Napalm was originally delivered in a 100 lb chemical-weapons bomb, the M47. In the strategic bombing campaign against Japan, napalm incendiaries were responsible for the significant destruction of Japanese cites by fire. Boeing B-29 pathfinder aircraft dropped the M47, and the bulk of the following bombers dropped clusters of 6.2 lb M69 bombs. The M69 ignited and ejected the napalm fill from its tail after a delayed fuze allowed the bomb to penetrate the building that it hit. After mid-1944, the U.S. tactical air forces employed a wide variety of sizes of firebombs or napalm bombs against Japanese forces and defensive positions. These bombs were often auxiliary fuel tanks that were simply filled with the napalm mix and equipped with an igniter. Napalm attacks were often cited for their psychological value as well as for their physical destruction. After World War II, napalm continued to be used as a generic term for fire-producing weapons, even though the original components that provided the name were no longer used.
Jerome V. Martin
Birdsell, Dale, and Brooks E. Kleber. The Chemical Warfare Service: Chemicals in Combat. Washington, DC: Office of the Chief of Military History, U.S. Army, 1966.; Bjornerstedt, Rolf, et al. Napalm and Other Incendiary Weapons and All Aspects of Their Possible Use. New York: United Nations, 1973.; Kerr, E. Bartlett. Flames over Tokyo: The U.S. Army Air Forces' Incendiary Campaign against Japan, 1944–1945. New York: Donald I. Fine, 1991.; Stockholm International Peace Research Institute. Incendiary Weapons. Cambridge, MA: Massachusetts Institute of Technology Press, 1975.