After confirming that Bering was not a return, but had just come from Siberia, Liu Yu's heart was completely happy.

It was a bonus.

Bering must have a map of Siberia in his hand, and Bering's level of drawing is definitely higher than that of the group of people under his hands. I don't even know how high it is.

Since someone else has it, after snatching it, isn't it your own?

After figuring this out, the topic at the dinner table was much more relaxed.

Liu Yu no longer asked some questions that might arouse suspicion, but complained about Dashun. It is too narrow to say that Dashun is too narrow-minded, the emperor is a Confucian, and neither a new nor an old Christian like him can be an official......

Hannibal, who listened to the words, was also happy, and felt that this was the first time he had heard about the internal religious conflict in Dashun since he came here, which was greatly beneficial to the conquest of the south in the future.

The meal was almost over, and both parties thought that they had gotten what they wanted, and they were in a very good mood.

After sending Liu Yu out of the castle, Hannibal came to two conclusions.

One: There are serious religious conflicts within Dashun, and those believers in Dashun can be used by those who go south in the future, at least to take advantage of their discontent.

Two: The smugglers of Dashun hope that the Russian fortress can be further south, so that it will be convenient for smuggling. In the event of war, these smugglers can help pass on intelligence and information.

Liu Yu, who left the castle, also came to several conclusions.

One: The castle is well repaired, and Hannibal does have an attempt to expand the castle after the spring of next year. The castle where more than 500 soldiers were stationed, he wanted to make meritorious contributions to capture this guy, and the storming was purely a dream, and he had to think of other ways.

Two: Since Bering has come here, and he has brought a Japanese with him, it is likely that he will take a boat into the sea after the Heilongjiang River melts.

Three: The Cossacks were too poor in discipline and too heavy, and this was a characteristic that could be exploited. Sun Tzu said: Profit and temptation, chaos and take. It seems to be prepared for such an enemy army that is too gangster.

Four: The Russians' supplies were very problematic, and the highest commanders and brigadier generals of the garrison were happy to nibble on rye bread. When the maid cleaned up the table, she secretly hid the rest of the bread in her skirt.

With these probing conclusions, we returned to the trade area where the transaction was completed.

Jiao Lao Butu and Du Feng and others all breathed a sigh of relief, Jiao Lao Butu came out with Liu Yu, if something happened to Liu Yu, he couldn't bear the responsibility; Du Feng is still looking forward to following Liu Yu to resist with merit, if he is really detained by the Rakshasas, his life will be over.

"If you don't enter the tiger's den, how can you get a tiger? Adults brave the tiger's den this time, and you will gain a lot. Your Majesty will be appreciative of it. ”

Jiao Lao Butu patted a sentence, and Liu Yu smiled: "If you have a job, it is a matter of duty." Even if it is meritorious, how big do you think this function is? What a fly in the ointment. ”

It seems to be unintentional, but in fact, it is a test of Jiao Lao Butu, whether he wants to do a big vote.

Jiao Lao Butu smacked slightly, tasted the taste, and then looked at Liu Yu, and found that he was staring at the Cossacks in the distance and the boat behind the dock.

Looking at Liu Yu's eyes, Jiao Lao Butu didn't know why, but he believed that Liu Yu was definitely ready to do a big job.

If you change to someone else, you may not dare to do it. can think about Liu Yu's family background, arrogant Butu thought to himself, I already like meritorious service. The sky is falling, there is a high top, and smashing it will hit you first. If you dare to do it, I will dare to do it.

"That's true. Even if there is merit, it is only a matter within the division. On that day, the adults said that the things that are within the division come first, and if the things within the division are done, they can naturally do some extraneous things. What is inside and what is outside is not something I can know. Everything is at the disposal of adults. ”

Liu Yu retracted his gaze, smiled at Jiao Lao Butu, and said no more.

Jiao Lao Butu thought to himself, you are the deputy in the team, and I don't have such a hard relationship, and I don't know the proportions of this matter.

It's done, the main credit is yours, and I'll follow to divide some soup; Then this responsibility is naturally your big one, and I am the one who is small.

I am willing to make extra contributions, but I don't do the things that give orders, and you have to bear the responsibility. But if you are willing to bear it, I will definitely dare to do it.

Liu Yu understood what Jiao Lao Butu meant, and didn't think there was anything wrong. All I want is an attitude of "dare to follow".

With the caravan, he left the castle-controlled area of the Rakshasa and made a few circles back to where the other half of the people were camped.

After a day's rest, Liu Yu called all the "cultural people" in the team who were literate, responsible for drawing, and knew reconnaissance skills. Let the officers such as Jiao Lao Butu also come to watch.

A sand table was made out of snow on the ground, roughly making the appearance of a Rakshasa castle, and wooden sticks were used to simulate cannons, soldiers, etc.

After a while, they will have to move separately, which requires those in charge of mapping and reconnaissance to understand what exactly they are trying to detect. What is useful information and what is important.

In addition, it is also time to choose a smart and clever one, go back to report a letter, and send a note.

These people looked at the model of the castle on the snow, and one by one they were in trouble.

Some of them had studied Western studies and even been baptized, but they had never learned how to lead troops into war, and they knew nothing.

Many people's understanding of leading troops to fight is still in the realm of "opening the bag, shouting, and ambushing the soldiers with a cannon sound".

How to capture it, this is the secret of the generals and nobles. Even if you want to make meritorious contributions, you have a weak heart, and it doesn't make sense to write nonsense, so it's better not to write it.

How to attack the castle? Surround the past, the first to reward a hundred taels of silver, and there must be a brave man under the heavy reward?

Liu Yu also knew the level of everyone, so he didn't talk about how to attack the city first, but talked about how to defend the city first. In other words, he talked about the defense system of the fortress and why the fortress replaced the high city wall.

These people are capable officials, but in fact they are all smart people, and they are all killed in tens of thousands of people. Qi Guogong is qualified to say that Bai Yunhang, the county magistrate of Fuqing County, is an official of sesame mung beans, Qi Jiguang is a hereditary four-grade noble, etc., but ordinary people can't say it.

Liu Yu also said some logic, and after he roughly explained it thoroughly, including Jiao Lao Butu and others, they were all in a cold sweat.

This baston ...... So hard to attack?

Those who were born in the families of world soldiers such as Jiao Lao Butu and Du Feng could understand the meaning of how many troops could be deployed from the beginning, and those people didn't even understand this.

But even if Jiao Lao Butu and the others understood, they still didn't understand what was going on with the defense system of the fortress.

really listened to Liu Yu's explanation, and they were all secretly frightened. I thought to myself, such a fortress, with five or six hundred soldiers garrisoned, wouldn't it only be able to rely on several times to surround it? Otherwise, even if you have the courage, you will be killed for a day or two, and all the pits and valleys will be killed, and all that courage will turn into urine.

At the end of the Hundred Years' War in 1449, the siege of Evre was bombarded for 17 days. In 1645, the heavy artillery bombarded Jiangyin and fell, and the defenders of the city had the will to die, but it was difficult to have a one-year period for Zhang Suiyang; It means that the classical urban defense system of the Eastern and Western cold weapon era is coming to an end.

These things that Liu Yu talked about scared everyone into a cold sweat, but they didn't exaggerate in the slightest.

With the popularization of muskets, the projection firepower increased, and there was geometric support, and the three sides were shot, and the strong attack could not be carried out in sufficient numbers, and 10,000 people could only line up in hundreds of hundreds to send people to the head.

If you use shelling, the thick base wall will have no effect for three or five days.

Dig a tunnel to blow it up, but it's still a thick slope that collapses, and it's still useless.

Even if Vauban was at its peak at this point, the dug zigzag trench was close to the moat, and the defenders could continue to kill at the breastwork next to the trench, and with the cover of the main fortress behind them, it would still be difficult to break through.

So close, the attacker's artillery can't cover it, because it will hurt his own people; The attacker's musket could not be covered, as the defender crouched behind the breastwork; The attacking hand-to-hand combatants had to face both the enemy behind the breastwork and the fire from the main fort.

In general, if you can get to the moat, you have to send grenadiers.

Throwing a grenade can go around the breastwork, but the problem is that Dashun doesn't have a dedicated grenadier, and I've not even heard of such a class.

Even if Dashun has cannons, and there are quite a lot of them, if you want to blast the fortress open, it is also a technical job.

It is necessary to blast out one "one" along the bottom of the city wall, and then two verticals, and the crater should be presented as a "凵" character.

Then a special artillery officer or engineer will judge where the weak point of the force of the word "凵" is, and bombard that point until the fortress wall collapses...... Dashun should not have any artillery officers and engineers who specifically understand this.

Around the attack and defense of the fortress, siege and defense have become a science. Just like the Mo family who was the most able to defend the city during the Warring States Period, it did not rely on the art of war but on technology and mathematics.

Although the castle in front of you is rudimentary, the Russians have been stationed here for decades and are constantly renovating. It seems rudimentary, and with the defensive system of the fortress, it is difficult to attack.

If you want to take it, in addition to a long-term siege, you can only follow Vauban's set of civil engineering excavation tactics.

After a whole day of dry talk, most people still don't understand it.

But a few people roughly understood. After asking which of those who understood understood the most, Liu Yu asked everyone to disperse.

Back in the tent, Liu Yu took out a pen and paper and wrote his first letter very carefully.

In addition to introducing the situation along the way, he also used this Rakshasa castle as a template to introduce in detail the siege method of Vauban, the principle of zigzag trench excavation, the use of artillery, the formation of grenadiers necessary for the siege, and so on.

Without Tian Ping's partner by his side, his writing was extremely poor, and the whole article was full of vernacular, and he also drew six or seven pictures, and wrote about a few thousand words.

After sealing the letter, he found the person who understood the most and told him to return to the capital with the three riders and bring it back. If Your Majesty asks, let the person who understands the most put a sand table.

Seeing these people leave, Liu Yu was also relieved.

He completed the first step of being a certain sense of "Tian Feng", the lord did not accept the advice, and finally hit his head and broke the blood. As for whether the lord is Yuan Shao, it seems that it should not be now.

The stuff I wrote was all useful.

It is very useful, and the emperor must have praised him after reading it, recognizing that he is not Zhao Kuo Ma Yan but indeed has his talent.

But it's all, because Liu Yu knows that it is impossible for the imperial court to use this method.

The Heilongjiang River basin can be used for soil work for a short time, with ice melting in May and snow falling in August, and only three or four months can be used for soil work.

In order to contain Tsarist Russia, quell the rebellion in the northwest, and let the Khalkha Mongols accurately stand in line, the imperial court will definitely seek speed and fierceness.

The logistical pressure of this kind of ghost place is so great, the chaos in the northwest is unknown, and it is impossible to spend a few years with Rakshasa here.

Vauban siege required a huge artillery force, specialized engineers, and the most ferocious grenadiers in hand-to-hand combat to break through the last breastwork. Without these great shuns, the efficiency will be greatly reduced.

Besieging a city, several times the number of troops, according to Liu Yu's method of "tactically correct and strategically", it will take a month to say the least.

Along the Heilongjiang River, there are many castles, all doing this, when the snow flies in August, how many can be captured?

When winter comes, it is more difficult to replenish and maintain the army. The longer it drags on, the more likely it is that the Rakshasa side will increase its troops, the more suspicious the loyalty of the Khalkha tribes to Dashun will become, and the higher the probability that the northwest side will take advantage of the situation and get married to the Rakshasas.

Tactically, civil engineering operations should be fought slowly to reduce casualties, which is the right way, and the army can continue to fight, and morale will not be damaged too much.

Strategically, it is necessary to storm quickly, very quickly, at any cost, and to capture as many castles as possible within a year, so as to quickly negotiate peace, at any cost.

This is what Liu Yu calls "useful". It works, but it doesn't work, at least not in this battle.

There were so many people killed in this battle that the imperial court might choose to try reforms, and those who died storming the castle were the price of the so-called change.

There are too many people who simply die, and it may not necessarily change.

But if there are more people who die, and there are people who come up with ways to kill fewer people before they die, then it is possible to change.

At the end of the recital, Liu Yu deliberately added a sentence of "begging for a beating": Now the situation, it is better not to talk about it, the time is in me, and continue to immigrate to enrich Liaodong. First, in accordance with Western military law, artillery and grenadiers were trained. After three or five years of forming an army, we will fight again. If he hadn't done what he had said, there would have been heavy casualties.