Glassblowing

“ Glass is made into vessels, as most people know, by "blowing." The workman takes a dab of molten glass on the end of a long metal pipe, and putting his mouth to the pipe blows the glass—soap-bubble fashion—into a hollow bulb. Then by a rapid and dexterous series of alternate and repeated heating, blowing, and spinning, and 15 manipulation with tools, most fascinating to watch, he shapes it into the form required. If a flat sheet be required for window glass it may be run out flat when liquid, or blown as described above, and worked into a cylindrical form, split open, and unrolled. ”

“ What it is that he aims at expressing by means of this often sombre glass cannot indeed be better presented than in his own words:—‘Mist and dews half shroud and half reveal the fine veinings and splashings in a grey jade-crystal vase. A thick flushing of rose-tinted glass is carved into a chimera-like flower, half influorescent, half smiling, half weary, half orchid, half pansy. A beetle drags its slow length over the rust of the lichens. Side by side with flesh-tints and carnations we see bold touches of coral pink. A pale gleam steals through the dull maze of iridium. ”

“ There is a choice collection of fragments of millefiori and banded glass in the British Museum, [25] and a still larger one in the Industrial Museum at Vienna.
52 A broken fragment of glass will indeed often tell us more than a complete vase. We can, for example, see from it whether the pattern passes continuously through the whole thickness of the glass, or whether it has been inlaid, or perhaps pressed into the surface when hot. In one case we have a process that reminds us of mosaic work; in the other there is some approach to a champlevé enamel, only with a base of glass instead of metal. ”

“ Of late years each country has been learning so much from the others that the newest effort is very much in one direction. It seems to be agreed that the art of the window-maker begins with glazing, that the all-needful thing is beautiful glass, that painting may be reduced to a minimum, and on occasion (thanks to new developments in the making of glass) dispensed with altogether. A tendency has developed itself in the direction not merely of mosaic, but of carrying the glazier’s art farther than has been done before and rendering landscapes and even figure subjects in unpainted glass. ”

“ PRESSED GLASS Many articles are made by pressing glass into molds, that is, the molten glass is poured into molds and is pressed against the sides of the mold by means of a plunger. Imitation cut glass is pressed in this way.
PLATE GLASS The large sheets of plate glass used in store windows are not blown, but rolled. The molten glass is poured from the fire clay pots upon a cast-iron table and is rolled flat by means of a large iron roller (Fig. 24) . The glass is then in the shape of plate glass, but is rough on both sides. ”

“ It is lamentable to think of the quantities of old glass that have been, and are in process of being, wholly lost through neglect alone. An ancient glass painting is composed of many pieces of glass, of various sizes, held together by means of leads, i. e. narrow strips of that metal, having a groove on either side sufficiently wide to receive the edges of the glass. From age, and other causes, the leads become decayed; a piece of glass drops, or is blown out of the leads by the wind; the leads, deprived of its support, become gradually relaxed in other parts ”

“ Layard speaks of this vase as being shaped and hollowed on a turner’s lathe after being ‘blown in one solid piece’ (Nineveh and Babylon, 1853) —a curious expression for one who interested himself so much in the manufacture of glass! We may, perhaps, regard it as having been carved like an object of rock crystal out of a solid piece of glass. We know of nothing like it from Egypt, but then the Egyptians had no love for transparent, colourless materials; from an early time, as we have seen, they had covered their beads of rock crystal with a blue glaze (cf. p. 20) . ”

“ Cut glass is a fine setting for flowers of strong colour, but kills the paler hues, and above and beyond all is the dark moss-green glass of substantial texture that is fashioned in an endless variety of shapes. By chance, gift, and purchase we have gathered about a dozen pieces of this, ranging from a cylinder almost the size of an umbrella-stand down through fluted, hat-shaped dishes, for roses or sweet peas, to some little troughs of conventional shapes in which pansies or other short-stemmed flowers may be arranged so as to give the look of an old-fashioned parterre to the dining table. ”

“ At the front of each of these squatting monsters, men, silhouetted against the fierce glow from the doors, move about like puppets on wires—any noise they may make is drowned in the mastering roar of the fire. A worker thrusts a long blowpipe (in glassworkers' terminology a wand) into the molten mass in the furnace and twirls it rapidly. The end of the wand, armed with a ball of refractory clay, collects a ball of semi-liquid glass; the worker must estimate the amount of glass to be withdrawn for the particular size of the bottle that is to be made. ”

“ Blowing a Bulb or Expanding a Join.—Prolonged heating is necessary in order that the thick parts may be heated completely through. Blowing should take place by stages, in order [Pg 99] that the thin parts, which tend to expand first, have time to cool. The thick parts can then be expanded by further blowing and thus a bulb or expansion of even thickness can be obtained.
Cutting Glass.—The most useful method for general use is by means of the file or glass-blowers' knife. Either file or knife must be kept sharp by grinding. Neither file nor knife should be used on hot glass. ”

“ If glass-blowing had been a perfectly new invention of Graeco-Egyptian or Roman times, some specimens illustrating the transition from core-moulding to blowing must have been discovered. The absence of traces of the transition strengthens the supposition that the revolution in technique merely consisted in the discovery that it was more convenient to finish the base of a vessel before its mouth, and such a revolution would leave no trace behind. The roughened inner surface and the adhering particles of sand may also be accounted for. ”

“ The purity of glass, its adaptability to colour, and its remarkable ductility while hot for blowing, twisting or drawing into threads, differentiates it from all other materials and methods of treatment. Its tradition dates from the remote past, for glass-blowing is represented on the tombs at Thebes, B.C. 2500. It was also used in Egypt for vitreous pastes for bronze and gold cloisonné jewellery, and for the small bottles or Stibium, with chevron patterns, in yellow, turquoise and white on a coloured ground. ”

“ In the production of hollow glass-ware by hand, the glass-blower avails himself to the full of the property so characteristic of glass of assuming a pasty or viscous condition when suitably heated; by raising or lowering the temperature of his material, the blower can at will render it stiffer or more fluid; by blowing he can distend it, draw it out by the aid of gravity or centrifugal action, or he can mould it with the aid of rods and tongs of suitable shape, while at times he allows it to fall or festoon under its own weight while held aloft. ”

“ I have now to speak of another class of moulded glass, of what is, in fact, a true ‘hollow ware,’ made by 57 blowing a vesicle of glass into a mould. This is the first time that we unmistakably come across the use of the blowing-tube. In the case of glass it is practically impossible to use a mould in the shaping of a hollow vessel without some such method of forcing the viscid material into its place by pressure from the inside. ”

“ Perhaps the earliest type of English glass is one with a waisted bowl, engraved with a full-blown rose, and supported on a rib-twisted stem; but those on stems loosely air-twisted may sometimes be as old.
There is a glass in the British Museum with a bell-shaped bowl engraved with a rose, a pink, and a third flower of undetermined species; this we may take as a good type of the earlier drinking-glass. The bowl is divided from the air-twisted stem by a hollow bulb containing a sixpence of Charles II. dated 1679. ”

“ There would be no advantage in building up whole windows in this way; but for the rendering of the flesh and sundry minute details in a window for the most part heavily leaded, this fusing together of tesserae, and even of little pieces of glass cut carefully to shape, seems to supply the want of something more in keeping with severe mosaic glazing than painted flesh proves to be.
Glass painters are allowed to-day a freer hand than formerly. They are no longer exclusively engaged upon ecclesiastical work; domestic glass is an important industry ”

“ Surely so much information has rarely been compressed into one print as we find in the main illustration to this part of Agricola’s text (Plate XXXVIII.) . Here at one working-hole (fenestrella) we see a workman gathering the glass at the end of his fistula or blowing-iron, another is shaping the gathering upon the marver at his foot, a third is vigorously blowing the paraison to the required size, and a fourth is swinging another round his head. On the ground lie scattered moulds of various forms, and here, too, we may discover the forceps (pucella) used in shaping the glass. ”

“ In very much of his work the glass-blower is guided more by the feel of the glass than by what he sees. The power of feeling glass can only be acquired by practice, and after a certain amount of preliminary failure. ”

“ Thus on the same piece of glass he could depict among the grass white daisies and yellow buttercups and bluebells blue as nature, he could give even the yellow eye of the daisy and its green calyx; and, by judicious modification of his stain, he could make the leaves of the flowers a different shade of green from the grass about them. The drawing of the flowers and leaves and blades of grass, it need hardly be said, he would get in the usual way, tracing the outline with brown, slightly shading with half tint, and painting out only just enough of the ground to give value to his detail. ”

“ A window of ancient glass needs releading. The lead has decayed and the whole is loose and shaky. The ancient glass has worn very thin, pitted almost through like a worn-out thimble with little holes where the alkalis have worked their way out. It is as fragile and tender as an old oil-painting that needs to be taken off a rotten canvas and re-lined. If you examine a piece of old glass whose lead has had time to decay, you will find [Pg 316] that the glass itself is often in an equally tender state. ”

“ Instead of the beautiful clarity and perfect transparency we are accustomed to associate with glass, there is often a streakiness or cloudiness visible in the material, together with numerous bubbles and flaws. If the striations are horizontal, the glass is of an earlier type than if they are perpendicular. The sides of the bowl are often irregular, and the stems are often clumsy, uneven, badly balanced, and altogether disproportionate in point of size to an eye accustomed to the slenderer style of modern glassware. An important point is the junction between the bowl{24} and the stem. ”

“ The cutting and putting together of the glass is called glazing, and it is this that gives the window colour; while the enamel work is spoken of as painting, and gives detail, richness, and texture.
I shall presently show that the glazing and painting are really two separate crafts, having separate origins and development, and that stained glass as we know it, or as it should be called in strict accuracy "stained-and-painted" glass, is the product of their union. ”

“ The clear white glass, somewhat thick and heavy compared with later examples, is often ornamented with appliqué bosses of coloured glass; such glass is sparingly decorated with opaque enamels, and this decoration takes the form of little beads or studs, at times combined with an imbricated pattern in gold. We sometimes meet with large bowls on low feet (a form of drageoir or sweetmeat dish) which are so decorated. There is, however, no finer example of this style of ornament than the standing beaker with cover in the British Museum (Slade, 362) . ”

“ A modern glass-blower, when making an amphora-shaped vase, finishes the base first, fixes an iron rod to the finished base with a seal of glass, severs the vase from the blowing iron, and finishes the mouth, whilst he holds the vase by the iron attached to its base. ”

“ As to the slab-glasses—"Early-English," "Norman," or "stamped-circles"—which are chiefly affected by this question, the texture and surface upon which their special character depends is sometimes a very useful resource in work seen against, or partly against, background of trees or buildings; while against an entirely "borrowed" light perhaps, sometimes, it can almost dispense with any painting. The grey shadows that come from the background play about in the [Pg 228] glass and modify its tones, doing the work of painting, and doing it much more beautifully. ”

“ As there were to be seen lumps of unshaped glass lying scattered about in various parts of the workshop, as well as relics of glass bottles and other vessels, together with the tools by which they were produced, it was obvious, that the art of glass-making formed also a pursuit of the potter, either as a hobby, or as a regular avocation. Masthlion himself was attired in his working clothes, and was smeared with clay and grime of the furnace from head to foot. ”