CHAPTER IV.

CRUCIBLES AND FURNACES FOR THE FUSION OF GLASS.

Fire-clay and silica-brick--Manufacture of glass-melting pots--Drying and first heating of pots--Blocks for tank and other furnaces--Uses of silica brick--Furnaces-- Coal-fired and gas-fired furnaces--Gas producers-- Regenerative furnaces, principles and construction of Siemens’ furnaces--Recuperative furnaces--General arrangements of modern tank furnaces--Relative advantages of tank and pot furnaces _p._ 54