Xuzhou East China Sea has produced crystals since ancient times, among which Qu County is the most. Mi Fang led the fleet north to Youzhou this time, in order to befriend Liu He, so he prepared various gifts, but only a few pieces of crystal stones entered the eyes of the eldest prince, which has to be said to be a coincidence.

Liu He was even more excited than he was when he saw a beautiful woman after seeing the colorless crystal, just because he wanted to use this magical stone to make a sharp weapon that could speed up the course of the war.

This sharp weapon, known as the telescope in later generations and the "clairvoyant" in modern times, was invented by Westerners in the early 17th century. As for its use, Liu He, as a plane that crosses time and space, is very clear, so he has been thinking about this matter in his heart. Now that Mi Fang has sent colorless crystals thousands of miles away, Liu He will naturally not let go of this excellent opportunity to arm himself.

Colorless crystals are naturally formed, extremely pure, extremely transparent, and the color of the whole crystal is almost the same as the color of water when placed in water. Water is colorless, so this crystal is called colorless crystal, in fact, colorless is also a color.

Compared with natural purple, yellow, green, pink and red crystals, the process value of colorless crystals is obviously much lower, but only this colorless crystal can replace transparent glass, and even higher purity than ordinary glass. Before the real glass technique appeared, if Liu He wanted to get the telescope out, he could only use pure natural colorless crystal as the lens of the concave lens and the convex lens.

From the perspective of technology, high-purity colorless natural crystal can completely replace colorless glass, which can be proved from the fact that many old people in later generations like to use stone mirrors.

Stone mirrors are crystal glasses. There are two kinds of crystal glasses, white crystal can be used for reading glasses and myopia glasses, and citrine can be used for flat glasses. Because of the high hardness of crystal, it is difficult to scratch the mirror; Because of its high density, it has a natural anti-fog function; Also because the crystal belongs to water and has the characteristics of coolness, so the eyes of the elderly will not be dry when they wear stone mirrors to watch TV.

In fact, Liu He's telescope made of colorless crystals is not reluctantly usable. but violently destroyed the heavens......

In Guo Jia's doubts and Xu Yue's expectations, Liu He appeared at the Jicheng Command Office on time the next afternoon, and outsiders thought that he had come to the Office to handle military affairs.

In the small, airtight courtyard guarded, five craftsmen stood in front of a table with worried faces, and on the table were two bronze cylinders that they had carefully crafted all night's sleep.

To be honest, several craftsmen still haven't figured out what the use of this thing that the eldest prince asked everyone to make is going to do, they just strictly follow Liu He's requirements to inlay the polished water lens into the copper cylinder, and then put the three copper cylinders from thin to thick and add an anti-falling hoop.

Before Liu He came to the table, he picked up a "copper cylinder" and carefully inspected the appearance and workmanship. Then he turned his face to Xu Yue.

Xu Yue nodded and said, "It is completely made according to the size of the pattern, and the error will not exceed two hairs." ”

Liu He then twisted the copper cylinder out of the joint, tried the tightness, and then closed it again.

"A few masters have worked hard, you go to rest for the time being, I want to go out of the city, and when I come back, I will definitely reward you!" Liu He said this. took Guo Jia and Xu Yue out of the small courtyard, and then boarded the car and left the headquarters.

Along the way, Liu He couldn't put it down and played with the "copper cylinder" in his hand, but he didn't tell Guo Jia and Xu Yue what it was for.

Wait until the carriage drives out of the north gate of Jicheng for ten miles and comes to a clearing with a wide field of vision. Murong Ping, who was in charge of the guard, led a thousand infantry scattered a hundred paces away, surrounding Liu He, Guo Jia, and Xu Yue in the middle.

Liu He pointed to the army mountain range in the distance and said to Guo Jia and Xu Yue: "You look hard towards the mountain to see if you can find anything. ”

Guo Jia and Xu Yue then stretched their necks and looked vigorously towards the mountain. As a result, nothing could be seen except the silhouettes of the taller trees on the mountain.

Liu He picked up the "copper cylinder" in his hand, and then continued to expand and adjust. It wasn't until he saw a mountain man in the mountains who was collecting firewood that he handed it to Guo Jia, and then said, "If you look carefully in the direction of my finger, you will see what is under the tree!" ”

Guo Jia was suspicious, imitated Liu He's movements, put the heavy copper cylinder on his right eye, and then closed his left eye.

The next moment, I saw that Guo Jia's whole person seemed to be frozen.

Liu He's heart was very happy, and then he picked up another monocular, and after some adjustment, handed it to Xu Yue, who was already impatient beside him. Xu Yue picked up the telescope and also looked in the direction of Guo Jia's observation, and then almost dropped the telescope on the ground by mistake.

The two scribes, who usually pay great attention to their appearance and demeanor, were ruined at this time, they were like two playful children, holding the outer cylinder of the telescope with both hands, constantly adjusting the direction, expanding the mirror body, and making a loud and screaming sound in their mouths, as if they had discovered a world that they had never seen before.

"Look, Gang River! There are two forest deer mating in the col over there! ”

This is Guo Jia's exclamation.

"Fengxiao, have you seen it? There's a woman taking a bath at the bottom of the waterfall! ”

This was Xu Yue's excited voice.

Liu He watched two "shameless" people peeping at Lin Lu mating and women bathing there in broad daylight, and he felt a chill in his heart, so he simply got into the carriage to save shame.

When Guo Jia and Xu Yue had had enough, the two finally came to the car, and then looked at Liu He with the eyes of a monster.

Guo Jia gritted his teeth and said, "Tell me honestly, how many such magical ideas are still in your mind that have not been exposed?" ”

Liu He stretched out his hand, "Hehe, give me back the clairvoyant mirror first, and I'll tell you." ”

"Don't even think about it!" Guo Jia clutched the copper cylinder tightly, as if Liu He wanted to rob his daughter-in-law with him.

"Clairvoyant, that's a good name! Childe first invented the 'twist' number, then invented various symbols, and then charcoal, abacus, and double-line accounting...... Now that you have invented the clairvoyant mirror, you are really the first clever person in my Han Dynasty, are you the Mo family giant of this generation? Xu Yue looked admired and curious.

Liu He shook his head and denied that he had a half-penny relationship with the Mo family.

"With this thing, I can use it to observe the sky in the future, it's amazing!" Xu Yue held the telescope in his hand as if he was holding a treasure.

Liu He suddenly remembered a very important matter, and hurriedly said to Guo Jia and Xu Yue: "You must remember that you must not use a clairvoyant mirror to watch the sun, otherwise your eyes will be seriously injured, and you can even be blind!" ”

Guo Jia and Xu Yue nodded together, obviously seeing that Liu He was not joking with them.

Liu He remembered one more thing, so he said to the two: "If I merge these two clairvoyant mirrors left and right, then I can look into the distance through the lens with both eyes at the same time, wouldn't it be better?" ”

Guo Jia and Xu Yue nodded at the same time, and Xu Yue couldn't wait to go back to the city to let the craftsmen build binoculars.

Liu He was not in a hurry, he hesitated for a moment, but decided to tell Xu Yue all the remaining knowledge.

"Gonghe likes to study celestial phenomena, and you can think about making a very large telescope, as long as the crystal stone used to polish the lens is large enough, you can even ask a craftsman to help you build a super-large telescope that is more than a foot long and more than two feet in diameter. With this clairvoyant mirror, you can clearly see whether there is Chang'e on the surface of the moon on the night of the moonrise. In addition, if you ask a craftsman to help you polish a few perfectly flat brown or green filter lenses, you can also look directly at the sun as long as you place them in front of the lens opening, so that it doesn't hurt your eyes, and then you will find something that will surprise you even more......"

Liu He sat in the car, slowly recalling the basic knowledge about astronomical telescopes in his mind, while Guo Jia and Xu Yue had fallen into the realm of madness.

Imagine being able to see what's on the moon, to be able to see countless stars in the night sky, and even to be able to look directly at the sun!

Guo Jia first came back to his senses from his infinite imagination, and he told Liu He with a serious face: "Childe, the magic of this thing has far exceeded the imagination of the world, and it must be strictly controlled in our hands!" ”

"It's a must! Do you think I'm foolish in putting those craftsmen under house arrest at the Command? I just talked about some of the uses of the clairvoyant, you might as well think about what would happen if you used this object on the battlefield? ”

"If you hand over the clairvoyant mirror to the general who leads the army to fight, and let him stand on a high place and command the army to arrange and retreat, you can have a clear view of the entire battlefield, and the enemy army will have no way to hide, it is really terrifying!"

"Hehe, you said that if I give this thing to Zhao Yun, Zhang He, Xu Rong and other main generals, should the Xianbei people be extinct in the north in the future?"

"What the Hu people rely on is nothing more than rapid guerrilla warfare, if our main general gets this sharp weapon, then in the future, no matter which direction the Hu people come from or which direction they flee, it will be in the eyes of our main general, and then their advantage will be gone, and it will be difficult to think of extinction."

"Alas, Yan Rou won't be able to enjoy this treatment this time. But in the future, I will have more good things to leave for the Hu people outside the Saiwai, and when the time comes, you will know that this clairvoyant mirror is actually nothing! ”

"It's time again!" Guo Jia and Xu Yue protested loudly at the same time.

Liu Hexian finished his swing and returned to the city again under the escort of a group of guards. Guo Jia and Xu Yue each held a monocular clairvoyant in their arms, for fear of being seen, so they hid in the car and never showed their heads until they entered the yamen of the Command Office.

Several craftsmen not only received a large amount of gold and silver wealth, but were also rewarded by Liu He with a token symbolizing status and status, which was engraved with the words "Shangzao".

Several craftsmen were actually very afraid that Liu He would kill people, because the words he said yesterday were too terrible, but Liu He did not mean this, but instead offered them as "living treasures", and now everyone can finally sleep with peace of mind. (To be continued......)