Drive to the Tang Dynasty, where supplies are refreshed daily!

This time, Yu Yu opened her mouth and grabbed it, then slowly began to eat it.

As long as it's edible, it's not a big deal.

Afterwards, Xiao Ran asked Sun Simiao to take a look and received an affirmative answer, which put his mind at ease.

The little princess was overjoyed and hugged Yu Yu tightly, exclaiming, "That's great! What's wrong?"

Yu Yu had no idea what was happening and was still chewing away. The way it looked was just like the little princess, who was half asleep but still couldn't stop eating.

Xiao Ran pulled the little princess up and said, "Let's go back first and let Yu Yu rest. Only by resting well can Yu Yu grow up properly."

The little princess nodded, "Okay~"

So Xiao Ran led the little ones back to the living room.

After returning home, the little ones were restless and wanted to see Little Swallow.

The swallow's injuries have almost healed, and the splints on its wings have been removed.

The big swallow probably noticed that the little swallow's injuries had almost healed, so it would come over from time to time these past few days and perch on the windowsill, instead of waiting for Xiao Ran and the others to take the little swallow out as before.

When Xiao Ran brought the little ones to his room to see Xiao Yanzi, he found that Da Yanzi was also there, perched next to the box containing Xiao Yanzi.

Xiao Ran looked out the window and smiled.

"This swallow is quite clever."

His room window opens inwards and outwards. Although it wasn't locked, it's quite impressive that this big swallow could open the window from the outside.

"Big Swallow~" The little princess walked towards the big swallow.

The adult swallow was feeding the baby swallows and didn't move when it noticed Xiao Ran and the others coming. It wasn't until the little princess came over that the adult swallow chirped twice, but it didn't fly away and stayed by the baby swallows' side.

The little princess reached out and touched the big swallow.

The swallow gently touched the little princess's hand with its beak.

"Hehe~ Little Nangjun~ Big Yanji is here~"

Xiao Ran nodded with a smile, "I saw it, it came to see Little Swallow."

After saying that, Xiao Ran stepped forward and said, "Little Swallow is almost fully recovered now. Since Big Swallow has returned today, let's put Little Swallow back."

Xiao Ran kept telling them that Little Swallow couldn't leave her flock, which made them realize that Little Swallow would leave sooner or later, so they were given a heads-up.

Now that they know they have to send Little Swallow back, the little ones are reluctant, but not too sad.

"Alright then~" The little princess lowered her head and reached out to touch the big swallow.

"Big Yanji~ You have to be good to Little Yanji~"

The other little ones also gathered around, reluctantly touching Little Swallow.

Watching them reluctantly say goodbye to Xiao Yanzi, Xiao Ran picked up the box containing Xiao Yanzi and went outside.

The swallow seemed to sense something and quickly flew back to its nest, chirping and gesturing towards the outside.

Xiao Ran had someone bring a ladder, then, with one hand protecting the little swallow, he climbed up to the swallow's nest and carefully placed the little swallow inside.

Inside the swallow's nest, two large swallows were both there, staring intently at Xiao Ran's movements without moving.

After Xiao Ran put Xiao Yanzi inside, he climbed down the ladder.

After Xiao Ran landed, he could still hear the chirping of swallows from the nest, which sounded very cheerful.

The little princess looked up at Xiao Ran, "Little Yan's home!"

Xiao Ran nodded. "Yes, it went home."

A short while later, two large swallows flew out; they still had to support their family.

The grocery store came to pick up the goods once in the past few days, and Li Shimin also sent Cheng Yaojin to remove the glass yesterday. Xiao Ran has been spending the last two days either playing with the little princess or going fishing.

The mahjong set has already been made by craftsman Liu. Li Lizhi, Princess Yuzhang, Zhang Erya, and Zhang Jinhe are currently playing mahjong at home, while the little princesses are playing around. Xiao Ran simply took his fishing rod and went fishing.

A short while later, a large fish broke out of the water.

"Let's have braised fish for lunch today," Xiao Ran said.

"Little Nangjun, Little Nangjun~" the little princess's cheerful voice rang out.

Xiao Ran smiled and looked behind him, "Sizi, what's wrong?"

The little princess carried a stone over as if it were a precious treasure.

"Little Nangjun, come and see! Look really good!"

Xiao Ran took a look and realized it was just an ordinary pebble, but its bluish color made it quite beautiful.

"Where did you find this?" Xiao Ran asked.

Xiao Ran was afraid that they would go to the water's edge when the servants weren't looking.

The little princess said with a grin, "It's right here!"

She pointed towards Princess Chengyang and the others.

Xiao Ran was relieved, then instructed, "That's good. Si Zi mustn't go near the water, understand?"

The little princess nodded obediently. Xiao Ran had said this many times before, and the little princess knew it was because he was afraid she would fall into the water.

Xiao Ran saw that Princess Chengyang and the others had formed a small circle and were doing something, so he walked over.

"What are you doing?" Xiao Ran asked.

The little ones looked up, and Princess Gaoyang said, "We're picking up stones. There are so many pretty stones here."

Children always like strange and unusual things, especially girls, who love pretty things, no matter what they are, even if it's just a stone. So Xiao Ran didn't mind and just said, "Remember to wash your hands after you pick up the stone, okay?"

The little ones nodded obediently and then began picking out their favorite stones from the pile.

These stones were all found around here, and then put together for everyone to choose from.

Xiao Ran didn't take it seriously at first, until he saw a stone that looked somewhat familiar.

"Where did you pick up this stone?" Xiao Ran asked, picking up a bluish-gray stone.

Di Renjie pointed to a small mound not far away.

“There.” Xiao Ran walked over there and indeed there were two more identical stones.

The stone's surface wasn't smooth, with some fine lines. When the sunlight shone on it, it gleamed faintly. He bent down and picked it up; it felt heavy in his hand and had a firm texture.

Xiao Ran stroked the surface of the stone, and suddenly his eyes lit up. The stone looked exactly like limestone!
Actually, there's nothing special about limestone, but looking at it, Xiao Ran suddenly remembered something that all the transmigrators knew how to make: cement.

He had hand-rubbed the kang (a heated brick bed) before, but he did very little back then. Now that he remembered it, Xiao Ran planned to make a large-scale batch.

Thinking of this, Xiao Ran stood up, let the little ones play by themselves, and then went to the glass workshop to find Cheng Chumo and the others.

Xiao Ran knew how cement was made, but the amount made would vary, and the temperature and other factors would definitely need to be tested.

If Xiao Ran were to do it himself, wouldn't he be exhausted? So Xiao Ran's first thought was to ask Cheng Chumo and the others.

"Old Mo, Old Qin, Sanlang, look what good stuff I found!" Xiao Ran laughed as he walked in.

The three people were looking at the glass furnace when they heard this and came over.

Cheng Chumo was the first to ask, "Young master, what good stuff do you have this time?"

After seeing clearly what Xiao Ran was holding, Cheng Chumo exclaimed in surprise, "A stone?"

Xiao Ran smiled, "This isn't ordinary stone. Remember the cement I made when I was building the kang (heated brick bed)? This is the raw material!"

Qin Qiong and the others knew that Xiao Ran had used cement to make the kang (heated brick bed), but Qin Huaidao had only heard of it and had never seen it.

Xiao Ran didn't beat around the bush. He pulled the three of them to a place to sit down and said, "Cement has a lot of uses. I used it to make a kang (a heated brick bed). But after mixing cement with water, it can be shaped like mud. Once it dries, it's much stronger than stone."

Fearing they might not understand, Xiao Ran added, "Take our gunpowder for example. If we were to use it to blast cement, it definitely wouldn't break. Even if it could, it wouldn't be so easy, and we'd need to use a much larger quantity."

Once Xiao Ran said that, they immediately understood.

"This cement is really that amazing?!"

They had only heard their family members mention it before; Xiao Ran said that cement was strong, but they really had no idea how strong it was.

Xiao Ran nodded. "Yes, once the city wall is cast with this cement, it will be extremely strong. Moreover, this cement can also be used to pave roads. Roads paved with cement are flat and smooth, and they won't become muddy after rain. Carriages and horses can travel on them quickly and steadily."

“We can also build bridges. Most of our current bridges are wooden or stone bridges. Wooden bridges are afraid of fire and water, and stone bridges are difficult to build. If we use cement to build bridges, they will be sturdy and durable, and we can build them bigger and wider.”

None of them were fools; they all understood what the cement represented. Their eyes lit up immediately, and Li Ke even said, "Young master, how do you make this cement? Just tell me."

Xiao Ran didn't stand on ceremony; he had asked them for help in the first place.

"Besides limestone, cement also requires clay and iron ore powder. Except for iron ore powder, the raw materials are all common and easy to find. Moreover, cement is not too difficult to make."

"First, crush the raw materials such as limestone and clay, then mix them evenly in proportion, put them into a kiln and calcine them. After they reach a certain temperature, take them out and grind them into a fine powder with an appropriate amount of gypsum. This is cement. After mixing it with water, it can be used," Xiao Ran said.

"Put it in the kiln and fire it?"

Cheng Chumo's eyes lit up, and he pointed to the kiln next to him, "We have a kiln right here! Perfect for making cement!"

Xiao Ran nodded, "Yes, but we need to collect all the materials first."

Cheng Chumo immediately patted his chest and said, "What's so difficult about that? Leave it to me!"

After saying that, Cheng Chumo was about to leave when Li Ke quickly stopped him.

"Wait, don't rush! This isn't as simple as it seems."

Then Li Ke said, "Limestone is easy to obtain, it just costs some money, but iron powder is difficult to collect. Besides, shouldn't we inform His Majesty about this matter first?"

Xiao Ran thought about it and nodded, "That makes sense, we should indeed tell Uncle."

The four of them set off immediately, quickly packed up, and headed towards the palace with the limestone.

At this moment, Li Shimin was processing memorials. Upon hearing that Xiao Ran and his three companions were requesting an audience, he put down his vermilion brush and, smiling, ordered, "Summon them in."

Xiao Ran greeted Li Shimin with a smile: "Uncle."

The other three also quickly bowed.

Li Shimin was somewhat surprised to see Xiao Ran and the others arrive. "Why did you all come together?"

Xiao Ran stepped forward and handed the limestone in his hand to Li Shimin: "Uncle, do you still remember the cement I made when I was building the kang (a heated brick bed)?"

Li Shimin nodded. "I remember you said back then that this cement was extremely strong."

As he spoke, Li Shimin picked up the limestone, examined it carefully, weighed it in his hand, and asked in confusion, "Then cement is made from this bluestone?"

Xiao Ran nodded and explained, "That's right, but it's not entirely accurate either."

"To be precise, cement is made by calcining and grinding limestone, also known as bluestone, and clay, iron powder and other raw materials. After being mixed with water, it can be shaped and becomes extremely strong after drying."

In fact, Li Shimin was already interested when he heard Xiao Ran say that cement was strong, but he was too busy at the time and simply ignored it.

It would be best if Xiao Ran decided to do it himself now; he hadn't forgotten what Xiao Ran had said about building a swimming pool with cement.

If you can build a swimming pool there, then you can definitely use it to reinforce the dam!

Spring has arrived, and when the rainy season comes in the south, there will likely be flooding again. Although it hasn't happened yet, Li Shimin is already worried about it. The cement issue has come at just the right time.

Li Shimin then stepped forward, patted Xiao Ran on the shoulder, and said, "This cement will be very useful! Just tell me what you need!"

Xiao Ran smiled and said, "With your words, things will be much easier. Limestone is not uncommon. We can have the Ministry of Works go to the countryside to buy it. The more the better. Clay is also very common. We just need to find the kind that is fine and free of impurities. As for iron powder, we don't need too much. It's mainly used to adjust the properties of the cement."

After saying that, Xiao Ran looked at Li Shimin and said frankly, "It would be too slow for us to collect these things ourselves, so we will trouble Uncle Shimin with the task of collecting materials."

Li Shimin waved his hand, "This is all for the sake of the Tang Dynasty! I am the emperor, how can I talk about trouble?"

Xiao Ran and the others came here so that Li Shimin could find someone to collect materials and also to inform him of this matter. Now that the matter was settled, the group rushed back without even having lunch.

Xiao Ran and his three companions were completely oblivious to their hunger, their minds and eyes solely focused on making cement.

They don't have enough materials for large-scale production right now, but they can take a small amount of each item and make a batch first.

So on their way back, they also brought back a batch of raw materials.

Upon arriving at the glass workshop, the four of them got out of the car and had their belongings moved inside. Then, a furnace was set aside to be used for making cement.

Returning to where they had started, Xiao Ran said, "Besides the raw materials, the firing temperature is also crucial. The glass kiln should be able to reach the required temperature, which is around 1,400 degrees Celsius."

"When firing, you have to keep a close eye on the kiln fire. The temperature can't be too high or too low, otherwise the clinker won't be up to standard. After the clinker is fired, take it out and let it cool. Then add a small amount of gypsum and grind it into a fine powder. That's how you make cement."

Cheng Chumo scratched his head, "Fourteen hundred degrees?" (End of Chapter)