In this world, it is always easy to talk, but it is difficult to do something practical.

Build a fort for Xin'an Town to accommodate the earth cannon that was dismantled from the observation deck. This should not be a difficult task. At least at the beginning, according to Wu Han's expectations, this was a very simple project. But after actually starting, he realized that it was really messy. It was either improper manpower configuration or insufficient materials and tools. Other problems could be solved with a little brain. However, when the construction was about to start, Wu Han was completely stunned when encountering the fatal problem of insufficient cement.

Cement, a building material that people were most familiar with in the pre-war era, seems to have low technical content, but it is not something that a few laymen who have never been involved in this industry can study it by slapping their heads together.

A considerable part of the finished cement in Taohuayuan stocked in the early Taohuayuan was destroyed by the flooding and humid air during the flood period. The remaining inventory was so pitiful that people couldn't bear to start. Although there were a large number of steel bars and wires in stock, these things could not replace the role of cement. Since there was no cement, it was only second-hand, Wu Han plunged into the library to search for information and finally chose Sanhedi as the main building material for building the Xin'an Town Fort.

Sanhe soil sounds quite mysterious, far less familiar than reinforced concrete, but the composition of this material is not complicated. Just use three main ingredients: ripe lime, sand, and clay, supplemented with ingredients such as slag, and then use it as Sanhe soil.

If you are worried that the strength is not strong enough, just boil glutinous rice into a thick slurry and mix it into Sanhe soil, it can greatly increase the viscosity and increase the overall strength. If various processes are handled properly during the construction process, the structural strength of Sanhe soil building will not be much worse than that of cement. To be honest, the biggest difference between Sanhe soil and cement is actually consuming manpower. Unlike cement, just water and maintenance, if the Sanhe soil building wants to be solid, it must use the ramming method to ensure that the building itself has sufficient structural strength.

When the survivors of Xin'an Town were busy with spring plowing that was related to their own meal problems, all their manpower and material resources were concentrated on this fort recommended by Wu Han. Considering the rigor of life and death, the people in Xin'an Town have been extremely enthusiastic about their work this time.

The demand at the realistic level is the best driving force. The lesson of being bombarded by the mercenaries last time is believed to be impressive enough. Now no one is needed to supervise and mobilize. People in Xin'an Town are voluntarily working overtime and working day and night. They are determined to strive to build this fort in the shortest time.

The construction site where the fort was built was full of heat, and Wu Han was not idle either. He would not interfere with the people in Xin'an to help the people in Xin'an to rammed earth. However, it still took him a lot of time to ask experts and search for information and study the design plan of the fort. In contrast, although this big thing about building the fort was tricky, Wu Han did not feel too embarrassed.

Since Wu Han could DIY a local cannon with his stomach, the design of the fort would naturally not stump him. It was just to spend more time studying. The real headache is much more complicated than commanding an amateur to repair the fort. This question is quite simple, that is, where does gunpowder come from? The launching medicine of cannons is extremely demanding, at least far greater than the appetite of guns. Suppose the turret in Xin'an Town is completed, just configuring a certain number of shells here is enough to empty the inventory in Wu Han's hands, let alone the expense of training the gunners. How can such a big thing not cause a headache?

Taohuayuan has been using old money, and the bulk hunting rifle is used less and less. Now, with the new cannon, a big company that swallows gunpowder, the already tense supply and demand relationship is becoming increasingly stretched.

Wu Han also had his own plans. Since he decided to build a fort, no matter how difficult the conditions were, he could not deduct the ammunition needed to train the gunners. Otherwise, what was the difference between drawing out a few cannons that were not accurate and being used as decorations? For a moment, Wu Han did not come up with any good idea, but a master behind him gave him a move. Since he held this trump card, Wu Han became determined. After halfway through the fort project, he immediately pulled the surplus labor force and started another major project, and began to transform the toilets in the settlement in Xin'an Town with great fanfare.

“Yes, renovating the toilet is the best way to solve this problem.”

Faced with the survivors' doubts that were not understood, Wu Han was extremely confident at this moment. He put on a confident attitude to guide the country, fooling the people in Xin'an Town were stunned, and in the end they did not dare not act according to his instructions. Wu Han's motivation for renovating the toilet this time was extremely simple. He needed gunpowder, and the toilet in the Xin'an Town stronghold was the best way to provide raw materials, so the toilet had to be rebuilt. Under Wu Han's command, all the domestic waste and the manure and urine of human, livestock and poultry in the Xin'an Town stronghold were concentrated, and were buried shallowly in the land covered by a piece of straw shed, covered with a layer of empty soil to prevent flies from attracting them.

After completing the main project, a circle of low walls was surrounded by three-piece soil on all sides of the land, which was a measure to prevent the erosion of rain in summer.

Looking at the basically completed toilet renovation project, Wu Han looked excited, which made the survivors of Xin'an Town who came with him confused. No one knew why this gentleman was so enthusiastic about the reincarnation of the grains. If others didn't know the mystery, Wu Han certainly knew it.

Through the transformation of various microorganisms in the soil, I believe that it will not take too long to decompose and rot and naturally produce nitric acid. The free nitric acid produced begins to combine with potassium, sodium and other elements in the soil to form nitrates. Therefore, the main raw materials needed to make black gunpowder grow out of the ground so easily, which is really a magical scene to the outsider. Peach Blossom Land itself guards the hot springs, and it is not difficult to get the deposited sulfur from the springs, and charcoal is even simpler.

Although the dense primeval forest near the Peach Blossom Land is nowhere to be found in the nuclear winter and the flood, the remaining trees are enough for the humans at present. No wonder Wu Han is so proud at this moment. After careful calculation, the gunpowder problem that has been troubled for a long time seems to be solved. However, behind this plan, thanks to the advice of experts, it has been ignored by someone gorgeously. Although the power of black gunpowder is indeed a bit inferior, it is always better than living a good fortune! Moreover, although the performance of black gunpowder is not satisfactory, it is not impossible to improve.

In the future, nitric acid is produced through purifying soil nitr, and then using degreased cotton, starch and nitric acid to produce high-efficiency explosives such as fire cotton, which is also a very attractive career.

After more than 40 days of intense construction, the Xin'an Town Fort has been completed, and the construction speed is unprecedented.

Looking at the cannon that was rotating freely on the turret, the deep and dark muzzle made people feel a sense of oppression. When watching the work that took a lot of effort at close range, Wu Han smiled with satisfaction, then clapped his hands and said loudly:
Chapter completed!