<P> In the 1840s the invention of vulcanized rubber allowed the making of small hand - held catapults, either improvised from Y - shaped sticks or manufactured for sale; both were popular with children and teenagers . These devices were also known as slingshots in the USA . </P> <P> Special variants called aircraft catapults are used to launch planes from land bases and sea carriers when the takeoff runway is too short for a powered takeoff or simply impractical to extend . Ships also use them to launch torpedoes and deploy bombs against submarines . Small catapults, referred to as "traps", are still widely used to launch clay targets into the air in the sport of clay pigeon shooting . </P> <P> In the 1990s and into the early 2000s, a powerful catapult, a trebuchet, was used by thrill - seekers first on private property and in 2001 - 2002 at Middlemoor Water Park, Somerset, England to experience being catapulted through the air for 100 feet (30 m). The practice has been discontinued due a fatality at the Water Park . There had been an injury when the trebuchet was in use on private property . Injury and death occurred when those two participants failed to land onto the safety net . The operators of the trebuchet were tried, but found not guilty of manslaughter, though the jury noted that the fatality might have been avoided had the operators "imposed stricter safety measures ." Human cannonball circus acts use a catapult launch mechanism, rather than gunpowder, and are risky ventures for the human cannonballs . </P> <P> Early launched roller coasters used a catapult system powered by a diesel engine or a dropped weight to acquire their momentum, such as Shuttle Loop installations between 1977 - 1978 . The catapult system for roller coasters has been replaced by flywheels and later linear motors . </P>

When did leonardo da vinci invent the catapult