Abstract: The problem of focusing the radiant energy collected by a heliostat at a fixed point as the collector tracks the sun is resolved by mounting the reflector on a circular frame such that its focal point is located along the axis of symmetry of the frame. Means are provided for pivoting the reflector axis about its focal point. This includes a plurality of parallel, curved tracks, each of which is a portion of a circle that intersects the circular frame, and means for rotating said tracks about the frame. With the plane of the frame inclined at an angle to the surface of the earth that is the complement of the site's latitude location, the focal point is advantageously positioned between the plane of the frame and the surface of the earth.