Ever since the invention of rockets 30 years previously by Feng Yisheng, the Ministry had been developing new devices, such as smokescreen shells, "spiny fireballs" able to halt the advance of enemy cavalry, and incendiary projectiles for setting fire to the enemy's stocks of materiel.
自從三十年前馮義昇發明火箭以來，北宋的兵器部門不斷地研發新的火炮：煙球能發放煙幕，蒺藜火毬可以阻擋敵人軍馬前進，火毬可以用來燃燒敵人的戰略物資。