It seems that a round hook can be hung on anything thick, such as a battlement, and will remain stable, while a square hook will be difficult to hang stably.

This seems to be related to mathematical knowledge.

Li Mengxi couldn't help but frown, why is the circle hook stable no matter how it is leaned?

Probably, any point where the circular hook touches the battlements is the same distance from the center of the circle.

The direction of the reaction force of the battlements on the ladder seems to be always perpendicular to the ladder, is that true?

Li Mengxi was confused.

I am not very good at mathematics and cannot study this seemingly simple but actually mysterious problem.

Seeing Li Mengxi's frown, Liu Bei thought that Li Mengxi had thought of another good way to attack the city ladder, so he left him alone and silently stood with Li Mengxi on the edge of the city, watching the sunset.

After thinking for a long time, Li Mengxi couldn't figure out why round hooks could be placed securely at the top of the city, but other shapes could not.

"Erxi, do you have any ideas?"

On the side, Liu Bei asked.

"Ah?" Li Mengxi, who had just recovered his senses, looked at Liu Bei in shock, "What do you think?" Li Mengxi was confused.

"Siege ladder," Liu Bei patted the siege ladder and asked with a smile, "Meng Xi, do you have any ideas on improving the siege ladder?"

"It's better to use round hooks for siege ladders. If nothing else works, only round ones are the best." Li Mengxi shook his head and said.

This evening, Li Mengxi learned a little more about the siege ladder.

Soon, it was getting dark, and Li Mengxi and Liu Bei were still waiting at the top of the city, waiting for the carpenters from the carpenter camp to finish the new siege ladder and inspect it.

"Xuan De Gong, in order to train troops in the city, our army stayed for two days. Time is tight and cannot be delayed. I think tonight, we can let the carpenter battalion build the siege spine overnight until the siege spine can withstand actual combat. How about it?"

Li Mengxi asked.

Liu Xuande nodded in agreement. It is true that we don't have much time, so we can squeeze in as much time as possible. The carpenters have to work harder these two days and build the siege tower as soon as possible while there is still a city available here.

"That's fine, I'll just keep watch tonight and you can sleep well." Liu Bei smiled and patted Li Mengxi's shoulder gently.

"Uh, okay." A smile appeared on Li Mengxi's face, "Then I will wait until early tomorrow morning. Xuande Gong's siege spine has been made indestructible!"

Liu Bei laughed and said that if Li Mengxi came with him early in the morning, he would be able to see the invincible siege spine that could be used to attack the city.

After a while, it became completely dark, and Li Mengxi said goodbye to Liu Bei at the top of the city.

I went back and saw my younger brother. He was staying by the campfire waiting for dinner. Someone gave him some ginkgo seeds. Brick only had two left to eat. He was reluctant to eat the last two and held them tightly in his hands.

One in each hand, when his brother came back, he happily gave one of them to his brother.

Then Brick threw his ginkgo into the bonfire at the edge. The ginkgo seeds were roasted and the shell exploded with a pop.

Brick took a small stick and quickly pulled out the seeds of the ginkgo. He held the ginkgo in his little hands, burning it but not willing to throw it away. He switched it back and forth between his hands and kept blowing it, hoping to cool it down quickly.

Ginkgo is Ginkgo biloba. Its seeds have a white shell, so they are called ginkgo.

The kernels of ginkgo seeds are bitter and Li Mengxi doesn't like to eat them, but his younger brother treats them as melon seeds and eats them with great pleasure.

Li Mengxi took two firewood sticks, took out a small piece of charcoal from the fire, and then placed the ginkgo seeds on the charcoal. The charcoal would not burn the ginkgo shell immediately, so Li Mengxi put the ginkgo seeds on fire after a while.

The ginkgo turned over and he carefully roasted a small ginkgo seed like a prawn for a long time.

When the shell explodes, it means it is ripe.

Li Mengxi picked up the roasted ginkgo seeds, blew on them, and peeled off the shell with his hands. The inside was roasted and the flesh was ripe and not burnt at all.

"Brick, open your mouth."

"ah-"

Li Mengxi threw the ginkgo into his brother's mouth.

My little brother, this stupid kid doesn't know how to bake, so he just threw the heat and it was all burnt.

The ginkgo seeds roasted by my brother were not mushy at all, but they were delicious. Brick admired his brother very much.

In the evening, all the country warriors who participated in the military training were given meat, and they did not have a share in the baggage team. The bored country warriors in the baggage team who had been idle all day couldn't stand idle anymore when they saw others eating meat.

After dinner, Lao Tie and the others asked if they could find some work to do.

"Well, I was busy with military training during the day, so let me see you tomorrow and ask."

Hearing what Li Mengxi said, Lao Tie and the others were relieved.

After a busy day, Li Mengxi didn't think anything was wrong. As soon as he stopped and just finished eating, he felt sleepy and took his brother back to sleep.

It was another fruitful day. I learned sharp siege tactics, as well as the essentials of city defense, and also knew how to optimize the siege ladder. Just thinking about it, Li Mengxi quickly fell asleep.

——

In the evening, Liu Bei came to the carpenter camp alone. He saw that the carpenters in the carpenter camp were still rushing to build the siege spine. Liu Bei urged them to eat and rest first, and then work again in the evening.

At 4:00 p.m. in the evening, the siege spine was repaired and reinforced.

Two teams of carpenters, one of which increased the strength by stacking materials, replaced the thin branches on the roof with long wooden bars split in half and as thick as a bowl. After building the roof, they used straw

The rope was strangled to complete the reinforcement in such a simple and crude way.

The other team started with the structure of the siege vertebra. They found that it was easy to prevent the wooden planks from being smashed, but the support structure under the wooden planks was easily damaged. Therefore, when the second team thickened the roof, they deliberately placed

A triangular structure is added to the chassis.

Triangles are stable, a theory discovered by mathematicians.

However, before this theory was discovered, carpenters had long known that triangles made things stronger.

The two siege cones were pushed to the bottom of the city again, and a row of torches on top of the city clearly illuminated the siege cones on the drawbridge.

Bang!

Liu Bei smashed the millstone down, and the roof of the siege roof was cracked again.

Although it has been reinforced and its strength has increased a lot, there has been no qualitative change.

This chapter is not finished yet, please click on the next page to continue reading the exciting content! Then came the second siege cone with a modified structure. It performed much better than in the evening. This time the siege cone did not fall apart, but the roof was still damaged.

Cracked.

Still not enough, these two siege vehicles still did not have the protection required for a tough battle.

After Liu Bei said some words of encouragement, the carpenters pushed back the broken siege spine.

Half an hour later, the repaired siege spine came again.

The roof has been made thicker.

Carpenters directly connected tree trunks as thick as a bowl to form the roof.

The roof of the shed is made up of trees as thick as a bowl.

Boom!

The stone from the top of the city was smashed down, but the tree trunk on the roof of the shed was not broken, but it flew up because the connector of the falcon was damaged.

Still not strong enough.

Carpenters who master skilled carpentry skills are the most high-end technical talents in the rebel army. Although most of them may not be literate, their wisdom is a valuable asset.

The tree trunk seems to be able to withstand the stones thrown down from the city wall, but the strength of the mortise and tenon joint is not enough.

The two carpenter teams, who were originally in a competitive relationship, began to discuss solutions together, and finally they unified their opinions.

No matter whether you continue to pile wood or modify the structure, the pallet truck is too narrow. If you want to go further, you must make the truck wider and larger.

Two carpenter battalions began to modify the frame.

If so, on armored vehicles and tanks, the frame is equivalent to the chassis.

The wheels are ready-made, as are the planks.

Just knock off the axle, replace it with a long axle, and then use wooden strips or branches to widen the car board.

It took a while because I had to modify the car.

After waiting for a long time, Liu Bei saw the carpenter battalion pushing the siege tower and holding torches.

In the light and shadow of the torch, Liu Bei at the top of the city could clearly see that the new siege cone was much larger.

——

Liu Bei picked up the stone mill and threw it down from the top of the city.

Boom!

The heavy stone mill hit the siege vertebral column, and the siege vertebral column was pushed back, but the roof of the shed was not damaged.

Liu Bei had a smile on his face.

Then Liu Bei remembered that when he was discussing with Li Mengxi during the day, Li Mengxi drew a very vivid sketch on the ground. The siege spine could be very large, and the siege soldiers also squatted under the roof to avoid the rain of arrows, stones, gold, juice and other objects on the city.

The siege vertebra has a solid outer shell, and the soldiers tied inside and pushing the siege vertebra provide the siege vertebra with forward momentum.
Chapter completed!