text: Major developments: Bomb shells gain an iron casing. Fire lances are equipped with projectiles and reusable iron barrels. Rockets are used in warfare. "Fire emitting tubes" are produced in the Song dynasty by the mid-13th century and hand cannons are recorded to have been used in battle by the Yuan dynasty in 1287. The earliest extant cannons appear in China. The Mongols spread gunpowder weaponry to Japan, Southeast Asia, and possibly the Middle East as well as Europe. Europe and India both acquire gunpowder by the end of the century, but only in the Middle East are gunpowder weapons mentioned in any detail.