Zhang Yifan didn't want to say it, but he would talk about it after the on-site inspection. However, now that he heard Zhu Di asking, and saw that the other people in the hall also wanted to know very much, he thought about it, so he changed his mind, and felt that it was okay to say it first.

So, he looked at Zhu Di with an expectant look on his face and said, "There is a long-distance means of communication that can be used, that is, to build a signal tower on the top of the highest mountain, if the enemy is found, the signal tower will send a signal, in this way, it can be transmitted over a long distance, I think this means should be able to solve the problem you just mentioned!"

When Zhu Di heard this, he couldn't help but be speechless, and with a disappointed face, he said to Zhang Yifan: "Yifan, you ...... Isn't this the beacon tower! This thing has been around for a long time, don't you know?"

Xu Da and the others were also disappointed when they heard it. I thought it was a good way, but I didn't expect it to be the method of the beacon, who doesn't know this?

In the end, the big horse is still from Liujia Village, and he may have talent in other aspects, but he has no experience, so he thought he had come up with a good solution, but it turned out to be something that he had been using for a long time.

Thinking about this, Xu Da also opened his mouth and explained to Zhang Yifan: "The beacon tower can indeed transmit information, so that we can know that the enemy has entered the customs. However, the beacon tower cannot let us know the specific situation of the enemy and what the movement is, we can only know the approximate number of enemies entering the pass. It's the number of enemies, and you can send a message by burning a few beacon fires, and if you have more, you won't be able to do anything!"

Listening to his detailed explanation, Zhang Yifan smiled slightly and said, "I know the beacon tower, but I'm talking about the signal tower, which is different from the beacon, the signal tower can convey more information, and can even talk to people like people, and can explain the enemy situation in detail."

"What?" When Zhu Di heard this, he was very surprised, and he was immediately overjoyed, and immediately asked, "Say, tell me quickly, what does your signal tower look like, and can explain the enemy situation in detail?"

Xu Da and the others were also surprised when they heard this, but most of the expressions on their faces were suspicious.

After so many years of war, or, since ancient times, I have never heard of such a signal tower, which not only has the convenience of the beacon, but also makes up for the shortcomings of the beacon?

Impossible, right?

Compared with them, Zhu Di, who knows Zhang Yifan better, is already overjoyed. He knew that Zhang Yifan said that there was, that is, he really had it!

Zhang Yifan listened to it and explained confidently: "This signal tower can be understood as the appearance of a person, and it can be expressed in different ways of using hands and feet to represent different words. Now the question is to know if there is a suitable hill in the north to build this signal tower to facilitate the transmission of news!"

At this point, he paused and then added earnestly, "With the help of a telescope, you can see farther and see more clearly. Of course, there is a disadvantage to this way of signaling towers, if it is raining, snowy, or foggy, the view will be blocked, and the message may not be delivered."

When Xu Da heard this, he was immediately overjoyed, as a famous general who has led the soldiers to fight all his life, he knew the importance of the news the most, so he was the first to ask: "Big horse, how far can you explain this kind of news transmission?"

As for the flaws of the weather, it doesn't matter. After all, beacons are also affected by the weather. And this kind of extreme weather is still a minority. If the message can really be conveyed clearly, the impact on the war will definitely be difficult to predict.

When Zhang Yifan heard the question, he turned his head to look at Xu Da, who was surprised and expectant, and replied without hesitation: "Theoretically, it can be as detailed as a human speech, but it will take a long time to deliver the message in this way, so it will be more concise and concise, but it can also explain the details clearly."

Speaking of this, he emphasized, "Therefore, the location of the signal tower is very important, and in addition, it is also necessary to select a group of soldiers with flexible brains to do this. Once I coded them, I trained them and taught them how to deliver messages."

Zhu Di, Xu Da and others didn't understand what coding meant, but when they listened to Zhang Yifan's words, they could feel Zhang Yifan's confidence and knew that he had indeed come up with a good solution. The key point is how to express what you want to say with your actions.

At least for

For them, they still can't imagine it. But what is smart is left to a smart person.

They didn't know that the signal tower introduced by Zhang Yifan, or this kind of thinking, was invented during the French Revolution in the original history, and was the result of many revisions, which was praised by the French at that time and included in the four major inventions of mankind: printing, gunpowder, compass, and "long-distance communication symbol language".

What Zhang Yifan wants to do is the best signal tower in history, that is, to convey information with the least number of combinations, and the key point is, of course, encoding.

In the following days, after Zhang Yifan settled down in Yanwang's Mansion, he immediately began to work on the formulation of the signal tower.

In the way of coding, he still decided to compile a small book of commonly used words, and then identify one of the characters by the horizontal and vertical coordinates. The advantage of this is that any word only needs two horizontal and vertical coordinates to be decided.

As for the signal tower, as long as there are ten different representations from 0 to 9, it is fine, so that the operation can be simple and the structure will not be complicated.

Zhang Yifan drew the structure of the signal tower on paper, and Zhu Di immediately asked people to build the signal tower. In order to be able to see clearly, the tower should be as large as possible.

At this time when they were busy, Li Shanchang didn't stop for a moment, and quietly went south to return to Beijing. He didn't even tell anyone else, he just left a letter saying that he wouldn't bother them, but in fact he was afraid of being retained.

When he looked back at Beiping City, which was about to be invisible, Li Shanchang had a smile on his face: he finally fooled the big horse to the front line, and it was impossible to have results in three or five years. If one doesn't get it right and something happens, that's even better.

As the first hero who followed Zhu Yuanzhang to conquer the world, he has been in Beiping for two or three months, so he naturally understands the situation in Beiping very well. That is, it did not form an advantage over the Mengyuan army at all. If it's just inside the Great Wall, it's nothing. But if anyone can't resist and wants to attack, the forces of both sides will inevitably change, and it will be very dangerous.

And King Yan, hehe, just wanted to make a great contribution. If Xu Da hadn't watched it, it is estimated that he would have been out of the customs long ago. Now that he is going back, and the big horse is coming, he may be able to strengthen King Yan's determination to fight.

It's time to start the gong! When the time comes, I will "wait for good news" in Nanjing!

Thinking of this, Li Shanchang stopped looking back and went straight south!

What Li Shanchang probably didn't expect was that no one cared about his departure at all. All the generals were staring at the signal tower that the pony mentioned.

There is an advantage to concentrating on things, and it is easy to do what you want to do.

As soon as Zhang Yifan's signal tower drawings came out, Zhu Di asked Zhang Yifan to demonstrate the real thing the next day.

The signal tower erected on the flat ground is somewhat similar to a human arm, the joints are movable, and it is easy to do by swinging the two arms to form 10 different ways to represent the ten numbers from 0 to 9.

Zhang Yifan commanded them to make corresponding gestures, and at the same time took out the code book he hurriedly came out and explained it to Zhu Di and Xu Da who were standing beside him. To put it bluntly, the way this kind of signal tower is transmitted is actually very easy to understand.

It is to translate the words you want to say into numbers according to the codebook, and then use different gesture combinations to transmit the message through the signal tower. As long as you see it, you can pass it on. With a telescope, you can see from farther away.

Although Zhang Yifan said before, the transmission of messages from this kind of signal tower is like talking to people, which is still a bit exaggerated. However, it is undeniable that this is the kind of beacon that can really speak.

Chinese characters can be concise and concise, which will be more efficient than the transmission of Western letters.

After Xu Da understood how the entire signal tower operated, he was overjoyed and immediately decided to go out and select the hill to see where to deploy the signal tower, so as to cover as many areas as possible.

This task does require experienced generals to do this, but, admittedly, it is also a hard job. However, Xu Da doesn't care, as long as this thing is done well, Mongolia *** either don't enter the customs, if you enter the customs, the weather is good, the imperial court

The officers and soldiers will be able to know them well.

If, at this point, it is not enough to deal a heavy blow to the invading enemy, then it is really better to go back to farming.

On Zhu Di's side, he immediately selected soldiers with flexible minds throughout the army, and Zhang Yifan trained them on how to operate the signal tower.

The vast majority of the officers and men in the army are illiterate. As a result of the selection, it was found that most of them were those who had been trained in the martial arts hall.

Fortunately, one signal tower only needs one literate person to do it, and it doesn't matter if the other people who guard and operate the signal tower are illiterate. Even some of the signal towers that are just used for transit, it doesn't matter if none of them are illiterate, you just need to record the content expressed by the signal tower and do it again.

A month later, when Zhang Yifan's training was almost complete, Xu Da had also returned, marking the mountains to be deployed on the map.

Generally speaking, it is mainly along a horizontal line of the Great Wall, and then there are three longitudinal lines from the Shanxi border to the Shanhaiguan side, which basically radiates the entire area north of Beiping with a relatively large grid.

Next, naturally, the hill selected by Xu Da, the soldiers who built the signal tower and deployed the operation and garrison of the signal tower, and all the telescopes in the army were also collected and distributed to the soldiers of these signal towers. It will not be re-equipped with the generals until a new batch of telescopes arrives in Nanjing.

At the beginning of November of the thirteenth year of Hongwu, these deployments were basically completed, and then the practice phase was held.

The news is transmitted to the designated signal tower from the Beiping side, or the signal tower from the border gate transmits the message to Beiping. In the beginning, if you are not skilled, you will make mistakes. When the weather is bad, some signal towers are too far away to be seen with the help of telescopes.

For these situations, Zhang Yifan, Xu Da and others thought of ways to improve, or use remedial measures to optimize this signal tower communication method.

It is undeniable that no matter what shortcomings this signal tower has, it is an unparalleled speed advantage for this era.

As long as it takes half a day, Beiping will be able to know what is happening anywhere. This was unimaginable before.

With the help of this signal tower, the experienced Xu Da immediately readjusted the ***. As for how to deploy, Zhang Yifan doesn't understand. According to Zhu Di's explanation, it seems that there are deliberately flaws, and there is something that can be quickly deployed, in short, Xu Da has adjusted the troops on the northern front line, especially Shanxi and Beiping, according to the new communication method of signal towers.

Zhang Yifan has been hearing Zhu Di's nagging recently: It's winter, and Mongolia should be coming, right?

In the past, I was afraid of being harassed, but now, Zhu Di is looking forward to ***!

According to Zhang Yifan's impression, in the original history, there is indeed a record: in the first month of the fourteenth year of Hongwu, the Yuan general Duoer did not spend time and committed Yongping. Xu Da was ordered to lead an army with Tang He and Fu Youde to discuss it.

However, now Zhang Yifan's butterfly wings have caused great changes. Therefore, he didn't dare to guarantee that in the first month of next year, the Duo'er Buhua outside the gate would come to attack?

Since he couldn't be sure, he simply didn't say anything.

In winter, Beiping is colder than Nanjing. When the cold wind is howling, it is even more cold and biting.

Therefore, most of the time, Zhang Yifan shrank in the house and did not dare to go out. Fortunately, there are ondols in the north, and the house is absolutely warm.

Honeycomb coal, a convenient and easy-to-use heating product, has been brought by Zhu Di and spread in Beiping.

Xu Da has even ordered it to be promoted in Shanxi. According to the news Zhang Yifan heard, anyway, northerners are saying that this year's winter is not cold! This made Zhang Yifan almost believe it, and after going out for two days, he fled back to the house!

It began to snow heavily outside, and in King Yan's mansion, Zhang Yifan and Zhu Di's family were brushing hot pot.

Zhang Yifan eats vigorously, brushing the meat of the hot pot, but authentic lamb, but Zhu Di doesn't have much appetite, just said to Zhang Yifan: "I said Yifan, now that we are strong and strong, there is nothing to practice again, I think it's okay, right? want

No, next spring is in full bloom, how about going out and fighting?"

When Zhang Yifan heard this, he didn't raise his head, continued to brush the lamb, and said at the same time: "Fart, I can't look at it, just the assault rifle in the army, it's an eyesore to watch. The tower matter is over, and I'll change this assault rifle when I get back!"

The assault rifle is the most primitive musket, which is inferior to the arquebus, whether it is power, shooting distance, or reload speed, it is crushed in all ranges. As a traverser, he naturally looks down on the assault gun.

When Zhu Di heard this, he was immediately overjoyed, and he dared to love his brother-in-law with a good idea. He was about to ask when he heard hurried footsteps outside.