The Mythology & Folklore Database
His light was seen on dark nights like a lighted lantern on the sheep-paths on the hillsides. If he happened to be far off, no one was deceived, as his ungainly movements betrayed him as "Lantern Jack in search of his sheep," and as the saying goes:
An ignis fatuusThe time when he generally succeeded with his mischief was when he found someone all alone travelling a path on open fields. He would begin by appearing as a small speck of fire, of a clear blue flame, which he moved before the wayfarer along the middle of the path until his attention had been secured; then the flame would gradually grow until its brightness would completely blind him, after which the traveller was entirely at Jack's mercy, and he would lead him where he pleased.
Deceives not many of us.
Stories are related of men who have been led miles out of their way in this manner, especially young men going to see their sweethearts on dark winter nights.