when did the chinese first use gunpowder as a weapon
History of gunpowder At this point the formula contained too little saltpeter (about 50%) to be explosive, but the mixture was highly flammable, and contemporary weapons reflected this in their deployment as mainly shock and incendiary weapons. One of the first, if not the first of these weapons was the fire arrow.[13] The first possible reference to the use of fire arrows was by the Southern Wu in 904 during the siege of Yuzhang, when an officer under Yang Xingmi by the name of Zheng Fan (鄭璠) ordered his troops to "shoot off a machine to let fire and burn the Longsha Gate," after which he and his troops dashed over the fire into the city and captured it, and he was promoted to Prime Minister Inspectorate for his efforts and the burns his body endured.[14] A later account of this event corroborated with the report and explained that "by let fire (飛火) is meant things like firebombs and fire arrows."[13] Arrows carrying gunpowder was possibly the most applicable form of gunpowder weaponry at the time, as early gunpowder may have only produced an effective flame when exposed to oxygen, thus the rush of air around the arrow in flight would have provided a suitable catalyst for the reaction.[13]
Machine gun The first successful machine-gun designs were developed in the mid-19th century. The key characteristic of modern machine guns, their relatively high rate of fire and more importantly mechanical loading,[4] first appeared in the Model 1862 Gatling gun, which was adopted by the United States Navy. These weapons were still powered by hand; however, this changed with Hiram Maxim's idea of harnessing recoil energy to power reloading in his Maxim machine gun. Dr. Gatling also experimented with electric-motor-powered models; this externally powered machine reloading has seen use in modern weapons as well.