Also known as spud guns, potato cannons are inexpensive and often homemade devices that use air pressure or combustion to launch potatoes—or other projectiles—at high speed. Typically built and used by hobbyists, potato cannons are usually made of plastic piping, which is readily available at hardware stores. They are inherently dangerous but are generally not illegal. Similar devices include hail cannons, bird-scarers, and chicken cannons, which are used for what specific, practical purposes? Discuss