Today's Gypsies, who have lived in Prague for only two generations, light a ritual fire wherever they work, a nomads' fire crackling only for the joy of it, a blaze of roughhewn wood like a child's laugh, a symbol of the eternity that preceded human thought, a free fire, a gift from heaven, a living sign of the elements unnoticed by the world-weary pedestrian, a fire in the ditches of Prague warming the wanderer's eye and soul.