In this way, the self-sufficiency system of the city of Kuozhou was formed, and the barley hoarded in the city was used to make tsampa, but the stock of barley was too small, so that tsampa could only be used as a snack, and the main food source was goat's milk and yak milk, and old or sick cattle and sheep could be killed to improve their diet. If they continued to hold on to this arrangement, the first to hold out must have been the Tang army besieging outside the city, and the supplies carried by the enemy's cavalry would last at most a month, but they were able to hold out until the spring of the following year.

If Lord Ben planned perfectly, as long as the veteran soldiers of the Tang army division were tired and the arrows were exhausted, he would inevitably retreat, and he could take the opportunity to go out of the city to pursue, and the speed of the cavalry in this ravine and ravine might not be able to outrun the foot soldiers, and the entire Kuozhou and Shanzhou would still be theirs at that time.

Li Siye soon led the rear army to the city, circled around the city wall of Kuozhou, and then set up camp and invited Tian Zhen, Duan Xiushi and Xu Bin to the account.

Tian Zhen took the lead in asking him for instructions: "We have captured more than 20,000 people from Dongdai, four more slaves, and 50,000 heads of livestock alone, are we going to send them to the rear to give Lun Weiliang?"

"No need for the time being, I just went around Kuzhou City, maybe the Tubo people are going to engage in a war of attrition with us. The city of Kuozhou was originally the garrison of the Longyou Ningsai army, the city wall was stronger than I imagined, and it was very difficult to capture it in a period of time, so it was necessary to prepare for a long-term war. ”

Duan Xiushi asked: "But now that it is winter, the grass and trees have withered and yellowed, how can we afford to support more than 50,000 livestock." ”

Li Siye said: "This is not a problem, the animals on the plateau are very cold and hunger tolerant, and the withered yellow grass and yak can also be eaten, and there are many pines and cypresses in the mountains near here, and the plateau sheep can also eat pine needles and cypress leaves to survive the cold winter." In the future, there is no need to worry about consumption, our army will often eat mutton to improve the diet, so these cattle and sheep will only be less and less every day, not more. The order was sent to the whole army, and tomorrow, except for the besieging troops, the rest of the sergeants will go to the mountains to cut grass and cut down pine branches, and send some people to help the herdsmen build felt tents. ”

The Tang army took the initiative to set up camp outside the city of Kuozhou, and divided and built two camps as temporary residences for the surrendered slave tamers Dongdai. Then mobilize the vast number of herdsmen, taking advantage of the fact that the first snow of this winter has not yet arrived, collect some yellow grass in advance as a winter reserve.

These are all preparations for prevention, but fighting with the Tibetan people is the worst way to last resort, of course, we must find a way to capture the city of Kuzhou as soon as possible, which is the root cause of all problems.

Li Siye constantly sent people to gather information and ask all about the situation in the city from the mouths of these obedient Dongdai officials. He roughly understood that even if Su Biru expelled 20,000 tamed slaves from the city of Kuzhou, the city was still filled with nearly 160,000 people and livestock. Among these people, there were nearly 70,000 combat forces, which was equal to the total strength of the Flying Tiger Cavalry and the Han Navy. More are ordinary Tibetan herders and livestock. Feeding so many people and animals requires a lot of food and forage.

Thinking of this, his eyes suddenly lit up, and he instructed the guards in the tent: "Invite the four Dongdai Dongben to the tent." ”

After the four leaders of the slave tamers of Dongdai were surrendered, they were given a great degree of preferential treatment, and the Hexi army continued to let them manage their respective tribes, and also conferred honorary official positions such as Zhonglang General. Still, they were a little apprehensive. The rulers of the world are just as difficult to serve, and if they are a little ineffective, they are afraid that the Tang army will find an excuse to get rid of them.

Hearing that Li Siye invited them to enter the big tent of the Chinese army, the four of them were very frightened, and after entering the tent in turn, they knelt down and hugged their chests and said: "See the king for his humble position." ”

Li Siye stepped forward to help them up, invited the four of them to sit down, and asked, "You have also stayed in the city of Kuozhou for a while, do you know where the forage and grain are hoarded in the city?" ”

The four of them hurriedly stood up and said, Li Siye waved his hand and said: "Don't worry, say it one by one, if it is not comprehensive, others can add it." ”

One of them glanced at the other three, and said first: "The grain in the city is all hoarded in the cellar in the center of the city, but the forage stock is too large, and only a part of the grass hut can be built, and most of it is stacked in the open air. Su Biru was worried that the Tang army would attack the city with fire when it attacked the city, so the forage accumulation point was some distance from the city wall. ”

"Oh." Li Siye's eyes lit up and asked, "Is there a specific location, the distance from the city wall?" ”

"This, lowly ......" While this person was stuck, another person took the initiative to step forward and said: "I know that because of the hoarding of forage, it occupies almost all the area in the center of the city, but the periphery of each forage field is more than eight hundred steps away from the city wall. ”

"More than eight hundred steps?" Li Siye regretted a little that he didn't bring the Xuanwu cannon in. If the forage yard was more than 800 steps away from the city walls, then the weapons he placed outside the city would have to have a range of at least a thousand paces, a range that only an improved basalt cannon could achieve.

Now I am afraid that it will be too late to send another order to mobilize Xuanwu artillery, from Gulang County to Kuozhou is nearly 500 miles, the mountain road is rugged, even if the transportation of ten Xuanwu cannons is a great loss of manpower. Rather than seek the nearest and farther, it is better to improvise a weapon that can throw a fiery thunderbolt within a thousand paces.

Although they did not carry artillery, they carried a large amount of fire and grease in advance, which they used as sharp weapons for siege. However, now it seems that good steel should be used on the blade, and using the forage in the city as an offensive target is the best tactic to defeat Subiru.

With a smile on his face, he waved his hand to the four of them and said, "The information you provide is very important, let's go down and rest first, if we can capture Kuzhou City this time, it will be a great achievement." ”

The four of them bowed down and hugged their chests together: "It is our honor to serve the king. ”

After they walked out of the big tent, Li Siye immediately sat down in front of the desk, spread out a large piece of paper, and sketched a sketch on it. Then he ordered the general Xu Bin to invite him to the big tent.

After Xu Bin entered the tent, Li Siye handed him the sketch and said, "We have learned that the Tubo people have piled up forage in the center of Kuzhou City, so we need something to throw a fierce fire thunder full of grease into the center of Kuzhou City, this is this kind of thing. ”

Xu Bin pinched the drawing and blinked, this thing looked like a watermelon, and he could see the things hanging with lines underneath, like a basket. It may also be because Li Siye's painting skills are too poor, he really can't see what this is.

Li Siye pointed to the drawings and said: "Let's make a few large Kong Ming lanterns, the inside is made of flexible bamboo and wood woven frames, and the outside is wrapped and sewn with cowhide, which is airtight. A copper furnace is hung underneath and filled with grease, and a large oil twister is rubbed and ignited to make the air heat expand and rise. At the bottom hung a hanging basket, which contained two soldiers and a number of fierce fire mines. When the wind is blowing, identify the direction and light the Kong Ming lantern, float into the forage field in the city of Kuzhou and throw it. It can cause a raging fire in the center of the city, burning all the forage of Subiru, and the city of Kuzhou will be destroyed. ”

Xu Bin happily crossed his hands and boasted: "The lord is really resourceful, this plan is a good way to conquer Kuozhou and defeat Su Biru, I will send people down to rush to build, and strive to make seven or eight within five days." ”

The materials for making hot air balloons are ready-made, and the yak skins in the felt tents of the Tibetan herdsmen abound, and these women have been ordered to sew them overnight, and they may not know that the thing they sew can plunge the Tibetan people in the city of Kuozhou into a sea of fire and despair, and if they know it in the future, they don't know how to feel.

The ingenious children of Hexi have woven a frame out of mulberry sticks, the women have sewn the skins on, the brass oil stoves have been secured, and ten hot air balloons are lined up on the camp.

This kind of immature hot air balloon is more dependent on the weather, and the wind is also required to be moderate, and the hot air balloon that is too large is difficult to control and is easy to be blown away by the wind.