Edward R. Lewis (1800s) – Spring gun
There is debate about who invented the spring gun to scare away trespassers. While some sources attribute its invention to Edward R. Lewis, the patent he was granted in 1887 pertained to a toy. The toy consisted of a metal tube on a wooden support with a wire trigger mechanism that required only a simple motion to activate the trigger release. The wire was attached to a holder, and the trigger would release when the holder was disturbed, causing the toy to shoot a projectile. While Lewis did not mention using the toy as a booby trap, some people may have repurposed it for that use.