This is a name that is sometimes applied to a phenomenon perhaps more frequently called Jack-o'-the-Lantern, or Will-o'-the-Wisp. It seems to be a ball of fire, varying in size from that of a candle-flame to that of a man's head. It is generally observed in damp, marshy places, moving to and fro; but it has been known to stand perfectly still and send off scintillations. As you approach it, it will move on, keeping just beyond your reach; if you retire, it will follow you. That these fireballs do occur, and that they will repeat your motion, seems to be established, but no satisfactory explanation has yet been offered that I have heard. Those who are less superstitious say that it is the ignition of the gases rising from the marsh. But how a light produced from burning gas could have the form described and move as described, advancing as you advance, receding as you recede, and at other times remaining stationary, without having any visible connection with the earth, is not clear to me.