Horror, Sleaze and Trash.

Throughout the 18th and 19th century, grave-robbing was quite prevalent. Due to this, many cemeteries were protected with cemetery guns. The one above is from the Museum of Mourning Art. The gun sits on a turret, allowing it to move freely. It would be set up with a tripwire, meaning that when the unsuspecting grave robber got close to the grave that he intended to rob, he would trigger the weapon, killing him.