Speaking of Qin Shihuang's sword, there is such a historical story:
At the end of the Warring States period, after Qin destroyed Korea and Zhao, he went north to the south of Yan. Yan is located in the south of the Great Wall and north of Yishui. It is a country with few people and weak strength, and the monarch and his ministers are uneasy. Yan Taizi Dan used to be a pledge of Qin, and the king of Qin was not very friendly to him, so he fled back to Yan. In order to prevent Qin Jun from going north, he planned to send an assassin, Jing Ke, to assassinate the king of Qin. Jing Ke broke up with Taizi Dan in Xiao 'an, took the head of Commander Fan of Qin, prepared a map of ceded territory for peace, and fled all the way. Xianyang Palace, the king of Qin, Jing Ke visited the king of Qin and showed him the map. The map was completely opened, revealing a sharp dagger. The king of Qin panicked, and the minister of the Qing Dynasty screamed, Your Majesty, draw your sword! Draw your sword! But Qin Wang's sword is too long, so he can't pull it out in a hurry. At this moment, Xia Wuji, the physician, used his quick wits and threw the medicine pot at Jing Ke. Taking advantage of this moment, the king of Qin, reminded by all the ministers, pushed the scabbard behind his back and pulled out his sword. When the sword went down, it cut off Jing Ke's left leg and saved the day.
Here's a problem. Iron swords in the late Spring and Autumn Period and the early Warring States Period are generally only 30 ~ 40 cm long, and the longest is only about 50 cm. Therefore, when Jing Ke stabbed Qin, the king of Qin would not be unable to pull out the sword because it was too long. What is Qin Shihuang's sword at this time? In 1970s, the bronze sword unearthed from the pit of Terracotta Warriors and Horses in Anqin, Xi 'an, solved this mystery.
Twenty-two bronze swords were found in the pit of Terracotta Warriors. The whole body of the sword is narrow and long, like a willow leaf, with different lengths ranging from 95 cm to 8 1 cm. As a melee weapon, sword can increase its length, improve self-defense and lethality. Therefore, with the emergence of composite casting sword technology, the length of bronze sword is greatly increased. These bronze swords are the longest known bronze swords in the Warring States period. The production process of swords is very formal. Some swords are still sheathed when they are unearthed, and the sheaths are rotten. After two years underground, these bronze swords were still extremely bright and cold when they were unearthed. Through scientific examination, it was found that the surface of the sword was oxidized by chromium salt, and a dense oxide layer with a thickness of 10 micron was formed on the surface. This discovery shocked the world. Because the rust prevention technology of chromium treatment was patented by Germans in 1930s and 1960s, and China used it for the rust prevention of weapons as early as 2000 years ago, which is really a miracle. As a generation of leaders, Qin Shihuang was overjoyed, with "many treasures". The sword he wore should be the most advanced at that time, that is to say, its length should be at least 90 cm. Therefore, when Jing Ke stabbed Qin, there was a danger that he could not draw his sword for a while. A long sword almost changed the course of China's history, which was probably unexpected by Qin Shihuang.
Qinshi