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.
McCall has explained how the work should be installed and how its filmic and three-dimensional elements combine in a way that encourages interaction from viewers:
The proportions of this projection vary, but the scale is large. The base of the cone, an emerging circle of light projected onto the wall, is tall enough, at between eight and eleven feet, to fully incorporate several spectators, and the length of the beam may be anything from thirty to sixty feet. This three-dimensional object, like sculpture, calls for a mobile, participating spectator, and, like film, it takes time. To fully see the emerging form it is necessary to move around and through it, to look at it from the inside and from the outside…