Abstract: Glass is mass-produced with a glass melting furnace comprising a melting tank, at least a wall surface in contact with molten glass thereof being made of refractory material, at least one pair of electrodes placed so as to be in contact with the molten glass held in the melting tank for ohmically heating the molten glass held in the melting tank; and at least one metallic member, at least a surface of which is made of metal and placed so as to be substantially always in contact with the molten glass held in the melting tank. Every metallic member is, when the melting tank is filled with the molten glass, placed so as to be substantially always outside an electric current flowing region which is formed by the electrodes into the molten glass held in the melting tank.

Abstract: Glass is mass-produced with a glass melting furnace comprising a melting tank, at least a wall surface in contact with molten glass thereof being made of refractory material, at least one pair of electrodes placed so as to be in contact with the molten glass held in the melting tank for ohmically heating the molten glass held in the melting tank; and at least one metallic member, at least a surface of which is made of metal and placed so as to be substantially always in contact with the molten glass held in the melting tank. Every metallic member is, when the melting tank is filled with the molten glass, placed so as to be substantially always outside an electric current flowing region which is formed by the electrodes into the molten glass held in the melting tank.

Abstract: A process for the production of a molded glass article is disclosed, said process comprises the steps of: applying wet treatment to a surface of a lead oxide-containing glass material, thereby forming a hydrated layer having a lower lead oxide content than that of a basic glass; heating the glass material having the hydrated layer; and press-molding the heated glass material. According to the process, a molded glass article having no cloudiness can be obtained and lead is not deposited on the surfaces of the molds used.

Abstract: On shearing a melted glass stream flowing along a first direction at a first speed into a melted glass lump flowing along the first direction at a second speed faster than the first speed by a cutter section, the cutter section is closed and opened along the first direction and is also moved in a second direction substantially perpendicular to the first direction. While the cutter section is moved in the second direction, the motion of the cutter section is controlled at a third speed between the first speed and the second speed.