"Your Majesty, Niangniang, if you two listen carefully, you can find that this telegraph can actually make two sounds, one is such a short sound, and the person on the other side can record it as a dot when receiving this signal, which is read as "drop", and the other is such a long sound that can last for a certain time, and the person on the other side can record him as a horizontal line when he receives this mark, which can be read as "click", and His Majesty and Niangniang can listen carefully! ”

Drunken Wind Xuan.

In order to explain the telegraph transmission mechanism to Li Er and the eldest grandson, Li Zexuan explained the principle while personally operating the telegraph, in fact, the principle is very simple, it is nothing more than the length of time the electric key is closed, to control the telegraph to send out two different signals.

"Well, that's true, but just that, I'm afraid I can't pass on the news, right?"

Li Er saw Li Zexuan's demonstration, and he was amazed at the magic of the telegraph in his heart, and asked suspiciously.

"Your Majesty, these two monotonous signals alone certainly cannot fully express what the two sides of the message are trying to express. The telegraph also needed to be used with a codebook. ”

Li Zexuan explained with a smile.

"What is a codebook? You kid won't finish the conversation all at once? ”

Li Er frowned and said unhappily, daring to deliberately take the bridge in front of him, this kid is really bold enough~!

"Well, back to Your Majesty, just now the minister said that you can send two kinds of signals from the telegraph machine, recorded as dots and horizontal lines, and the minister later combined this point and the horizontal line, each combination represents a number, for example, a point and four horizontal lines represent the number "1", and so on, a total of ten numbers, and then the transmitter can let the four numbers combine with each other to represent a word, so that there are 10,000 combinations, that is, through this method, you can express 10,000 different words! And each combination, the corresponding text, is the code book that Xiao Chen said! ”

Li Zexuan stood with his hands in his hands, and talked a little coercively, what he wanted was that he had a rare opportunity to pretend to be forced in front of Li Er, not pretending to be white.

In fact, what he just said was the famous Morse code in the modern history of the world. In 1832, the Russian diplomat Schilling built a machine that used the galvanometer pointer to deflect to receive information. Later, in 1835, after three years of study, the American painter Morse succeeded in replacing human words with the "on/off" and "long" of electric current.

Morse code is an early form of digital communication, but unlike modern binary code, which uses only zero and one or two states, it includes five types of code: dots, strokes, pauses between dots and strokes, short pauses between each character (between dots and strokes), medium pauses between words, and long pauses between sentences. Then use different combinations of dots and strokes, representing twenty-six English letters and ten Arabic numerals, to achieve perfect communication.

Later, Morse code was introduced to China, and it has undergone some improvements, almost as Li Zexuan just said, but on the basis of the original, there are some more combinations.

Li Er was frowning and thinking, but he didn't pay attention to Li Zexuan's underwhelming appearance, otherwise he would have to reward the two big-footed girls. Empress Eldest Sun inadvertently caught a glimpse of Li Zexuan's expression, and she couldn't help but want to laugh.

"I see! That's a good idea, you kid! But according to what you say, isn't the so-called codebook free to change? ”

Li Er himself is a person with great wisdom, putting aside the electromagnetic knowledge that does not belong to this era, he can still understand the principles of these cipher combinations alone.

"Your Majesty is really discerning! As His Majesty said, this codebook can be changed at will as needed, as long as both sides of the message use the same codebook! Officially, due to the ever-changing nature of the telegram cipher, the security of the two people passing messages to each other is ensured, so that even if the message sent is intercepted by others, others look at those dots and strokes, and they don't know what the meaning of this information represents! ”

Li Zexuan heard Li Er's question, his eyes lit up, and he secretly said that the ancients were not stupid, and he only had some knowledge more than them.

"Heh~! You kid don't pat on the back! Oh, listen to what you just meant, can the message sent by this telegraph machine still be intercepted by others? ”

Li Er's heart was dark, but he scolded with a smile on his face, but he was a little puzzled, in his mind, the news sent by the telegraph was transmitted, silent and invisible, how could it be intercepted?

"Back to Your Majesty, the telegraph transmits information, in fact, it is equivalent to the military messenger transmitting military information through text, and they all have the possibility of being intercepted! All you need is a high-power receiver, and then adjust the receiving frequency of this receiver to the corresponding band, and you can capture the telegram information sent by others. Of course, this is only theoretically possible to be intercepted, because the principle of making the telegraph is only proficient in the whole world! ”

Nothing can be invincible, although the electromagnetic waves emitted by the telegraph are invisible and silent, but as long as the method is appropriate, it can still be captured, in some anti-Japanese war TV dramas, there are not often some underground party interceptions, deciphering the enemy's telegram plot!

"In the Army~~"

Li Er's heart moved, and he muttered to himself, although he didn't know what the hell "power", "frequency", and "band" were, but this did not prevent him from obtaining other key information from it, he looked at the telegraph on the table again at this time, and his eyes slowly became more and more hot, this is the artifact of the country! With the telegraph, wouldn't Datang be invincible in the war in the future?

He had fought all his life, and immediately thought of how great the telegraph would be if it were used in the army.

"You just said that you are the only one in the world who is proficient in the production principle of the telegraph?"

Li Er squinted his eyes, looked at Li Zexuan and said.

Well, Li Zexuan's heart tightened, he felt a trace of danger, could it be that he had just pretended to be too forced?

"Back to Your Majesty, you should... That's how it should be! ”

From Li Er's tone, Li Zexuan couldn't hear anything wrong, he could only reply stubbornly.

"Can this telegraph be mass-produced? Can it be used for the transmission of intelligence in the military? ”

Li Er didn't have any special expression on his face, but there was a trace of expectation in his heart.

"This...."

Li Zexuan wanted to scold his mother in his heart, but sure enough, Lao Li wanted everything he saw! What a bandit!

"Your Majesty, at present, the telegraph is only in the experimental stage, his transmission distance and working time are not stable, Xiao Chen can use it to chat with Yu Xi, but if it is used for intelligence transmission in the army, it is first necessary to solve its power supply problem, and then its signal transmission distance problem......"

"Chat? You're actually planning to use this telegraph to chat? ”

Before Li Zexuan finished speaking, Li Er couldn't help but interrupt, and saw him staring at him, with an expression of wanting to eat people, if it weren't for the eldest grandson beside him, he would have to draw his sword and chop Li Zexuan to feed the dog!

"Uh, Your Majesty... Your Majesty! ”

Li Zexuan secretly shouted that he was going to suffer, and the special mother said in a hurry, this is a pill! The robbers are going to eat people!

......................

(End of chapter)