The History of Glass
by American Glassware Association

Glass Review - July/August 1982

Glass predates man, for in the prehistoric fiery volcanoes, it was first produced by nature. Pieces of it today are called obsidian by the geologists. Chunks of this "nature made" glass are found now as they were many, many centuries ago by cavemen who chipped cutting edges from it for knives, arrowheads, hatchets and other similar articles to assist him in conquering the many hazards of early existence just as modem man now has learned that glass has many applications to ease his way of life. Possibly nothing has contributed more to the convenience and comfort of civilized life than glass. In reality it is a basic material metal, such as steel, bronze and brass, used in the manufacture of many useful utensils for everyday living. Therefore, it is well worth the time you spend in learning something of the history, method of manufacture, and usefulness of this product.

Just where "man-made" glass was first produced is not authentically known. It began to be mentioned in historical records that would indicate the story of "man. made" glass began about six thousand years ago. According to the Roman historian, Pliny (lived 23 A.S. - 79 A.D.), some Phoenician merchants with a cargo of natron (carbonate of soda) landed on the coast of Palestine, near the mouth of the Belus, built their fire, and, finding no stones on which to place their cooking pot, took some of the pieces of natron for this purpose. When the natron was fused by the heat it mixed with the sand and produced streams of a viscous, unknown fluid, later called glass. Some authorities doubt the reliability of this origin tale.

There are in existence records that show that about 2,500 years before the birth of Christ the Egyptians and perhaps some of their neighbors had learned how to manufacture a sort of viscous glaze that could be smeared on their pottery and make it last longer and look better, after it had been fired in a simple oven. This kind of glass is called frit and it is used today on china and porcelain enamel goods because it has the characteristic of fusing onto the mass upon which it has been spread and cannot be washed or scraped off.

Solid glass vessels were made at least 3,500 years ago in Egypt and possibly Syria. Elongated thin glass rolls were wound around molds formed of sand. This glass was opaque or crudely colored and was not transparent. As layers upon layers of these rolls were placed around the sand core, a hollow vessel was formed when the glass had hardened; the sand was dumped out and a cup-like bowl remained. Small cups, perfume and oil bottles, beads and very small objects for personal adornment were greatly prized by the nobility and royalty. These trinkets became an export article of trade. This process was probably pursued for over 1,000 years.

Transparent glass is about 2,500 years old, the oldest example that we find being bottles. The value of transparency in glass had the effect of extending its use quickly and widely for bowls, bottles, windows and for mirrors. Just when the art of blowing glass originated we do not know, but blown glass objects found by Dr. Petrie, when the City of Tel-el-Amarna in Upper Egypt (built by Amenhotep IV about 1400 B.C.) was excavated, gives us one authentic date. In this early process, a tube of glass was scaled at one end, reheated and then the blower forced air from his lungs into this heated tube which forced it to bulge out and create hollow articles. "Ennion," a Sidonian, practiced this art between 100 B.C and 100 A.D. He blew these tubes into beautifully carved molds. He learned how to make colored and also an ivory white glass which was translucent. In his work we have probably the first trademarking of glass for often he imprinted on his pieces this phrase, "Buyer remember, I Ennion, made this."

During the period of the early Roman Empire, about the year 1 to 300 A.D., glass began to become a household implement and table glassware, bottles, jars, bowls vases and lamps and so many other things that are well known today and found frequently in our own homes were used quite generally in the homes of that period.

Of course, the glassware of that era was not finely finished; it did not have the clarity nor the color brilliance of today's product but nevertheless, it was perfectly serviceable and for that time was really quite acceptable. It was, however, inexpensive enough so that almost everybody could have the glass they needed. These Roman glassmakers produced beautiful bowls out of colored sections of glass for the "class" trade. They engraved gold leaves between layers of glass and they cut magnificent glass cameos. As workmen, they were highly skillful and their work was unsurpassed.

The huge Roman Empire had begun to disintegrate in the late 5th Century A.D. and it was then that the center of glass manufacture started moving east to Persia. The Persian and Saracen did much towards advancing decoration on glass but did not improve the quality of the glass itself. Bottles and lamps were enameled with exquisite design. Glass molded pieces in the form of animals and deep cut pieces, many now preserved as museum exhibits, point to the superb craftsmanship of the Ancient Near East from 800 to 1300 A.D.

As Europe emerged from the Dark Ages and after the Crusade Period, the art of glassmaking drifted back to Italy, where fragments of the earlier industry existed. Venice was a great seaport of the time and a center of world trade. It was there on the Island of Murano that the manufacture of glass was revived. Glassmaking was a secret art; however the factories were a fire hazard. The Island of Murano being out of the city was well located as a spot where the industry could thrive. The merchants and manufacturers on the Island of Murano were naturally very anxious to keep this highly lucrative and now thriving business for themselves. They made the then scarce glass blowers nobles of the realm, had them sign pledges that they would stay forever on the Island of Murano under penalty of death if they tried to escape.

Regardless of all these precautions the art did spread, first to the Black Forest region of Germany and later to France and England. These northern factories produced all sorts of hollow ware many times copying the elaborate Venetian types. In these new locations, there was plenty of fuel, sand, and alkalis with which to make glass and it was not long before these areas began to be as famous for their glass as Venice had previously been.

The English began to produce glass in the 16th Century. In that far off island there was plenty of wood and the glass workers soon found their way there. George Ravenscroft, an Englishman, in the early part of the 17th Century was the first to add lead oxide successfully to the ordinary glass batch in such a fashion that beautifully clear and brilliantly reflective glass resulted. This was the beginning of what was and continues to be metaphorically called, "crystal glass." The glass cutters of Holland soon recognized its beauty and began to import it for they were then the masters of copper wheel and diamond stipple engravings. During all this period, glassware was greatly sought by royalty and the nobility. It was pretty expensive and only a few people could enjoy it. Much cathedral glass was produced for adorning the church windows of these places of worship. Better homes had "crown" glass windows.

Fuel was getting short in England and it seemed to the businessmen who were engaged in the glass industry there that America would be a good place in which to manufacture glass. There was abundant fuel and sand seemed to be plentiful. The other chemicals could be imported from Europe. About that time, the London Company was formed and eight Dutch and Polish glassmakers were sent in 1608 to start a factory in America. Captain John Smith finally located his group on a peninsula on Chesapeake Bay at what is now called Jamestown. The first glass plant was started about a mile out of town at Glass House Point across the creek from the settlement The United States Park Service has found ruins of this plant and are now making arrangements to restore the factory with the financial help of the U. S. Handmade Glassware Industry.

Records indicate that glass was made at the new factory, and some was shipped back to England though authentic pieces were never found. Disease, the Indians and terrible living conditions finally overcame this first attempt at glassmaking but it did establish the fact that glass was the first factory-made product produced in America.

The glass industry in America continued in a rather dilatory fashion through the rest of the 17th Century and it was not until the early 1700's, when organized factory production was started by Caspar Wistar in Salem, New Jersey, and Baron Steuben near Lancaster, Pennsylvania. Then glass was really commercially and successfully produced in America Both of these factories made bottles, window glass, goblets, bowls and other off-hand pieces of which there are several in valued museum collections.

Early in the 19th century marks the beginning of what might be called the glass factory period. In Cambridge, Somerville, and in some of the other suburbs of Boston, Massachusetts, well managed and prosperous glass factories were in existence from the beginning of the 1800's. These plants produced all types of glass - window glass, bottles, tumblers, stemware, tableware and lighting ware (whale oil founts and hurricane shades).

To Deming Jarves goes the great distinction of being the first "glass industrialist." He started the Boston and Sandwich Glass Company in Sandwich on Cape Cod in 1826. At that factory the first pressed tumbler was made in 1827. Patents on the art of pressing glass by mechanical methods were issued to this young and ambitious company so that by 1850 it was one of the most up-to-date and efficiently managed industrial plants in this country. It was the outstanding factory, and inspection trips of it were sought by manufacturers throughout the world. To the Sandwich plant belongs the credit of making glass articles at prices "Main Street" could purchase just as today's glass articles can be bought everywhere at prices that make it the most sought after product that can be purchased at popular prices.

The peculiar consistency of glass adapts it to a wider use than almost any other material. Glass, when cold, is a hard, crystal-like substance. When it is heated, it is a liquid and it may he either poured into moulds, blown or pressed into forms, or spun into threads and woven. Woven glass has the pliability and soft sheen of satin. It is a remarkable fact that while the chief quality of glass is transparency all the materials that compose it are opaque. The mysterious agent that produces the change is fire. Glass is really the offspring of fire.

Since the beginning, the two essential elements required by glassmakers have been silica and alkali. Glass falls naturally into two divisions - glass of maritime countries, where the alkali is soda - and glass of forest countries, where the alkali is potash. At all times silica has been derived from solid quartz, either in the form of rock crystal or of white pebbles from the bed of rivers, and more frequently from sand obtained from the seashore or by excavation.

Soda was obtained by the Mediterranean people from the ashes of certain plants growing in salt marshes or from seaweed. Inland people got their alkali by dissolving with lye the ashes of various trees and plants. In Germany and Bohemia this potash was obtained from beechwood; in France from the bracken fern. The quality of the glass depended upon the preparation of this soda or potash. In all cases there is need of a second base and this, generally speaking, is lime used in connection with the soda; or oxide of lead, which is used in connection with the potash. The soda family embraces the beautiful glass of the Romans and of the Mediterranean countries; the enameled ware of the Saracens; and all the artistic productions of the Renaissance, including the Venetian, or Murano glass. The potash family includes German, Bohemian and French "forest glass". All of these chemicals are found in abundance in the United States today.

Since the first glass factories were established in the United States there has been a wonderful progress in glass manufacture, not only in the application of the fuel, but also in the machinery developed to produce glass automatically, and in the quality of the glass as regards durability and tensile strength. Not only have the Americans produced many beautiful artistic pieces of glassware, but the usefulness of the glass has been applied to almost every conceivable purpose, and different types of glass have been developed and applied to fill exacting specifications.

In the manufacture of window glass, which was formerly blown at the end of a pipe and swung into long cylinders, then broken off, the cylinders split and flattened into window glass, we have gone to the blown cylinder automatic machine type, and now to the drawing of glass from the molten tank in flat sheets, and all that is required is for the glass to be annealed and cut into the desired shape.

Bottles which were formerly manufactured by being blown to shape on the end of a pipe and then formed in molds of different sizes are now all manufactured on full automatic machines from ten to sixty per minute in proportion to the size and weight of the item. The Owens Bottle Machine revolutionized the glass container industry beginning in 1905. The manufacture of electric light bulbs has progressed similarly from the hand-blown method. All electric light bulbs are now manufactured in a full automatic way by means of a continuous belt forming machine.

Automobile headlight lenses for directing the light below the level of the headlamp when properly aligned were formerly manufactured on a slide lever press. The increase in the production of automobiles has made it necessary to manufacture lenses also by the full automatic machine method. The design of the lens has been changed from the single filament to the two filament type, which projects both an upper and a lower beam.

Plate glass, formerly manufactured all by hand, is now a full automatic process. The plate glass manufactured in this country is the finest glass manufactured in the world. Laminated or safety glass is a new branch of the industry, and is formed by two thin layers of window or plate glass being put together with a layer of polyvinyl butyral and the whole subjected to compression. This safety glass is finding use in bank windows and windshields for automobiles and other applications which have developed since World War II.

Heat resisting glass as developed in the United States in the production of glass oven ware has contributed to a great extent in recent years to the satisfaction and delight of the housewife. Practically all desirable articles of cooking and baking utensils now are made in oven glass. Further use for heat resisting glass, which is greatly increasing in popularity, is the all glass heat resisting coffee maker. Borosilicate glass (oven glass and top of the stove ware) and its many derivatives now has extensive use in industrial machines, pumps, piping and scientific and laboratory ware and equipment.

A use for heat resisting glass is as a lens or cover glass in floodlights for aviation fields, which, with 1500 and 3000 watt lamps, generate heat of more than 800 degrees Fahrenheit, in other words, a heat that on the surface of the floodlight could cook a meal. This glass at this intense heat withstands the attack of the elements, such as rain, wind, sleet, snow, etc., without breaking. Items in tableware, where their quantities justify, are also manufactured in a full automatic way. An undertaking without precedent is the manufacture of a glass lens measuring 200 inches in diameter, now used in a reflecting telescope at Mt. Palomar Observatory in California. There are now a great many different types of glass, among them the barium crown flint glasses used for optical purposes.

The fuel originally used by the early colonists was wood, then charcoal and later coal was used. A few of the old deep-eye coal furnaces are still giving good service. Natural gas was discovered in the United States, and, beginning about 1883, ultimately proved to be an ideal fuel for use in manufacture of glass; however, its increased cost has turned glass manufacturers to the use of oil and also producer gas. The use of these latter two fuels has grown rapidly in the last few years. However, probably more glass is produced today by gas as a fuel than any other type, though producer gas manufactured from bituminous coal has become an important source of fuel in the industry. The coal is put into large retorts and air and steam are blown through the coal bed which gasifies the coal. The gas is taken away from the retort in a large pipe and it very closely resembles yellowish-brown smoke. This gas is used in a glass factory in its raw state, called "raw producer gas" and has an initial heat when entering the furnaces of 600 to 800 degrees Fahrenheit.

World War II stimulated glass manufacturers to develop glass for special used that ten years ago would have been considered fantastic. The noses of some projectiles were actually made of glass and the Flying Fortress crew was protected by the non-shatterable laminated glass, transparent yet with almost no distortion of vision. Without glass, fire control equipment, land mines, and radio and radar glass parts, World War II could not have been won. The Post War II era has seen great development in atomic energy and glass has been called upon many times to assist in the scientific advance that is being made in applying this great new storehouse of power to industry.

The last official United States Department of Commerce report states that the total production of glass in 1952 was a billion and a half at factory selling price level. This total includes plate, window, cathedral, wired, opalescent and all other types of sheet and building glasses estimated at $485,000,000; glass containers for food and beverages estimated at $542,000,000, the remainder approximately $473,000,000 is classified as pressed and blown glassware which includes table and cooking ware, tumblers, illuminating, technical, scientific, industrial, fibre, optical glasses and lenses.

This information gives you some idea of the value and importance of the several sections of the glass industry in this country. The increase in glass production due to its technological advancement has placed the glass industry in the "billion dollar group" among the most important industries in the United States. There are about 140,000 people directly employed in the industry. We are now living in the "glass age" but the future of glass is boundless.

Prepared by the American Glassware Association, New York