The night before yesterday, Li Xin was in Yongle Fang and made the two pieces of superb water jade into two convex lenses.

Then yesterday, Li Xin spent another day, adjusted the appropriate focal length, and then fixed it with a wooden cylinder, making the world's first monocular!

Although this telescope is extremely simple, only about seven or eight times the magnification effect, and the cost is very expensive, it has to be said that this is a rare thing that is unique in this era, and it will definitely make the Chengde Emperor feel novel.

What's more, if this thing can be applied to the army, it is equivalent to the fact that there are more clairvoyants in the Great Jin Dynasty, and some military scouts who are born with better eyesight can even borrow this telescope and become a veritable "clairvoyant".

You must know that this is an era of extremely poor combat conditions, and generals and troops may even get lost, and if they can anticipate the enemy's opportunities on the battlefield, they will take advantage of the unknown amount of advantage.

Although Li Xin had never been in contact with the glass industry in his previous life, he probably knew that it was a mixture of quartz sand and soda ash and the like, but he didn't have a specific formula, and if he wanted to figure it out, it would take at least several years or even more than ten years to slowly figure it out.

Right now, the telescope made of natural crystal he is carrying can be said to be unique.

Of course, the Dajin royal family sits on the world, if the Chengde Emperor likes it, even if he uses natural crystals alone, he can also make a lot of them.

The process of the Son of Heaven's holy birthday is that the hundred officials go first to congratulate the table, and then the Son of Heaven accepts the worship of the hundred officials, and in the evening, a banquet is set up in the palace to invite the civil and military officials.

At this time, the Seven Princes and the civil and military officials had already entered the Changle Palace, and Ji Lingxiu also tidied up his clothes and prepared to go in.

However, there is no place for Li Xin in the main hall of Changle Palace, Li Xin can only wait outside the hall, and in desperation, Captain Li handed a wooden box in his arms to the ninth princess, and whispered: "Your Highness, this is the congratulatory gift I prepared for you for Your Majesty. ”

Ji Lingxiu took the wooden box a little as if she didn't understand, turned around and entered Changle Palace.

Li Xin stood in the shade of the palace gate of Changle Palace and waited, he knew that it would not be long before someone inside would summon him in.

Because this thing is very magical, once Emperor Chengde asks what it is, the ninth princess can't say why, and she will "confess" Li Xin.

Of course, this is not a bad thing, but a great thing.

Li Xin is now just a vine attached to others, if he is attached to the Seventh Prince, he can only be a vine for a long time in the future, but if he can enter the sight of the Chengde Prince, he may become a tree himself, even if it is a very thin small tree, it is much better than a vine.

After closing his eyes at the gate of the main hall for more than half an hour, a little eunuch hurriedly ran out of the Changle Palace, glanced left and right, and asked sharply, "Who is Li Xin?" ”

At this time, in addition to Li Xin, there were some people waiting outside the hall, most of whom were people who were not qualified to enter the hall like Li Xin.

Li Xin's face was calm and he took a step forward.

"The next official is Li Xin."

The little eunuch bent over Li Xin: "Captain Li, Your Majesty has summoned you, come in with me." ”

Li Xin nodded, straightened his clothes, followed behind the little eunuch, and stepped into Changle Palace.

In the main hall of Changle Palace, Li Xin is not the first time to come, the last time he came, it was when he just came back from southern Xinjiang, and the Son of Heaven in Chengde asked, so Li Xin also understood the rules that should be there, and after entering the main hall, Li Xin took a deep breath and knelt on the ground: "Yulinwei Li Xin, knock on the Holy Son of Heaven, the Holy Son of Heaven has no borders." ”

This sentence was still taught by Ji Lingxiu to Li Xin in the morning, and it was a congratulatory message to the Son of Heaven on his birthday.

At this time, the Son of Heaven of Chengde was playing with a wooden tube in his hand, and from time to time he put it in his eyes to look into the distance, and Princess Qinghe was standing beside the Son of Heaven, with a somewhat cramped expression.

In this way, it is not difficult to guess what just happened.

Chengde Tianzi played for a while, looked at Li Xin who was kneeling on the ground, and smiled: "Get up and speak." ”

Li Xin stood up, still keeping his head down.

Chengde Tianzi put the clairvoyant mirror on his right eye, closed his left eye, and pointed the mirror at Li Xin at the bottom of the imperial stairs, and could easily see the young man's falling hair, Chengde Tianzi put down the clairvoyant mirror, and was amazed: "It is indeed a wonderful thing, Fang Xiaojiu sent it, I still don't believe it, Li Xin, how did this thing come about?" ”

The Emperor of Chengde was an extremely smart emperor, and after seeing this thing, he immediately thought of its usefulness.

Military!

The Great Jin Dynasty is now singing and dancing on the surface, but there are hidden dangers on both the north and south, especially in the south, if this thing can be used on a large scale, then the war will be like a normal person bullying a blind person, and he will take the lead.

Li Xin said in a deep voice: "Your Majesty, this thing can only be made with the best water jade, and the cost is extremely expensive, Princess Qinghe spent a lot of money to get such a thing out of filial piety, and she wants to please Your Majesty." ”

Chengde Tianzi put down the clairvoyant mirror in his hand with some disappointment, turned his head to look at the ninth princess, and said with a smile: "Xiao Jiu has a heart, go back and take things back in the palace, you can't let my little daughter suffer." ”

Ji Lingxiu hurriedly saluted the Son of Heaven in Chengde and said with a smile: "Father and Emperor have a birthday today, it is normal for children to send some things, it is good for the father to like it, and the daughter does not dare to ask for anything from the father, lest the mother concubine want to talk about her daughter again." ”

Chengde Tianzi squinted his eyes, reached out and touched the head of the ninth princess, and said with a smile: "Okay, it's hard for you to be filial, so I will accept this thing." ”

At this time, it was only the princes and the princesses who had finished sending the congratulatory gifts, and the civil and military officials had not yet begun, and the Chengde Emperor turned his head to look at the hundred officials under the imperial stairs, and said indifferently: "Go on." ”

The great eunuch Chen Ju stepped forward and sang loudly: "Hundred officials congratulate the gift." ”

So, the process continues.

Li Xin bent over and said, "Your Majesty, the ministers are retiring." ”

The one who can stand in this hall is at least a fifth-rank official, and there is no place for Li Xin here, so he naturally has to go out and wait.

Chengde Tianzi squinted his eyes, pointed to a position in the corner, and said lazily: "You just stand there and wait, you don't have to go out, I will look for you in a while." ”

Li Xin hesitated, bowed his head and said, "Your subordinates obey the order." ”

At this moment, the civil and military officials in the hall all set their eyes on this young man.

Among them, Zai Fu, who was talking to Li Xin, and Huan Chu, the servant of the door, glanced at this young man deeply and smiled.