Landlord of the Tang Dynasty

Chapter 296 Telescope

The door shuts the doors of the front and back rooms, and the cotton thread is stretched straight and taut through the hole carved in the middle of the door.Xu Qing read to the bamboo tube:

"Under the bridge in front of the gate, a flock of ducks swam past, come and count them, two four six seven eight."

After Xu Qing finished speaking, he continued to say to the bamboo tube: "Xu Qi, did you hear that? If you hear it, say in the bamboo tube that you heard it." After speaking, Xu Qing put his ear to the bamboo tube and listened for a while, maybe Xu Qi was stunned. Yes, I'm only going back to Xu Qing now.I only heard a weak but clear voice coming from the bamboo tube, Xu Qi whispered from the other side of the bamboo tube: "I heard..."

Xu Qing smiled immediately, glanced at the suspicious four girls, and said to the bamboo tube, "Then come here and tell Xue'er what you heard."

There was only a creak outside the door, followed by footsteps, Xu Qi opened the door and came in, very surprised and said: "Really! I really heard it!"

"Under the bridge in front of the gate, a flock of ducks swam past, come and count them, two four six seven eight!"

Xu Qi said excitedly, laughing loudly.

Huang Shimei took the bamboo tube in Xu Qing's hand and looked at it: "No, you two may be in collusion. This time I will talk. Xu Qi, go and listen?"

Xu Qi shook her head and said, "Why don't I go talk to each other and listen to each other? That's how you will believe it..."

Xu Qi ran over again, arranged the bamboo tubes as before, and straightened the cotton thread. Huang Shimei also pressed against the bamboo tubes and listened.The other three girls also leaned their heads together, wanting to hear it too.

Luo Xiuxiu was hugged by Xu Qing before she could get close to her. This little girl has always been a little distant from Xu Qing since she was broken that day.Unless Xu Qing asked for it, she would never ask for kisses or hugs.Xu Qing almost thought that she was frightened by the co-sleeping that day. After all, Xu Qing showed no mercy to Xueer and Xiaoyue. That scene was indeed a bit crazy.It was only later that Xu Qing figured out that Luo Xiuxiu was only indifferent in that aspect. Of course, this did not delay Xu Qing's enthusiasm, but strengthened Xu Qing's desire to conquer.

Luo Xiuxiu sat on Xu Qing's lap, leaning against Xu Qing's arms, only smiling but not speaking.

Behind the door, all the girls were surprised and delighted, talking to Xu Qi with bamboo tubes one by one.Xu Qing had eaten enough tofu, let go of Luo Xiuxiu, stood up and said, "How is it, my Shunfeng ear is not bad?"

Huang Shimei was convinced, she smiled and said coquettishly: "Hey, big brother Xu, my big brother Xu is the most powerful..."

Xiaoyue also nodded and said: "Yeah, young master is the best!"

Luo Xiuxiu also went to listen to it, and she did hear it, but she just said: "Xu Qing, this thing is good, but you can't hear it if it's far away?"

Xu Qing was actually very satisfied with the result, but fortunately the surrounding area was relatively quiet, otherwise the cotton thread would not be able to transmit sound waves so far.

He nodded and said: "If you replace the cotton thread with strings, the effect will be better and the transmission will be farther. However, if you really want to spread the sound ten miles away, you need to borrow something from the sky."

All the girls asked in unison, "What is it?"

Xu Qing smiled and said, "Electrical..."

There was a time when Xu Qing really wanted to create electricity, but after thinking about it, it would be useless to create electricity, at least it would be useless without him now.But the faces of all the girls turned cold, and they hurriedly said: "No, Shunfenger is not allowed to do it!"

Xu Qing wondered: "What's the matter, don't you want it?"

All the girls said in unison: "That's electricity, it can kill people, what do you want with that thing?"

Xu Qing laughed, it turned out that the girls thought that when he said borrowing electricity, he was borrowing thunder from the sky.Looking at the silly but serious expressions of the girls, should Xu Qing be moved or moved?
Xu Qi quietly put away the "shunfeng ear" made of bamboo tube..."

Everyone sat down, and it was time for dinner again. After eating together, Xu Qing asked Old Man Ni to invite the engraver to the study.

When asked, the carver said that he can carve medicine jade, but the oval has not been carved.Xu Qing took out a new piece and drew the arc, but the engraver still said that he was not sure, saying that the medicine jade was too brittle, and it would be broken when he cut it.As he said that, he gave Xu Qing a solution. After talking, Xu Qing went to hire someone who can make medicine jade, and just made a piece of it.

Xu Qing asked him if he could find it, and the engraver said that he couldn't find it either.Helpless, Xu Qing took out what he had polished and asked him if he would polish it.

This time, Xu Qing got a satisfactory answer, and the engraver said that he could polish it.He also said that if he polished the polished one in Xu Qing's hand, he would have great confidence.However, it is necessary to temporarily make a polishing machine.Xu Qing clapped his hands. Isn't there a carpenter at home? Call the carpenter over.

The carpenter and engraver got together, and in the afternoon, a simple polishing machine came out.It is manpower.The big wheel has a small wheel, and the small wheel is equipped with a cloth with relatively high friction, and the unevenness of the glass surface can be removed by continuous polishing.

There were still some small protruding corners, so Xu Qing took the whetstone and rubbed them carefully.He took five quilts and spread them on the ground, and that night he started the development of the first convex lens in history.

Accompanied by Xu Qing, the engraver also forced himself to work overnight.

In less than three hours, the convex lens is formed.After finishing the convex lens, Xu Qing handed over the medicinal stone material bought from Luonan County to the engraver, and saw him use it for practice. He could do whatever he wanted, as long as it could be processed into what it is today, it would cost one tael of silver!
The few pieces of jade in Xu Qing's hands have a light transmittance of [-]%, while the ones bought in the county are slightly worse, but they still have a look of between [-] and [-].If this engraver is proficient, then use high-grade medicinal jade to make convex lenses for him in the future, wouldn't it be flattering?

Holding the two pieces in his hand, Xu Qing was so excited that he couldn't sleep all night, Huang Shimei was also excited, and took advantage of this sleepless night to squeeze out Xu Qing's inventory.

On the second day, without waiting for dawn, Xu Qing got out of bed, not for anything else, just because of the saying that there are only exhausted cows and no plowed land.Seeing Xu Qing's back staggering away while supporting the wall, Huang Shimei smiled with satisfaction.

And of course, to make a telescope!
Sitting in the study, Xu Qing carefully recalled the principle of the convex lens he learned in junior high school. He found that the vibration fluctuation and interference diffraction learned in high school and college are nonsense and impractical at all.

"Focus, uh, focal length, isometrically reversed image..."

Xu Qing lit a candle on the table, with the convex lenses in his left hand, and the imaging board temporarily used by rice paper in his right hand, and finely adjusted the distance.

The estimate is almost the same, mark it with a straight wooden stick, this is double the focal length.

Old man Ni was sleeping in the room, the older ones had short sleep, at this point, in fact, he had woken up a long time ago, but the weather was too cold and he refused to get out of bed.

At this moment, someone kicked open his door and said eagerly: "Old Man Ni, hurry up and find a pipe that is this long and wide, bamboo!"

(End of this chapter)