NATIONAL

[ ACCELERATED WEATHERING AND FADING APPARATUS, BEING APPARATUS FOR TESTING OR DETERMINING THE EFFECT OF LIGHT, WATER, MOISTURE, TEMPERATURE, ATMOSPHERIC CONDITIONS, REFRIGERATION, HEAT, ETC., ON MATERIALS SUCH AS PAINTS, VARNISHES, LACQUERS, ASPHALT, RUBBER, TEXTILES, SYNTHETIC PLASTICS AND PROTECTIVE COATINGS, ON THE COLOR FASTNESS OF DYES, PIGMENTS, ETC., AND ARC LAMPS AND CARBONS USED IN SUCH APPARATUS; ] CARBONS FOR USE IN MOTION PICTURE PROJECTOR, MICROPROJECTOR, STEREOPTICON, PHOTOGRAPHIC, PHOTOENGRAVING, AND BLUE PRINT APPARATUS AND IN OTHER MEASURING AND SCIENTIFIC APPLIANCES; ELECTRODES AND GRAPHITE POWDER FOR USE IN SPECTROSCOPIC ANALYSIS APPARATUS AND IN OTHER MEASURING AND SCIENTIFIC APPLIANCES