Old And Sold Antiques Auction & Marketplace
Antiques Digest Browse Auctions Appraisal Home

Old And Sold Antiques Digest Article

The Glassmaker's Craft

( Originally Published 1940 )

There are several special circumstances that should be kept in mind in thinking of the early American glass industry. The only item on the favorable side of the ledger was an abundant fuel supply. Against this there stood the painful lack of skilled labor. Glassmaking and glass-blowing are not crafts which a man may step into through some natural aptitude. They require a complexity of traditional information and a variety of technical skills that can result only from long and disciplined training. The failure of the guild system in America, and the impotence even of the simple apprentice system, hardly made for an abundance of this type of craftsman. Other nations, well aware of their value, passed laws against the emigration of glass-men. Those who came to America were smuggled from their homelands.

These smuggled glass workers were jealous of their skill and, despite agreements to the contrary, they were not too anxious to convey this skill to native novitiates. Also, recogniz ing their rarity and consequent independence, they were inclined to be arrogant, and generally speaking, to take advantage of their importance in a very human way.

Indeed, glass men held a very superior rank in the general order of craftsmen. There had been a time in Venice when all glass blowers had been made Burgesses and it was even per missible for noblemen to marry their daughters and have noble issue! Later, in France, the exclusive right to make glass was assigned by the King to various noble families in this and that province and was considered one of the most valuable concessions. In such cases it was not a question of mere ownership or management, but of actual practice. Says a writer of the time: "The gentlemen work only twelve hours, but without resting, and always standing and naked. . . ."

It should be remembered that glass-blowing is such an arduous and health-destroying labor that it was customary, except at the establishment of Doctor Dyott, to work only six to nine months out of every year.

A 17th century commentator observes: "It must be owned those great and continual heats, which those gentlemen are exposed to from their furnaces, are prejudicial to their health; for coming in at their mouths, it attacks their lungs and dries them up, whence most are pale and short-lived by reason of diseases of the heart and breast, which the fire causes; which makes Libarius say . . . `they were of weak and infirm bodies, thirsty and easily made drunk' . . ."

In addition to drunkenness and general unreliability of the workmen, there were the Salamanders to be considered. These were horrendous creatures which made their abode in the flame of the furnace itself. The frequent disappearance of glassblowers, even those who were under contract, was sometimes attributed to these supernatural beasts which often, when no one was looking, reached out and snatched a luckless craftsman and cruelly devoured him within their roaring sanctuary, to the considerable regret of his employer. At any rate so the tale was told when itinerant glassworkers disappeared without notice.

The types of glass most commonly used in Colonial times were flint, crown, common window, bottle, and plate.

Flint glass, or crystal glass, was an English discovery and quickly surpassed in popularity the Venetian and Bohemian glass which had previously dominated the market. It is made by adding a high percentage of lead to the elements of the glass. Lead gives lustre, heightens refractory power, increases weight and fusibility.

A common formula for flint glass was: "one half sand, one third red lead or litharge, one sixth potash, and a little saltpeter, manganese and arsenic to improve the color." To this mixture about one fourth by weight of "cullet" was added; that is, broken glass of the same type.

Today glass is usually melted in metal vats, but up until about 1863 it was necessary to use earthenware pots. Thus the potter was a very necessary man around the glassworks, and every glassworks had its pot-room. This is another aspect of the travail of early glassmaking. The manufacture of these pots was no simple matter. They had to be made of a very special clay in order to resist the intense and prolonged heat, and the chemical action of the glass matrix. In the early days of America the best clay for this purpose, that of Stourbridge, in England, had to be shipped to this country at high prices. This was a slate clay, usually brown. Suitable clay was discovered in Delaware and Missouri early in the 19th century, but until well into the third quarter of that century most of it was still imported from Europe.

Once the necessary clay for the melting pots was obtained and pulverized into a fine dust, it had to be exposed to the elements and allowed to "ripen" for about a year. Then a quantity of broken pots, called "potsherds," equivalent to the "cullet" in the glass mixture, was cleaned and ground and mixed with the ripened clay to the amount of about one fifth by weight. Water was added, to make a thick paste, which was "worked" with the bare feet, "bugging," to the consistency of putty. The resulting substance was again put away, for more ripening, for as long as half a year. Then the pot was carefully built up and shaped by hand, taking several more weeks. A third ripening of from six months to a year was then necessary. At last came the actual baking and annealing. To top it all, if the pot was a success and had a clear ring while at high temperature in the furious flame of the glass oven, its average life was less than two months! From this it may be seen that the glass industry was not a venture to be taken up light-heartedly. As a matter of distressing fact, the greater number of glass-men were financial failures until the advent of the machine age, when the pressing-machine greatly curtailed the romantic craft of glass-blowing and took glass out of the luxury class.

The construction of the furnaces and of the glass-room itself depended upon the type of glass being made. In the case of lint glass, a round or elliptical furnace was used, in a room usually large and square with a high ceiling. In the case of bottle glass the furnace was usually oblong or square, and the room was often oblong.

In addition to his pots and furnace, the necessary tools of the early glassman were: the blowpipe, a hollow tapering tube from four to seven feet long; the pontil, (pronounced "punty"), an iron rod somewhat shorter than the blowpipe; the marver, a polished, cast-iron plate; the pucelas, a pair of tongs with dull wooden blades fastened together with a flexible metal bow; large and small shears for cutting off excess glass. Also, various pincers, compasses, rulers, blocks and paddles of wood and metal. In spite of the advent of machine-made glass, the tools and processes of fine, hand-made glass have not changed or modified appreciably for centuries.

In the making of a piece of blown glass, the batch of glass was cooked for the required length of time, (ranging anywhere from sixteen hours to three days, depending on the type of glass), at a temperature as high as 1 2,000 degrees Fahrenheit. Then an assistant to the boss-blower dipped the heated nose of the blowpipe into the crucible until a sufficient quantity of the hot glass, called "parison," adhered to it. He then rolled this lump of viscous glass on the marver, to give it a regular shape. Next the loaded blowpipe was presented to the boss-blower who, by reason of his uncanny skill, was the Number One man of the glassworks. As the boss-blower blew the glass shape expanded, and as he swung his blowpipe the shape lengthened. When he was satisfied, the long iron rod, the pontil, was brought with a small blob of glass on the end of it. This enabled it to adhere to the end of the blown bulb opposite the blowpipe. Then the "wetter off," by means of a piece of iron dipped in cold water, broke the blown glass bubble off from the blowpipe so that it was now handled by the pontil. This was handed to the "chair-man" who rolled it back and forth on the arm of his chair and gave it its final shape by means of the various simple tools, such as paddles and pincers. Finally the shaped piece was broken off from the pontil and carried on a tray to the leer, or annealing oven, where it was subjected to a long and slowly decreasing heat to assure its resistance to varying temperatures.

When the pontil has been broken away from the shaped piece a rough spot, called the "pontil mark," is left on the base. This is the characteristic identifying mark of all hand-made, blown glass, early or modern, for it remains in one form or another, even if it has been to some degree smoothed off by reheating, or ground away, leaving a slight hollow.

The most extraordinary of the early blowing processes was that described for the manufacture of "crown glass," that is, the "bulls-eye" type of window glass. All early window glass was blown. The processes of "plate glass," made by simply pouring it onto flat iron or copper tables, was a later development. The ordinary early window glass was blown into cylinders, then split and flattened. Not so with crown glass.

The formula for this required ". . . . kelp and white sand . . . . in proportions of eleven of kelp to seven of sand." The kelp, or seaweed, had of course been subjected to a lengthy burning process to reduce it to a mineral ash. In time, carbonate of soda replaced the help and produced a clearer glass. After this had been cooked from sixteen to twenty hours, a proper sized "gather" was taken onto the end of the blowpipe and blown into a large, thin sphere. A pontil was attached to the side opposite the blowpipe and the blowpipe detached, leaving an aperture of from one-and-a-half to two inches. The sphere was then re-introduced into the furnace and rapidly whirled by the craftsman who held it by the pontil. As the sphere began to soften in the furnace heat the artisan whirled it faster and faster, until through centrifugal force the opening opposite the pontil began to expand. Judging the operation carefully, he kept on whirling the glass bubble until, in the words of an eyewitness, ". . . . the aperture suddenly flies open with a loud ruffling noise, which has been aptly compared to the unfurling of a flag in a strong breeze; and the glass becomes a circular plane or sheet of from four to four-and-a-half feet in diameter, of equal thickness throughout, except at the point called bullion or bulls-eye . . . ." where the pontil is attached. The craftsman continued the whirling in order that the circular glass plate might maintain its shape, and gradually withdrew it from the fire. After annealing it was cut to the proper shape and size.

That this extraordinary process was responsible for many of the windows of early American buildings demands a special tribute to the craftsmen who were able to master it.

Sometimes a mold was used in order that a pattern of some sort might be raised or impressed on the surface of the article. In this case the process was simply to do the blowing inside the mold. The molds were made of brass, iron, and occasionally of very hard woods. The designs were usually cut intaglio so that the patterns on the finished glass were raised. The molds were usually made in two, three, or four parts. A two part mold, commonly used, was opened and closed by a foot pedal operated by the blower.

One part molds were also used and required a special technique of blowing. They were made in miniature. The "gathering" of glass was blown into them, then contracted by means of an inhalation of the breath, and removed from the mold. It was then blown out to full size, the pattern expanding uniformly with the glass. Work of this kind was, of course, seamless, while objects made in the two, three, or four part molds showed seams where the parts were joined unless the piece were thoroughly, "flashed," (reheated), or unless the seams were cleverly made to coincide with some element of the pattern.

The models for molds were usually carved of mahogany and from them was made the "master mold," from which, in turn, were made the actual molds for the glass. Needless to say, much of the beauty of this type of early glass depended upon the artistry of the mold maker.

The liquor flask is one of the most interesting, as well as important items in American craft history. Covering its manufacture an early authority writes: "The common green or bottle glass is made of the coarsest materials; sand, lime, sometimes clay, any kind of alkali or alkaline ash, whose cheapness may recommend it to the manufacturer, and sometimes the vitreous slag produced from the fusion of iron ore. The mixture most commonly used is soap-makers' waste, in the proportion of three measures to one measure of sand. The green color of this glass is occasioned by the existence of a portion of iron in the sand, and it may be also, of the vegetable ashes of which it is composed. When castor-oil or champagne bottles are wanted, a portion of green glass cullet is added, to improve the color."

From this mixture, after it had been properly cooked and skimmed of impurities that had risen to the top, the flasks were blown in the manner described, but usually in a two section mold operated by the foot.

"The finisher then warms the bottle at the furnace, and taking a small quantity of the metal on what is termed a ringiron, he turns it once around the mouth forming the ring seen at the mouth of bottles. He then employs the shears to give shape to the neck. One of the blades of the shears has a piece of brass in the center, tapered like a common cork, which forms the inside mouth; to the other is attached a piece of brass used to form the ring. The bottle is then lifted by the neck on a fork by a little fellow about ten years of age, and carried to the annealing arch. . . ."

Bookmark and Share