Coming to the place designated by Lu Bu, the man waved his shovel and dug a big hole in the flat ground.

When Zang Ba arrived, it was already afternoon.

The passage didn't go deeper, and it was dark.

Lu Bu's tent was not far from the mouth of the newly opened well.

Although the roadway support was solved, the light source was not solved, and he couldn't fall asleep after turning over and over.

Coal mines are no better than anywhere else.

When going down the well with an open flame, once it encounters a gas gush, the explosion is quite light.

If it causes a dust explosion, not only will the entire mine be destroyed, but also an unknown number of lives will have to be lost.

At the end of the Eastern Han Dynasty, although few nobles took human life seriously, Lu Bu knew very well that the decline in population would inevitably lead to local weakness.

To dominate the world, population is the real most important resource.

Making a cold light source?

There was no such technology in the Eastern Han Dynasty.

Using the Night Pearl?

Lu Bu hadn't thought of this method at all.

Not to mention whether you can find the Night Pearl, even if you do, how many will you have to use in the entire mine?

All the coal excavated was sold, but I am afraid that it will not be enough to purchase the cost of the Night Pearl.

As he pondered what to do, a small dot of light flew past him.

Firefly!

Lu Bu was overjoyed in his heart, and hurriedly shouted: "Someone! ”

Zang Ba, who was patrolling with the guards, ran over quickly: "Wen Hou! ”

"Let people catch fireflies." Lu Bu said: "Put them in a bamboo cage, you can temporarily use them to light the well!" ”

Zang Ba was confused, and he didn't understand why Lu Bu had to use fireflies for lighting.

Lu Bu also ordered: "Pass the order, no one enters the mine, no open fire is allowed." ”

Although he didn't understand the reason, Zang Ba still agreed.

That night, the guards caught a lot of fireflies nearby.

The light emitted by a single insect is very faint, but many insects together are enough to illuminate a large area nearby.

Lu Bu didn't have much joy.

In the summer, fireflies can be found in the wild, but in the autumn the insects are mostly dormant or die.

There will be no more cold light sources for illumination.

We have to find another way to solve the light source.

Fortunately, with the fireflies, he can only delay for a month or two.

The mine is under construction, and the Xuzhou military camp is also in full swing.

Countless people participated in it, and the barracks changed day by day, and it seemed that it was not far from completion.

Since the construction of the coal mine began, Lu Bu has been staring.

The place he chose was particularly shallow for the coal seams.

Shovel away the floating soil at the top, and the coal is below.

As the passage extended, countless truckloads of crushed coal were sent to the ground every day, and Lu Bu had people select the gangue, add yellow mud and beat them into briquettes to transport them to Pengcheng.

Chen Gong didn't stay with him for too long, and returned to Pengcheng after two days.

The people who migrated to Pengcheng were sent in batches to build villages outside the city.

Seedlings were planted on land that was once uncultivated.

The shops in the city are also open.

Lü Bu rebuilt Pengcheng, and Zhang Shiping brought many merchants.

Chen Gong showed the usefulness of coal in front of them, and the merchants were all amazed.

At the beginning, Lu Bu asked people to develop toothpaste, including Zhang Shiping, and all businessmen were not optimistic.

Later, although it opened up the sales channel of the nobleman's back house and made a lot of profits, the audience was too small after all.

Coal is a different story.

It can replace firewood and charcoal and burn even longer than both.

The worst thing is that Chen Gong's price is actually lower than the price of firewood on the market.

The low price and burning for a long time make the businessmen ready to move.

Soon the first batch of coal sent to Xiapi was sold out.

The entrance to the mine extends day by day, and Lu Bu ponders every day how to find a suitable light source to replace the fireflies.

A month has passed, but he has never found a way.

In the tent, there was a small bamboo cage on the table in front of Lu Bu.

In the bamboo cage, there is a small firefly flying around.

I've been staring at the fireflies for a long time, but I haven't hinted at him for creating a cold light source.

"Wait for you, Gong Chen sent someone to deliver a letter." The off-the-books guards preached.

"Ask him to come in." Lu Bu commanded.

The curtain was lifted, and the guard led a man in.

The person who came was wearing armor, and it should be a soldier drawn from the army by Chen Gong.

The messenger held a bamboo tube in both hands and handed it to Lu Bu: "Duke Chen ordered me to send a letter to Wen Hou, saying that there is something important and that Wen Hou must return to Pengcheng as soon as possible." ”

The guard took the bamboo tube and handed it to Lu Bu.

After the bamboo tube, Lu Bu took out a scroll of silk with small characters written on it from it.

After opening the browsing, he instructed the messenger: "You go back and tell the public station first, and say that I will leave early tomorrow morning." ”

The messenger retreated, and Lu Bu explained to the guards: "Invite General Zang." ”

It didn't take much for Zang Ba to come.

When he entered the tent, he asked, "What does Wen Hou command?" ”

"You take a look at this first." Lu Bu handed him the letter.

Zang Ba took the letter and read it: "Cao Cao sent someone again?" ”

"The letter can be described as a mixed bag." Lü Bu said: "The coal we sent back was sold out, which is enough to prove that the coal mine can feed the army. But the people sent by Cao Cao wanted to urge us to send troops to attack Huainan. ”

Lu Bu stood up: "Jingzhou Liu Biao has long been eyeing Huainan, so he didn't make a move, but he was just waiting. If we attack Huainan and have a bad rhythm, it will lead to annihilation. ”

Looking at Lu Bu, Zang Ba didn't say anything.

"Fighting too fast caused Cao Cao to be jealous, and he will send troops to Xuzhou sooner or later." Lu Bu said: "If you fight too slowly, once the Jingzhou army comes, our army will fall into a bitter battle." Cao Cao really gave us a big problem. ”

He then asked Zang Ba: "Have you found any suitable talents to manage the coal mine?" ”

"There are a few, but they haven't started yet, so I'm afraid they won't be able to take on the big responsibility."

"We can't be here all the time." Lu Bu instructed: "Let people call them, I will explain some things, the coal mine will be handed over to them to take care of first, and you will accompany me back to Pengcheng." ”

Zang Ba instructed the guards to call the men.

The few people he chose were all kind and knew a few words.

For the people of the late Han Dynasty, coal mining was a completely new business.

The more capable people are, the more obsessed they are with changing the status quo.

What Lu Bu needs now is an honest person who follows the steps step by step.

Only an honest person will be completely obedient and will put the things he has explained in place.

Several people who were about to take over the place arrived, and Lu Bu dissected what he knew about the coal mine one by one.

It wasn't until a few people fully understood that Lu Bu asked them to retreat.

There was nothing to say that night, until dawn, and Lu Bu rushed to Pengcheng with Zang Ba and a team of guards.

Riding their horses and galloping, they came to the outside of Pengcheng in just over half an hour.

Chen Gong, who had already received the news, ordered the city gate to be opened as soon as it was dawn.

When Lu Bu and the others returned, the city gate was already open to greet them.

After entering the city and going straight to the official mansion, Lu Bu dismounted, and Chen Gong greeted him from inside: "Wen Hou can be regarded as back!" ”