Moving away from his Rickey’s earlier Calderesque mobiles, Planes and Circles, from 1957, demonstrates the additive manner in which Constructivist sculptures built form. Wire circles capped with flat, rectangular, polychrome stainless steel planes sit on several parallel wires that fit tightly together and complete the top edge of a square frame. The circles are secured to the square by a pendulum that swings on a pair of bearings. The planes, attached tangentially to the wire circles, leave the circles unbalanced and prompt their pivoting motion. As the circles rotate, the planes emphasize their movement. Rickey constructed form in the space within the outline of the core square and the wire circles and, further, through the colored rectangular planes that create a circular volume as they trace a path of motion.

from Kephart, Passages of Light and Time: George Rickey's Life in Motion (Notre Dame, 2009)