Tibet

Everyone entered the city in oil-walled vehicles. Han Chang'an City was also polarized. Except for the three major palaces, Changle Palace, Jianzhang Palace and Weiyang Palace still belonged to the royal forbidden gardens. There were troops standing guard and people were not allowed to enter or leave. The rest of the city was basically closed. I don’t care anymore.

The pavilions and pavilions of the former wealthy families in the city are gone, and the exquisite multi-story wooden buildings have disappeared. Instead, there are endless mud houses. Now the roofs are covered with snow, which does not look ugly. After the snow melts, it becomes Ugly slums.

The road was icy and the ground was slippery, making it impossible for carriages to move. Everyone had to get off the car and walk. The ground was in shocking rags, with large and small pits everywhere.

Chen Huan was in charge of road infrastructure. He blushed and said quickly: "I will send people to fill in all the road pits tomorrow and then spread wheat straw for people to walk on."

Li Ye nodded, "Let's find a place to sit down!"

The road was too bad to walk, so everyone entered a teahouse along the street, went up to the second floor and sat down. The waiter brought a charcoal basin, and everyone warmed themselves by the fire while drinking hot tea.

"Your Highness, why was Han Chang'an City abandoned?" Duan Xiushi asked curiously.

Li Ye said slowly: "There are two reasons why Han Chang'an was abandoned. One is that the terrain is low-lying. Once the Wei River rises and bursts its banks, the city of Han Chang'an will be flooded, or it will become flooded if there is heavy rain.

The second reason is that the groundwater is polluted. Domestic sewage is usually discharged from the city through tile pipes. I originally thought that it was discharged directly into the Wei River. Later I found out that only a small part of it was discharged into the Wei River. The rest of the sewage was in the Wei River. Seepage wells were dug in the city and domestic sewage was poured into the wells.

Anyway, out of sight, out of mind, it doesn’t matter for a few decades, but after a hundred or two hundred years, the groundwater will be polluted by sewage, and the well water will become bitter, salty, and dirty. It’s really impossible to live in a capital city without a water source. , so the Eastern Han Dynasty moved its capital to Luoyang. "

"Then the water quality in Chang'an is also bad now. Is it the same reason?"

Li Ye nodded, "That's right. Chang'an has a population of one million. For more than a hundred years, how have all kinds of sewage been treated? Although most of them flow into Fengshui, Bashui, Chanshui, and finally into the Weihe River, it is undeniable. There are still a lot of sewage seeping into wells. The water quality in Yonghefang, where I lived when I was young, was very dirty and the well water was very bitter. As a result, people who drank raw water easily fell ill, and ordinary people did not live long.

If we want to realize the resurgence of the Tang Dynasty, the big problem we face is first of all how to solve the pollution of water sources. We can only slow down the pollution. It is definitely impossible to completely solve it. At least we must ensure that everyone boils the water before drinking it. This is We face another big problem, how to solve the problem of living fuel. "

Cui Guangyuan used to be Jing Zhaoyin. He was very familiar with Han Chang'an City. He stood in front of the window and looked outside, and said: "Fuel is indeed a big problem. I remember that during the Tianbao period, there were big trees on both sides of the streets in Han Chang'an City. Now the trees are All gone."

Liu Yan smiled bitterly and said: "Not only are there no trees here, there used to be a lot of trees in Guanzhong. They have also been cut down heavily in recent years. It was only this year that they were forced to stop. However, many of the trees in the past have disappeared, and the trees in Chang'an City have basically disappeared. They are gone, only some remain in temples and forbidden gardens.”

During the Tang Dezong period in history, someone discovered thousands of trees measuring seven to eight feet high in a ravine in Tongzhou, Guanzhong. The whole court immediately celebrated. They actually discovered trees measuring seven or eight feet high in Guanzhong. It was an incredible thing. Prime Minister Pei Yanling Immediately flattered, "Because of the emperor's sage, this auspicious sign came from heaven!"

The seven-eight-foot tree is as tall as a seven- or eight-story building, which shows the serious environmental damage in Guanzhong in the late Tang Dynasty.

Of course, there must be towering trees in Zhongnan Mountain, but it is not a place where people live together.

Li Mi nodded, "In the past, the emperor's authority was strict, and people were strictly prohibited from cutting down trees. Violators were severely punished, so everyone looked at the trees with greed, but no one dared to cut them down. After the Anlu Mountain rebellion, the emperor's authority fell, and the people began to cut down trees unscrupulously. It is used to burn fire. This is why His Highness wants to promote coal. Only by replacing wood with coal can the trees in Guanzhong be preserved."

Chen Huandao: "But burning coal in the room for heating in winter can easily lead to poisoning. This problem needs to be solved."

Li Ye shook his head and said: "Coal stoves are never allowed to be heated in the room, unless there is a chimney to discharge the soot outdoors. Therefore, we promote coal not for heating the people, but for boiling water for cooking.

When there was no coal, people burned firewood in the kitchen. If there was no kitchen, they would do it outdoors. The same goes for coal stoves. In fact, it is what we did in Jincheng County. Now we just follow the same method in Chang'an. "

"Your Highness is talking about briquettes?"

Briquettes were popularized by Li Ye when he was in Jincheng. A little sulfur and gunpowder were mixed in the tunnel. A piece of briquettes only cost a few cents, which was much cheaper than buying firewood. It was promoted well in Longyou.

Li Ye smiled and said to everyone: "For ordinary people, the key is price. A bundle of firewood costs one hundred cents and can be burned for about six or seven days. Similarly, one hundred cents can buy thirty coal cakes, which is fine. In ten days, you can not only cook, but also boil water. If you want to boil water, a bundle of firewood can only be used for three days. It is obvious that coal cakes are much more cost-effective. "

Liu Yan chuckled and said: "You're right, only if it's profitable will everyone use it!"

Chen Huan thought for a while and said, "What should I do if I don't need a coal stove for heating in winter?"

Li Ye smiled slightly and said: "Then grow more cotton, make it cheaper and keep you warm when you wear it."

Everyone burst into laughter, and Duan Xiushi said with a smile: "There was a fire in my house last night, so I realized how powerful cotton is!"

Li Ye was startled, "There was a fire in Commander Duan's house?"

Duan Xiushi said sheepishly: "It's not a big problem to burn down an independent utility room. There are thirty kilograms of cotton in the utility room. The housekeeper went to look for cotton at night. The huozhezi accidentally lit the cotton on fire, and it exploded. It burns so fast that it’s shocking. I advise everyone to be careful. Cotton burns easily and cannot put out fires at all.”

Duan Xiushi's words made Li Ye's eyes light up. What did he think of? Cotton, nitrocellulose, explosives, he suddenly thought of the solution to the iron shell fire mine.

After returning from Chang'an City in the Han Dynasty, Li Ye immediately rushed to the Firearms and Gunpowder Department.

The Firearms and Powder Administration is located in the south of the city, about ten miles away from Chang'an. It is a factory formerly owned by the Ordnance Supervision, covering an area of ​​about 100 acres. There are more than a dozen large stone houses inside, which are used as warehouses and research and development sites.

The experimental site is in the Zhongnan Valley further south.

At present, the head of the Firearms and Powder Department is still Hu Jiuling. He is responsible for managing and maintaining the operation of the Firearms Department. The craftsmen below are focused on developing firearms.

At present, the iron fire thunder has been successful, but the yield rate is too low. If you click on ten, you can only explode one or two. This actually doesn't make much sense.

Li Ye ordered Hu Jiuling to summon several main craftsmen. Currently, the three main craftsmen are responsible for the entire development of Iron Fire Thunder.

The chief gunpowder craftsman was called Zhang Huan, who was responsible for preparing the gunpowder. The master craftsman who made the iron shells was called Du Sheng, and the master craftsman who made the firearms was called Jing Sgnian.

"Let's talk about it! What's the problem with the low success rate now?"

Hu Jiuling sighed and said: "The three that were successful before were all above one hundred kilograms. Because the amount of gunpowder was sufficient and the skin was thin, it could explode. Once it dropped below one hundred kilograms, it would not work. Your Highness, the key is that the power of the gunpowder was not enough." ”

Gunpowder maker Zhang Huandao said: "According to His Highness's suggestion, we added an appropriate amount of sugar. The burning speed is indeed faster and the effect is good. The explosion power is also stronger, but the iron shell still cannot be exploded. I am still experimenting and looking for more information." Good material.”

Li Ye nodded, "I'm here to give you a plan this time. Try it with lint!"

"What is lint?" Several people were confused.

Li Ye smiled slightly and said: "Go to the cotton spinning factory in Xianyang. They use a cotton gin to peel the cotton from the cotton seeds, but in the end the cotton seeds are still wrapped with a layer of white short fluff, which is cotton lint. The fire will dissolve the cotton seeds." Soak the cotton wool in the concentrated solution, then dry it thoroughly, then use this cotton wool containing nitrate powder as a filling, and then conduct a test to see what the effect is? "