A little about the making of glass - Part II

by Evelyn M. Allen
Issue #17 - September 1974

The first Glass Makers came to America in 1608, with the Virginia Colonists. Glass making was America's very first industry. At Jamestown still stands an operating replica of a glass house built by the Colonists. They imported ware to England. Success was short lived, but in 1621 the London Company started another "glass~house" at the same place to mint glass beads to use in trade with the Indians. The product must not have met satisfaction with the Indians because they "burned out" this mint and "Old Jamestowne" on March 22, 1622. It didn't stop the glass-makers. Glass making in the New World became fairly well spread.

In 1654 Smedes opened a plant at New Amsterdam, Wistar in New Jersey about 1750, in Pennsylvania by Steigel about 1760, Amelung in Maryland in 1785 O'Eara in Pittsburgh 1797, Duval in (West) Virginia 1813, Carothers in Wheeling 1820, and the Sandwich Glass Company by Jarvis in Massachusetts about 1825. The industry reached out into New York State and further into the Ohio Valley area. Cambridge Glass Company was founded in 1901 and sold to Imperial Glass Company of Bellaire, Ohio in 1960.

The glass industry is one of the very few that starts its manufacturing with basic raw materials. The raw materials are all chemicals. Some are mined as minerals, others created especially for the glass industry by chemical process. A simple glass can be made from Silica Sand, Soda Ash, and Limestone. The major raw material is Silica Sand, a pure white sand mined washed and cleaned. The purity of this depends, to a large extent, on the final quality of the glass.

Next in importance is Soda Ash, Potash, nitrate of Soda, and Nitrate of Potash. Alkalies, which are all manufactured products. Equal to the proceeding are Limestone, Burned Lime and Lead Oxide, In addition to those principal components, a number of other materia1s are used for the purpose of refining, others for giving the glass specific chemical or physical properties, giving the glass opacity, brilliance or clarity and others for creating colors. In the latter group are metals or metal oxides which are used in the most concentrated and purest form. Impurities of natural minerals or manufactured chemicals, particularly oxide of iron, are the worst troublemakers of the glass maker. Purity of all raw materials is very necessary. Great care in selecting of raw materials, shipping, storing and handling also is a necessity.

More next month.