Edward Lewis had a problem with people trespassing on his property, especially poachers. Unfortunately, the only way to prevent people from coming on to his his land would be to hide out on the property at all hours, day and night.
Lewis solved this problem by developing a spring gun, which he patented on May 3, 1887. The spring gun was made of a metal tube which sat atop a block of wood with a wire attached to a trigger mechanism. The other end of the wire ran across the ground or was stretched across an area and attached to a post or a tree. Anyone disturbing the wire would cause the gun to discharge, thereby shooting the trespasser.