"Boya is such a genius. With just a few words of advice, he can survey and dispatch the required siege and deploy it so thoughtfully. Standing on this building, the south wall of Chang'an City is on the east side, and within a few miles, you can even see whether there are enemies behind the wall standing by.

I have seen the history of famous generals in the past dynasties for many years, but I have never seen such a precise calculation and adaptable trick to local conditions. I am afraid that from now on, even if there is war in the world, the defenders of the city will have to specially build a corner tower that is higher than the city wall to cover the observations of the siege. At least, Chang'an is too huge and it is difficult to use enough troops to defend each city wall. This is the case.

Well, Aliang, your building is well built. I heard that you personally surveyed and mapped the site? You are only fifteen years old and are so skillful in arithmetic and map surveying. It is a rare genius. This fire mirror is also well polished and can see it very clearly."

On April 25, with the completion of the first watchtower in the southwest corner of Chang'an City, Liu Bei personally climbed the tower to look around with great enthusiasm, holding a copper-tube telescope made of a fire-equivalent mirror polished by Donghai County crystal stone and a fire-equivalent mirror. He was very happy to see it and couldn't help but express his praise.

Of course, the crystal stone was sent by Mi Zhu's caravan. It was a practice for several years. Who told Mi Zhu's hometown to be in Donghai County? Even if it was occupied by Cao Cao, the commerce was still endless.

There is no secret to the deployment of 30,000 to 40,000 enemy soldiers in Chang'an City.

Because the building was just built, in order to reduce the load bearing, everyone else rested on the platform downstairs or on the middle floor. Only Liu Bei and a lookout hand in charge of the guards, plus Zhuge Liang, a total of three people reached the top floor.

Zhuge Liang has only arrived in Guanzhong recently. The war is about to end. Li Su wrote a letter to ask him to come and see the world. Zhuge Liang has also made some contributions in the survey and construction of siege positions and the manufacturing of observation equipment, so he has just received attention from Liu Bei.

A young man who was just fifteen years old and had just barely been able to become an official, the lord would not have expected him to be more, because he was Li Su's most proud disciple, and Zhuge Gui's entrusting him back then.

The lookout hand was also Liu Bei's personal confidant. When he went upstairs just now, of course, the lookout hand climbed along the ladder first, and then pulled two hemp ropes with hooks on it.

Those hemp ropes are naturally used as safety ropes. After the lookout hand stands, the hook of the safety rope is tied to a section of wooden stakes that were deliberately not cut flat on the top of the wooden staircase. After hanging it, you must continue to hold it with your hands.

Then Liu Bei tied the other end of the safety rope to his waist and climbed up the ladder. In the end, Zhuge Liang also got up.

At first, Liu Bei was brave and thought it was quite troublesome. But after using it, he realized that this small design was very clever and cost-effective. While strengthening the safety factor, there was not much extra operation, so he quickly decided to adopt it in batches. In the future, the military building of the Wang Tower would be based on this arrangement, so as not to have any accidents such as soldiers falling down and falling to death.

After being proud of it for a while, Liu Bei asked Zhuge Liang out of curiosity and chatting: "Aliang, you calculated the location of the siege of the city and the building that you are all calculated by yourself? Or did Boya teach you in detail?"

Zhuge Liang proudly said: "The basics of mathematics, the 'geometric principle', of course, was taught by Master Li. He also said that this is what the Western Qin Dynasty math book "The Originals of Geometric". He also gave me a book, but did not say how to calculate, but just said that the results of surveying and mapping are called 'trigonometric function'.

The location of the building and the viewing range of the viewing field are calculated based on this. If the king is interested or doubted, I will show you..."

Because there was no paper and pen on the building, Zhuge Liang said, and pulled an arrow from the quiver in the quiver, as if he wanted to directly portray the calculation on the wooden floor.

"No need, no need, no need, Gu understands Boya and your character. He doesn't seek much understanding. He thinks it's troublesome. Gu believes that you are all calculated. Let's talk about how you teach craftsmen to polish it, both Fire and Fire and Fire.

Liu Bei quickly stopped him and used the telescope in his hand to change the topic. He thought to himself that I don’t understand mathematics, so you can’t tell me about it with such a big fanfare, and I can’t verify it.

The fire-equivalent mirror in the telescope is naturally a convex lens. This thing was very ancient when Western Archimedes was found, and everyone understands the principle. The fire-equivalent mirror is of course the name temporarily named by Zhuge Liang and Li Su, which is a concave lens.

Fortunately, the topic Liu Bei changed was also Zhuge Liang's pride, so Zhuge Liang's show-off mentality was quickly led to a new direction, and he said complacently:

"There is nothing in the fire-Qi Mirror. The craftsmen from the ancient Han Dynasty decorated the Weiyang Palace and built the Zhang Palace. Ban Gu also mentioned in the "Xidu Fu" that as long as the round crystal beads can be slightly polished and thinned, flattened, gathering the sunlight at one point, allowing the hay and dead wood to burn, it is considered qualified.

It was Master Li who taught me the "principle of refraction" that if the fire is in harmony with the reverse fire, you can see far. However, the fire is in harmony with the reverse fire, and there is no focus, so it is impossible to verify the quality of the polishing. The polishing itself is not difficult, and the difficulty lies in the acceptance. The craftsmen do not know whether the polishing is in place.

However, based on my experience of supervising the construction of a new iron smelting workshop in Lidao last year and repairing casting molds, I suddenly had a whim and thought of a way to accept it. I first took a standard and exquisite and round fire mirror. As a model, I cast a pile of sand shapes that are harder and more wear-resistant than crystals, and used these sand shapes to grind the fire to achieve the reverse fire.

After the reverse fire mirror is polished, use a new standard abrasive tool to put it together to avoid wear errors in the mold itself. If the mold is tightly matched and there is no gap in the middle, you can make a set.

As for determining whether the thread is tight, first drop the warm and melted loose glue into the pit of the reverse fire mirror, then put the standard mold in, wait for the loose glue to cool down and set, take out the mold, use a clamp to measure whether the thickness of the loose glue is consistent, or directly observe whether the light transmitted from behind the translucent loose glue is distorted. If the hard loose glue is too thin in a certain place, the light transmission of the loose glue will definitely be distorted, which means that the corresponding position of the reverse fire mirror has not been ground enough, so you need to file some more."

Zhuge Liang showed off the "yin and yang mold quality inspection method" he thought of himself to ensure that the two convex lenses and concave lenses have the same degrees. Liu Bei was not interested in listening to these principles at first, but now it is helpful to his strategic deployment, so he finished listening with great interest.

The two of them were middle-aged and young, and they were on the lookout table and talked about military affairs for a while. Zhuge Liang was not qualified to talk to Wen’s military affairs, but now it is a rare opportunity. He has gained the first opportunity to show his talents in the military field in his life.

Liu Bei thought about it and felt that Li Su helped him cheat, and he had a great advantage. He couldn't help but sigh: "If I had known this new style of building layout, I could have mastered the city's defense so clearly. I wanted to really adapt to the situation and attack the weaknesses among the three gates of the east and south sides of Chang'an City.

But before Boya left, why did he persuade Gu to attack the North Gate with a firm idea? Such a clever plan, he just used it to deceive Li Ju and Li Ru. The damage left by Wei Jie and others in the north of the city had been gradually repaired by Li Jue, but now it is only the inner gate of the gate that is still unable to be repaired. This weak advantage on the north side is nothing compared to the uneven distribution of the enemy troops in the other three gates and has major deployment weaknesses.

But because the city wall on the north side was two feet higher than the other three sides, the observation was not good, and in order to deceive the enemy, our army deliberately did not set up a watchtower building on the north side. Isn’t that a blind attack and mute battle? I don’t know if Boya walked for two days and did not reach Huayin, did he see Your Majesty, how did his Majesty tell him."

It turned out that Li Su did not participate in everything here in full. He had told Liu Bei before that political cards were also very important and advised Liu Bei to meet him first, so Liu Bei sent him to meet the emperor.

Anyway, Li Su thought that this was a construction site within five or six days, so why bother someone like him to keep an eye on it every day? That would be useless.

Let young people like Zhuge Liang who have never seen the deployment of the siege preparation stage directly see how the world's number one siege war should be planned, and observe and participate throughout the process, so as to give Zhuge Liang an experience of increasing the price.

And who made Zhuge Liang's talent points in his early life go against the science and engineering direction? He asked him to start from this perspective of military engineering technology and strategic planning, which was the most helpful for his growth.

As for what Liu Bei mentioned, "The city wall on the north side of Chang'an City is higher, and it is more difficult to attack without flaws in defense facilities", that is also an objective fact. From the Han Dynasty to the Tang Dynasty, Chang'an City was built in this way.

Because the palaces of these two dynasties are located in the north of Chang'an City, once the north gate is broken, it will soon be able to reach the palace, so it must be built very high. In the Beiheng Gate of the Han Dynasty and the Guangtai Gate of the Tang Dynasty, the Beigong Gate of the Weiyang Palace and the Xuanwu Gate of the Taiji Palace.

Moreover, due to the north side, the rituals and laws, even the urn city could not be built. In ancient times, the emperor had to sit north and south, and no one could live in places more north than the emperor in the city. Therefore, a small rectangular corridor space between the North Hengmen and the North Palace Gate could be used to achieve the defensive effect equivalent to the urn city.

(The Tang Dynasty was a rectangular area between Guangtai Gate and Xuanwu Gate, which made a guest appearance in the Wucheng, so Li Shimin shot his brother and was ambushed here.)

From this perspective, as long as Li Jue feels that he blocked the Beihengmen, he will definitely not believe that Liu Bei deliberately "giving up the easy and seeking difficulties" and continues to attack from the north. The wall is too high, so no one has obviously defeated once and insisted on fighting from here.

...

Liu Bei himself doubted himself and couldn't bear to let Li Su teach him. As a "bad strategy" for spare tires, the enemy will of course be even more suspicious and shaken.

However, Zhuge Liang was not shaken. After hearing Liu Bei's various benefits of attacking the east and south sides, and even wavering in the deployment of troops, Zhuge Liang was just a newborn calf who was not afraid of the tiger:

"It is human nature to be so shaken by the king. Master Li's plan is just because he is too realistic. All fakes can be used at any time. In fact, I doubted it so much three days ago. Wanglou had just finished surveying and selecting the site. Fortunately, Master Li had answered this question for me before he left. Unexpectedly, the king also had the same wavering as I did today."

When Liu Bei heard this, he secretly reflected in his heart: He was a long-time general who had been fighting for eleven years and had known his military service for a long time. This was the first time Zhuge Liang had been with Wen Wen for military affairs. He was only fifteen years old, so he could be wrong like an orphan?

Although, he was not mature enough when he heard Zhuge Liang's tone, he was considered a "humble opinion" in Li Su's opinion. He could be as clumsy as Liu Bei, and he was also very amazing in Liu Bei's opinion.

If Zhuge Liang had to be the first to be a counselor of military affairs for two or three years in the future, with this talent, wouldn’t he immediately surpass him Liu Bei?

In fact, Liu Bei overestimated Zhuge Liang in this regard. This overestimation is not because Liu Bei did not have enough knowledge of people, but because he had too little "sample capacity". The current evaluation of Zhuge Liang's military talent is limited to his current insights on this battle.

The battle in front of us happens to be a siege battle. The siege battle has the lowest requirements for the generals to "respond to changes" and is a tough battle. It does not require much adaptability, but it just takes advantage of Zhuge Liang's scientific thinking. So in this way, Zhuge Liang and Liu Bei's talent in attacking and defending the city looks similar.

If you take a field battle and a mobile war for Zhuge Liang to practice in his first place, then the level of knowing the military will definitely be far worse than that of Liu Bei now. After a few years of experience, you will not be able to catch up.

Liu Bei didn't know that he had misjudged, so he asked with interest: "Oh? You asked this question before Boya left? That's similar to Gu's opinion. Then you tell me, how did Boya answer you at that time? Why did he insist on attacking the North Gate?"

Zhuge Liang knew that the opportunity to show was coming, and replied in high spirits: "Mr. Li often said, 'War is a continuation of politics'. For the king, it is certainly one aspect to break through Chang'an in this battle, reduce the difficulty of siege and reduce the casualties of soldiers.

However, it is also very important to save all officials and people more and establish their prestige in the center of the court. Otherwise, if Li Jie is rampant and killing us, we will inevitably be attacked by those who are interested in the future.

In ordinary siege battles, most of the people in the city are in the same mind as the defenders, because most of the defenders are locals. On the contrary, the siege is the side of the city. Because they are foreign troops, there are inevitably many casualties and injuries in the siege. After a long period of time, the generals often have to promise that the soldiers will not be granted a sword and will plunder for several days.

But this time and then, today's battle is reversed. Although Li Jue defended the city, two-thirds of his troops were Hu people, but the king's troops were kings and Han people. With the Han army regaining the Seoul occupied by the Hu people, we must be decisive and decisive, and seize the center in an instant and disintegrate the enemy's command over the entire city.

This will prevent the enemy from organizing the massacre after knowing that they will be defeated, and also prevent them from having enough time to organize and prepare to burn the imperial palace and the ancestral temple. Therefore, breaking through the north gate and directly taking over the Weiyang Palace is the first priority after entering the city."

Of course, these words are not something Zhuge Liang's current military talent, but just a remark after discussing with Li Su.

As for how Li Su thought of this level, it was not that Li Su was good at fighting, but his professional reasons in his previous life, he looked through history and knew too much about historical events.

In Li Su's view, today's battle to recover Chang'an, the environment, and the situation of our enemy can be compared with the Jingyuan mutiny in the middle and late Tang Dynasty.

During the Jingyuan mutiny, the border army with Hu Hua from Jingyuan was ordered to go out to serve the king. After walking to Chang'an, the court was stingy with money and property and did not give rewards. The troops directly mutinized and occupied Chang'an City. Then the court went through all the troubles and finally regained Chang'an by Li Sheng, a famous general of the late Tang Dynasty.

The source of the Jingyuan mutiny was equivalent to Anding County of the Han Dynasty, which was similar to the place where Li Jue lost his decisive battle before. The Hu Hua problem of the border army in the late Tang Dynasty was as serious as the Han Dynasty. In the late Han Dynasty, the Western Liang army used a large number of Qiang and Hu soldiers, and the Tang Dynasty also used Hu generals such as An Lushan, so the types of conflicts between the army and the government were similar. Both Hu soldiers who were ignorant of the righteous betrayed the court without getting enough money.

During the Jingyuan Mutiny, in order to prevent the rebels from burning down the Tang Dynasty imperial palace and ancestral temple, Li Sheng insisted on attacking the northern city gate, rushed into the Xuanwu Gate from Guangtai Gate, and directly recovered the Tai Chi Palace control center.

The original words quoted by Li Sheng from "Zizhi Tongjian" are: "The market is narrow. If the rebels ambush the troops and fight, the residents will be in amazement and confusion, it will not be beneficial to the official army. If they attack from Yuanbei and destroy their hearts, the rebels will definitely run away. In this way, the palace will not be broken and the market will be worry-free, which is the best strategy."

Of course, Li Su would not remember the original words on Zizhi Tongjian, but he could understand the truth. The key is that when you know that this is a battle where "the enemy will continue to fight stubbornly after the city gate is broken", you should fight like this.

The ordinary tactic of picking soft persimmons can only be applied to situations where "the enemy will be unable to fight if the city gate is broken and they will not want to resist anymore", and cannot deal with deadly hard-working elements who are ready to die.

We must be realistic and distinguish the types of enemies, analyze specific problems in detail, and use different strategies to deal with different types of enemies.

After listening to Zhuge Liang's retelling, Liu Bei could not help but benefited a lot.

Liu Bei couldn't help but exclaim: "Boya and his nephew can be said to be very knowledgeable and analyzed in detail. They can formulate tactics according to the differences between enemy soldiers and generals, and according to the enemy's requirements, and recognize the keenness of people's hearts, which will make the younger generation fearful.

Gu didn't expect to adjust the siege strategy specifically based on Li Jue's characteristics. In this way, he continued to follow Boya's statement, east and west are only used to lure the enemy to divide weak troops, and the north gate is the main attack, and directly take the Weiyang Palace and the ancestral temple!

Alas, Your Majesty is not good at doing well. For his own safety, he abandoned the ancestral temple and ran away, which made Li Jue crazy. If we attack slowly this time, let Li Jue come back and burn the Taimiao with fire, wouldn’t it be a sin? Even if Your Majesty is the emperor and has a body of gold, he shouldn’t have abandoned his ancestors and fled, alas.”

Liu Bei chatted with Zhuge Liang for a while and confirmed the final strategy. It was almost noon and the sun was scorching. It was so hot that it was so hot that it was so uncomfortable that they continued to tie the safety ropes and change the lookout hands to continue to observe.

However, there is no telescope for ordinary lookouters. The thing needs to be kept confidential and there should not be too many people handling it. Only when the enemy is about to siege the city, it is obvious that the enemy's dispatch is abnormal, so they will occasionally send a senior general with the telescope to take a look.

——
Chapter completed!