The idea of using gunpowder has been in Guo Song's mind for a long time, but although the military effect of gunpowder was discovered early, the development was very slow, and it could not play a decisive role in the victory or defeat of the war, and could only play an auxiliary effect.

Until the emergence of such carriers as guns, gunpowder gradually replaced cold weapons, but it takes national strength and the rapid development of the entire science and technology, and the emergence of guns will come naturally, in the Tang Dynasty, where the highest annual output of pig iron is only two million catties, talking about guns is undoubtedly a fool's dream, even if there are early muskets, they are far from being the opponent of archery and archery.

However, gunpowder still has its role, in fixed operations, such as defending the city, attacking the city or attacking passes, fortresses, etc., gunpowder can indeed play a decisive role, this is the original intention of Guo Song to make gunpowder, the Hexi army is insufficient, must have some black technology to assist in defending the city.

According to Guo Song's instructions, the soldiers have ground the completely dried gunpowder into coarse particles the size of mung beans, and a soldier found a porcelain bottle of incense, the biggest feature of this porcelain bottle is that the whole body is closed, and there is only a very small eye, this is what Guo Song wants, the gunpowder explosion is mainly caused by the violent expansion of gas, then the confined space is the top priority, paper bags, wooden barrels, clay pots, porcelain bottles, iron cans, the Song Dynasty upgraded step by step, and finally invented the cast iron thunder.

Then there is the fuse, the fuse is relatively simple, just roll up the nitrate powder with a long strip of paper, but it is such a simple thing, Guo Song and a few pro-soldiers sweated and were busy for a morning.

"Envoy, what is this?" Several of the soldiers asked puzzled.

"It's called Porcelain Fire Thunder!"

Guo Song smiled slightly: "Let's find a place to experiment!" ”

They found an open space behind the barracks, and at this time, dozens of generals were also invited by their own soldiers.

The soldier put the porcelain bottle filled with half of the gunpowder on a large wooden box, poured some fire oil around the porcelain bottle, and hung the fuse downward, although the fuse test was not bad, but after all, it was the first time to use, he did not dare to be careless, and could not ignite it directly.

"Guys, I invented a gadget, and I don't know if it will work, so I'll show you."

Guo Song asked everyone to retreat a hundred steps away, he lit a rocket, pulled out his bow, and shot an arrow, and the arrow hit the fire oil on the wooden box, and the fire oil ignited.

"Good archery!"

Everyone burst into cheers, they are all experts in knowing goods, Guo Song shot this arrow can just ignite the oil, even if he takes a hundred steps through Yang, he may not be able to do it.

"I let you look at the porcelain vase, not the archery!" Guo Song didn't have a good airway.

The flame ignited the fuse, the fuse burned very fast, and the ashes burned, but the porcelain bottle did not move, the first time it failed, Guo Song waved his hand, and apologized to everyone: "Sorry, failed!" ”

As soon as he finished speaking, he just listened to 'Bang! There was a loud bang, and a puff of smoke rose into the air, causing everyone to crouch down.

Guo Song was also stunned for a long time, he laughed and said: "Damn, I thought it was a failure, but I didn't expect it to be." ”

He walked forward quickly, and the soldiers followed and were just about to pick up the porcelain vase, Guo Song hurriedly said: "Don't pick it up, I'll see how far it has flown up." ”

"Envoy, it's about thirty steps!"

The soldier found the farthest piece of porcelain.

At this time, the generals trembled and asked, "Envoy, what is this?" ”

"It's called...... This is called porcelain fire thunder, which is a firearm, and it has no power yet. ”

Guo Song was telling the truth, the power of the porcelain piece was still too small, and the other party could defend it by raising a shield, and there was almost no shock wave, which could only be regarded as a preliminary test.

The generals looked at each other, they had never heard of this kind of firearm, and Liang Wu couldn't help but ask, "Then what is its function?" ”

Guo Song wanted to slap him, 'Didn't you see the explosion on the table?' In fact, no one has the concept of this explosion, and the porcelain fire thunder is not competitive enough, Guo Song had to sigh and say: "This is a very good thing to ignite, a little more convenient than a rocket." ”

He asked the soldier to pour a packet of gunpowder powder on top of the wooden box, told everyone to back down a little, threw a fire fold and threw it on, only to see 'Boom! With a bang, the gunpowder burned rapidly, and black smoke rose into the air.

Everyone immediately understood, applauded warmly, Guo Song smiled: "Wrapping it in paper and tying it to an arrow can quickly ignite the enemy's tent and make it into a fire harrier, which can even fly several miles away, and is the best firearm for long-distance fire attack." ”

At present, it is still a step away from the powerful explosion, but its combustion properties can be used quickly, and can even be used in the battle against the Great Dou Tu Valley.

..........

For the generals, Guo Song's gunpowder test was just a new thing, just to distract them and open their eyes, and the freshness only lasted for more than two hours, and they immediately threw themselves into intensive preparations.

The next day, Guo Song ordered Zhao Xiu to lead 20 soldiers to continue to make porcelain bottle fire thunder, Zhao Xiu has a talent in making gunpowder, he was responsible for the previous grinding and bottling, and he was able to succeed at one time, Guo Song then taught him the method of making fuses and paper cannons, so that he could understand it himself.

Guo Song himself led 3,000 cavalry to the Great Dou Ba Valley........

The situation in Longyou was extremely serious, and after the Tibetans received the news of the mutiny in Chang'an, they immediately realized that this was an excellent opportunity for them to start a war and plunder the Tang Dynasty.

The Tibetan minister Shang Jiezan immediately made a decision, he persuaded the Tubo Zanpu, sent the three army to kill to Longyou, Hehuang was the main force, 12,000 troops quickly captured Shanzhou and Kuozhou, and marched to Lanzhou, the other two army sent troops to Lintao all the way, and the other way sent troops to fight the valley to strengthen the defense of the valley and prevent the Tang army from killing out of the valley.

Tubo attacked the city and plundered the village all the way in Longyou, hundreds of thousands of people in Longyou fled when they heard the news, but there were still many people who were caught, Tubo needed all kinds of resources, food, livestock and population, in order to enrich the national strength, their goal was very clear, that is, to loot materials and population, send back to Tubo, and the Han people expanded production as slaves.

In just five days, seven states in Longyou have fallen.

At this time, Lanzhou was also in a panic, more than 100,000 people in Jincheng County fled with their families, and the 2,000 Hexi Army also arrived in time, gathered 840 craftsmen and their families from the Longyou Military Weapons Institute, a total of more than 5,000 people, and carried out the materials and weapons in the warehouse.

"How much grain is in the warehouse?" An Rengui accidentally found that there were at least tens of thousands of stones of grain stored in the official warehouse.

Li Huang, the assassin of Lanzhou, said: "There are 55,000 stones, which is the military rations of the Longyou Army, and it is still small, at most there are as many as 300,000 stones." ”

An Rengui was a little embarrassed, they couldn't carry this amount of food, let alone throw it to Tibet.

Du Siye, who followed An Rengui to migrate the craftsmen, said: "You can distribute them to the people, there are many people in the city, and each family will share a little, and it will be almost over." ”

An Rengui was overjoyed and said to Li Huang, the assassin: "Distribute food immediately, I can let the soldiers assist you." ”

Generally, it is a capital crime to distribute military rations privately, but now Li Huang can't take care of it, he immediately asked the officials to notify the people of the city to come to receive food, and hundreds of thousands of people flocked to come.

In just half a day, 55,000 stone of grain was given to the people of Mancheng, and tens of thousands of grains were reduced to zero, allowing the people to flee with them, and the Hexi army began to retreat north.

Lanzhou's own population has more than 100,000 people, plus more than 100,000 people fled from Shanzhou, and the people of Jincheng County have nearly 300,000 people.

At this time, the appearance of the Hexi army made the people suddenly see hope, whether the Hexi army wanted to or not, the people of the city followed the Hexi army to the Yellow River.

Hundreds of thousands of people on the banks of the Yellow River cried and panicked, and dozens of large rafts loaded with people sailed back and forth on the Yellow River, sending boats of people to the other side, but it was still too slow, and it would take at least ten days to transport all the people.

At this time, Liang Wu led 5,000 soldiers to meet him, and the number of giant rafts on the Yellow River increased to 300, greatly speeding up the speed of the people crossing the river.

Liang Wu divided the soldiers into five groups, each with 1,000 soldiers, and escorted the people to Liangzhou in batches.

This result was really unexpected by the officials in Hexi, who thought that only 30% of the people of Lanzhou would come to Hexi, with a population of 30,000 or 40,000 at most, but they did not expect that in the end, the people of the entire Lanzhou and Shanzhou fled.

Pan Liao had no choice but to evacuate half of the people to Ganzhou, Guo Song brought back more than 20,000 donkeys and mules from Guanzhong played a huge role, the old and weak women and children rode donkeys and mules, while the young men rode horses or walked, a huge team retreated to Zhangye under the escort of a thousand cavalry.