Li Yuanqing laughed and said: "Because the old king of Beirong is seriously ill, but he has not yet determined the heir. Now is a critical moment for several princes to compete for the throne. ”

"So the princes began to gather their forces and get closer to their capitals. The herdsmen and troops who had gone south in Beirong are now gradually retreating. ”

When Liu Pan'er heard this, she breathed a sigh of relief slightly, "That's good, although going south can snatch some supplies, but where are these things comparable to the throne?" ”

With enough time, she will be able to prepare more.

Whether it is repairing the Great Wall or preparing more grain and grass, it can better resist the invasion of Beirong.

Li Yuanqing nodded, "Yes!" The old king was seriously ill and did not die for a day, and these princes did not have the energy to go south. ”

"No one wants to be too far away from Beirong at this time. In the event of the death of the old king, even if they robbed a lot of supplies, they would end up making wedding dresses for others. ”

Liu Paner, who was still a little worried, is now completely relieved.

"Dabao, your father is back now, report to your father about the progress of your experiment."

Li Dabao wiped his mouth and replied very seriously: "The cement that was fired recently, after half a month of exposure, has no cracks, and the strength is also very high. ”

"It doesn't matter if it's used to build roads or the Great Wall. In addition, when I was firing these cements, I passed through a barren land, and the stones and dirt were all black. ”

"I had people dig it up and found out it was coal. This thing is used for smelting, firing cement, and it is especially good. ”

"It's cold in the north, but you can't use charcoal for heating, because using charcoal in a closed house can poison people. Unfortunately, I haven't thought about how to get rid of the poison gas yet. ”

Hearing this, Liu Paner and Li Yuanqing looked at each other, and they knew the reason.

Carbon monoxide poisoning.

Charcoal heating must be ventilated, otherwise carbon monoxide poisoning will die.

This stuff is of great use.

Coal can be dug in the ground, which proves that the coal mine is very shallow and the excavation cost is relatively low.

Li Yuanqing asked: "Dabao, where is this coal mine?" ”

Li Dabao replied: "In a piece of Gobi more than 100 miles away from Sangcheng, the coal mined is used to burn cement. Those finely crushed powders are useless, and it's a pity to waste them. ”

"But that thing can't be used to cook or heat, it belongs to the tasteless food, and it's a pity to abandon it."

Li Yuanqing smiled, very confident in this, "I have a lot of use for pulverized coal!" ”

"Dad, what's the use of those pulverized coals?" Li Dabao is curious, as coal mining increases, so do the particles of pulverized coal.

During this time, he was worried and didn't know what to do with the coal dust.

Li Yuanqing replied: "It can be used for cooking!" ”

Li Dabao hurriedly waved his hand when he heard this, "No, I tried to use it before, and those pulverized coal have smoke and impurities when they burn, which is very choking." ”

Liu Pan'er pursed her lips and smiled, "Your father has a way, then let him deal with it, maybe he can really do it." ”

Honeycomb coal, such a good thing, of course, has to be made.

There are not many mountains and forests in the north, and the firewood needed at home is purchased from outside. They are all sold to the city by villagers who live far away in the mountains.

More and more trees are cut down, but fewer people are planting, so that now there are fewer and fewer green trees.

If you have coal to use for cooking, you can reduce the amount of firewood and plant more.

After eating, Li Yuanqing drew the tools for making honeycomb coal, "Dabao, can you find your blacksmith and make it for me according to the size?" ”

Li Dabao nodded, "This thing is simple, it should be able to be made." Dad, when do you want it? ”

"The sooner the better, of course." Li Yuanqing replied, "With this, you can make honeycomb coal." ”

"Honeycomb coal?" Li Dabao frowned, "Dad, do you want to use this to make pulverized coal into cylinders?" How many holes are there in it to speed up the combustion? ”

Li Yuanqing nodded, "Yes, does it look like a honeycomb?" ”

Li Dabao still frowned, "Dad, even if you put water on those pulverized coals and make them into cylinders, but after they are dried, they are not strong, and they will fall into powder when touched." ”

Such an attempt, he has already made, unsuccessful.

Li Yuanqing smiled, "Then have you tried to add mud to it?" Mix it with those pulverized coals, and it will stick together? ”

Li Dabao was stunned for a moment, thought for a moment, and with his experience, he quickly deduced the conclusion, "Soil can be used to stick to the city wall, and of course it can also stick to pulverized coal." Maybe it really works. However, the ratio of mud to soil is different, and the burning effect must be different. ”

"Dad, I'll have someone get a few jars of pulverized coal tomorrow, and when the tools are ready, let's try and find the best ratio."

Li Yuanqing nodded and patted Li Dabao's head, "Okay, I'll leave it to you." ”

Li Dabao smiled, "Well, it's a trivial matter." By the way, when will the walls be repaired? I sent someone to bring the cement over. ”

Li Yuanqing thought that there was little rain in the north, and even in summer, it would still be able to start, "As soon as possible, while those princes in Beirong are vying for the throne, let's repair the place where the city wall on the plain collapsed." ”

Li Dabao nodded, "Well, okay, let's repair the city wall first, and we'll talk about the rest later." As for the recipe that Your Majesty wants, I am going to write an excerpt, Dad, you present it to Your Majesty for me. ”

Li Yuanqing nodded, "I've seen your cement, it's good to be able to reach that level." Dabao, you are really suitable for learning about things. However, the strength of this thing can be as high as possible, and maybe you can use these things, mixed with bricks and stones, to build a house with several floors. “

This house is much better than a wooden house, waterproof and fireproof.

Li Dabao thought so, "Dad, you're right, I will continue to work hard." ”

"In addition, I also prepared some things for Shuyuan. Dad, when you send someone to the capital, tell me, and I'll send the things over. ”

Li Yuanqing smiled and patted his adopted son on the shoulder, this kid grows up fast, and he will inevitably be like his father in the future, a man who stands up to the sky. He can also be worthy of his dead comrades.

"Good boy, that's the right thing to do. You are good to your future daughter-in-law, Shuyuan is married, and she will have the same heart with you in the future. The Qi family governs the country and the world, if a small family can't manage it well, how can it manage so many people? How can you be up to the task? ”

Li Dabao looked at his father Li Yuanqing with admiration, "Dad, thank you for teaching me." I understand what you say, and my mother often tells me. Husband and wife are one, trust each other, I am assured that I am working hard outside, and I am assured that she will handle housework. Husband and wife work together, and the days can be more prosperous. ”