GB111986A - Improvements in and connected with Prismatic Glassware for Illuminating Purposes. - Google Patents

Abstract

111,986. Holophane, Ltd., (Holophane Glass Co.). July 26, 1917. Globes; shades.-In a glass globe or shade comprising two layers of glass having prisms on one or both the surfaces which face each other, a part of the globe or shade is formed of one layer of glass only. One of the layers may be of blown glass and the other of pressed prismatic glass. In one form, the upper part of the outer member is of pressed glass and the lower part is preferably of blown glass. The inner member, made preferably of pressed glass, extends only down to a plane passing through or just below the source of light. The whole or part of the outer surface of the outer member may be etched or sand-blasted. In a modification in which the shorter member is outside instead of inside the larger member, the facing surfaces may be etched or sand-blasted. Fig. 3 shows a glass reflector in which the part below a plane passing through the source of light is double. The outer member 1 may be etched or sand-blasted, or may be of opal or coloured glass. Fig. 4 shows a glass reflector for indirect lighting. The outer member is preferably of blown glass 1 and the inner member 3, which extends over the lower part only, has prisms on its outer surface.