After ten years of accompanying me in my studies, the entire court begged me to shut up.

When Yang Shen stepped into the Left Spring Palace again, Zhu Houzhao had been waiting for a long time.

"Yang, Master Wang still needs some time to recover. You can tell me why the latrine could explode?"

"Does Your Highness really want to learn?"

"Yes! I really want to!"

"Oh well!"

Yang Shen nodded, it seemed that he was destined to do something for the Ming Dynasty.

"First, we need to introduce a concept: what exactly is a thing?"

"Your Highness lives amidst all that is visible and invisible, tangible and intangible—all things, or matter. Behind matter lies a profound principle, called physics, which is the Tao that Lao Tzu pursued throughout his life!"

The Mo Jing states, "Duan is the first among the disordered forms!"

"This end is the smallest indivisible unit that makes up an object, also known as an atom."

"To truly grasp the Tao, one must begin with the atom..."

Yang Shen began to impart basic scientific knowledge to Zhu Houzhao. Zhu Houzhao listened very attentively. When some parts were too obscure and difficult to understand, Yang Shen would stop and wait patiently.

Surprisingly, Zhu Houzhao learned very quickly!

Yang Shen originally thought that the ancients had no foundation and found it quite difficult to learn scientific theories.

However, the reality was quite the opposite. Three days later, Zhu Houzhao had already mastered the basic chemical formulas.

You should know that chemical formulas use English letters and numbers, which are no less difficult for educated people in this era to understand than scribbles.

Zhu Houzhao learned it without any difficulty, and even mastered balancing in just half a day!

Holding a formula in his hand, he said thoughtfully, "So, biogas is the organic gas produced by the fermentation and decomposition of feces?"

Yang Shen nodded upon hearing this and said, "That's why I said that marsh gas can only be burned, not used as a weapon."

"That's a real shame..."

Zhu Houzhao sighed, then suddenly said, "Since it can burn, it can be used as fuel!"

Yang Shen replied, "Theoretically speaking, it is feasible. However, it would require building a biogas digester for fermentation, and the manufacturing process for the pipes and valves would be very complex, especially in terms of the high requirements for materials. With the current level of materials, it would be difficult to achieve that."

Zhu Houzhao thought for a moment and then asked, "Yang, what is that rubber you just mentioned?"

Yang Shen explained, "Rubber comes from rubber trees in Southeast Asia and has strong elasticity, resulting in good sealing properties. For gas transmission like biogas, the most important factor is sealing."

Zhu Houzhao suddenly asked, "Could leather be used instead?"

Upon hearing this, Yang Shen's eyes lit up, as if he found it to be very reasonable!

Zhu Houzhao is quite something; he actually thought of using leather instead of rubber!

With the sealing problem solved, everything else becomes easier. The valve material can be tested, and the manufacturing process is even easier to handle. The Ming Dynasty has no shortage of skilled craftsmen, and without considering mass production, it can be completely handcrafted.

But why insist on focusing on biogas? Why not use that time and energy for something else?

"Your Highness's suggestion is excellent, but I feel it's unnecessary for the time being."

"Oh? Why?"

"Methane... isn't that important right now. If Your Highness is interested, I will talk about how to improve firearms, the application of steam engines, and many other more important theories."

Zhu Houzhao nodded, but there was still a hint of resentment in his eyes.

Yang Shen keenly noticed this, and with a thought, asked, "What does Your Highness intend to do?"

Zhu Houzhao immediately became interested and said, "I'd like to rebuild the latrines and then pipe them to the kitchen to use biogas for cooking. I wonder if that's feasible?"

Yang Shen smiled and said, "The theory is feasible, but in practice, we will definitely encounter many problems, and it may even end in failure. Is Your Highness prepared?"

Zhu Houzhao nodded repeatedly and said, "A wise man acts first, and his words are followed by others! I'll build the biogas digester first, and then I'll amaze Father!"

Yang Shen nodded in agreement. Although biogas digesters were not particularly technologically advanced, what was important to Zhu Houzhao was enlightenment. He wanted him to accomplish something first, build confidence, and lay the foundation for the future technological innovation of the Ming Dynasty.

Without further ado, the two began designing the blueprints for the biogas digester, discussing as they drew.

The funds for the renovation of the latrine in the East Palace have been approved, and the bricks and sand have been arriving in the past few days.

Liu Jin took the blueprints to the official in charge of the Ministry of Works to discuss the matter, but was unexpectedly rejected.

Zhu Houzhao said displeasedly, "Didn't you tell him that I drew the blueprints?"

Liu Jin replied with a wronged expression, "I did tell them! But that young official is stubborn and said that the renovation of the latrines was a set of regulations set by the Ministry of Works and the Ministry of Revenue. If it needs to be changed, it needs to be approved by his superiors. He can't make the decision."

"This is outrageous!"

Zhu Houzhao snatched the blueprints and was about to leave.

Yang Shen quickly stopped him and asked, "What is Your Highness going to do?"

Zhu Houzhao said, "Of course we're going to demand an explanation. Why is it that my words have no effect on matters concerning the Crown Prince?"

Yang Shen said, "Your Highness, please calm down. Let me go instead!"

"That's fine then, Liu Jin, you'll go with Yang, the study companion!"

"yes!"

Liu Jin, whose injuries had not yet fully healed, limped as he led Yang Shen to the Ministry of Works.

Just as he reached the main gate, a young official walked towards him, and Liu Jin quickly said, "That's him!"

Yang Shen clasped his hands in greeting and said, "I am Yang Shen, the tutor of the Crown Prince. I have come on His Highness's orders to discuss the reconstruction of the latrines in the Eastern Palace!"

The other party returned the greeting with clasped hands and said, "Wang Shouren, a Jinshi (successful candidate in the highest imperial examination) from the Ministry of Works' Construction Department!"

Yang Shen couldn't help but feel a tightness in his chrysanthemum; this person was none other than the famous Wang Shouren!

Before he could speak, Liu Jin said sarcastically, "Wang Guanzheng, revising the blueprints is His Highness the Crown Prince's decision. If you have any doubts, Yang, the attendant, will explain it to you. If you continue to insist, can you bear the consequences if His Highness the Crown Prince blames you?"

Wang Shouren frowned and said, "I have already explained; I cannot make this decision!"

"Who gave you the authority to make that decision? You just need to follow His Highness's orders!"

"That won't do. The funds are allocated by the Ministry of Revenue, but the materials required for this blueprint have doubled. Where will the money come from? It also requires a large number of precision parts. Where am I supposed to find them for you?"

"I don't care, it's His Highness the Crown Prince's decision anyway!"

Wang Shouren no longer wanted to argue with him, so he shook his head and turned to leave.

Yang Shen stepped forward and said, "Wang Guanzheng, please wait!"

Wang Shouren stopped and said with difficulty, "I am just a junior official who has passed the imperial examinations, without even a formal official position. It just so happens that the job of repairing the latrines fell to me because no one else was available. Why are you two making things difficult for me?"

Yang Shen explained, "His Highness the Crown Prince's modification of the blueprints was not intended to cause trouble, but rather he had more important considerations."

"Very well, then tell me, why build such a large latrine? And why pave it with blue bricks? Isn't that a complete waste? Not to mention laying pipes to the kitchen—what's the point of that? Forgive me, but I truly cannot understand how the latrine and the outhouse are connected."

Liu Jin grew angrier as he listened, and was about to step forward to reprimand him when Yang Shen stopped him.

"Wang Guanzheng, may I explain?"

Wang Shouren nodded and said, "I would like to hear the details!"

Yang Shen squatted down, spread the blueprints on the ground, and then gave a brief explanation of the design concept for the biogas digester.

Wang Shouren listened patiently, his expression gradually becoming serious.

For the average person, this might be hard to understand.

But Wang Shouren was no ordinary person!