Mayne Reid. The headless horseman (№ 330225)

On the North side of the Prairie suddenly there were some completely black columns. They had no specific shape and were continually changed in size and shape;they stood motionless, then glided over the charred earth like a giant on skates, bending and leaning to each other, as if in fantastic shapes, some kind of dance. Imagine the legendary titans that come to life on the Prairie of Texas, and danced in a frenzied Orgy.