Chapter 26 Section 19 Sun Yuanhua, an expert in Western artillery, and "Western Magic Machine"

Sun Yuanhua was an expert in the development of Western artillery in the late Ming Dynasty. His "Xifa Shenji" was a monograph on Western artillery in the late Ming Dynasty, which had an important impact on the development and use of artillery in the late Ming and Qing dynasties. Sun Yuanhua, styled Chuyang, named Huodong, was born in Jiading (now Shanghai).The date of birth is unknown. "History of Ming Dynasty Biography of Xu Congzhi" attached his biography, saying that he was "good at Western artillery, and Xu Guangqiyun was the best."Qing Emperor Qianlong's "Jiading County Chronicles" said that he was "extremely talented, curious, learned from Shanghai Xu Guangqi, learned from Western learning, and was good at firearms."Because of the two strategies of Chen Beijing and border defense, he was praised for painting the front of the strategic army.In September of the second year of Tianqi (1622 A.D.), Sun Yuanhua served as the Secretary of the Ministry of War and assisted Sun Chengzong, the governor of Liaodong, to build city defenses in Shanhaiguan.In the third year of Tianqi (AD 1623), he followed Ning Qianbing Dao Yuan Chonghuan and stood firm in Ningyuan City. He was responsible for the transportation and management of 11 Western cannons in Shanhaiguan and presided over the cannon making. The "Ningyuan Great Victory" in the sixth year of Tianqi (1626 AD) neutralized the military exploits.In the early years of Chongzhen, he served as a member of the military department, Wailang, and was soon promoted to doctor.In the third year of Chongzhen (1630 A.D.), he was transferred to governor of Denglai on the recommendation of his teacher Xu Guangqi.According to Xu Guangqi's intention, he hired Portuguese artillery divisions to Denglai to manufacture Western artillery and trained soldiers in using Western artillery.He wrote the Western firearms technology learned from the Italian missionary Matthoeus Ricci (1552-1610 AD, who came to China in 1582) into "Western Magic Machine".In the fifth year of Chongzhen (1632 A.D.), Kong Youde and Geng Zhongming, the generals of Sun Yuanhua, rebelled against the Ming Dynasty and surrendered to the Qing Dynasty, captured Denglai and captured them.Sun Yuanhua attempted suicide and was released by the rebels.In September of the following year, he was executed by the Ming court.He is the author of "Jingwu Quanshu", "Xifa Shenji" and so on.

"Xifa Shenji" was completed five years before Chongzhen (AD 1632), and the original manuscript was lost in the war. The existing Guxiangcaotang version (see Figure 17) published according to its copy in the first year of Qing Emperor Kangxi (AD 1662) is divided into two parts. The next two volumes contain about 30,000 words and 19 pictures.The book records more than 30 formulas for launching gunpowder; expounds the method of designing other parts according to a certain ratio multiple based on the size of the artillery caliber; puts forward the requirement that the weight of the projectile and the amount of charge should be proportional to the caliber of the artillery; Created a new type of siege artillery vehicle; designed a variety of convex turrets that are easy to take advantage of firepower.

"Xifa Shenji" fully reflects Sun Yuanhua's thoughts on firearm design.He believes that the development of firearms must be rational, "deduce the beauty of physics", and conform to the characteristics of things before they can be made into suitable finished products.After a series of test shots on the relationship between the range of the artillery and the angle of fire, it was pointed out that if the shooting of the artillery starts from the straight shooting position, that is, zero degrees, the range of the artillery will gradually increase with the increase of the elevation angle. close.In addition, Sun Yuanhua believed after research that the shells do not fly in a straight line after being fired from the barrel, but "use their straight and curved momentum; if the curved momentum is more than half, they cannot kill people."It means that when the cannonball flies in the air, it not only flies forward in a straight line, but also falls under the gravity of the earth, forming a curved trajectory. After passing the apex of the curve, the speed slows down, the kinetic energy decreases, and the lethality weakens. Finally, the speed is zero and the lethality is reduced. disappear.Although his discussion is not as thorough as that of Galileo Galilei (1564-1642 A.D.) on parabolas, it is not far behind, and it is a major breakthrough in ancient Chinese ballistic theory.In his "Illustrations of the Guntai", he made a preliminary explanation of the reasons for the strong vibration after the firing of the large artillery: when the artillery is fired, "the air of the gun exits, the air is excited, and the movement of the air is the fastest, so all the valleys are answered ( That is, the echo), if it is close and cracks, it can dislodge walls and shake stones."This is a simple explanation of the phenomenon of shock waves generated after the launch of large shells, and it is also a great progress.