Glassmaking

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GLASSMAKING

GLASSMAKING. American glassmaking at the beginning of the twenty-first century is a vast industry supplying global markets. Flat glass, used for fenestration, the automotive industry, and television and computer screens, accounts for the bulk of production; American glass works provide immense amounts of glass for international building projects. Though basic techniques of the modern flat glass industry have been in place since the mid-twentieth century, continual improvements are made in manufacturing, especially in developing new combinations of layering and coating glass for specific purposes.

Early American Glassmaking

An early attempt at glassmaking took place in Jamestown, Virginia, in 1608. Production was probably limited to blowing crude bottles and glass beads used as barter with Native Americans. Other glass works came and went in Massachusetts, New York, and Pennsylvania until 1780, when a glass factory was established in Glassboro, New Jersey. This glass works passed through many ownerships until 1919, when Owens Bottle Company bought and modernized it with automatic production.

Two names stand out in early American glassware. The first is Henry William Stiegel (called "Baron" Stiegel). Stiegel became, through marriage, the owner of an iron furnace, and went on to own a second iron furnace and three glass manufacturing houses. Between 1763 and 1774, Stiegel's factory in Manheim, Pennsylvania, produced superior decorated and colored flint glassware (also called lead glass), a heavy, brilliant glass that is used also to make paste jewelry. Stiegel's success inspired other glassmakers, and glassmaking spread to Pittsburgh and the Ohio River Valley. These new glass works not only supplied window and bottle glass to the newly settled country, but also created table glassware with discernible Midwestern designs. The second important name in early American glassware is John Frederick Amelung, who established the New Bremen Glassmanufactory in Frederick County, Maryland, in 1784. Using free-blown, mold-blown, cut, and particularly impressive engraved methods,

Amelung produced items that were as advanced as high-quality European glassware.

New Glassmaking Techniques

In the first quarter of the nineteenth century, glassmakers in America began to use two significant techniques. Factories in New York, New England, and Pennsylvania adopted a technique called "blown three-mold": usually three molds were needed for each piece, and the glass-maker would blow glass into incised metal molds to produce imitation cut glass. In Pittsburgh, at the New England Glass Company in Boston, and at the Boston and Sandwich Glass Company in Sandwich, Massachusetts, glass was at first pressed into a mold by hand, but after 1825 mechanical means were used. This innovation boosted small family businesses into a flourishing industry that spread across the country and abroad. Fancy-looking, inexpensive glassware became readily available as techniques improved. Using coal instead of wood for melting furnaces gave higher, more consistent temperatures. Natural gas, discovered in western Pennsylvania in 1859, proved to be even more controllable and cheaper than either coal or wood. American glassware companies, benefiting from increasing numbers of skilled European immigrants, produced distinctive articles in varying shapes, colors, and effects.

Sheet glass in the eighteenth and nineteenth centuries was made by blowing glass, using one of two methods. The Boston Crown Glass Company used the crown method from 1793 to about 1827: glass was blown, rotated to form a large plate, then cut and formed into rectangular sheets. The cylinder method required a large (six foot by two foot) cylinder to be blown, then opened to form a flat sheet. This became the more popular method because it created larger panes.

Twentieth-Century Innovations

By the twentieth century, flat glass was produced mechanically by drawing glass upward with a metal rod or bait and onto a metal roller. The glass was then passed over a flattening table to be cut into large sheets and commercially sized panes.

Wherever flat glass had to be free from distortion—in mirrors, auto glass, and shop-front windows—plate glass was formed by rolling, then was polished and buffed to a high sheen on both sides to an even thickness. Mirrors were made by backing glass with mercury and tin, later by using silver nitrate. Plate glass with a high proportion of lead was used as safety glass to protect medical personnel from radiation. A three-layer safety glass was developed in 1956 for use in atomic-energy plants.

Sheet glass is sometimes made with wire mesh fed into the molten glass to prevent shattering. Double-glazing and insulating glass that performs like a thermos is commonly used for windows as an energy-saving device. Glass rolled or pressed with figured designs give textured effects, commonly used in bathroom windows. Frosted glass is plate glass etched with hydrofluoric acid to produce a matte effect, sometimes called obscure glass. Sandblasting gives a similar effect but makes a weaker pane and is harder to clean. Safety glass for automobile windows is made by laminating a sheet of plastic—originally celluloid, but later a clear, non-yellowing polyvinyl chloride (PVC) type of plastic—between two sheets of plate glass to prevent windows from shattering when struck. Bullet-resistant glass uses several layers of glass and plastic.

Another innovation, glass brick, became a popular architectural device in the mid-twentieth century as it let natural light into such areas as hallways. Pyrex, in use by 1920, is one of several trademarked names for the heat-resistant glass-cooking utensils made by adding boric oxide to silica and alkali. Stovetop vessels were introduced in 1936. Borosilicate glass is resistant not only to high heat, but also to corrosive materials.

Glass fiber (also called fiber glass or spun glass) was used in ancient Egypt to decorate glass vessels. Glass fiber is produced by modern methods to make fine filaments, which can be combined to form single strands and woven into fireproof textiles for translucent undercurtains. Glass wool is made by forming filaments into mats that are used for heat insulation, electrical insulation, and air filters, and to reinforce plastics on aircraft parts, boats, buildings, and cars.

By the end of the twentieth century, with growing interest in environmental concerns, recycled glass had been used for various products from soda bottles to road building.

Fine Glassware and Art Glass

Probably the most recognized (and imitated) American art glassmaker was Louis Comfort Tiffany. In the last two decades of the nineteenth century, Tiffany used iridescent effects and fantastic colorings in his free-blown and manipulated wares.

In the twentieth century, the name Steuben became associated with high-quality blown glassware. The Steuben factory was acquired by Corning Glass Works during World War I to help meet wartime need for technical glass. A chemical formula was developed that could make glass as pure rock crystal. In 1933, Steuben Glass assembled a design, production, and marketing team that produced fine modern American glassware inspired by colonial designs. Inexpensive American glassware from the twentieth century includes milk glass usually used in kitchens, and, from the Great Depression of the 1930s, Carnival or Depression glass that was a popular giveaway to draw the public to gas stations and fairgrounds. This fine glassware had become a nostalgic collectable by the late twentieth century.

Much of the American art or studio glass production was centered just north of Seattle at the beginning of the twenty-first century. Renowned glass artist Dale Chihuly helped found the Pilchuck Glass School in that area in 1971.