Our daily life can not be apart from using glass, but do you know process of making a glass is not easy as we think. It is quite complicated. Glass is made by a combination of sand, flint, soda, and limestone. In some case, it is also added with one or other of the fixed alkali or with a metallic oxide. All of those substances are put into a furnace to be burnt. The heat in the furnace must be kept up until the glass is brought to a state of perfect fusion. And during this process any scum which arises must be removed by ladles. When the glass is perfectly melted, the glass-blowers commence their operations.
The next step is separation of mixture to make two kinds of glass. They are adapted to different uses. They are plate glass and bottle glass. There is a little different process between them. For the bottle glass, the mixture from furnace is flowed through with air, while for the plate glass the mixture is directly flowed to rollers to be formed. The plate is cast 1/2 an inch thick or more, and is ground down to a proper degree of thickness, and then polished. Meanwhile, the mixture of bottle glass is flowed into removable mold. It needs a period of time to wait the mixture is formed to be bottle. After it is dried off mold is removed. By following these directions, we know a new knowledge of making glass.