The Virginia rebels have invented a diabolical instrument to cripple the horses of our cavalry. It is constructed of four pieces of rod iron, sharpened less than a quarter of an inch in thickness, and about two inches long. Four of the ends are made to centre together, and they project from the middle in the form of arms. To the extreme end of each is welded out a very sharp spherical point. These are intended to be sprinkled through the woods and over the roads, to prevent the advance of cavalry. No matter how thrown, one of the points will stand perpendicularly, and when the horse treads upon it, it will enter his foot, and disable him on the spot.
(Liberator, Feb 20, 1863, pg 1)