Xiong Jing didn't know what Xiang Yan was thinking, and if he knew it, he would definitely think he was crazy. Because of the limitations of saltpeter purification - the purification of saltpeter is not as simple as dissolution and crystallization. One of the important steps in the purification of saltpeter is to add appropriate wood ash. The wood ash is potassium carbonate, and the carbonate in the potassium carbonate will be replaced with the calcium nitrate and magnesium nitrate in the nitrate soil to form calcium carbonate and magnesium carbonate that sink in water; at the same time, the nitrate in the potassium nitrate and the potassium ions in the potassium carbonate to form new potassium nitrate. In addition to calcium nitrate and magnesium nitrate, there are sulfates and chloride salts in the nitrate soil, which can only be separated by multiple recrystallization.

This is a scientific method. The ancient method was to add peel glue to cook together, or add sugar, radish and fresh water to cook together. But whether the salt cooked in this way can be pure and whether it can reach twenty miles or thirty miles away, and only geniuses can be eroded for dozens of miles. Anyway, Guan Tianpei wrote in his memorial:

‘I personally surveyed the two cannons of Dajiao and Shajiao, which were in the east and the slant. The width of the port was 1,113 zhang (1 Qingzhang = 3.2 meters), and the cannon position below 5,000 jin, and the cannon was far away, ranging from more than 100 to two or three hundred jin. The power was still weak. You must have more than 6,000 jin of cannons to reach the distance Cui Jian. The cannon was only as big as the middle stream, and it was useless to be strong...’

According to the Qing Dynasty, four taels of medicine were used per 100 kilograms of medicine, and twelve-five kilograms of cannons were used (596 grams of Qing kilograms, that is, 4.47 kilograms); according to the Qing Dynasty, the weight ratio of artillery fired medicine to shells was 1:1 (Humen Shajiao Fortress Smoke Pier, the inscription was engraved on the six thousand kilograms of iron cannons: in the summer of the 15th year of Daoguang,... Six thousand kilograms of cannons, 15 kilograms of food and medicine, made by Chanshan Cannon House Li Chenhuo and others), rather than the common 1:3 in modern Europe.

The angle of the sand-corner cannon that Guan Tianpei personally surveyed was unknown, but it must be not five degrees, and must be greater than ten degrees or even more. With 4.47 kilograms of gunpowder, he got 570 kilograms (and the width of the mouth of Qi Gong, the governor of Guangdong and Guangxi, measured the width of the mouth, which is more than one thousand one hundred and seventy kilograms, taking the average; the "cannon only reaches the middle flow", that is, 570 kilograms, according to the clear zhang, is 1824 meters). The standard for the twelve-pound cannon (the total weight of the twelve-pound cannon weighs 2,000 kilograms) is only one quarter of the 3,000 kilograms of the 1.13 kilograms of the 3,000 kilograms of the 5.44 kilograms of solid bullets, and at the elevation angle of five degrees, the range is 1,488 meters; at the elevation angle of ten degrees, the range is 1,911 meters.

Using four times the launching medicine, the launching shells weighing only 82% were barely the same as the range of ten degrees of elevation angle of the twelve-pound cannon. Looking closely, the power of this gunpowder is better than that of the gunpowder made by the Chuangfu (according to the last test, the power of the Chuangfu gunpowder was only one-fifth of the power of modern gunpowder), but this is very limited. If the difference in the weight of the shell is ignored, its power is only one-quarter of the power of modern gunpowder.

Of course, there are many other factors that can produce such a small power of gunpowder, such as moisture over time, such as non-granulation (in fact, the granulation effect is also very limited, the heat of granular gunpowder is 736.6 kcal/kg; the heat of powder gunpowder is 620.9 kg/kg), such as the surface of saltpeter sinking into the bottom of charcoal during transportation, such as the rough inside the gun barrel, the surface of the shell is not smooth, etc., but no matter what, the power of gunpowder made of purifying soil nitr according to traditional processes is very limited. Only by purifying according to scientific methods or simply using saltpeter without impurities can the gunpowder be maximized.

Xiang Yan wanted to use gunpowder to open Xianyang City, which was not feasible in Xiong Jing's opinion. It was not feasible because black gunpowder could not blow up the city wall. Even after World War II, there were cases of using 6.2 tons of black gunpowder to explode the 37-meter city wall. The wall was 14 meters high and more than twenty meters thick [Note 7: "History of the People's Liberation Army Review of the People's Liberation Army 1945-1949 Volume 1" Liu Tong P: 528.]. One of the reasons for the inability to use underground tunnels to blast is that he does not have so much gunpowder.

Although the ratio of the width of the city wall, the height of the city and the width of the upper width is 3:2:1, in fact, the ratio of the width of the city wall in the Yuan Dynasty, the height of the city wall is 4:2:1. That is, if the city is fourteen meters high, the width of the city wall at the bottom is twenty-eight meters, and the width of the top of the wall is only seven meters.

After the pre-Qin period, many things were degenerated. The Weiyang Palace in the Han Dynasty was 4.6 square kilometers, the Changle Palace was 6.6 square kilometers, the Daming Palace in the Tang Dynasty was 3.3 square kilometers, and the Forbidden City in the Beijing Palace was only 0.73 square kilometers. Of course, this is the scale of the palace. The wall building may be due to technological advances, such as the wall covering bricks, which makes the ratio of the bottom, the city height, and the upper width become smaller and smaller.

In this era, the ratio of the width of the bottom, the height of the city, and the width of the upper width is 6:2:1. Xianyang is a world-class city, built with six plates, and the height of the city is 7.2 meters, with a circumference of the foot of the city, which is 14.18 meters; the width of the bottom is three times the height of the city, that is, twenty-one and six feet, which is 42.55 meters. In addition, in order to prevent the city from flooding, the walls of this era also have slope protection at the foot, plus the inner and outer slope protection, the thickness of the city foundation is as high as 60 meters.

Six-two tons of gunpowder exploded Linfen, which was more than 20 meters thick in the wall base. With the power of the current gunpowder, Xianyang, which was 60 meters thick in the wall base, it would be estimated that at least 30 tons or even more gunpowder would be needed. According to the ratio, this is more than three tons of sulfur, and the last time Hu Dansao branch only brought 127 kilograms of sulfur.

The Yanshi Pass was built in the mountains and the Guancheng was about ten meters thick. Xiong Jing estimated that it would require three tons of gunpowder. Three hundred kilograms of sulfur Hu Dansa branch could still bring it, but if he had to get three tons of sulfur, it would be impossible. Unless he really found the sulfur mine, or the fleet found a new source of sulfur in India, Seleuc, and Yingzhou.

If there is insufficient sulfur that makes it impossible to explode the Xianyang city wall, the other is a simple tactical problem.

Xiong Jing was not a good choice for a good cavalry to enter Xianyang City without fighting on the plains. Xianyang's population was 600,000, not including the defenders and guards in the city, and each household had 60,000 people. The Qin people were not from Qi. Under the strict Qin law, the Qin people had long become a war machine. Even if the Hezong Army, who was trapped in street fighting in strange cities, could only kill 60,000 Qin troops. Such exchanges were really unprofitable. And when he attacked one by one, Zhao Zheng would have run away long ago.

"If gunpowder can break through Xianyang City..." Xiang Yan was still crazy due to the pungent smell of gunpowder after the explosion.

"If this can defeat Xianyang City, the affairs of the world will be settled!" Li Qi went crazy afterwards.

"There is insufficient gunpowder. Xianyang City is 60 meters thick and cannot explode." Xiong Jing said, "The city protection outside Xianyang City is fifteen meters wide. How can our army cross the pond and dig the cave? The Qin army in the city has more than 100,000, and how can 30,000 cavalry win?"

"In this way, infantry should be born in this battle." Li Qi continued. "If there are 100,000 infantry..."

"Then enter the city from Shangjun?" Xiong Jing asked back. "How do you know that the Qin army cannot transfer troops back to Xianyang in time? It takes more than 1,700 miles, and the infantry can reach Xianyang at least twenty days. Before the infantry arrived in Xianyang, the Qin army has arrived in Xianyang."

The strategy of entering Qin from Shangjun was a rejected. In addition to the three countries' unwilling to dispatch infantry to make a big fuss, the speed of the Qin army's return to aid was also an important reason. In the Battle of Huayang, the Qin army relied on boats for only eight days and left Xianyang to arrive at Huayang. Now, the time for returning to Xianyang from the Zhao front line is estimated to be no more than fifteen days.

Even though the Chu warships intercepted the Qin army on the Yellow River and forced them to abandon their boats and walk, the Qin army in Jingxing could travel 300 miles in Jinyang (now Taiyuan). The Fen River was along the Fen River. Xianyang to Huayang was on the same water, and Jinyang to Xianyang, and only the last three hundred miles of the section of the Yellow River to Weishui was reversed.

It is equivalent to saying that, the Hezong Army has a journey of more than 1,700 miles, and the Hezong Army walks throughout the journey, and the Qin army walks 300 miles, and the Qin army goes down the water for 1,100 miles. The Hezong Army has the advantage of first-mover attacking, but because of the Feixun Qin army, the Qin army is not much slower to react. And the most important thing is that the Hezong Army needs to rely on robbery and conquer passes, such as Ziwuling and Juyuan Pass; and the Qin army is completely marching on the inside.

Xiong Jing would think of the disadvantages of the strategy of going from Shangjun to Qin. He shook his head again and emphasized: "The army from Shangjun to Qin cannot reach Xianyang. Moreover, there is insufficient gunpowder and the Xianyang city wall cannot be blown up."

Under the temptation of gunpowder, Xiang Yan and Li Qi were both a little abnormal, but Xiang Yan calmed down first. He knew that the goal could not be expanded blindly. He said, "I dare to ask the king, why is gunpowder insufficient?"

"There is nothing needed for gunpowder in the State of Chu." Xiong Jing explained. "It needs to be transported from other countries."

The gunpowder turned out to be made of. Xiang Yan was a little awakened. He asked, "How many can it be?"

"I don't know it either." Xiong Jing said, but in order to reassure him, he said again: "Of course we will be able to break through the Yanshi Pass City."

"Of course." Xiang Yan replied solemnly, "I am willing to attack Qin with the king."

"Good!" Xiong Jing smiled and spent half a ton of gunpowder. Xiang Yan nodded as expected.

"However, please do not stay away from my shogunate." Thinking of Xiong Jing's battle in the Hung Gou, Xiong Jing had gone out alone to meet the enemy, Xiang Yan was very worried that something might happen to him, so he said again: "And never attack the enemy without authorization."

"No." Xiong Jing also pointed at the key point, "I will never attack the enemy without authorization, I will only..."

The king liked a concubine of the King of Qin. Because Li Qi, many people in Chu have known about this. Xiang Yan did not object to Xiong Jing's hobby. He only hoped that Xiong Jing would not have any trouble, let alone act without permission.

"Gunpowder is of great use, so please buy more of the things you need." Xiang Yan's topic returned to the gunpowder itself. He now had a premonition that the emergence of this weapon would change the war itself.

"I also hope to buy more of the unscrupulous people, but there are few in other countries. What can I do if I don't?" Xiong Jing smiled bitterly. Many things are very impressive, but in fact, it is another matter. But sulfur cannot be transported by Hu Dansa. Sogdian merchants are very cunning. The more important you say, the more he will increase the price and reduce the amount. When the spring of next year begins, people should be sent to Yingzhou to find it. If you see a volcano, you will climb the mountain. You don't believe that you can't find sulfur.
Chapter completed!