Color reversible, mirror surface glassy materials from plumbite-treated cellulosics

Claim 1

A PROCESS FOR IMPARTING TO SILICA GLASS OR CERAMICS REVERSIBLE SURFACE COLORATIONS WHICH ARE VISABLE FROM THE ONE SIDE IN A MIRROR-LIKE FINISH, WHEN VIEWED FROM THE SAME SIDE AS THE LIGHT SOURCE, AND ARE SEMI-TRANSPARENT OR CLEAR WHEN VIEWED FROM THE OPPOSITE SIDE, THE SAID PROCESS COMPRISING: A. CONTACTING A PLUMBITE-TREATED CELLULOSIC SHEET FLATLY AGAINST A SILICA GLASS OR CERAMIC SURFACE, THE SAID CELLULOSIC SHEET CONTAINING ABOUT FROM 8% TO 15% LEAD, B. HEATING THE CONTACTED MATERIAL IN A CLOSED OVEN, OR OTHER LIMITED OXYGEN ENVIRONMENT, AT A TEMPERATURE OF BELOW 200*C. AND ELEVATING SAID TEMPERATURE TO ABOUT FROM 600* TO 800*C. AND MAINTAINING THE ELEVATED TEMPERATURE FOR A PERIOD OF ABOUT 60 MINUTES TO OBTAIN A CHEMICALLY BOUND UNIT OF ASSEMBLED COMPONENTS WITH HARD SURFACES, C. COOLING THE SAID UNIT SLOWLY TO AVOID FRACTIONATION OF THE COMPONENT PARTS, AND D. REHEATING THE PLUMBITE-TREATED SIDE OF THE SAID UNIT WITH A GAS-AIR FLAME OF ABOUT FROM 1,000* TO 1,500*C. TO OBTAIN COLORATIONS IN THE GOLD, SILVER, AND PURPLE RANGE UPON HEATING FOR PERIODS OF ABOUT FROM 1 TO 5 MINUTES, THE LESSER QUANTITIES OF HEAT YIELDING THE GOLDEN TONES, THE MEDIUM QUANTITIES THE SILVER TONES, AND THE HIGHER QUANTITIES THE PURPLISH TONES.