made sure to send them to Liu's house safely, and then protect them to return to Xiangyang safely. Anyway, there was nothing to do, so Li Gengyun agreed to the request of the head of the guards, and went to the explosives test place together under their escort.

The site of the test explosives was in the southwest of the secret base, a desolate mountainous area in which they had dug a pit to test the explosives according to Li Gengyun's previous instructions. A few days ago, there was a heavy snowfall in Xiangzhou, these days just as the snow began to melt, and now the deep pit has been filled with snow, after they came here, the head of the guard arranged for those soldiers to clean up the stagnant water, and at the same time beckoned another team of soldiers to prepare for observation and protection of the place where Li Gengyun was sitting.

After about half an hour, the water in the pit was almost cleared, and the two guards threw a full-size stone slab into the pit. Because only one experiment was slightly successful, and the slate was cracked, and the others were blown away, so there was only one cracked slate in the pit, and a few small stones were placed on the slate, which just left a small slit for the slate, so that the developed gunpowder could be placed in the slate crack.

The fire rope that links the explosives is tied to a dry bamboo pole, and the length of the fire rope is about three meters, which is actually a rope stained with oil, which is arranged by Li Gengyun himself, after all, the fire rope is not easy to make, and a large number of fire ropes will be needed to make arquebuses in the future. So from now on, it is necessary to carry out the reserve of the fire rope, thinking that although the effect of the oil rope is worse than the fire rope, it is still no problem to ignite the explosives, and in terms of production cost, the oil rope is much cheaper than the fire rope, and it is easier for the test to accept.

"Explosive test No. 38 begins."

"The explosives are placed, and the oil rope is connected!"

"Mr. Li, please order!"

"Ignition!"

"Ignition!"

With Li Gengyun's order, a soldier in charge of lighting the fire outside the pit lit the oil rope on the bamboo pole, and then immediately ran away, hiding behind a boulder and waiting for the result. And Li Gengyun's location is about 100 meters away from the deep pit, and the leader of the guards here has also set up several huge rocks, the purpose is to prevent the explosives from exploding and injuring this side, and at the same time, they can also observe the experimental situation of the explosives in the deep pit through the thin slits between the boulders.

"Bang!"

With a loud bang, the slab that had been pressed against the explosives flew violently, popped out of the pit, and fell to the ground, intact.

"Explosive test No. 38 failed! Do a site cleanup! ”

"Yes!"

When the leader of the guards saw the stone slab flying up intact, he also shook his head and gave orders to the other soldiers helplessly, and he said to Li Gengyun embarrassedly: "Mr. Li, we are used to it, and I hope Mr. Li will not be surprised." ”

"It doesn't matter, there will always be failures in experiments, and besides, if it is so easy to succeed, wouldn't the whole world have begun to enter the age of firearms?"

Li Gengyun replied with a smile, and then looked at the explosives bag of a flatbed truck behind him, and he was also a little helpless, and secretly said in his heart, I don't know if this will bring me a surprise!