Pen Huo Qi

The Pen Huo Qi（Chinese: 噴火器; Pinyin: pen huo qi, "spray fire device"） is a double-piston pump naphtha flamethrower used in 919 CE in China, during the Five Dynasties and Ten Kingdoms period. The flamethrower was carefully documented and illustrated in the Chinese military manual known as the Wujing Zongyao, compiled in the year 1044 AD during the Song Dynasty. Among various descriptions of equipment and components of the device, the book also provided instructions for how to keep up maintenance and repair of double-piston flamethrowers.

Advances in military technology aided the Song Dynasty in its defense against hostile neighbors to the north, including the Mongols. The earliest reference to the flamethrower in China was made in 917 CE, written by Wu Renchen in his Spring and Autumn Annals of the Ten Kingdoms. In 919 AD, the siphon projector-pump was used to spread the 'fierce fire oil' that could not be doused with water, as recorded by Lin Yu (林禹) in his Wu Yue Bei Shi (吳越備史, "The History of Wu and Yue"), hence the first credible Chinese reference to the flamethrower employing the chemical solution of Greek fire Lin Yu mentioned also that the 'fierce fire oil' derived ultimately from China's contact in the 'southern seas', Arabia (Dashiguo, 大食國, "Great Food Country"). In the Battle of Langshan Jiang (Wolf Mountain River, 狼山江) in 932, the naval fleet of the Wenmu King of Wuyue defeated the fleet of the Kingdom of Wu because he had used 'fire oil' (huo yóu, 火油) to burn his fleet; this signified the first Chinese use of gunpowder in warfare, since a slow-burning match fuse was required to ignite the flames. The Chinese applied the use of double-piston bellows to pump petrol out of a single cylinder (with an upstroke and downstroke), lit at the end by a slow-burning gunpowder match to fire a continuous stream of flame (as referred to in the Wujing Zongyao manuscript of 1044 CE). In the suppression of the Southern Tang state by 976 CE, early Song naval forces confronted them on the Yangtze River in 975 CE. Southern Tang forces attempted to use flamethrowers against the Song navy, but were accidentally consumed by their own fire when violent winds swept in their direction. Documented also in later Chinese publications, illustrations and descriptions of mobile flamethrowers on four-wheel push carts appear in the Wujing Zongyao, written in 1044 AD (its illustration redrawn in 1601 as well).