As the sun sets, Nicholas II leaves Jesse Mack's farm with a "biu" from Charles, and emerges in a garden surrounded on all sides by buildings with green walls, white pillars, and green roofs.

The garden was planted with many plants that Charles had never seen before, and the wind carried the moisture in the wind.

The guards of the enemy, as if facing the enemy, were relieved of the battle after confirming that it was Nicholas II, but their eyes fell on Charles.

When Charles had followed Nicholas II out of the garden, a young guard whispered to the man next to him, "Captain, could that child be Your Majesty's ......?"

"Don't talk too much, how can you talk nonsense about your majesty's family affairs?" his captain stopped him from what he was about to say, "there are some things that you just need to know." ”

Nicholas II led Charles into the buildings around the garden, where Charles realized that it was a palatial-looking palace.

Crystal lamps are lit on both sides of the corridor, oil paintings protected by gold frames hang on the white walls, and the white ceiling is delicately painted with gold lacquer.

A silver-haired and red-faced human maid dressed in a maid's costume was already waiting there, and when she saw Nicholas II coming, she bowed, "Welcome Your Highness back to the palace." ”

Nicholas II said to her: "Prepare me a dinner, bring it to my office, and prepare him a drink, he has eaten dinner." ”

Then he continued to point to Charles and said, "Then prepare a room and two sets of clothes for him." ”

After the maid had retired, Nicholas II said to Charles, "She is the head maid here, and if you need anything, speak to her." ”

Charles nodded.

The corridor was not long, and at the end was a large door decorated with gold.

When Nicholas II led Charles to the gate, two guards on both sides of the gate pushed open the door.

Behind the door is a magnificent hall with an area of thousands of square meters. The floor of the main hall is paved with dark smooth marble, and in addition to the various patterns, it seems to be a map in the center. The walls and ceilings around it are decorated in bright red with gold patterns, and the frames of the huge glass windows on both sides are also made of gold. Directly opposite the gate is a high platform about one meter high, on which is placed a rough stone chair carved out of rock, without any decoration, and the coat of arms of a double-headed eagle is carved on the back of the chair. On the wall behind the stone chair is a huge double-headed eagle coat of arms made of gold.

"This is the Catherine Hall," Nicholas II told Charles, "where ceremonies are held in the Winter Palace." Every year between the autumn equinox and the spring equinox of the following year, we would move here from across the river. ”

He then pointed to the stone benches in the ornate palace that were rougher than the stone benches in the park, and said, "Before the establishment of our Rurik Empire, our ancestors sat on a stone on the top of a hill on the other side of the river and ruled the land. When Fyodor became the first king of Rurik, he built the stone into what is now the Double-headed Eagle's Seat. From then on, it was the throne of every emperor. When I moved here, it came along. ”

Upon approaching, Charles scrutinized the rough "dragon chair".

"Would you like to sit on it and try it?" asked Charles with a smile.

Charles shook his head desperately, this is a real guy, and it is not a copycat dragon chair in the scenic spot, and each person sits for fifty yuan to take a picture.

There are doors in the two sections of the main hall that lead to the rear, and Nicholas II led Charles into one of them, and behind both doors there was a corridor.

"The place where we were just now was the work area. Nicholas II continued to work as a guide for Charles, "and after passing through this corridor, there is the living quarters of the Hermitage." ”

Finally, Charles was led by Nicholas II to a spacious office. The walls on both sides of the office were filled with bookshelves, and near the doorway were four sofas in a circle, with a coffee table in the middle and a desk in the back, and a map on the wall behind it, with many labels on the map that read records.

Nicholas II asked Charles to go to the sofa to rest first, and after reading the books on the shelves, he sat down behind the desk himself.

Then the chief maid came in with a cart, and while the chief maid gave him a drink, he saw that Nicholas II's dinner in the cart consisted of a cutlet, a bowl of vegetable soup, and a few slices of white bread.

The books on the office shelves are philosophical and technical, and almost every book has a note written by Nicholas II.

In a book called "Slime Breeding Techniques" by a dragon named Virdra, on the page describing the types of feed used in slimes, Nicholas II wrote on a note "Considering the possibility of using it in sewage treatment".

Charles smiled slightly, and then beckoned the head maid, who was waiting for Nicholas II to eat—in fact, waiting for him to finish eating and putting away the dishes—and asked her to bring him a pen and paper.

Then Charles wrote and drew on the paper.

When Nicholas II had finished his dinner, he came to Charles's side and watched curiously at what the nephew was writing.

The sewage in this world is basically domestic sewage, coupled with the low population density, generally speaking, it is directly discharged into the natural water body, and there is no need for sewage treatment.

However, in densely populated places such as Avalon City, Forge Holy Land, and Corn City, a large amount of domestic sewage will still cause a small area of environmental pollution.

Charles' pharmaceutical workshop is even more polluting, and it is said that they almost got into a fight with their neighbors downstream of the creek that runs through the territory a long time ago. Therefore, their home has lit up the technology tree of sewage treatment.

▦→▩→⍌→⌨→⊍→≋

After Charles drew a set of slime wastewater treatment process flow diagrams, Nicholas II asked him to explain.

Charles then pointed to the "▦" and "▩" and explained to Nicholas II: "These are coarse and fine screens, which are used to filter large pieces of debris in the sewage. ”

( ̄ᐦ ̄)☞⍌: "This is a primary sedimentation tank that allows the sediment in the sewage to settle down. ”

( ̄ᐦ ̄): ☞⌨ "This is the aeration tank, where the slimes live, and they will eat the dirt in the sewage." Because the density of slimes in the water is too high, it is necessary to install a device to supplement the air at the bottom of the pool. ”

This kind of device that bubbles out of a goldfish bowl to oxygenate the water was the most important thing in the sewage treatment system, and the problem of those aquatic slimes dying from lack of oxygen caused by the excessive density of those aquatic slimes has plagued Charles's ancestors for many years. In the end, they used a water wheel to drive the bellows and coated a bamboo tube sealed with slime glue as a ventilation pipe.

( ̄ᐦ ̄)☞⊍: "This is a secondary sedimentation tank, where the sludge can be precipitated, and then the clean water on the top is drained away, and the sludge at the bottom is a good fertilizer. ”

After listening to Charles's explanation, Nicholas II asked some questions about the data, but Charles didn't know the situation of the aquatic slime here, so he could only let Nicholas II organize professionals to slowly experiment.

In the end, Nicholas II took the blueprint and said that he would let the experts evaluate and experiment as soon as possible, and if he could, put it into construction as soon as possible.

Unbeknownst to Charles, Nicholas II later named the first sewage treatment plant in Abyss City "Royal Charles Sewage Treatment Plant I" in honor of Charles' contributions, almost killing Diana who got the news.

Later, this "Charles sewage treatment process" began to be promoted. In the field of sewage treatment, Charles's name has been passed down with sewage.