Volume 2: Residence in the Capital Chapter 92: Cao Chong Weighing the Elephant and Archimedes' Principle
When the emperor asked this question, the miserable condition of Zhou Xun, the chief academic officer of the Imperial College, was suddenly ignored, and the atmosphere became unprecedentedly lively.
After all, this group of young men who came from noble or official families usually avoided the school officials even when they were seeking pleasure, and they were often scolded for being unlearned. It was impossible to expect them to sympathize with Zhou Xun.
Especially Lu Sanlang, who was looked down upon all day, was the first to speak up and shouted: "Your Majesty, I dare not say that there must be a secret scroll hidden in the plaque inscribed by Emperor Taizu, but I know that Emperor Taizu is unfathomable and always prepares for rainy days. He can be said to be a rare saint since the beginning of the world. Anything he can do is possible!"
When Lu Sanlang spoke, Zhang Chen also echoed him, fearing that the world would not be in chaos: "That's right, the emperor's deep intentions are beyond the comprehension of mortals like us!"
After the representatives of these two dandy young men gave their opinions, the others naturally did not want to lag behind and vied with each other to express their admiration for Taizu and, at the same time, to discredit the Imperial College without making a fuss.
For them who had accumulated resentment for many years, this was almost an instinctive choice. Even Zhu Er, under Zhu Ying's pushing, said hesitantly that Taizu inscribed a plaque to hide the secret scroll, maybe, probably, or... it was very likely!
Seeing these noble students taking advantage of the situation, Luo Siye wanted to help his master, but he couldn't find a good reason, so he could only stand a little further away and worry. As for Zhou Xun himself, he was shaking like a sieve, his face was pale, his lips were trembling, and he couldn't say a word.
Amidst the clamor, the emperor smiled and looked at Zhang Shou, who was silent, and suddenly asked with great interest, "Zhang Shou, why don't you say anything?"
Zhang Shou said calmly, "Your Majesty, I am wondering what material the Taizu used to write the plaque."
"Oh? Are you thinking about this?" The emperor raised his eyebrows thoughtfully.
"If I remember correctly, it was made of dark wood. It was shipped to the capital as a treasure by local officials. According to the Records of the Great Ancestor, there were more than a dozen dark woods, except for the charcoal- like parts, which were fine-grained and hard as copper and iron. They sank immediately in water. So when the Imperial College was built, the plaques of the Suan Ke and Ge Wu halls were all made of dark wood."
"Emperor Taizu required it to be thick and solid. Each plaque is very large. At least several people are needed to carry it. If we want to make more, there won't be enough. The remaining ones are just scraps. There are still a lot of them hidden in the palace treasury. I only have people carve some small ornaments. Although dark wood is occasionally found in various places, it is rare to find such good quality material."
"Besides, sending it all the way to the capital would be a waste of money and manpower. Emperor Taizu accepted the gift and reprimanded the governor, so no one would send it all the way to the capital now. Even so, some people thought that the Yinchen Wood had too much Yin energy, but Emperor Taizu said that the Imperial College had too much Yang energy, which was just right for balancing Yin and Yang, and they stopped them."
Seeing that Zhang Shou was still frowning in thought, he simply waved his hand and said, "If you are curious, you can come over and knock on it. The sound is very special."
Since the emperor had spoken, Zhang Shou certainly would not be polite, and immediately stepped forward, squatted down, stretched out two fingers and knocked on the edge and center of the inscription. Finding that it was indeed difficult to tell whether it was hollow, he pondered for a moment, then stood up and faced the emperor.
Before he could say anything, the emperor asked with a smile: "I want to ask you, is there any way to identify whether there is a secret scroll of Taizu inside without destroying this plaque inscribed by Taizu?"
Zhu Ying was startled and was about to push this difficult task to Zhang Shou, but she didn't expect Zhang Shou to turn his head to look at her and smile at her. Although he didn't say anything, she couldn't help but have a thought that surprised even herself.
Could it be that Zhang Shou really has a solution ?
"Your Majesty, may I ask a few words to this servant who came forward to denounce the Grand Secretary?"
Seeing the emperor wave his hand with a look of "please do as you please", Zhang Shou bowed and thanked him with a smile, and then walked towards the servant who was also kneeling on the ground. However, he stopped when he was still three or four steps away from the servant, and only felt relieved when he saw Ah Liu quietly move to his side from the corner of his eye.
There's nothing you can do. Once you're shot by an arrow, everyone is an assassin... You can't blame him for being too suspicious!
He squatted down and looked at the servant with level eyes. Seeing the desperate look on his face, he asked in a friendly manner, "Since you said that the Grand Secretary racked his brains to find the secret scroll in the plaque inscribed by Emperor Taizu, how did you know about it?"
"I saw with my own eyes that the Grand Secretary went to the Imperial College storehouse every day. Every time he went there, he would circle around the plaque, as if he was obsessed with it. He would often tap on it with his fingers and mutter to himself. I once heard the words 'Secret Scroll' with my own ears!"
"Oh, then how do you know there are a hundred secret scrolls?"
"In the past three years, the Grand Secretary has sent people to collect a lot of unofficial history about Emperor Taizu, and put them all in the library of the Imperial College. When I went to clean it, I turned to a page where he had marked it, and it was exactly the 100th chapter of Taizu's secret scroll! And I sneaked into the storehouse and knocked on the plaque! If the middle part of the plaque was not completely hollow with a large piece missing, I would have heard a clue when I knocked on it!"
The servant turned his head and looked directly at Zhou Xun, saying word by word, "If you don't believe me, you can ask other people in the Imperial College whether the Grand Secretary hangs out in the warehouse every day! Apart from this plaque, there is nothing else in the Imperial College's warehouse that is worth him going there every day!"
After these words were spoken, not only Zhang Chen, Lu Sanlang and others suddenly realized what was going on, even Luo Siye couldn't help but feel a little surprised and doubtful.
He and Zhou Xun had worked together for more than three years. It was pure nonsense to say that the plaque inscribed by Taizu was taken down by Zhou Xun. However, Zhou Xun would often go to the warehouse where the plaque was stored when he had nothing to do. So it was true. He had seen it several times!
He once asked out of curiosity, but Zhou Xun said that he was admiring the calligraphy of Emperor Taizu. He thought about it and didn't take it seriously.
Could it be that Zhou Xun had read too many unofficial histories somewhere and actually believed the nonsense about the secret scroll hidden in the plaque?
The problem is that if you want to take out the secret scroll, you will definitely destroy this precious plaque inscribed by Taizu, and what do you want to do?
This isn't one of those legendary stories about gods and ghosts, with no treasure map or secret vault inside the plaque!
The emperor also said with a smile: "I didn't expect there would be such a secret. Zhou Xun, what do you think?"
"There is absolutely no such thing. There is absolutely no such thing!" Zhou Xun, filled with shame, indignation and anger, seemed to have no idea how to defend himself. He just kowtowed with tears streaming down his face, repeating these four feeble and powerless words.
The emperor saw that Zhou Xun could not get any information from him, and Zhang Shou had already stood up and walked slowly towards him, so he smiled and asked, "Zhang Shou, you have finished asking questions, what's the solution?"
"Your Majesty, I have an idea."
Zhang Shou nodded in a positive tone and said calmly, "If Your Majesty says that the dark wood used to make the plaque inscribed by Taizu is no longer available, then I am naturally helpless. However, since there are still many scraps in the palace treasury, I have an idea. May I ask Your Majesty, are those scraps added together as heavy as this plaque inscribed by Taizu?"
"Well..." The emperor hesitated slightly, then looked at Chu Kuan.
Chu Kuan immediately smiled and said, "Those scraps are a huge pile. Although I haven't weighed them, I think there should be a lot. However, although the old and new Taicang warehouses have large scales for weighing grain, it may not be accurate to weigh the weight of a plaque like this, and then by analogy, weigh the same weight of scraps."
Zhang Shou nodded and said, "It doesn't matter if you can't weigh it. Your Majesty, with your erudition, must have heard of the story of Cao Chong weighing an elephant in the Records of the Three Kingdoms."
"Oh, of course." The emperor smiled even more happily.
Zhang Shou said calmly, "Since it takes several people to lift this plaque, it is naturally difficult to weigh it accurately. In this case, we should treat it like a giant elephant and put it in a specially made boat that is about the same length and width as the plaque on a calm pool. Then, we should carve a notch according to the draft. Then, we should move the plaque out and put the leftover pieces of the dark wood in one by one until the draft is level with the notch."
“Since it is a small piece, it is relatively easy to accurately determine the amount of scraps of the same weight.”
The emperor could not help but nod slightly: "Well, not bad, what's next?"
Zhang Shou glanced at the whispers over there, who were obviously discussing the story of Cao Chong weighing the elephant, so he continued speaking.
"Then, tie the plaque with the Taizu's inscription to a rope and sink it into a completely filled pool. When the plaque is put into the water, the corresponding amount of water will be discharged. When the water surface is completely calm, pull the plaque out, and then record the height of the water surface in the pool after the plaque is out of the water. Next, fill the pool completely again, wrap the same weight of the dark wood scraps in a fishing net and put them into the water."
"Next, we will fish out the wood one by one and see if the water level after drainage is the same as when the plaque was fished out. If they are, it means there is no difference between the two, and the plaque inscribed by Taizu is solid..."
This time, before he finished speaking, Lu Sanlang had already interrupted with sudden enlightenment.
"I understand ! If the second engraving is significantly different from the first, it means that objects of the same weight are of different sizes. Naturally, the inscription is hollow, and there must be something mysterious inside!"
Zhang Shou had always looked up to Lu Sanlang's mathematical talent. Seeing his quick reaction, he smiled and nodded, "That's right. This way, we don't need to destroy the plaque inscribed by Taizu to know whether it is hollow and whether there is a so-called secret scroll hidden inside!"
In fact, for such a large plaque, the theoretical method that can be achieved under pure and perfect conditions is not accurate, because there is a high possibility of splashing, the accuracy of the incision is difficult to guarantee, and the center of gravity is difficult to determine. Moreover, two pieces of dark wood that look the same may not have the same density, not to mention a pile of scraps that may have different densities.
Therefore, combining Cao Chong's method of weighing the elephant with Archimedes' principle is just a test for fun.
However, the emperor's attitude was very suspicious, so he suspected that the emperor just wanted to hear a solution, and didn't really care about the final result...
Zhu Er, who was pushed to the back by Zhang Chen and others, opened his mouth so wide that he could hardly close it. It was amazing that Zhang Shou could come up with a solution, but how could Lu Sanlang understand it so quickly? Wasn't he a playboy like himself?
