ABSTRACT
Glass, formed by the reaction at high temperature, of sand, soda, lime and certain other ingredients, is made in a large gas-fired tank furnace, by heating to a temperature around 1,500 degree C. To form the molten glass into a sheet, it first passes from the tank into a drawing kiln, a relatively small extension to the tank and separated from it above the level of the glass surface by a “tweel” and “shut-off.” Sheet Glass is the most commonly used glass for general glazing. It is fire-finished, and in consequence the two surfaces are never perfectly flat or parallel. This accounts for a certain amount of distortion of vision and reflection which is unavoidable with this type of glass. Sheet Glass is made in various thicknesses which are described in terms of ounces per square foot. Sheet Glass is commonly used in factories, housing estates, and for horticultural purposes.
