Cut glass

“ In quality, tint, feel, and ring the plain blown glass was a beautiful product, and when it was cut or engraved the decoration was done by fine craftsmen and often with excellent taste. Old glass has its own peculiar charm; the dark beauty of the crystal metal, the variety of form, the bell-like ring when flipped, the satiny feeling of the surface, the sparkle of the cut facets, and the combination of gracefulness and usefulness attract a collector: in cabinets it shines, gleams, glows, and sparkles in a reticent, well-bred way. ”

“ How to Cut Glass.—Hold the cutter as shown in the illustration (fig. 5) , a little [Pg 38] sloping towards you, but perfectly upright laterally; draw it towards you, hard enough to make it just bite the glass. If it leaves a mark you can hardly see it is a good cut (fig. 10b) , but if it scratches a white line, throwing up glass-dust as it goes, either the tool is faulty, or you are pressing too hard, or you are applying the pressure to the wheel unevenly and at an angle to the direction of the cut (fig. 10a) . Not that you can make the wheel move sideways in the cut actually ”

“ 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. ”

“ Wheels of fine sandstone fed with water are used for making slighter cuts and for smoothing the rough surface left by the iron wheels. Polishing is effected by wooden wheels fed with wet pumice-powder and rottenstone and by brushes fed with moistened putty-powder. Patterns are produced by combining straight and curved cuts. Cutting brings out the brilliancy of glass, which is one of its intrinsic qualities. At the end of the 18th century English cut glass was unrivalled for design and beauty. ”

“ Some manufacturers press in the design by putting the glass into moulds in its moulten state, but this makes the cheaper glass commonly called Pressed to imitate the cut variety. Then the glass is cooled and the effects are often good enough to fool the ordinary person. Cut glass can always be distinguished from the pressed by feeling the inside of the cutting, [172] where it is the deepest, and if there is a slight lump corresponding to the cutting it is surely cut and not pressed. ”

“ Experiment 65. To cut window glass. The common glass cutter is a small very hard steel wheel mounted on a handle (Fig. 85) . Practice with one on a pane of glass: place a ruler on the glass, draw the wheel along the ruler (Fig. 86) with sufficient pressure to scratch the glass, place the under side of the scratch exactly over the edge of the table, and press down on both sides.
FIG. 85
A GLASS CUTTER
51 Experiment 66. ”

“ But if toughened glass cannot be cut by the diamond, it can be readily cut and polished by the wheel, as for lustres and the like, so that wine-glasses and articles of cut glass-ware can be toughened directly they are made, and cut and polished subsequently. ”

“ We have only as yet spoken of the processes of cutting and painting in themselves, and as they can be practised on a single bit of glass; but now we must consider them as applied to a subject in glass where many pieces must be used. This is a different matter indeed, and brings in all the questions of taste and judgment which make the difference between a good window and an inferior one. Now, first, you must know that every differently coloured piece must be cut out by itself, and therefore must have a strip of lead round it to join it to the others. ”

“ It is very important to be careful that the lead is truly straight and not askew, otherwise, when you use it in leading, the glass will never keep flat. The next operation is to open the lead with a piece of hard wood, such as boxwood or lignum-vitæ (fig. 50) , made to your fancy for the purpose, but something like the diagram, which glaziers call a "lathykin" (as I understand it) . For cutting the lead you must have a thin knife of good steel. Some use an old dinner-knife, some a palette-knife cut down—either square across the blade or at an angle—it is a matter of taste (fig. 51) . ”

“ While it is hot plunge the glass under water, letting the arm go well under to the elbow, so there will be no vibration when the glass is struck. With the free hand strike the glass outside the line of cutting, giving a quick, sharp stroke with a stick of wood, a long-bladed knife, or the like, and the cut will be as clean and straight as if made by a regular glass cutter. ”

“ An attempt is sometimes made to imitate the appearance of cut glass, but the rounding of the angles during the reheating process destroys the sharpness of the effect and allows of the ready detection of the imitation, while the cheapness of the decoration when applied in the mould has frequently led manufacturers to grossly over-decorate, and, therefore, destroy all claim to beauty in their wares. ”

“ To give satisfactory colour the best of pot-metal glass is essential. Structural conditions which a man is bound to take into account in his design are—that the shapes he draws must be such as can readily be cut by the glazier; that his lead joints must be so schemed as, where not lost in the glass, to form part of the design, strengthening, for example, the outlines; that his plan must at intervals include provision for substantial iron bars which shall not interfere with the drawing. ”

“ If the glass is not very thick it can be cut with a pair of scissors, a large pair being preferable. While cutting hold the glass beneath half a foot or more of water, and it can be readily cut any shape desired. ”

“ The earliest examples of English cut glass are perhaps the thistle-shaped glasses, originally fashioned in Bohemia but adopted by Scotland as representing the national emblem. Apart{20} from these, the ogee-shape was most commonly selected as being more amenable to artistic treatment than the bell.
The stem is usually knopped and cut into facets, and is invariably hexagonal in shape. ”

“ They will find it to be extremely agreeable and pleasant, and the few difficulties which they meet with in their first attempts will be readily overcome by perseverance, or by applying for assistance and advice to gentlemen engaged in the pursuit of this interesting profession.
Moulded and Cut Glass.—Flint glass is now very commonly blown in moulds, and this art has been brought to such perfection that moulded decanters and tumblers have an appearance very similar to that of cut glass. ”

“ There is a third method of avoiding lead glazing. If little jewels of coloured glass be cut out of various sheets and placed upon white glass they become fused at a sufficient heat in the kiln, and adhere more or less firmly to the glass on which they are laid; but this process of “annealing” is not very safe. Still less to be depended upon is the fourth process of “enamelling.” In that case the coloured glass is applied in the form of a paint upon a sheet of white. Fusing at a comparatively low temperature, it rarely gets quite firmly fixed. Nor has it the depth of pot-metal colour. ”

“ To grind glass. Rough edges of glass can be ground smooth by means of emery paper. For example, to smooth the edges of the glass bottle you have just cut in two, use the file for the rough work, then lay a piece of emery paper on a plate of glass, emery side up, pour a little kerosene on it and rub the rough surface on the emery with a rotary motion (Fig. 91) . ”

“ Now, further, you must understand that you must not cut round all the sides of a shaped piece of glass at once; indeed, you must only cut one side at a time, and draw your cut right up to the edge of the glass, and break away the whole piece which contains the side you are cutting before you go on to another. ”

“ Glass is cut by means of wheels of different sizes and materials, turned by a treadle, as in a common lathe; some are made of fine sandstone, some of iron, others of tin or copper; the edges of some are square, some round, and some are sharp. They are used with sand and water, or emery and water, but stone wheels are used with water only. The glass-cutter also uses rods of copper with knobs at their ends, for making round indentations; these turn on their axis, so that the end cuts a round hollow in the glass. ”

“ 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 ”

“ One of the earlier operations of the glazier is to prime the sash, that is, to give it a coat of thin paint, for the purpose of making the putty adhere more firmly to the wood. He next takes the dimensions, in inches and eighths of an inch, of the groove or rebate in which each square of glass is to be fixed, and then proceeds to cut squares of those sizes from the semicircular pieces in his crate. ”

“ Then the blow-pipe is put in, and with a quantity of the sticky mixture attached to it is then blown out into a large bulb, just as ordinary window glass is, and cut off and flattened out on big tables to cool. The beauty of the quality of stained glass is very largely owing to the irregularity of the thickness of it, and you often get subtle variations in the colour, streaks, blotches of colour and so on; the thickness of the glass makes quite an appreciable difference in the depth of the colour, as you can easily imagine. ”

“ If several pieces are cut off promiscuously, four may be selected which have exactly the same angle, so as to form an even support to the sides. The glass being perfectly clean, dry, and as warm as can be conveniently held by the hand, fix the bottom and then the sides by means of the very best sealing-wax, which will perfectly adhere to the glass. ”

“ Well, each of those bull's eyes came from the center of a sheet of crown glass just where a lump of hot glass was attached so the blower could whirl or spin it from the middle and make it into a flat disc. But, as you can readily understand, a sheet of glass with this mark or defect right in the center will never cut to advantage, and therefore only comparatively small pieces can be got out of it; there is much waste. Yet, as the man says, it has a wonderfully brilliant surface. ”

“ His process consists in heating the glass to be toughened to a temperature close upon its softening point, and then plunging it into a bath of oil, or into a mixture of oleaginous substances kept at a much lower temperature. When this operation is successfully performed, the glass acquires properties very similar to those of Rupert's drops; it becomes much less fragile than ordinary glass, but when sufficient force is employed to fracture it, the whole flies into small pieces. It cannot be cut with a diamond, but is immediately disintegrated when the outer skin is scratched to a certain depth. ”

“ The black marks along the top edge are diamond-cuts, good and bad, coming straight towards the spectator. The two outside ones are very bad cuts, far too violent, and have split off the surface of the glass. Of the two inner ones the left-hand one is an ideally good cut, no disturbance of the surface having occurred; the right-hand a fairly good one, but a little unnecessarily hard. Passing over B for the present—C is a similar piece of glass also magnified 15-1/2 diameters, with wheel-cuts seen endwise (coming towards the spectator) . ”

“ Now the side you first looked at is the side to cut on, and the side to paint on, and it is the side placed inwards when the window is put up.
The reason is this. Glass is made into sheets by being blown into bubbles, just as a child blows soap-bubbles. If you blow a soap-bubble you will see streaks playing about in it, just like the wavy streaks you notice in the glass. ”

“ Morris replied stiffly. "I am buying for a customer a present. Ain't it?"
Klinger nodded.
"Honestly, Perlmutter," he said, "I never seen the like how things happen. No sooner you start to sell goods to a feller than somebody is engaged oder married in his family."
"He must be a pretty good customer the way you are blowing yourself," Morris commented.
"I bet yer!" Klinger said as he walked away; "and if you would be in our place you would do the same."
For five minutes Morris examined the cut glass, and when Flachs returned he had decided upon an olive dish of most intricate design. ”

“ The cutting is continued beyond the top of the stem on to the lower part of the bowl, so as to give a kind of finish. Sometimes, indeed, the cutting is made to include the bowl in a scheme of decoration, and the rim is engraved with conventional designs, wreaths of flowers, etc. Towards the end of the eighteenth century the facets became long flutes.
The process technically known as glass-cutting is essentially one of grinding and polishing. The grinding is done by a wheel, made of cast-iron, and made to rotate rapidly by a continuous band passing over a revolving shaft. ”