The problem that Mu Tou encountered was so serious that he had no idea what to do.

That is, he had no way to chisel a piece of stone into a cylinder that was not too thick.

It was not that the stone was too hard to chisel, nor that his strength was too weak, but that he had no way to carve a perfect circle on the stone slab that would become a millstone.

Since he couldn't draw a perfect circle, he couldn't carve a perfect circular millstone either.

It was really frustrating to say that the task of carving a stone mill was actually stumped by something he had never thought of before.

He tried for a long time but failed to draw a perfect circle on the granite slab. In desperation, he had to ask the carpenter for help.

After hearing what Mu Tou said, Bo came without saying anything, but he was a little dissatisfied in his heart. Isn't it just a circle? It's such a simple thing.

As a result, after picking up the stone and drawing on it for a while, he became lame.

It turns out that a seemingly simple circle is not easy to draw at all.

Shitou, who often held the "pen", passed by here. After understanding the dilemma of the two people, he volunteered to do it.

Although the circle he drew was smaller than the ones drawn by the wood and the lame ones, it was still a little worse.

After trying for a while and failing all the time, the clever and studious Stone was also annoyed by this simple circle.

He wanted to ask the Son of God for a solution, but the Son of God had gone to the Salt Mountain. After hesitating for a while, he had to ask the second wisest witch in the tribe for help.

Wu was very enthusiastic about making soybeans from beans, and after hearing about this, he came over immediately.

After some discussion, he was still helpless.

For a moment, several people held their heads and thought hard.

A simple circle stumped all of them.

Wu scratched his scalp in distress, and lost a lot of hair. His already sparse hair became even thinner, and his hair was getting closer to the Mediterranean Sea...

Han Cheng was in Yanshan at this time.

After explaining the structure of the stone mill to Mu Tou, he brought his army of dogs and some people from the tribe to the Yanshan.

The stone mill can be made by Mu Tou and others, but he will have to make the brine himself.

The salt mountain at this time has also changed a lot compared to a few years ago.

The desolate scene has been reduced a lot and there are many more people.

In one place in the salt mountain, there are a lot of scattered gravel, and there are also many traces of human chopping on the stone walls.

These are the traces left by the people of the Qingque tribe, who have been hammering salt mines to boil salt here for a long time.

There is not much grass growing around the spring that has been expanded and renovated not far from the salt mountain, as well as downstream.

On the one hand, it was trampled back and forth by the people who cooked salt, and on the other hand, it was also related to the thin layer of white frost on the ground.

This is a man-made saline-alkali land, and it is foreseeable that it will continue to expand over time.

This was the first trauma left on this land by the people of the Qingque tribe as human civilization continued to develop.

The salt ore was crushed and placed in a large stone mortar until it was crushed into as much foam as possible, then placed in a large ceramic basin filled with water and stirred to melt.

After a little settling, place a charcoal-wrapped burlap bag on top and start filtering…

People who often come to boil salt have already become very skilled at this.

But this time it was different.

In the past, when a basin of water containing dissolved salt ore powder was filtered to the end, the remaining turbid sediment would be poured out. However, this time the Son of God did not do that. Instead, he had people keep the turbid water mixed with a large amount of fine stone foam and store it in a pottery jar.

Although they didn't know what use the Son of God had for these things, they still did it.

Of course, Han Cheng wanted these things to make brine.

His idea was simple. The previous process produced salt, and he thought the brine was among the things that were filtered out.

Brine is a very toxic substance, mainly because it contains a lot of chemical components. He has also heard of people committing suicide by drinking brine.

If people consume too much salt mines that have not been filtered, purified, and refined, they will also cause poisoning and death.

Comparing the two, it is not surprising to know that brine is among the things that are filtered out.

What makes Han Cheng feel difficult is how to extract brine from these impurities.

Han Cheng stared at the turbid clay basin for a long time, feeling overwhelmed and at a loss.

Time travel is not really suitable for liberal arts students.

If you travel back to a familiar dynasty, as a liberal arts student, you can use familiar poems to slap the faces of historical celebrities, or based on the historical process you are familiar with, you can have foresight and change the course of history quietly and invisibly.

But if you travel directly to this era, you will be really at a loss.

Whenever he encountered knowledge of physics and chemistry, Han Cheng would feel frustrated as he had no idea where to start.

"Cook them, too."

Han Cheng, who is in a dilemma, can only try his best to save the situation. No matter whether it works or not, he will just give it a try.

Even if the method is unreliable, it is better than sitting here and feeling melancholy without any solution.

The person who was cooking salt was a little stunned when he heard Han Cheng's words. Could it be that salt could be cooked from these things that were thrown away in the past?

Although he was confused, his hands were not slow and soon set up another pottery jar.

Pour the muddy water mixed with a lot of stone foam into it and start boiling.

After a while, the water boiled and white steam rose. At the same time, the water became more turbid.

Han Cheng, who was standing aside and watching, couldn't help but sniff. The possibility of obtaining brine using such a crude method was really not very high.

The flame continued to burn, and the water in the pottery jar gradually disappeared. Some white things appeared at the bottom of the jar, mixed with a lot of fine stone foam.

Han Cheng asked someone to stop the fire, took out a small amount from inside, and licked it gently with the tip of his tongue.

It's full of flavor. In addition to the salty taste of salt, there are some other messy flavors mixed in.

Although he couldn't tell what the taste was, it was certain that it was not pleasant at all. Han Cheng couldn't help but grin after just one lick.

And with this licking, some stone foam remained on the tongue, which was extremely uncomfortable.

Han Cheng rinsed his mouth for a long time before he recovered.

I guess only a pervert like Uncle Lu who used to practice his tongue on a mountain of salt could withstand such a taste.

After rinsing his mouth, Han Cheng picked out the small white pieces mixed in the stone foam bit by bit, with a look of confusion on his face.

Now the question is, is this thing brine?