After the meeting was over, the "Sky Fire Operation" was officially launched. Huan Fan's name was just right. Isn't the fireball thrown by the stone casting ball falling from the sky? It's really worthy of its name. Just thinking about the picture of the fireball thrown by the six hundred stone casting cars forming over Chen Cang is enough to make people feel refreshed and pleasing to the eye.

However, to promote the implementation of the Sky Fire Operation, Wei Jun still needs to make a lot of preparations in this regard. First, it is making straw rope balls, which is a relatively simple thing. It is winter now, and parasites are withered. Wei Jun only needs to send people to pick weeds, weave them into straw ropes, then soak the straw ropes in oil, wrap them into rope balls, and the fire rope balls are finished.

The straw rope ball is simple to make, but the Wei army mainly lacks oil. If the Sky Fire Operation wants to cover the entire Chencang City, the most important thing is oil. Because Chencang City has excellent fire resistance, only by igniting and detonating Chencang can it be ignited and detonated.

To this end, Cao Liang urgently issued an order to various places in Guanzhong to prepare as much oil and fat as possible to Chencang. In addition, flammable items such as sulfur saltpeter are also on the list of raising them.

Since Cao Liang spyed on Chen Cang, the Wei army's attack on Chen Cang stopped, which made Zhou Tai very puzzled. Is it because the Wei army retreated due to difficulties, or is there any other trick?

So Zhoutai personally climbed the city and looked into the distance, but found that the Wei army was harvesting hay everywhere. Looking at the rack, he was preparing to make some firewood to keep warm.

This made Zhoutai not surprising. After all, the weather is getting colder day by day, and the weather is colder. The Wei army, who is in the wild, naturally could not withstand the biting cold wind, so it is common sense to roast the fire to keep warm.

However, Zhou Tai sneered secretly that the cold winter in the northwest is not as cold as the Central Plains. When it was the coldest days of the year, the bitter northwest wind was like a knife, which could blow the cold into people's bones. The Wei army could not stop the cold from hell with their thin tents. At that time, they would probably freeze a large area to death, and the Wei army's attack would naturally collapse.

The Wei army went all over the world to clean up the weeds. In Zhoutai's opinion, that was just a foolish behavior? If you want to burn fire to keep warm, it is far better to chop wood than to chop wood. After all, burning wood is far more efficient than burning weeds. No matter how much grass is, it can only be destroyed by burning it for a moment, and it does not burn as long as firewood.

Logically speaking, this is the most common common sense? Normal people will understand it, but Zhoutai really doesn't understand why the Wei army sent troops to cut weeds on a large scale? Should we use weeds to feed horses?

But Zhou Tai also knew that although horses eat hay, hay used as feed cannot be fed by simply cutting some weeds? Many weeds are still poisonous. Horses will be poisoned after eating them. Usually, horses have a more picky appetite. As war horses, they need to be fed in concentrate so that the war horses can always maintain strong physical strength? Obviously, the Wei army could not cut weeds to feed the horses casually.

But besides this? These weeds have no other uses? They can only be used to make fire? Zhou Tai couldn't figure it out after thinking about it, but since he couldn't figure it out, he didn't think about it anymore. Anyway, the Wei army would do whatever it wanted. As long as it did not threaten Chen Cangcheng's defense, Zhou Tai wouldn't bother to care.

The Wei army has been attacking Chen Cang for more than 20 days, and almost all the troops that can be invested, and all the siege weapons are also taken turns to fight. However, under the command and dispatch of Zhoutai, Chen Cang's defenders were united and fought to the death, blocking the Wei army's crazy attack and never let Chen Cang lose.

Zhoutai has already experienced the tricks of the Wei army's attack, which undoubtedly greatly enhanced Zhoutai's confidence. It turned out that the Wei army was not invincible in every attack. As long as Chen Cang defenders could persevere, Chen Cangcheng would never lose.

Zhoutai is full of confidence in this regard. Chen Cangcheng's soldiers are good and the food stored can satisfy the guards for at least two years. If they save some money, it will not be a big problem for three years. Zhoutai does not believe that the Wei army can encircle Chen Cang for three years, so this victory must belong to him.

Zhoutai ordered the defenders to monitor the movements of the Wei army day and night. When he found any abnormal situation, he immediately reported to him. Now the Wei army suddenly stopped attacking, but it did not mean that the Wei army would withdraw. On the contrary, there must be a great storm in peace, so Zhoutai must guard against the Wei army's surprise attack at all times and must not give them any opportunity to take advantage of it.

There was a busy scene on the Wei army's camp. A large amount of hay was harvested and piled up like mountains. In the camp, there were special soldiers responsible for rubbing straw ropes. These bundles of hay were rolled into thick and long straw ropes. These straw ropes were soaked by another group of Wei soldiers to soak oil, and then wrapped into straw rope balls the size of human heads.

The soldiers of various parts of the Wei army divided their work and cooperated, and the production of straw rope balls was very fast. In a few days, you could see straw rope balls piled up like hills in the Wei army camp.

The supplies trucks carrying oil-referential oil-referential oil-sulphur saltpeter have been in constant flow in recent days, constantly coming from Chang'an, transporting trucks of full loads of supplies to the camp.

There was no oil such as oil in this era, but there was also some animal fat. The main ingredient of the tincture oil in the hot oil cup was badger oil. The oil peeled off from an animal called badger has the characteristics of fast ignition and good ignition effect. Other oils such as pigs, cattle and sheep, although the effect is not as good as badger oil, if used in large quantities, they can also achieve a good ignition effect.

In addition to animal oils, there are also a lot of tung oil or rosin that are good at ignition, followed by sulfur and saltpeter.

In fact, Cao Liang knew that using sulfur, saltpeter and charcoal to be distributed in proportion can produce black gunpowder, but Cao Liang only knew one approximation, but he was not very clear about the specific ratio. Cao Liang tried it a few times, but at most he could only let these mixtures burn and not achieve the explosive effect. In the end, Cao Liang had to choose to give up. It seems that he could not get gunpowder without any chemical foundation.

However, if sulfur and saltpeter are added to the flame, it can not only aid combustion, but also produce a large amount of toxic and harmful gases, which are very choking. When inhaled too much, it can also cause poisoning. It is a chemical weapon.
Chapter completed!