how did jack o lanterns get their name
The term jack-o'-lantern was originally used to describe the visual phenomenon ignis fatuus (lit., "foolish fire") known as a will-o'-the-wisp in English folklore. Used especially in East England, its earliest known use dates to the 1660s. The term "will-o'-the-wisp" uses "wisp" (a bundle of sticks or paper sometimes used as a torch) and the proper name "Will": thus, "Will-of-the-torch." The term jack-o'-lantern is of the same construction: "Jack of (the) lantern."