Line Describing a Cone is made from a beam of white light emitted from a film projector positioned at one end of a darkened room. Passing through the projector is an animated film of a thin, arcing line that, frame by frame, gradually joins up to become a complete circle. Over the course of thirty minutes this line of light traces the circumference of the circle as a projection on the far wall while the beam takes the form of a three-dimensional hollow cone. Mist from smoke machines gives the beam of light a greater density, making it appear almost tangible.