The cave is located on the mountainside that is about to reach the top of the mountain, where there is originally a natural big cave, there are two holes before and after, the ventilation effect is very good, it was used to store materials before, and then it was valued by the South Gate Iron, so a fire kiln was built in it.

When he came to the mouth of the cave, a wave of heat came to his face, and Yuan Fang, who was already a little stiff, almost snorted comfortably, and hurriedly quickened his pace into the cave.

The cold on the body was quickly dispelled, the body was wrapped in warmth, the warmth was very comfortable, moving the somewhat numb fingers, looking up, there was something similar to a miniature brick kiln in the middle of the cave ten meters high, through a few small holes, you could see the red fire inside.

At this time, Nanmen Tiezheng was standing next to the kiln and a few workers pointing inside, when he heard the footsteps and looked back, he was stunned when he saw the smiling Yuan Fang, and then he was overjoyed, and quickly greeted him, bowing down: "I have seen Lord Yuan, generals." Yuan Fang stepped forward to help up the South Gate Tie, first asked for warmth, and then began to ask about the gas stone.

Nanmen Tie was very satisfied with everything here, he ate well, slept well, but the work was a bit heavy, and the three brothers had to burn gas stones for three days and nights, but these were nothing compared to what they got.

As for the firing of the gas stone, it was quite smooth, and with the support of the imperial power, the three brothers of the South Gate had sufficient materials, and they continued to try to improve it on the original basis to fire a new generation of gas stone with better quality.

The color of this gas stone is no longer as gray and white as before, but becomes milky white, and the gas produced after encountering water burns, showing a blue flame, according to Nanmen Tie, this blue flame has a higher heat, and with Yuan Fang's method, the time to melt the steel is shorter.

After listening to the introduction of Nanmen Tie a little proudly, he went to the warehouse to see the finished products produced before, Yuan Fang was quite satisfied, but there were only a dozen boxes of finished products in the huge warehouse, which made Yuan Fang a little surprised, Nanmen Tie They have been here for a while, and this output seems to be a little less.

As if seeing Yuan Fang's doubts, Nanmen Tie opened his mouth to explain: "Lord Yuan, it took us two days to get the kiln right after we came here, and then we started to burn gas stones, well, we can probably burn about five hundred catties of finished products every day, and this is just baked this afternoon, and the previous inventory was transported away at noon." ”

Yuan Fang suddenly realized when he heard this, but something was wrong when he thought about it: "No, we came from the imperial capital at noon, and we didn't find a convoy passing by on the way." Nanmen Tie scratched his head, he only burned the gas stone, and he didn't know anything else.

Seeing this, the veteran who had been accompanying him said: "Lord Yuan doesn't know, the gas stone is still in a confidential state for the time being, and there is no one for sale for the time being, and it is only used in the military factory now, so the previous gas stone was transported by the empire from the forest road in the west to the Xizhou military factory, instead of taking the official road to the imperial capital." ”

Yuan Fang nodded: "That's it, I'll say it." Well, in this case, you will leave me 500 catties of qi stone first, and then send someone to fetch it after I go back and discuss it with Your Majesty. Nanmen Tie and the veteran nodded again and again, they were very interested and didn't ask anything, this kind of thing is not something they can ask.

Yuan Fang is so intended, he wants the Meihua Chamber of Commerce to train a group of qualified welding workers, which is very important for future development, because not only military products need to be welded, but also civilian commodities, such as the main frame of the rolling mill that is currently in short supply, such as heating water pipe welding, etc., all need to be perfected by welding technology.

Also, in the near future, to manufacture ironclad warships, it will need more welding workers, and it may not be enough to rely on military factories alone, so Yuan Fang intends to promote this pioneering technology as soon as possible, anyway, as long as the formula of the gas stone is controlled, even if other countries know it, there is no way to obtain the basic requirements, if you want to learn, you can, as long as you take the money, the Plum Blossom Chamber of Commerce can train on your behalf, and you can also want gas stones, but you have to pay a sufficient price, this is Yuan Fang's plan, while developing the imperial industry, Improve the technical level of welders as quickly as possible, and in this way, open up the industrial technology market and earn more foreign exchange to enrich the national treasury.

Nanmen Xing and Nanmen Yang were still resting, Yuan Fang didn't bother, chatted with Nanmen Tie for a while, visited the somewhat simple fire kiln and left, heading to the top of the mountain, which is the core of the base, where the purpose of his trip is.

Nanmen Tie sent Yuan Fang and his entourage to the mouth of the cave and went back, the functional division area of the base has obvious boundaries, the workers who produce gas stones generally stay in the cave, as much as possible to avoid the leakage of the confidential core of the fog balloon, only on some specific days they can go out, but few people do that, the cave is big enough, enough for them to move, and here to put it bluntly, it is barren mountains and mountains, and it is winter, all the grass and vines are everywhere, there is really nothing to visit.

Out of the cave, he was instantly wrapped in cold, Yuan Fang, who had just recovered, couldn't help but shiver, looking at Sang Rou and the others who were following him, Yuan Fang couldn't help but wonder if he would go back here to rest at night.

Almost to the top of the mountain, a brand-new stone wall appeared in front of everyone, and the veteran took Yuan Fang and his party to the gate of the stone wall and explained: "This is to prevent the leakage of secrets, it was just built a few days ago, Lord Yuan, I will send it here, there are special guards guarding it, and they will take you in." ”

The simple wooden door opened, the veteran saw Yuan Fang nodding, and the guards who came out nodded politely and turned to leave, this is the rule of the base, each layer of guards is independent, the two sides are not allowed to contact at will and are not allowed to communicate with each other, this is also a means of secrecy.

The guards at the top and the core of the base were all old men who were here before, so they naturally knew Yuan Fang, and they did not pretentiously perform their duties to investigate, and warmly greeted Yuan Fang and his party to enter the core of the base, that is, the broken wall made of earth and stone.

Yuan Fang still remembered the nickname of this guard, and greeted him with a smile: "Big Bird, how are you doing?" ”

Big Bird is a very talkative guy, hehe smiled and began to talk endlessly, and what he has seen and heard during this time, of course, is some trivial things, fog balloons or some things involving confidentiality have not said a word, I don't know if it's really unclear or because of discipline I dare not say it.

Big Bird led the way while talking endlessly, and finally came to a tall warehouse, Big Bird finally stopped talking nonsense, said hello to the guards guarding the door, opened the small door to the side, and invited Yuan Fang and his party to enter.