Late Yuan Dynasty: I am the true emperor

Chapter 457 The Seeds of Science in the Model Class
Next to the central government is a courtyard that was part of the central government office of the Southern Tang Dynasty. When Zhao Gou moved south during the Southern Song Dynasty, he once thought of establishing his capital in Jiankang and had this place renovated. Now Lu Jin has come and renovated it again, so this courtyard was chosen to serve as a temporary school.

The classroom had been renovated according to Lu Jin's requirements. A podium was added to the front, and a blackboard was hung at both the front and back. Even the slogan that Lu Jin was familiar with was pasted above the blackboard, which read "Study hard and serve the motherland" in eight large characters.

If only a national flag were hung in the middle, two maps of China and the world were pasted on either side, and two 'Code of Conduct for Primary and Secondary School Students' were pasted on either side of the blackboard at the back, the layout would really be similar to a classroom in later generations.
In the left front corner of the classroom, there is a pendulum clock with a weight. This was a teaching aid made by Lu Jin when he brought craftsmen to make a marine clock and taught them the principles of clockmaking. The mechanical structure inside is made entirely of wooden gears, with a weight providing power. It needs to be wound manually, and the pendulum and escapement control the time, that is, the release speed of the weight. It should be the cheapest and most accurate timekeeping device that can be made at this time. In the future, it can be promoted in various places, or clock towers can be built directly in universities and cities.

At eight o'clock in the morning, as the school bell rang, Lu Jin arrived at the classroom on time. More than forty students, along with Song Lian, Zhu Sheng, Zhan Tong, Luo Ben, Chen Yu, and others who came to observe the class, were also there. They sat at the back of the classroom.

Lu Jin walked up to the podium, looked at the crowd below, and immediately said, "Class begins!"

Tao Guangyi immediately took the lead in standing up and shouting, "Everyone stand up, hello teacher!"

"Hello students, please sit down. Let's begin the lesson."

After everyone was seated, Lu Jin said, "You all did very well just now. The purpose of this science class we set up is not only to cultivate talents needed by the court, but also to serve as a model for all new schools in the country. Therefore, this class can also be called a model class. This includes school rules and regulations, classroom etiquette, and so on. So in this lesson, we will first talk about school etiquette and regulations."

"We are all Chinese people. What is Chinese? It is the beauty of clothing and the grandeur of etiquette. Etiquette is the difference between civilization and barbarism, and it is also the difference between us and the barbarians from all directions. Therefore, etiquette cannot be abandoned."

"But in the future, schools will be much larger and the number of students will be countless, so the old etiquette will no longer be suitable. Therefore, it should be simplified. Respect for teachers is a traditional Chinese virtue, so it should be preserved. However, there is no need to kowtow to teachers or give them any gifts. Everything should be simplified."

"From now on, students will address teachers as 'teacher' and other students as 'classmates.' If a student is late for class and wants to enter the classroom, they must knock on the door and say 'report' outside the door. They can only enter the classroom after the teacher has given permission. The same applies when students go to the teacher's office after class."

"If anyone wants to ask the teacher a question or speak during class, they must raise their hand first and get the teacher's permission before speaking. Do you all remember that?"

"Got it." All the students answered immediately. Song Lian, Chen Yu, and others were also taking notes in the back, writing down all the rules and regulations that Lu Jin had mentioned.

"In this first lesson, we'll start by talking about the school's rules and regulations."

Lu Jin immediately took the prepared list and read it out one by one on the podium, including the weekday system, five days on and two days off, electing class monitors and various subject representatives and group leaders, and students having to be divided into groups to do chores, such as cleaning the classroom, etc.

The school implemented military-style management. Students woke up at six o'clock every day and were led by the physical education teacher (a bodyguard appointed by Lu Jin) to run and practice marching. After half an hour, they ate breakfast, and at seven o'clock they had forty minutes of morning reading, during which the class monitor organized them to recite poems or formulas. After a twenty-minute break, classes officially started at eight o'clock.

There were eight classes a day, four in the morning and four in the afternoon, each class lasting 45 minutes with a 15-minute break. Classes started at 2 p.m. and ended at 5:45 p.m. Friday afternoons had two classes, almost the same as in later times. After the class schedule was determined, Song Lian and his colleagues were able to compile teaching materials accordingly.

The first half of the first class that day was spent on rules and regulations, and the second half was spent teaching them about clocks so that they could tell time on their own. The course content was not formally introduced until the second class.

"Today we'll be learning physics. Please open your books to the second chapter, 'Changes of State,' in the Gongshu Secret Manual of Physics."

After explaining the three states of matter—solid, liquid, and gas—as well as the phenomena of heat absorption and release between changes of state, and the principle of thermal expansion and contraction, Lu Jin finally asked the class a question near the end of the class.

"Now that you know the transformation between the three states of matter, the principles of heat absorption and release, and thermal expansion and contraction, what can we do using these principles? Students who know can raise their hands to answer."

Many students immediately raised their hands. Lu Jin pointed to a student who was the son of a craftsman from the Luzhou Ironworks, "Ye Chen, you speak."

Ye Chen immediately stood up and said, "Teacher, I saw a picture in the book of a thermometer filled with mercury in a transparent glass tube. It uses the principle of thermal expansion and contraction. Liquid mercury expands when heated, which means the temperature rises. However, the upper limit of the temperature that this thermometer can measure is relatively low. Can we use the same principle to make a thermometer that can measure higher temperatures, such as the temperature of molten iron?"

"The most difficult process in the ironworks now is frying steel, and the most difficult part of frying steel is controlling the heat. It requires experienced master craftsmen to judge by observing the color of the molten iron. I think this heat control is what the teacher called the temperature. If we could make such a thermometer, wouldn't everyone be able to become a master craftsman? They would only need to measure the temperature of the molten iron to know whether the heat is too hot or too cold."

"Sit down." Lu Jin nodded before saying, "Your idea is good. The heat is indeed related to the temperature. But you also mentioned the upper limit of the temperature. If you want to use the principle of thermal expansion and contraction to make a thermometer that can measure the temperature of molten iron, then the material you use to make the thermometer needs to meet one condition: it must have a higher boiling point than molten iron."

"Take mercury for example, which is liquid mercury. The boiling point of liquid mercury is about 357°C. Above this temperature, mercury will boil and vaporize, forming highly toxic mercury vapor. As for molten iron, the melting point of pure iron can reach 1538°C. Iron ore may need to reach 1600°C to melt into molten iron in a blast furnace. Even if pig iron contains impurities, its melting point is relatively low, but the temperature is at least 1400°C or higher."

"If you use mercury as a thermometer, it will expand and explode before it even comes into contact with molten iron, and then evaporate into mercury vapor. It is not only highly toxic, but also impossible to measure."

"And if you want to make this thermometer with other materials, the result will be the same. If it is a liquid material, there are very few that can reach the melting point of iron before boiling and evaporating. So this thermometer is not as easy as you think."

Upon hearing this, Ye Chen immediately asked, "Then, teacher, don't you have any other methods? If liquids don't work, what about solids? When you talked about clocks in the last class, you mentioned that there is a temperature difference compensator on marine chronometers. It is a device that compensates for temperature differences by using the elastic deformation caused by the thermal expansion and contraction of solid metal. Could you make a thermometer like that to measure the temperature of molten iron?"

Lu Jin nodded again and said, "What you said is also good, and it can indeed be used to make this kind of thermometer."

As Lu Jin spoke, he drew a sketch on the blackboard. "We can make a spiral metal spring. When the spring is heated, it will expand and unfold. Then, we can connect a pointer to the end of the spring and draw a dial with temperature scales. In this way, the metal probe will undergo elastic deformation due to the effects of heat and cold. The deformation will cause the pointer to point to different scales, and we can measure the temperature of the object being measured."

"But there is also an upper limit to the measurement. For example, if a spring probe is made of silver, copper, or steel, the temperature it can measure will definitely be lower than its own melting point. Considering that when the temperature of a metal rises to a certain level, it will also lose its elasticity, the upper limit of the temperature it can measure will be even lower than its own melting point."

"I think the upper limit of this type of thermometer is below 1,000 degrees Celsius. It still cannot measure the temperature of molten iron, but it can be used to measure the temperature of some steam or liquids. For example, it can be used to measure the temperature of distillation towers in the chemical industry, or in pulp boiling equipment, temperature measuring devices in sugar making and textile dyeing, etc. It still has great application prospects."

Ye Chen frowned upon hearing this and asked again, "Teacher, is there no other way to measure the temperature of molten iron? If the principle of thermal expansion and contraction doesn't work, then how did the Gongshu clan's predecessors determine that the melting point of iron is 1538 degrees Celsius?"

Lu Jin thought to himself that this student was very perceptive, so he explained again, "The principle of thermal expansion and contraction makes for a thermometer with a relatively low upper limit, but there are other ways to measure the temperature. Since we cannot directly measure high temperatures, why not first convert the heat into other measurable physical quantities and then measure it? Gongshu Shi used this indirect measurement method."

"For example, in thermal radiation power generation and light radiation power generation, molten iron itself is heating up and emitting light. The brightness of the light emitted by molten iron at different temperatures is also different. Light and heat energy stimulate certain objects to generate electric current. By measuring the strength of the current generated by the object, we can sense the temperature. In this way, we don't even need to touch the molten iron. We can just shine a thermometer next to the molten iron and measure the temperature by looking at the light intensity."

All the students' eyes lit up upon hearing this. Ye Chen was about to raise his hand to ask another question, but Lu Jin said, "This lesson is about changes of state. Electricity will be covered later. We won't go into detail today. Just get a general understanding. If anyone has any other thoughts, please raise your hand."

At this moment, another student raised his hand, and Lu Jin called on a student from the artillery class in Jiangnan, "Li Xianming, you go first."

Li Xianming is 15 years old this year. He had studied in a private school in Jiankang and had a certain cultural foundation. After Lu Jin crossed the river, he recruited soldiers in Jiankang. He volunteered to join the army. However, because he was young and literate, he was selected for the artillery class. His foundation was not bad. When he heard Lu Jin call his name, he first stood up, cupped his hands, and then said.

"Thank you, teacher. When you were talking about changes in the state of matter, you mentioned rain, snow, hail, and water evaporating into clouds. You also talked about the cycle of water in nature. So I was thinking, since we know the principle of rain and snow formation, can we use this principle to artificially control the weather?"

"The teacher said that clouds and fog are made up of tiny water droplets, but I noticed that even during droughts, clouds sometimes drift across the sky. Doesn't that mean there's rain in the sky but it doesn't fall? Could we use the principle of changes in the state of matter to make the clouds rain down in order to solve the drought?"

Upon hearing this, the entire class, including Song Lian and Zhu Sheng who were observing from the back row, couldn't help but exchange bewildered glances. Good heavens, artificially controlling the weather to make the clouds rain? Did he think he was the Dragon King? We'd seen plenty of people praying for rain during droughts, but this was the first time we'd ever seen someone try to make the clouds rain on their own.
However, the teacher on the podium was even more outrageous than they expected. Instead of scolding the student, Lu Jin praised him.

"Your idea is excellent. To learn the science of Gongshu, one must have a spirit of not believing in ghosts and gods. So-called wind, rain, clouds and snow are just natural phenomena in the world. They are nothing more than the heat absorption and release processes of sublimation, evaporation, volatilization, solidification, melting and deposition. Since we know the principle of rain and snow formation, we can certainly control its occurrence."

"Then let me ask you, clouds are made up of small water droplets. When they condense into larger droplets and fall from the sky, is it an endothermic or exothermic reaction? Should it make the clouds cooler or warmer?"

Li Xianming thought for a moment before saying, "It should be that heat is released and the water cools down, which is why it condenses into large water droplets."

Lu Jin nodded approvingly, "That's right. So if you want the clouds to cool down, you need a highly volatile substance to disperse into the clouds. By using the principle of heat absorption through evaporation, you can absorb the heat from the clouds, causing them to cool down, condense, and fall as rain."

"The principle is very simple, but there is a prerequisite: you have to be able to seed this substance into the clouds before you can achieve artificial rain."

Song Lian, Zhu Sheng, and the others sitting in the back row stared wide-eyed. Good heavens, they really could!
Li Xianming's eyes lit up as he listened, and he asked again, "Then what is the highly volatile substance that the teacher mentioned? Could you give an example?"

Lu Jin immediately said again, "The simplest example is dry ice, which is solid carbon dioxide. We have just learned about changes of state and we already know that gases are not empty substances, but tangible things. For example, the air we inhale and the waste gas we exhale contain not only components in the air that cannot be absorbed by the human body, but also carbon dioxide expelled by the human body."

“At room temperature, carbon dioxide is a colorless and odorless gas that we cannot see or touch. However, if we collect it and put it into a high-pressure and low-temperature environment, it can be solidified into a solid, similar to a white ice block. Because it is not made from water freezing into ice, Gongshu called it dry ice.”

"Carbon dioxide is naturally present in nature. Even if it is condensed and scattered into the clouds, it will not have a significant impact on the environment. You only need to make several thousand kilograms or even tens of thousands of kilograms of dry ice and throw it into the clouds. By utilizing the property that dry ice will quickly absorb heat and evaporate at normal temperature and pressure, turning back into a gas, it can absorb the temperature in the clouds and cause them to condense and fall as rain."

Li Xianming was stunned upon hearing this. "Several thousand or even tens of thousands of kilograms—how can something this heavy be scattered into the clouds?"

Lu Jin countered, "Weren't you from the artillery platoon? What do you think?"

Li Xianming was taken aback, then immediately said, "Put dry ice into exploding grenades and fire them into the clouds with cannons?"

Lu Jin nodded. "Using anti-aircraft guns to shoot dry ice into the clouds is a way to create artificial rain, but you can't build such artillery right now."

Li Xianming replied, "But we can build them eventually, can't we? Before you, teacher, who could have imagined that firearms could shoot bullets more than three miles away? As long as you are here, teacher, we can build them eventually."

Lu Jin immediately said, "You are very ambitious, but I want to tell you that during a drought, there will be fewer rain clouds than usual because the water in rivers and lakes is reduced, the evaporation of water is also reduced, and the rain clouds will be reduced accordingly."

"Even if you can use artificial rainmaking to squeeze out the last bit of moisture from the clouds, it's just a drop in the ocean. It can alleviate the drought, but it doesn't solve the root cause. To solve the drought, it's better to build more water conservancy facilities in normal times."

"Yes, teacher, I understand." Li Xianming nodded.

"Okay, sit down. Does anyone else have something to say?" Lu Jin asked again.

The students immediately raised their hands again. They were very enthusiastic about this kind of science class, since the old teachers in the private schools would never have told them such amazing things.

"Um, Mao Xin, what do you say?" "Yes, what I was thinking was that the teacher just said that we can collect the waste gas that people exhale and freeze it into dry ice. So this must require a device that can control the temperature. Is this device also made using the principle of evaporation and heat absorption?"

"Moreover, since this kind of device can be used to freeze dry ice, can't it also be used to freeze other things? If we can make this thing, wouldn't we no longer need ice cellars to store ice in winter? Could we just make ice directly in the summer?"

Upon hearing this, Lu Jin immediately praised, "That's right, we can indeed use the principle of evaporation to absorb heat for cooling, but we must know that heat doesn't just disappear; it can only be transferred and exchanged."

Lu Jin drew a diagram of a house on the blackboard, and then said as he drew, "For example, a house, you seal its doors and windows to form a closed space, and then introduce a highly volatile liquid into the room so that it can absorb heat from the room. Once it has absorbed enough heat, you introduce it into the outside and compress it back into a liquid to release the heat absorbed from the room to the outside, and then introduce it into the room again to continue absorbing heat."

"By continuously repeating this cycle, the temperature in the room or this enclosed space can be lowered until it reaches tens of degrees below zero, where water freezes instantly. At this point, you only need to bring in a basin of clean water, close the doors and windows, and the water will freeze into ice blocks in just a few hours."

"Of course, this is just one method. If the space you are cooling is not a house, but a sealed iron can, you can introduce carbon dioxide gas into the iron can and continuously pressurize and cool it down to make it solidify into dry ice."

"Similarly, the air around us can also be condensed into liquid using this method."

At this point, Lu Jincai scanned everyone and said seriously, "Of the several ideas and uses of changes of state that you just proposed, artificial refrigeration is the most practical and the easiest to implement at present."

"From the perspective of ordinary life, artificial refrigeration can make ice in the summer, producing more and cheaper ice blocks, so that there is no need to dig ice cellars in winter to store ice as in the past. Using ice blocks to cool off in the summer will no longer be a luxury enjoyed only by the rich and powerful. Ordinary people can also enjoy it, allowing them to buy ice blocks for very little money."

"Ice can even be used to keep food fresh, preventing meat and vegetables from spoiling and rotting too quickly in the summer. It has many uses and is very convenient for people."

"From the perspective of military and national affairs, the most important thing for a country is to ensure that the country has enough soldiers and food. So what does artificial refrigeration have to do with having enough soldiers and food?"

"Let me give you an example. Take firearms, for instance. The reason why our Holy Martial Army is invincible is because of firearms. And the most important thing about firearms is gunpowder, which is composed of three substances: saltpeter, sulfur, and charcoal. Among these, saltpeter is the most difficult to obtain."

“Natural saltpeter is scarce in nature and is often found in deep pits and caves, making collection inconvenient. Therefore, we now use the saltpeter field collection method, which involves collecting excrement from people’s homes and extracting saltpeter from it.”

"The common people also need this manure for composting, but now that we have taken it away, they can no longer compost. Without fertilizer, the yield per mu of grain in the fields will inevitably decrease."

"In other words, every shell fired by the Holy Martial Army soldiers on the front lines is not made with gunpowder, but with the people, the grain from your parents' fields! Every shell fired by the soldiers means our parents will have one less bite of food, and our brothers and sisters will have one more meal of hunger."

"Is there a way to have the best of both worlds, so that the court has an inexhaustible supply of saltpeter to support its army, and the people have an inexhaustible supply of fertilizer to increase grain production and ensure that the people have enough to eat?"

Upon hearing this, all the students present, as well as Song Lian and others listening in the back row, frowned and pondered. They hadn't understood how to collect saltpeter before, but now, after hearing Lu Jin's explanation—that every shell fired was like food for their parents—the analogy became very vivid, and they realized the seriousness of the problem.

Seeing that everyone was frowning in confusion, Lu Jin continued to guide them, saying, "Those who have read chemistry books beforehand should know that all substances in this world, whether gas, liquid, or solid, do not come out of thin air. Objects do not arise out of thin air; they can only be exchanged and transformed into one another through equivalent exchange among all things."

"So here's the question: why do human and animal excrement contain components that can fertilize fields and produce saltpeter? Where does this stuff come from? Since we have this stuff in our bodies, it must have come from something we ingested from outside the body."

"Humans eat grains, vegetables, fruits, fish, insects, birds and beasts. Presumably, this substance must be in these foods. However, the excrement of birds and beasts such as chickens, ducks, cattle, sheep and pigs also contains this substance, which means that they also obtain it from outside the body. What do birds and beasts eat? They also eat vegetables and grains, or grass and trees. That means that this substance originates from grass and trees."

“Plants need fertilizer to grow. If you fertilize the fields, grain production will increase and plants will grow more vigorously. If you don’t fertilize the fields, the land will become more and more barren and grain production will decrease. This shows that this substance is not in the soil.”

"But plants don't eat, they don't have legs, and they don't run around. So where does this substance in plants that can be used as fertilizer and to make saltpeter come from? Who could have imagined it?"

At this moment, Song Lian actually raised his hand. Lu Jin glanced at him before saying, "Mr. Jinglian, please speak."

Song Lian immediately stood up and asked, "Since it didn't come from the soil, could it have come from the water? After all, plants will wither and die without water."

Lu Jin nodded and asked in return, "Then, sir, can you extract saltpeter from water by boiling it? Can you fertilize the fields by pouring water on them?"

“That can’t be.” Song Lian was taken aback upon hearing this, and immediately realized that he had guessed wrong.

“Then it’s obvious. This substance doesn’t originate from water, so where could it come from? Who can answer that?” Lu Jin asked Song Lian to sit down and then asked everyone else.

At this moment, Fang Lanyue, a disciple from the ironworks, immediately raised her hand.

"Fang Lanyue, you speak."

Fang Lanyue immediately stood up and said, "Plants don't grow legs and run around, nor do they eat. The nutrients they need all come from the soil and water, but fertilizer and saltpeter are not in the soil and water. So, the only things that plants can come into contact with, besides soil and water, are the air that is everywhere around us."

"Moreover, the teacher mentioned earlier when talking about artificial refrigeration that air needs to be frozen into a liquid, so this substance must be something found in the air!"

"That's right, an excellent answer. It's the air that's everywhere around us! Please have a seat."

Seeing the shocked expressions on everyone's faces, Lu Jin spoke again.

"I've said it many times before: air is a tangible thing. From birth to death, people need to breathe every moment. If their mouth and nose are covered, their throat is choked, or they are drowning and cannot breathe, they will suffocate and die. This shows that air contains the components we depend on for survival."

"The same goes for animals. Livestock such as pigs, cattle, sheep, and horses, just like humans, if you cut open their bodies, you will find lungs used for breathing. Fish also breathe in the water. The organs for fish to breathe are gills. The organs for birds such as chickens and ducks to breathe are air sacs. Plants also breathe air. What are the organs for plants to breathe? Hmm? They are leaves."

Lu Jin then wrote a few more lines on the blackboard.

"It is known that there is waste gas in the air that we exhale, called carbon dioxide, and another component that sustains all life. What is it called? I won't tell you yet."

"Besides that, there is another ingredient that can be used to fertilize fields and also to make saltpeter. What is it called? We'll talk about it next time."

"So now we know that there are at least these three components in the air. In that case, can we extract and condense them from the air?"
"The air around us is everywhere, just like the seawater in the ocean, inexhaustible. Since we can boil the sea to boil salt and extract an inexhaustible supply of salt, can we extract fertilizer and saltpeter from the air to increase grain production, provide the army with an inexhaustible supply of gunpowder, and ensure that the court has enough soldiers and food? Of course we can!"

"So what are the different components in the air? What are they called, what are their functions, how do we extract them, and what can we do with them after extraction? We'll talk about that in our chemistry class this afternoon."

"Meng Zhifang will teach you math and geometry during the last two periods this morning. Chemistry class will be in the afternoon, so don't forget to bring your chemistry book."

"get out of class is over!"

"stand up."

"Goodbye, teacher!" Class monitor Tao Guangyi immediately shouted.

"Goodbye, classmates." Lu Jin then packed up his things and said to Fang Lanyue, "Fang Lanyue, the chemistry class representative, come to the Prince's Mansion to find me after school at noon to prepare teaching materials for the chemistry class."

"Yes."

As soon as Lu Jin left the classroom, the students burst into a noisy commotion. "Your Highness, this teacher is so unfair! He even tried to build up suspense like a storyteller, running off right at the crucial part about separating air! It's infuriating!"
Zhu Sheng, Song Lian, Zhan Tong, and others hurriedly caught up with Lu Jin. Song Lian even pressed on, asking, "Your Highness, can we really extract fertilizer and saltpeter from the air?"

"Of course, but it's very difficult. It requires artificial refrigeration, and not just ordinary refrigeration, but deep refrigeration. To put it this way, you all think that the northern desert is bitterly cold, but the coldest winter temperature in the northern desert is no more than minus forty or fifty degrees Celsius. It's not an exaggeration to say that water freezes instantly. But even in such a cold environment, the air is still a gas, which means that liquid air does not exist in nature."

"To condense and liquefy air, an ultra-low temperature of at least minus two hundred degrees Celsius is required, which can only be achieved through artificial refrigeration."

Zhu Sheng then asked in confusion, "But there are no such cold environments in nature. Can humans do it?"

Lu Jin countered, “Apart from the inside of a volcano, there are very few high temperatures in nature that can melt iron ore. Can’t a man-made iron smelting furnace just as easily turn iron ore into molten iron?”

"Gongshu's science is to learn the principles of the operation of heaven and earth, that is, the true principles of heaven, and then master and utilize them. By borrowing the power of heaven and earth and exercising the abilities of ghosts and gods, one can reverse yin and yang, hot and cold, and turn the height of summer into the depths of winter. This is science!"

Zhu Sheng and Song Lian stared blankly at Lu Jin's retreating figure upon hearing this. At this moment, they finally understood what it meant to 'use the power of heaven and earth to perform the abilities of ghosts and gods'.

Zhan Tong and the youngest member of the group, Luo Guanzhong, not only learned a great deal from Lu Jin's physics lesson and understood the causes of rain and snow, but also experienced the charm of science and became somewhat of a fan of science.

Seeing that Lu Jin had already walked away with the guards, Luo Guanzhong hurriedly chased after him and asked, "Your Highness, how can we artificially create ultra-low temperatures?"

"Didn't we all learn that evaporation absorbs heat and condensation releases heat, and this cycle can cool down an object?"

"But how can this be done?" Luo Guanzhong was still very puzzled.

"Think for yourself. If I tell you everything directly, what's the point of having a brain? Also, why are you asking this question? Weren't you going to observe the class and prepare to help compile the teaching materials? Meng Zhifang's math class is about to start. Aren't you going to listen to the class?"

"..." Luo Guanzhong looked at Lu Jin's back and was immediately annoyed. Why did he think of asking his teacher to recommend him for an official position as a Hanlin compiler? He should have directly become His Highness's student to study science!
(End of this chapter)