Winter is never a good season, at least for most people in Handan City.

Zhao Dan sat in the carriage, looked at the black smoke rising from every household around him, and asked Mao Sui in confusion: "Is it so common to burn firewood to keep warm in Handan City now?"

Mao Sui smiled and said, "The king doesn't know that coal has begun to be popularized in Handan City."

"Coal to keep heating?" Zhao Dan couldn't help but be stunned.

After Mao Sui's explanation, Zhao Dan slowly understood.

Due to the continuous expansion of Zhao State over the years, the demand for steel has also increased significantly, and the supply of coke required for steel has also increased accordingly.

As a deep processing product of coal, coke must bring large-scale coal production. Since Zhao State is located in the "Jin" with the richest coal production in China, that is, Shanxi, in a few years, Zhao State has now explored five large coal mines and carried out large-scale mining, and even the mining volume has exceeded the supply required for blast furnace iron smelting.

Under such circumstances, the Zhao State official began to supply coal to the residents of Zhao State at a large scale at a cheap price. At first, it was only around the coal mine, but later it gradually expanded to the south.

Until the previous year, Yu Xin, who was still a domestic history of Zhao, made an important decision after reporting to Zhao Dan: to allow merchants from Zhao State to mine and traffic coal, and the Zhao State's finance would charge a certain amount of taxes in this.

Unlike Qin, although Zhao also pays more attention to agriculture, Zhao Dan must understand the principle that food is the most important thing for the people, but Zhao's business atmosphere is also very strong.

In fact, except for Qin, the other princes of the Warring States Period had a very good attitude towards business. Qi even encouraged business since Guan Zhong's time, and communicated with other countries to increase Qi's fiscal revenue.

So when coal was opened from a state-owned resource to allowing the capital of merchants to enter, merchants suddenly burst out with great enthusiasm.

In just two years, coal, the fuel became popular in the entire Zhao State at a flying speed, replacing firewood and becoming the new favorite for heating among major cities in Zhao State.

Zhao Dan was also very surprised when he heard Mao Sui telling him all this.

In Zhao Dan's impression, China did not start using coke to smelify iron until the Han Dynasty. It was not until the Song Dynasty that coal was used as heating fuel to truly enter thousands of households.

Now, because of Zhao Dan, China's history of large-scale coal use is as early as 1,200 years ahead of schedule!

There is no doubt that this is definitely an improvement.

By replacing firewood with coal, it can greatly prevent firewood from being cut down by people, and protect the environment and prevent soil erosion.

The problem of soil erosion is actually very worthy of attention. Not to mention anything else, Guanzhong, which made its fortune in Qin, has completely declined after the Tang Dynasty due to severe soil erosion and climate change in history and has never become the center of China again.

As for the possible pollution caused by mining and burning coal... to be more selfish, even if the entire Huaxia land burns coal for 24 hours a day, it actually does not have any pollution effect on the earth's atmosphere, and it is completely within the scope of the earth's self-regulation.

After all, there is no saying of industrialization in this era.

But even so, Zhao Dan was somewhat sad when he looked at the sky on Handan that seemed to have turned a little darker above his head.

Will Zhao become the first city on the earth to experience air pollution in the future?

Forget it, let's talk about this later...

Zhao Dan coughed and said, "Mao Sui, remember to notify Handan City Order later and ask him to organize people to preach, so that the people should not let the people burn coal to keep warm in sealed houses to avoid gas poisoning."

Gas poisoning often happens in later generations.

Zhao Dan's carriage rolled around and took Zhao Dan to his destination this time, the workshop area of ​​Zhao State.

Zhao Dan came all the way to a workshop in the deepest part of the workshop area, which is also the most confidential workshop in Zhao State. It gathered the top craftsmen and workers of Zhao State, and was specifically responsible for studying various secret weapons for Zhao State.

The news of Zhao Dan's arrival had already been notified here, so when Zhao Dan got off the carriage, the general of Zhao State was already waiting here with all the masters of Zhao State.

Zhao Dan took a look at the belly and found that the Mo family spirit hadn't seen him for a few years. He had become unshaven and had a strong smell on his body, which made people dare not get close to him within ten feet.

OK, this fanatical tech otakus...

"I've seen the king!" Fu Zhen led the masters to salute Zhao Dan.

Zhao Dan covered his nose and coughed, and said to Baizhen: "Doctor, what's wrong with you? You want to call me here."

In addition to the Baniu Crossbow, Fu Zhen has devoted himself to research over the years and has made great contributions to the weapons and armor of armor of the armor of the cavalry, the standard crossbow of the Zhao army, the vehicles for transporting grain, etc.

Of course, Zhao Dan would not owe the most outstanding craftsman in Zhao State now, and gave Ku Zhen a title of doctor with a wave of his hand.

Although he is only a doctor, this doctor is already an absolute high-ranking nobleman.

Ku Zhen was awarded the title of doctor as a craftsman, which caused a lot of controversy in Zhao State, and even several important officials of Zhao State expressed dissatisfaction with this to a greater or lesser extent.

However, Zhao Dan ignored these opposition voices and passed this proposal with an extremely tough and unstoppable attitude, making Fu Zhen the first craftsman doctor in history.

Science and technology are the primary productive forces. As a time traveler, Zhao Dan knows this very well.

As the saying goes, buying horse bones for a thousand gold coins. The belly is really the horse bones that Zhao Dan needs to buy with a thousand gold coins. Zhao Dan wants to tell people in the world through this matter that they can be officials and titles only when fighting and studying. As long as you do a good job in scientific research, there is a way out!

After hearing Zhao Dan’s question, Ku Zhen smiled slightly, and a mysterious smile suddenly appeared on his face: "Your Majesty, please come."

He was really not talking nonsense, and walked straight to the back.

Zhao Dan was stunned for a moment, thinking that this kid actually dared to keep me in secret?

If it were someone else, then I would definitely not dare to be so pretentious in front of Zhao Dan. But the problem is that Fu Zhen is the chief craftsman of Zhao State and is the talent that Zhao Dan attaches most importance to. So Zhao Dan thought about it and decided to temporarily let Fu Zhen go and openly pretend to be so bad.

Let’s see what he has done before talking about it. If it really doesn’t work, you can make the calculations after autumn.

After a while, Zhao Dan and Fu Zhen came to a schoolyard in the workshop. The entire schoolyard has now been cleared, with only one wall standing there.

It can be seen that this wall was definitely temporarily built.

He waved his hand, and then the master craftsmen immediately disappeared.

After a while, the two masters carefully carried a big bag and then put the big bag into a hole buried in advance under the wall.

Zhao Dan looked at the scene in front of him, his eyes lit up unconsciously, and his heart began to pound. Could it be...

After seeing these masters burying this, he immediately said to Zhao Dan: "King, this thing is very dangerous. I ask the king to go to the high platform first and look at it from a distance."

Zhao Dan nodded and followed Ku Zhen to the high platform hundreds of steps away.

Seeing that everything was done, I shouted directly: "Light up!"

A master craftsman immediately fired the fire, then lit the fuse, and immediately ran to the opposite direction and died.

The long fuse burned quickly.

"Boom!"

After a shocking sound passed, thick smoke rose into the air. Even though Zhao Dan on the platform had already been mentally prepared, he subconsciously took two steps back. Mao Sui beside Zhao Dan was even more unbearable. He sat directly on the ground with a look of fear on his face.

The thick smoke gradually dissipated, and a large pit appeared in the place where the explosion just now. The walls that originally stood there had already turned into ruins in the explosion.

Zhao Dan watched all this quietly, and a smile slowly emerged from his face.

Gunpowder...you finally appeared!

His abdomen was really straightened, and his face was full of pride: "Please look, Master, I named this object - Zhentian Lei!"

Of course, there is a reason to be proud of the belly.

After he became a general in Zhao State, Fu Zhen received a secret order from Zhao Dan, which was to devote himself to the research and development of gunpowder.

At first, Fu Zhen was a little dissatisfied with this, but given that this was an order from Zhao Dan, Fu Zhen had no choice but to devote himself to it.

However, Kuchi Zhen never expected that when he saw the alchemists demonstrate the effect of gunpowder to him, he became completely addicted.

After several years of research, Fu Zhen finally successfully adjusted the gunpowder to a very reasonable ratio, which led to the scene that Zhao Dan saw today.

Zhao Dan could no longer suppress the joy in his heart, and he couldn't help laughing out loud.

After a long time, the smile on Zhao Dan's face slowly stopped and patted Bai Zhen's shoulder hard. He only felt that Bai Zhen looked cute at this moment. If it weren't for the odor on this guy, the odor on the body was too strong, even Zhao Dan wanted to give Bai Zhen a big hug.

Zhao Dan suppressed his impulse and asked to Ku Zhen: "How is the current output of this thunder in the sky? Can it break through the city wall?"

Kuro really thought about it and said, "King, to be honest, this recipe for the thunder of the sky was just made, so the output is still quite limited for the time being, but it will soon reach a considerable level. As for the power, I have actually tried it. If the walls of ordinary small cities only require enough gunpowder, then there should be no problem. But if a big city like Xianyang and Yingdu may not have any great effect for the time being. But please rest assured, as long as you give me some more time, it will be one or two years slower, as long as three or five years, any city wall will become vulnerable in front of the thunder of the sky!"

To put it bluntly, although this gunpowder has made great progress compared to the beginning, it is still in the early stage of application. Both the materials and the techniques still require a lot of improvements, and it cannot be as powerful as the tnts in later generations.

However, Zhao Dan was also satisfied with this, and he smiled and said, "Very good, very good. I announced that Ku Zhen will be promoted to a senior doctor from now on, and the other masters will each have rewards!"

After seeing the performance of Kuma, Zhao Dan was completely relieved, so when he left the workshop, Zhao Dan took out a small notebook with great care and handed it to Kuma Zhen.

"Steam engine?" Ku Zhen looked at Zhao Dan with some confusion.
Chapter completed!