Ren Baqian sat on a chair in a daze, this happened to be a shady place, and the temperature around him was like a fire.

According to the season of Great Summer, it is already late autumn, but the weather is still hot to death.

In the distance, there was a clanging sound of excavation on Damo Mountain.

After burning the mountain yesterday, a crack as thin as a hair appeared on the mountain wall, which made Gu Qiong and Tao Jiyuan very happy, and felt that they had found a way to dig this big mountain.

However, Ren Baqian is not as optimistic as the two of them, and it is estimated that it is only a little superficial, and there should be no change in it.

Of course, this is also the difference in the requirements of the two sides, Ren Baqian is thinking about obtaining iron ore that can build weapons that can equip an army of 20,000 people.

Da Yao's standard thick-backed long knife is not the kind of knife that ordinary people hold, each one weighs about twenty catties, and the iron ore needed is at least twenty-two or three catties.

And the thousands of prisoners on Damo Mountain can only mine 180 catties of iron ore a day, and they can only make four knives, and they are only more than 2,000 in two years.

You must know that Da Yao needs weapons not only in an army, including the Orions in the mountains, but also those iron tools that are needed daily.

Although the other iron mine, Liucui Mountain, did not go, Ren Baqian asked Tao Jiyuan when chatting before, it was in the mountains, and the mountain road was difficult to walk. Although mining is much easier, transporting it is also a big problem.

In a country with a population of 30 or 40 million, the output of iron ore in a year is only 10,000 catties, what can it do?

"My lord, my lord, today weighs at least four or five hundred catties, which is the amount mined in the past four or five days. ”

Ren Baqian didn't know when he fell asleep, and was awakened by Gu Qiong's loud and excited voice in his sleep.

"Oh, four or five hundred catties?" Ren Baqian rubbed his eyes, lit the fire and burned it for a day, then watered, and took another day to mine, but it was twice as fast.

"Then pull more timber out, it's better to mobilize some people in the surrounding cities to transport timber, and then burn the mountain separately, one day east and one day west, take turns to burn the mountain and mine, so that the efficiency will be improved." Ren Baqian stretched and said. I thought to myself that the mountains around me would become in a few years. After all, if you want to burn this iron mountain for mining, the amount of wood consumed in a year is not a fraction, but the growth of trees is a ten-year cycle.

In addition, as the surrounding timber decreases, it will be necessary to send timber from afar to maintain this mining speed, and the number of personnel used will be even greater. Let's do it for now, and then go back and study the concave mirror.

"That's what Lord Ren said. Tao Jiyuan saw that Ren had doubled the output of iron ore in eight thousand one or two days, and according to his words, he was afraid that he could increase it by three or four times, and he immediately admired it. "But I'm afraid this matter will have to be ordered by His Majesty. ”

"Let's go check it out. Ren Baqian got up and let Gu Qiong lead the way, and went to the foot of Damo Mountain to study and observe, and sure enough, as he thought before, it was just a thin layer, and the length of half a finger was about three centimeters.

"Tao Langzhong, I still have to bother you to give Your Majesty a fold and tell me about the matter here. Ren Baqian turned around and said.

At dinner, Tao Jiyuan and Gu Qiong still had excited looks on their faces, and Ren Baqian didn't disturb the enthusiasm of the two, but said: "I'll have a good rest tomorrow, don't bother me with big things, and you don't have to prepare meals for me." ”

"Yes, Lord Ren. ”

After saying hello to them, Ren Yaqian went back to the house and returned to Earth when everyone was about to go to sleep.

......

At this time, it was evening on the earth, and Ren Baqian first turned on the computer to find the news he had seen, but he quickly found it by typing in keywords, and there was more than one.

Experiments were made 70 years ago to make the first 50-kilowatt solar furnace with a liquid mirror, which could melt a 1-centimeter steel plate in 30 seconds.

A laboratory established 50 years ago, built with 10,000 concave mirrors, was able to reach 1,000 kilowatt hours, and instantly reached a high temperature of 3,500 degrees at the target.

The melting point of iron is only 1538 degrees, so it doesn't need to be that big at all, just a little smaller.

In a video online, a foreign guy melts iron with 5,800 fingernail-sized lenses attached to the lid of a satellite pot.

All this proves that Ren Baqian's previous ideas are feasible.

It doesn't need to be as big as a foreign laboratory, as long as it is one-tenth of the size, it can even be divided into ten parts and combined together, after all, it is just to melt the Damo mountain wall, and there are no high requirements for accuracy in all aspects, as long as the focus point is in a range to ensure that the temperature within the range is enough.

That night, Ren Baqian contacted a physics professor at a university in the city through Chen Qing, and met with him the next day, telling him his request, which required a concave mirror to make a movable and adjustable angle solar furnace that could melt steel three or four hundred meters away.

The other party needs to provide him with a solar stove that can be carried by a single person, as well as a series of plans for the mold he will make in Dayao in the future and the installation angles of all the concave mirrors.

This is very troublesome for Ren Baqian, but for the other party, this matter is very simple, after all, Ren Baqian does not have high requirements for accuracy in all aspects, and even throwing it to students can be completed, and the reward is 500,000.

After negotiating this matter, Ren Baqian returned to Dayao after resting for two days.

......

Liucui Mountain is actually on the periphery of Liuwan Mountain on the west side of Dayao, but if you want to reach the location of the iron ore, you have to walk on the mountain road for two days, and the mountain road is difficult, which is the biggest difficulty in transporting iron ore out.

A few days after leaving Damo Mountain, Ren Baqian walked on this mountain road.

When I first entered the mountain, it was fine, and the mountain road was fairly easy to walk, after all, this road is often passed.

However, as the day passed, the mountain road began to wind and become difficult, with a mountain wall on one side and a mountain stream on the other, and there was only a one-meter-wide road in between.

Although people can walk, they definitely can't do it with mounts and the like.

Even if a person can walk, he can't go fast.

At least Ren Baqian was dizzy every time his gaze swept under the cliff next to him.

You must know that there are two or three hundred meters below, and if you fall down, it will become a meatloaf.

Ren Baqian suddenly found that he had a big weakness, he was afraid of heights.

I didn't notice it before.

Seeing him like this, Fujiki was also worried, and followed him closely, ready to pull him at any time.

If something happens to this person, he doesn't have to go back.

After walking on this road for a long time, when he finally came to a valley surrounded by cliffs on three sides, Ren Baqian finally put down the heart he had been carrying, and felt that he was alive again.

The valley is not too big, and in addition to the guards of more than a hundred people, there are seven or eight hundred people mining here.

The iron content of the ore in Liucui Mountain is about 50%, and the difficulty of mining is much smaller. It's just that it's very difficult to transport ore out or inside here, so it's hard to scale.