The piece of machinery is used in the hay field. It is pulled by horses or oxen with the curved steel rods down on the ground and when the hay fills the area below the operator's seat, the operator steps on a pedal that engages a gear on the wheels to lift the series of curved rods thereby dumping the hay. This dumping of the hay gives the operator a bucking motion as the hay is released below him. The dumps are laid out in a line across the field to facilitate the hay wagons driving along the rows of dumped hay for loading onto the wagon. Horses and oxen are usually trained to move along the row with a voice command by one of the workers pitching hay onto the wagon. We even had these buck racks in Oklahoma when I was young.