A mobile supporting two spotlights and a fan hangs from the ceiling and rotates freely in the space. The main arm of the mobile has a spotlight on one end and another, identical arm suspended from a cable on the other. A second spotlight is mounted to one end of this pole, while a mechanical fan dangles from the other end just above the visitors’ heads. The fan causes the mobile to rotate so that two circles of light travel along the gallery walls, scanning the space.