Many Uses For Glass Discovered In The
Centuries Since It Was First Made
Talks About Common Things was written in 1891. Its purpose, as indicated by the name, is to give information about the familiar objects around us, and was especially intended as a teacher’s aid at that time. The material contained is very basic, but interesting from a viewpoint 125 years later, both as to how things have changed and, perhaps even more how they have not changed.
The following excerpt is from “Glass.”
“Glass is composed of a mixture of fine sand with soda, potash or some such material. Such substances are called alkalis. The sand and alkali are placed in a large furnace the shape of a cone. The fire is in the center and the melting pots are placed in a circle around it.
Strong heat is applied and soon the mixture is reduced to a soft, sticky mass. The workmen use long pipes with which they dip out portions of the melted glass. They then blow it into molds, the shape of bottles, vases, etc. they wish to make.
The varieties of glass now in use are made by slight changes in the manner of manufacture.Flint glass is made by using powdered flint [silicon dioxide] instead of sand. Glass made from this material is very clear and transparent. It is used for eyeglasses and optical instruments, and also for imitating precious stones.
Plate glass is used for very large windows such as are found in stores and public buildings. It is made by spreading the melted glass upon a flat plate of copper and making it level with a heavy roller. When it is cold it is polished with putty and emery until it is smooth. This glass is very expensive.
In making mirrors, the glass undergoes a process called annealing. The glass is placed so near the fire that it will become warmed through without melting. It is then allowed to cool very slowly. This operation prevents the glass from breaking easily. One side of the glass is then covered with quicksilver [mercury.] It will then reflect objects in front of it and is made into mirrors.
Crown-glass is the most common kind of glass. It is used for window-panes, tumblers and dishes.
Bottle-glass is made of the old melted glass that is left after different articles have been made. It is of a very poor quality and is dark in color.
Enamel is the name that is given to glass which is white like milk, and opaque. Oxide of tin is added to the melted glass to give it this color. Watch dials are made of it, and ornaments.
The following story has been handed down from former generations in relation to the art of making glass. Its truth cannot be vouched for, however.
“A party of pirates landed on the shore, somewhere in the northern part of Africa. They built a large fire of seaweed with which to cook their food. After the fire had burned out, they found pieces of glass in the ashes. The sandy ground upon which the fire had been built, and the alkali in the seaweed had united and the heat of the fire had converted them into glass.”
The Egyptians manufactured glass thousands of years ago, and from it made beads and imitation gems, also curious urns and drinking vessels.
The first country of Europe to engage in the manufacture of glass was Italy. From there it was introduced into England and later by the English to the United States.
For many centuries glass was very expensive and only royal families could afford articles made of it. It is now so plentiful and cheap that all may possess it in some form.”
Talks About Common Things was found at an estate sale in eastern Oregon.
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