“All-electric melter” means a glass melting furnace in which all the heat required for melting is provided by electric current from electrodes submerged in the molten glass, although some fossil fuel may be charged to the furnace as raw material. “Glass melting furnace” means a unit comprising a refractory vessel in which raw materials are charged, melted at high temperature, refined, and conditioned to produce molten glass. The unit includes raw material charger systems, heat exchangers, melter cooling systems, exhaust system, fuel supply and electrical boosting equipment, integral control systems, and instrumentation and appendages for conditioning and distributing molten glass to forming apparatuses. “Opal recipe” means raw material formulation of the following approximate proportions: 72 percent silica; 15 percent soda; 10 percent lime and magnesia; 2 percent alumina; and 1 percent miscellaneous materials.