The Chen people who were ordered to dig tunnels and build Yang Di did not know the real intentions of the King of Chu and the nobles. In their opinion, this was just a very normal way of attack.

Yang Di could not build directly under the city, so he could only choose to start outside the range of the feathered arrows on the city, accumulate forward little by little, and constantly use his condescending advantage to suppress the city head with the archer and gradually approach.

This is the stupidest way in the Mohist school, but the so-called "big tricks" are not crafted. If they are successfully accumulated, they will put huge pressure on the city walls.

Digging out tunnels is also a common method to use and is also very useful.

It is not to dig the tunnel directly into the city, but to dig the rammed earth wall foundation close to the city wall and dig and collapse the city wall.

If this method is combined with gunpowder, it is almost an unsolvable siege method of the city walls of this era.

However, even the Chu people could not have complete iron tools, so many disciples still used the stupidest method to dig.

Fortunately, there are many craftsmen in the Chu people, either in copper mines or in other mines, and digging holes can still be done.

Most of the Chen people who were excavated were those who had heard the propaganda of Mozhe. They had already had strict orders before. The Mozhe's words were nonsense, prohibiting them from spreading in the military camp. They were caught and asked to be beheaded.

There were people who supervised them later, and these people were worried that someone would report the news, so they didn't say anything. They just kept digging according to the command and wanted to get close to the city wall.

…………

In the city, a blind man crouching at the wellhead and listening to the pottery jar covered in cowhide, his ears suddenly moved, held his breath, and his heart pounded.

He was blind and was originally unknown in Shangqiu City.

But this time, the Mozhe recruited those with sharp hearing, not only could they eat wheat cakes every day, but also if they could find out the movement of the enemy, they would also have a bounty to get.

If the princes and nobles said it, the blind man naturally would not believe it. Many nobles would make such jokes just to smile.

But if it was said by Mozhe, the blind man believed it without thinking, and was sure that he had excellent hearing, and he might not be able to get those bounties.

The blind man has never touched the real gold, nor did he know how heavy the gold is, but he has heard of the preciousness of gold.

These golds are not produced by the ink, but as a guarantee, the Song Gong will always give them to you in the future, at least the blind man believes in the ink.

The blind man felt that his wealth was right in front of him and listened very carefully.

The subtle sound spread through the land, amplified at the wellhead, and in the pottery jar, vibrating on the cowhide on it, like a huge stethoscope, these blind men with sharp ears could clearly distinguish the direction.

The blind man coughed lightly, and immediately came over beside him, holding a ruler in his hand, and determined the direction on the right-standing orientation plate next to him, laying a piece of grass and silk, quietly waiting for the blind man's guidance.

The dark life of years has enabled the blind man to develop a skill in listening to sounds and defending positions. He can not only hear sounds, but also distinguish directions through sounds.

This was not the first time that the Mozhe next to him followed these blind men to listen to the movements, but it was the first time that he followed the secretary's instructions, using a ruler to determine the direction and then painted the direction on the grass and silk.

In the past, after the blind man heard the movement, he used different wellheads to determine which well was closest to determine the location of the enemy's excavation hole.

But this time, Shi said that not only could he judge the position and direction, but he could also roughly determine where the enemy's tunnel had been dug.

Most of the Mo people believed this statement. They were too lazy to be shocked, but they didn't know what to do.

Since the giant believed it, they had to do so.

A few dozen steps away or more than a hundred steps away, the blind men with sharp ears heard different movements, and the followers also drew these movements and stills one by one on the grass and silk to mark the directions.

In a large house, some people from Shi Zheng and some secretaries, as well as several carpenters were busy making some measurement tools.

On the large paper behind him was a simple map of Shangqiu, with various signs marked outside the city.

The enemy's watchtower, the huge rocks left by the Messenger to measure distance, some rivers, iconic fields, hills that cannot be leveled, etc.

This map is marked with some strange small squares for measuring distances, and is covered with thin lines.

Shi Jing and a few carpenters tried to make a small horizontal ruler and a semicircular scale plate to calculate the angle so as to calculate the distance.

These tools have never appeared before, but they are all extremely simple. The only difference is a trigonometric function table. Unfortunately, it takes a lot of manpower and a huge amount of time to make this thing.

Fortunately, the Mozhe needs to use it to defend the city, otherwise the cannon would not be able to be produced, and the development of trigonometric functions would not be so fast. Sometimes war is really one of the driving forces of mathematics.

What can be done now can only be roughly calculated using a ruler to calculate some sine cosines with some large errors, etc.

When Shi was busy, a Mozhe walked in with a giant's warrant and whispered a few words in Shi's ear. Shi followed him out and came to Moz's military tent.

Inside, the ink people gathered together and guessed that something might have happened.

After the irrelevant person left, Mo Zi smiled and pointed at the outside of the city: "The Chu people rely on the construction of Yang Di to cover the city, but in fact they were digging tunnels to attack the city. He had said before that the Chu people might pretend to attack the city to cover the wheat harvest, which seemed to be a good idea."

Speaking of this, Mo Zi was a little dissatisfied and said with a tweet: "More than thirty years ago, I fought with Gongshu in Chu. I have already said this method of digging tunnels to attack the city."

"In theory, there are still those who have never passed away that I have heard of back then. How could I dare to attack the city like this? This is something that makes me dissatisfied."

Everyone laughed, and Shi could probably understand what Mozi's dissatisfaction was: I have warned you that it is useless to do this, and you still do this, which is obviously not taking my words seriously.

This kind of extremely proud dissatisfaction.

Mo Zi shook a few pieces of paper in his hand and said, "Shi, come here. This is as you said, draw the direction that the Chu people heard when they dig the tunnel, and you must find the position as soon as possible."

After taking those sheets of paper, there are enough samples and finding the intersection points by connecting lines can be roughly judged in advance.

Gong Zaoye smiled and said, "Mr. I said, "When I look forward to the cave, I will be careful not to chase after the cave."

"Before the enemy's tunnel is determined, the guardian must not dig in advance. On the one hand, it is easy to hear it clearly, and on the other hand, it is easy to dig in the wrong direction."

"I once defended the city with Mr., and it was difficult to determine when the enemy had just dug. If you could, you would make another contribution."

Public smelting is not a compliment. If you have not obtained the cave, be careful not to chase. If you cannot do these six words well, it is likely that the enemy's cave has been dug up, and you have not made sufficient preparations yet.

The ink master received the order, and Shi also understood it: in short, it is to make ventilation ceramic pipes, just like gas pipes, and use a blower to blow the air here, pouring a large amount of smoke from these ceramic pipes into the tunnel.

Then use things like wooden boards to block the thick smoke from your side. Relying on the sealing of the ceramic tube, the thick smoke continues to blow into the other party's tunnel, forcing the other party to escape.

Since the size is clearly stated, it is not the first time to manufacture it. These seemingly important issues are not important in the Mohist school.
Chapter completed!