Abstract: A reflector apparatus comprises an upright elongated cylinder having a circular wall closed at one end by a semi-spherical hollow cavity wall, and closed at the other end by a plug fitted within the circular wall of the cylinder and fixed therein, the plug tapered downwardly to an elongated axial stake having a downwardly directed point. A rod extends axially upwardly from the semi-spherical hollow cavity wall for receiving a reflective plate, and a series of reflective stripes are circumferentially positioned in spaced arrangement over an outer surface of the circular wall.

Abstract: A particulate refractory mixture is disclosed which is suitable for combination with water to form a castable refractory having high strength, low porosity and enhanced resistance to molten aluminum. The mixture consists essentially of 79.5-89.5% by weight alumina, 10-20% by weight calcium aluminate and 0.5-1.5% by weight borosilicate frit.