cellulose dinitrate (pyroxylin). In a circus performance, gunpowder may be used to provide visual and auditory effects unrelated to the launching mechanism. Fireworks and smoke may also be used to increase the visual effect. The largest retailer of these human cannons is located in Greensburg, Pennsylvania. This supplier provides approximately 80% of all human cannon catapults. Risk More than 30 human cannonballs have died during the performance of this stunt. Among the latest was that which occurred in Kent, United Kingdom on April 25, 2011, where a human cannonball died as a result of the failure of the safety net. Landing is considered to be the most dangerous aspect of the act. Special forces The human cannonball principle is the subject of a patent application by the US Defense Advanced Research Projects Agency, whereby a rail-guided chair driven by compressed air is brought to a sudden stop, propelling the special forces member, police officer or firefighter onto the roof of a tall building. See also Frank "Cannonball" Richards William Leonard Hunt Ildebrando Zacchini Zacchini v. Scripps-Howard Broadcasting Co. Cannonball ride – a plot device used for example in the tales about Baron Munchausen and in the 1911 film The Adventures of Pinocchio References Further reading Shane Peacock. The Great Farini: The High-Wire Life of William Hunt (1995), . Richard Hooper. Flight of the human cannonballs, BBC News Magazine, BBC World Service, 3 September 2013 (with photos). External links The Human Cannonball in Action (video) BBC News article on being a human cannonball BBC News article on a female human cannonball The Straight Dope page about human cannonballs Human Cannonball (song by Loudon Wainwright III) Circus skills Shooting sports