After tightening the spring, Chen Jingke said to Xiao Sizi: "Are you ready? It's time to start."
Xiao Sizi nodded his little head solemnly and said: "Okay."
Chen Jingke swings the switch, and the spring rebounds to drive the gear to rotate at a constant speed. The gear drives the belt, and the belt drives the wheel at the other end, and the glass rotates at a constant speed.
The childish singing voice of Xiao Sizi sounded: "I have a little donkey, but I never ride it...it fell all over me and was covered in mud."
When the song ended, Chen Jingke also pressed the switch and the glass stopped rotating.
Then he praised: "Xiao Sizi sings so beautifully."
Others also applauded: "Xiao Sizi sings so beautifully."
It made little Sizi happy and shy at the same time.
After praising his own sister, Li Tai couldn't wait to ask: "Why did you ask little Sizi to sing to this paper cup? And then what?"
Chen Jingke said: "Don't worry, you will know soon."
After speaking, he reset the glass, wound up the clockwork again, and said to everyone: "Prick up your ears, the time has come to witness the miracle, don't be scared."
Then flip the switch again and the glass will spin.
Just when everyone was confused, a familiar singing voice came from the paper cup: "I have a little donkey, and I never ride it..."
Even though the sound was very weak, noisy, and slightly distorted, you could still tell that it was Xiao Sizi's voice.
Everyone opened their eyes and mouths wide, looking at this strange thing in disbelief.
Princess Chengyang was the first to exclaim: "Monster, Xiao Sizi's voice has been taken away by this monster."
Xiao Sizi himself was startled and said quickly: "No, no, I can still speak."
Everyone also reacted. Li Tai rushed over and looked at the gramophone excitedly, as if he had seen a treasure:
"What is this and how is it done?"
Everyone else also looked at Chen Jingke, waiting for his answer.
This time, Chen Jingke did not give in and explained in detail: "Sound can vibrate...the paper cup is a trumpet. If you speak loudly to it, it will vibrate..."
"The needle will also vibrate, and the vibration trajectory will be engraved on the glass below..."
"When we reset everything and the bamboo needle follows the traces carved before, it will produce vibrations with the same trajectory..."
"The vibration is transmitted along the bamboo needle to the paper cup, and the same sound will be produced...I call this thing a gramophone."
Everyone was confused, but at least one thing they understood was that this was not a monster but a machine that could be controlled by people.
Li Tai is the one who understands the most among everyone. The more he understands, the more interested he becomes in this thing. He said with some obsession:
"So that's it, that's it... Heaven really doesn't create useless things. Everything is useful, but we know too little."
Chen Jingke wanted this effect. Just as he was about to continue talking to induce him, he noticed someone pulling at the corner of his clothes.
When he lowered his head and saw that it was Xiao Sizi, he said softly: "Xiao Sizi, what's wrong?"
Xiao Sizi whispered: "I...I want to let Mother Yeye hear it."
Chen Jingke smiled and said: "Okay, I'll give it to you. I'll teach you how to use it later."
Xiao Sizi said happily: "Thank you, brother."
Princess Gao Yang was filled with envy, and then glared at Fang Yiai fiercely. Fang Yiai scratched his head and smiled innocently at her.
Princess Chengyang and Chen Jingke had a good relationship and were straightforward, so she said directly: "Brother, I want it too."
Chen Jingke glanced at Du He and said, "I only have this one on hand for now. I will teach Brother Qingquan how to make it later and let him help you make one."
Du He gave him a grateful look, and then said to Chengyang: "Don't worry, princess, I will make one for you as soon as possible."
Princess Chengyang was not in the habit of grabbing things with her sister, so she could only say with some disappointment: "Hurry up."
Du He said: "Okay, I promise I won't keep you waiting too long."
Princess Gaoyang on the other side finally couldn't bear it anymore and lightly kicked Fang Yiai.
Fang Yiai was naive but not stupid. He immediately understood what she meant and said to Chen Jingke: "Master, I... I also want to build one for Gao Yang, I don't know..."
Chen Jingke smiled and said: "Okay, I will give you a copy of the production drawings later."
Then he said to Gao Yang: "Look, now you know the benefits of having an obedient man."
Gao Yang's pretty face instantly turned red, and he stamped his feet in disbelief and turned around.
"Haha..." It was rare to see her shy, and everyone laughed.
Afterwards, Chen Jingke restored the glass and played it again.
It's just that you can clearly hear that the sound quality this time is obviously not as clear as the previous one, with more noise.
Chen Jingke explained: "There is a diamond chip underneath this bamboo needle. When it passes through the glass a second time, it will deepen the trajectory and cause sound distortion."
“The distortion becomes more severe the more times it is played repeatedly, until it is completely distorted.”
Li Tai said: "Then when playing, wouldn't it be enough to use a needle without diamond?"
Chen Jingke smiled and said, "Okay. Isn't this just to give you a demonstration so that you can better understand the characteristics of the gramophone?"
Everyone: "..."
Then Xiao Sizi pursed his lips and said aggrievedly: "Brother, is this... gramophone broken?"
"Uh..." Chen Jingke slapped his forehead, forgetting about her, and quickly reassured her: "No, no, the glass can be replaced at any time. Let's change the glass and record it again and it will be usable again."
Only then did Xiao Sizi show off her beauty again and said, "That's great. When I get back to the palace, I'll record one for Ye Ye and my mother."
Chen Jingke praised: "Little Sizi is so good."
After coaxing his little daughter-in-law, Chen Jingke said: "Although it can be changed, it cannot be changed casually."
"The closer the materials of the two needles and the cup are, the better. If the difference is too great, the vibrations produced will be different."
"This gramophone is still too crude. Subtle differences will affect the playback effect. It would be great if a better and more accurate gramophone could be made."
Li Tai immediately said: "Teach me the principles and we will study together. If it doesn't work, I will become your teacher."
Chen Jingke said dumbfounded: "You are Xiao Sizi's brother and you want to be your teacher. If you want to learn, just come to watch and I will teach you."
You, the Li family, can do it regardless of seniority, but I can’t.
Li Tai immediately said: "Okay, from now on I will come to you every day to learn and strive to make a better phonograph."
Chen Jingke smiled and said: "Do you only study phonographs?"
Li Tai was stunned for a moment and asked: "If you don't study it, what are you studying?"
Chen Jingke said: "The gramophone is just a fruit, and the knowledge of physics is the tree that grows the fruit. Don't you want to study this tree?"