After a few days, everything came naturally.

After all, Li Su is also a young man who is about to be 18 years old. How can he bear it when watching others show their love and show their love every day? How can he bear it?

After all, I have been developing a relationship with Cai Yan for more than two years. Even if I don’t talk about those aspects, the tacit understanding between the seniors and sisters is still very deep. I feel that I don’t need to look for it specifically when I write books and recite poems, playing the piano and playing the flute together.

On the fourth day after Zhang Fei's wedding, two days after Cai Yan's relatives left every month. On October 22, Li Su calculated that the day was very safe and was preparing to give her junior sister a surprise.

That night, he had dinner with Cai Yan in advance in a tacit way.

Because Cai Yong could not go to Ba County for the time being, he recently wanted to rebuild a temporary "Dongguan" or "Lantai" in Nanzheng, and re-categorize the books collected from Luoyang for people to learn and borrow.

Liu Bei also supported this cause very much. Not only did he ask for houses to be allocated, but he also specially found high and dry places outside the city to create some new libraries with more thorough dehumidification.

He also sent Zhuge Jin, who was originally a teacher with Li Su, as well as Zhuge Liang, Mi Wei and other school-age children from the civil and military families in Liu Bei's camp to do odd jobs and played guest librarians to help organize the display.

Therefore, Cai Yong was very busy these days and was not in Li Su's marquis's mansion at night and had to go back late at night. His daughter stayed with her prospective son-in-law for a while.

After eating a stew pot with mutton, dog, venison, and leeks, he asked the maid to clean up. Li Su took a break for a while and drank a cup of tea to digest the food. It was probably half an hour after the meal that he quietly pulled Cai Yan and showed her a good thing he had just made in the past ten days.

"Junior sister, do you know what I plan to use for the newly built cabin in the backyard?" Li Su induced the curiosity of her junior sister.

Cai Yan was indeed curious: "What are you doing? Ten days ago, I saw you found a lot of carpenters to work hard and fenced them up. But the wood is all good wood, including mahogany, sandalwood, and some of them I don't know. You just use good wood to build a small house without using bricks and stones, which is also luxurious enough."

In fact, in this new wooden house in the backyard, Li Su also used oak trees and a small part of camphor wood. His standard for choosing wood is just a few points:

First, it must be strong, waterproof and waterproof, preferably wood that can be built for ships and does not rot all year round. Secondly, it must be prevented from insects and mold, and it cannot be moldy if it is heavy in the long run. Finally, it is best to have a clear fragrance, such as camphor, which can both prevent insects and cover the smell.

After the house is built, the construction is like the shipbuilding anti-seepage process and then the hemp is made (use hemp fibers to pound in between the gaps of the wooden boards to compact it. You can search for the wooden boat hemp process on Douyin), and finally apply tung oil.

If these tricks were placed in the era when precious woods were very valuable in later generations, the price would be high. However, in the Han Dynasty, the greening was very good, and high-end wood trees were not so scarce, so Li Su would have no problem using them to build a house.

As for the purpose of this construction, of course, it is to steam a sauna. Didn’t Liu Bei say that taking a long bath to damage his vitality and can easily damage a man’s heroism? Then let’s change to steam a sauna to reduce the length of bathing.

In fact, this is not Li Su's invention, because the Romans had invented saunas more than a hundred years ago, in the late Gongluo period and early Diluo period. However, the Romans' original sauna was not very good at burning hearthstone. They often smoked the house black, and they could easily get carbon monoxide poisoning if they were not careful.

After all, in the era when there was no electric stove heating, the most serious problem with saunas was how to heat the hearthstone in a confined space, but not poison or die of hypoxia. The ancient Romans also knew that confined fire would suffocate people, so they often stolen the fire outside the house in advance, and then transport the reddish hearthstones into the cabin of the steaming sauna.

But Li Su made a little adjustment in the Romans' technology. He built a flue and a fire-making kang under the wooden house with bricks and stones, just like the Northeastern people who burned kangs in later generations. However, corresponding to the location of the Northeastern people's kang board, Li Su asked someone to lay a large iron plate. When making a fire, he burned the fire under the iron plate. Using the metal's thermal conductivity can quickly transfer heat to the house, and the carbon dioxide burned in the fire is isolated from the outside.

At the same time, Li Su worked hard before this iron plate was built. The blacksmith's metallurgical process during the Han Dynasty was not enough to form a high temperature to burn iron into iron, and at most it would only make the iron red hot and soft. But Li Su took advantage of the iron plate when the iron plate was hot and soft, and asked the craftsmen to embed the selected hearthstone on the iron plate. In this way, after the iron plate was cooled, the stone and iron fit very closely, at least the thermal conductivity was very high.

When steaming a sauna, water the hearthstone embedded in the iron plate directly to form enough water vapor.

Marco Aurelius, the last five sage emperor of the Roman Empire who was in power in the same period as Emperor Ling of Han, had to prepare four or five days in advance to steam a sauna, and opened many stoves and burned a lot of hearthstones. In the middle, servants were required to keep transporting the cold hearthstones out and replaced them with truckloads of red-burned hearthstones. Li Su was not that troublesome, and directly burned the iron kang to heat the hearthstone.

In addition, Li Su didn't like the pure little black room of the Diluo style, so he left a vent hole similar to a chimney in a corner of the wooden house. The vent holes were also made of two U-shaped bends, and the ventilation was slightly moderate to avoid lack of oxygen. Although the heat and water vapor would be lost, Li Su was not afraid of wasting fuel money, so comfort was the most important thing.

For lighting, he also left two round glass windows on the wall. His eyes were yellow and green, not completely transparent, but at least he could light in, and he saw the scene outside in a hazy way (square flat glass cannot be made)

The price of this small window is not much different from that of making it with gems. If outsiders see it, they will definitely be dumbfounded by its expensiveness.

A bathing man should be as luxurious as a bathing man!

Marco Aurelius enjoys the enjoyment he can use, of course he also wants to go, otherwise he would have lost the power of the great man.

...

"This room is called a steam bath. The advantage is that it can relieve muscles and fatigue without soaking your body in water. Brother Xuande has always thought that my bathing method hurts my vitality. I figured it out. When I went in, I wrapped my lower body with some cold water and wet bath towels around me. I changed it frequently, so I won't hurt my vitality."

Li Su led Cai Yan into a small dark room with only two small glass windows, introducing her new inventions in detail and surprises the girl.

"This... can you even take a bath in this dry and hot environment?" Cai Yan couldn't help but be curious. Out of his unknown fear of the small dark room, he grabbed Li Su tightly and did not dare to let go.

"Of course you can rinse it a little before steaming, and you have to rinse it again to wash your sweat off after steaming, but the time you wash in water will be many times shorter than taking a bath. Come and look at the shower in this small compartment at the door."

As Li Su said, there was an independent compartment pulling her junior sister to the entrance outside, which was about the same size as the entrance hall, and the middle door was also isolated from water vapor, so there was not much steam in the shower entrance hall, and there were also breathable holes.

Li Su took a leather tube made of nitro-beef intestines and a copper shower tied to the top of the leather tube from the shelf, and the hot water immediately spilled out, which was a shower, which was very comfortable.

Li Su cannot create a tap water fence switch, so he can only use the water pressure drop type to easily control the water flow - as long as the shower is held on a shelf higher than the liquid level of the copper water tank, the water will naturally not flow out. The copper water tank is embedded in the wall, half exposed outside the wall, and next to it is a brick and stone structure, which can make fire and boil water under the copper water tank.

In order to control the water temperature, there is a cold water tank next to it. When you touch it with your hands, you feel that the burning in the hot water tank is too hot, so you use a cow intestine tube to mix water at any time to adjust the temperature.

Cai Yan looked at all this, and didn't care about her coat being soaked in the shower, and she was still standing there stupidly:

"What a clever craft... Someone in the world can come up with so many tricks for bathing. Husband, where do you use this spiritual thought in your daily life? Is it used three parts to govern the country? This steam room and this shower are something that craftsmen can never think of it for the rest of their lives."

Li Su laughed jokingly and said, "You can't stand it anymore? Well, this is a dry bath towel. Anyway, you are wet. You can change this yourself and steam it to find out the real benefits of this thing."

He was not in a hurry to peek at it. Tonight it was just showing off his new inventions, so after throwing a few sackcloth bath towels to his junior sister, he went into the steam room very gentlemanly and watered the hearthstone to form steam.

Unfortunately, I don’t have a thermometer, so I don’t know how many degrees I have steamed. I can only estimate it based on my feelings in my previous life.

"It's probably forty or fifty degrees. Forget it, the first time steaming, don't scare the little girl, just try it out in drizzle."

If you are a fan of bathing like Li Su in his previous life, it would start with steaming 60 degrees every time, and it would often steam to 80 degrees.

The air was heated to 40 degrees Celsius, and Cai Yan also changed into a bath towel and came in. Li Su went out to get in the rain and changed into a cool bath towel to prevent the high temperature from killing sperm.

"It's so warm here... I can't believe it's winter at the end of October. I sweat a lot at the beginning, and I feel sticky. I quickly get used to it. Instead, I feel refreshed. I'm a little soft and can't lift my strength... It's such a good thing."

Cai Yan insisted on steaming for fifteen minutes, then leaned softly in Li Su's arms and felt dizzy.

Even if you drill a thick quilt in the bedroom, you are not as comfortable as here. There is no fireworks to burn charcoal basin to keep warm, only a humid atmosphere.

"Senior brother, can you cool down the temperature later so that it will be more comfortable to sleep here at night?" Cai Yan said in a daze.

"Then you have to put all the steam, otherwise you will faint." Li Suxiaoyao replied.

After putting the steam in the sauna, it is like a warm kang house. For Han Dynasty people who are still accustomed to burn kangs, warm kang itself is also a very attractive invention to improve the quality of life.

Those high-ranking officials and nobles burn charcoal basins to cover quilts, but they have to be tightly tidy in the winter. Even if they do that, they are painted in the quilt and can’t see anything. There is no free environment for taking a bath.

At least Li Su doesn’t need a quilt to do those things. Who can compare with this world? Which girl doesn’t envy this surprise?

"Senior brother, I'm a little bored. You put the steam out and I'll go and wake up again." Cai Yan was afraid that he would faint, so he forced himself to hold up.

Li Su thoughtfully opened the steam chimney and knocked on the glass window, signaling the fire-burning maid outside to extinguish the fuel from the kang.

Finally, he lit a red candle with a romantic and elegant atmosphere. If it was dark, what was the difference between them boiled crane and burning qin and local buns that were stuck in the quilt and “turn off the lights”?

He and Cai Yan are both top cultural people in the world. Their poems are of course the same.
Chapter completed!