EVER WONDER: Glass Making
By Jacque Scott
Ever think about everyday glass and how it came to be? It might surprise you if you learned that glass really is made in about the same way that you make taffy? First the materials are boiled together until the mixture is just right, and then it is poured into molds, or blown into bubbles of various shapes, or rolled into plates.
This seems a strange way of making something hard but brittle, doesn’t it? But, there are only a few basic things that make up everything and these are called elements. It is how they are put together in different combinations that give us all of the things that we see around us. You know how iron is melted and mixed with other materials to give us steel. In the same way sand, which is silica, and soda, or potash, are melted together. The mixture is then cooled and allowed to harden into what we call glass.
Before people learned to make glass, they had found two forms of natural glass. When lightning strikes sand, the heat sometimes fuses the sand into long, slender glass tubes called fulgurites, which are commonly called petrified lightning. The terrific heat of a volcanic eruption also sometimes fuses rocks and sand into a glass called obsidian. In early times, people shaped obsidian into knives, arrowheads, jewelry, and money. We do not know exactly when, where, or how people first learned to make glass, but it is believed that the first manufactured glass was in the form of a glaze on ceramic vessels.
Some people say that it really was the early Mesopotamians that gave us the art of glass making, because some pieces of well made glass have been found dating back to the third millennium BC. It can be traced back to 3500 BC in Mesopotamia. Archaeological evidence suggests that the first true glass was made in coastal north Syria or Mesopotamia. Then they gave it to the Egyptians.
But the early Egyptians might have found out how to make glass by accident. The soil there is mostly sand, and in Egypt straw stacks were burned. They would find lumps of glass in the ashes. Today we would probably think that an old soda bottle had melted but in old Egypt there were no glass bottles or manufactured glass of any kind. The sand had melted with the heat of the fire and mixed with the potash from the ashes. Those materials joined and hardened to become glass.
As the Egyptians got better at the art of glass making, they used an interesting method called core-forming. A shaped core was made of clay and dung, and molten glass was wrapped around it. It was then shaped by rolling it on a smooth surface.
Glass blowing came in at the end of the first century BC and revolutionized glass production. By blowing thru a hollow tube, the glass blower could make intricate things at the end of the tube.
So, the Mesopotamians probably taught the Egyptians, who taught the Greeks, who taught the Romans. Eventually, Venice, Italy became the most famous city in the world for making fine glass products. The Venetians spun glass into very fine threads and made wonderful colored glass windows for churches.
Another question answered… Don’t feel like you could do well on Jeopardy or maybe that Trivia board game next time the family has game night? God bless you.
