Chang'an, as long as it enters the fifth month of the lunar calendar, is basically not very suitable for human survival.

Because there was no rain, the sky was clear, the sun was white and bright, and the ground was hot.

So, the gunpowder workshop in Qujiang exploded again, this time without much damage, only one person was blinded in one eye by the sawdust that blew up after the gunpowder exploded.

Then, Liu Renliang came up with a lesson that gunpowder should not be exposed to the scorching sun.

Liu Renliang has summed up a lot of such experiences, and every one and every one of them can be called blood and tears.

From the explosion of Xianyang Bridge to now, a little more than a month has passed, but Liu Renliang's originally gray hair has all turned white.

Under the urging of Li Zhi and Li Ji, the formula of gunpowder has been basically finalized, and the next step is to purify saltpeter as much as possible.

Now that the formula has been finalized, the next step is to conduct a finalization test and a large-scale observation test.

The location was chosen in Qujiang.

The officials above the fourth rank in Beijing were invited, and Yun Chu and Wen Rou also wanted to go and see, but unfortunately, their level was not enough.

After Wen Rou went home and pleaded with the ancestor at home, he got the promise of the ancestor to take him to the experimental site.

Yun Chu asked Li Shen, but as a result, people didn't go to this kind of gathering with a high degree of secrecy at all, and they didn't even think about it.

Then, Yun Chu set his eyes on His Royal Highness Li Hong, the acting king, who was carrying his sister on his back to play the waterwheel at the small water feature on a hot day.

That's right, just six days ago, the emperor canonized his fifth son, Li Hong, as the acting king, a title equivalent to the treatment of a good product.

Looking at the sweaty acting king Li Hong, Yun Chu felt that he must have wanted to go to the military field of Qujiang School to see a magnificent gunpowder explosion at this time.

Li Hong was reluctant to go.

He felt that it was too hot, in Jinchangfang he could wear shorts, a small vest, a lotus hat on his head, and run around barefoot, after going to Qujiang, he had to wear several layers of clothes, and he had to give gifts to countless people, make a gesture, say hello, maybe he would meet people who had a lot of things to do to test his knowledge.

Therefore, he would rather carry a girl weighing more than 20 pounds on his back and fool around with the pandas in Jinchangfang for a day, rather than go to the school military field to be exposed to the sun.

The most important thing is that his father and mother will go to the school military field, what if he is arrested, it will affect his happy vacation time in Jinchangfang.

In the end, he didn't resist Yun Chu, especially under the threat of Yun Chu lifting his leg and throwing him into the water lily pond, he happily cried and agreed to Yun Chu's request and took him to the military field of Qujiang School to watch the explosion.

It is very troublesome for the king to travel, at least it is more troublesome than Li Shen, the king of Ji, there are as many as twelve palace guards alone, this is still in Chang'an, if he goes out of Chang'an City, his entourage will not be less than three hundred.

At the same time, others will be rewarded with a royal mansion, and those who do not have it will speed up the construction, and the acting king Li Hong does not have a royal mansion, it is said that Wu Mei spoke, saying that Li Hong is young and cannot do without her mother, so it is not too late for Li Hong to grow up to ten years old in the future.

Yun Chu felt that this was not the case, it was more likely that Wu Mei felt troublesome, there was a huge East Palace in the east of Chang'an, and when the time came, wouldn't it be more convenient to let Li Hong live in it directly, what do you want a dilapidated palace for.

It is estimated that Li Zhi also thought so, so he handed over the Ganlu Hall in the Taiji Palace complex to Li Hong to live in.

There is no royal house, the entourage, but the officials who are subordinate to the guard of honor are complete, Wang Shi is Shangguan Yifu, and Li Yifu is accompanied by Yunchu, and when Li Hong opens the mansion in the future, there will be more officials assigned to him.

Daizhou, the south controls the Central Plains, the north chokes the desert plain, and the Yanmen Pass in the fief is listed as the first of the nine border passes, which is not how rich it is, but it is true that there are many soldiers and horses.

This is also the fief that Wu Mei carefully selected for her eldest son, and I have to admit that Wu Mei broke her heart for her eldest son.

Sitting in the heavy carriage, Li Hong kept hitting Yun Chu's arm with his head, shouting over and over again, it's too hot, it's too hot.

Seeing that this little person was really hot enough, Yun Chu said: "When we arrived at the school military field, we asked Liu Renliang for some saltpeter, and we will use saltpeter to make some smoothies for you to eat." ”

"Liar, my father also said that most of the ice in the ice cellar has melted this year, and it has become a luxury to make an iceberg in the palace to enjoy the coolness.

He also said that if it weren't for waiting for Liu Renliang to finalize the gunpowder, he would have gone to Jiucheng Palace with his mother to escape the summer.

What my father lacks, can you figure it out? ”

"Yes, as long as you don't tell your father and mother, I'll help you get ice to relieve the heat."

"Why can't you tell your father and mother?"

"Because, as soon as you tell them, I'm going to be dragged to make ice for them, and I hate it."

"I hate going to the military field of Qujiang School, why do you have to force me to go, Master Shangguan said, don't do to others what you don't want to do to you."

"Because you can't beat me."

Yun Chu found that Li Hong was becoming more and more difficult to deceive, so he simply ended the conversation between the two with violence.

After arriving at the school military field, the entourage of the acting king could not enter, so only the acting king Li Hong, who was accompanied by Yun Chu, entered the school military field in a daze.

After Yun Chu entered the school military field, Li Hong didn't need it, and directly handed Li Hong to his master Shangguanyi, and Yun Chu found a windy and cool place to wait for the gunpowder test arranged by Liu Renliang.

For the sake of insurance, the explosion point was arranged 300 steps away, and it was a specially built half-section of the city wall, the thickness and height of the city wall were similar to that of Chang'an City, even if it was far away, you could still feel that the half-section of the city wall was carefully crafted by craftsmen.

It is likely that it was not the hand of Liu Renliang, but the emperor ordered him to build it, or Li Ji personally supervised the construction of a section of the city wall.

The purpose was to test the power of gunpowder.

Yun Chu felt that Liu Renliang's gunpowder might not be able to blow up such a city wall, and if he wanted to blow up such a city wall, he would have to have a lot of TNT, black powder, which would not have much destructive power on such a city wall.

When the sun was running, even if he stayed in the shade, Yun Chu still felt as if he was on fire.

When he was about to take off his obstructive coat, Li Hong came running with a teapot, Yun Chu took the teapot, and when his hand touched the teapot, he was taken aback, because the teapot was cold.

After opening the lid of the teapot and looking at it, I found that it was not only filled with sour plum soup, but also crushed ice tinkling in the sour plum soup.

"Where's the ice?"

"Liu Renliang gave it, according to him, saltpeter can be used to make ice, and these ices are made from discarded saltpeter."

Looking at the ice cubes in the teapot and listening to Li Hong's words, Yun Chu felt that there were many, many copper coins, and they flew away with wings in front of his eyes.

The aborigines of the Tang Dynasty already know how to make ice from saltpeter?

Li Hong said disdainfully on the side: "Just now you also said that saltpeter ice making is your family's secret secret.

Master Shangguan said that the art of saltpeter ice making had been discovered by the monks of the pre-Sui period, and it was said that the water fell into the saltpeter, and then froze, so the monks designated saltpeter as a cold thing.

Mr. Shangguan also said that even if saltpeter was not used, people in the Han Dynasty could already make ice in the middle of summer.

In the book "Huainan Zi Bishu", it is said that an urn is filled with some water, and then it begins to heat, and when it boils almost and the water in the urn becomes less and less, it is filled with water vapor. After a quick withdrawal of fire, the mouth of the urn is sealed, and the sealing material is mainly thick cloth.

After sealing the mouth, it sank into a deep well, and after three days, the urn was lifted, and ice was produced.

It's not unusual to make ice in the middle of summer, you big liar. ”

Yun Chu was stunned by Li Hong's lesson, and was speechless.

Although Yun Chu deceived Li Hong, Li Hong generously brought him a big pot of iced sour plum soup to relieve the heat, lest this big liar be roasted into scum by the sun.

The sour plum soup with ice and frosting tastes very good, and it will be full of comfort when you drink it, but unfortunately, the more Yun Chu drinks it, the more sour he feels.

After drinking less than half of it, the teapot in his hand was taken away by the tenderness that was about to be burned, and he drank the sour plum soup in one go, opened his mind, and fanned the wind hard: "How can you have this thing to drink, my grandfather gave me a bowl, and it was not my turn to drink it at all." ”

Yun Chu looked at it and said gently: "Have you heard of saltpeter ice making?" ”

Gently puzzled, he looked at Yun Chu and said: "I know, it's that saltpeter is too expensive, and there is no way to make a large piece of ice, so it's chicken ribs, that is, rich people who are greedy and greedy will get a little, and everyone uses ice on weekdays." ”

Yun Chu asked again: "Do you know the book "Huainan Zi Bishu"? ”

Gently and suspiciously: "It should be the book "Huainan Wanbi Technique", which was compiled by Liu Anmen, the king of Huainan in the Western Han Dynasty, and there are all kinds of wonderful things that only warlocks can use, why are you suddenly interested in this book?" ”

Yun Chu felt that his throat was very uncomfortable, and coughed twice: "Do you have this book at home?" Can you lend me a look? ”

Gentle smile: "This is an idle book I read when I was ten years old, and I naturally have it at home, so I will give it to you if you want." ”

Yun Chu grabbed Gentle's shoulders with both hands and said, "You'd better read this book again, it's very interesting." ”

Gently patted Yun Chu's hand, pointed to a group of soldiers who were digging tunnels under the big sun and said, "Don't speak, Liu Renliang's demonstration has begun." ”

Yun Chu looked around, and saw two earth dragons approaching the city wall, and as the dust was raised, a huge shield was buckled on top of the deep pit, which could resist the sharp arrows flying from the city.

After a while, a captain holding a red flag waved the flag, and saw a group of people, continuously delivering some square package-like things to the tunnel.

Soon, all the packages were placed, and a group of marmot-like soldiers ran out of the tunnel.

Gently and frightened, he said to Yun Chu: "Otherwise, let's go and watch under the shed built of giant trees, I always feel that this place is not very stable." ”

P.S. The next chapter will be released at 2 pm on the 2nd, you read it first, I will continue to write, the starting point of this book is the first release, welcome everyone to read it on the starting point app -