The technology for glass beadmaking is among the oldest human arts, dating back 3,000 years. Glass beads have been dated back to at least Roman times; the earliest glass-like beads were Egyptian faience beads, a form of clay bead with a self-forming vitreous coating. Glass beads are significant in archaeology because the presence of glass beads indicate that there was trade and that the beadmaking technology was being spread. In addition, the composition of the glass beads could be analyzed and help archaeologists understand the sources of the beads. Glass beads are categorized by the method used to manipulate the glass - wound beads, drawn beads, molded beads. There are composites, such as millefiori beads, where cross-sections of a drawn glass cane are applied to a wound glass core. A minor industry in blown glass beads existed in 19th-century Venice and France; the earliest beads of true glass were made by the winding method. Glass at a temperature high enough to make it workable, or "ductile", is laid down or wound around a steel wire or mandrel coated in a clay slip called "bead release."
The wound bead, while still hot, may be further shaped by manipulating with graphite, stainless steel, tungsten or marble tools and paddles. This process is called marvering, originating from the French word "marbrer" which translates to "marble", it can be pressed into a mold in its molten state. While still hot, or after re-heating, the surface of the bead may be decorated with fine rods of colored glass called stringers creating a type of lampwork bead; the drawing of glass is very ancient. Evidence of large-scale drawn-glass beadmaking has been found by archeologists in India, at sites like Arekamedu dating to the 2nd century CE; the small drawn beads made by that industry have been called Indo-Pacific beads, because they may have been the single most traded item in history—found from the islands of the Pacific to Great Zimbabwe in southern Africa. There are several methods for making drawn beads, but they all involve pulling a strand out of a gather of glass in such a way as to incorporate a bubble in the center of the strand to serve as the hole in the bead.
In Arekamedu this was accomplished by inserting a hollow metal tube into the ball of hot glass and pulling the glass strand out around it, to form a continuous glass tube. In the Venetian bead industry, molten glass was gathered on the end of a tool called a puntile, a bubble was incorporated into the center of a gather of molten glass, a second puntile was attached before stretching the gather with its internal bubble into a long cane; the pulling was a skilled process, canes were drawn to lengths up to 200 feet long. The drawn tube was chopped, producing individual drawn beads from its slices; the resulting beads were cooked or rolled in hot sand to round the edges without melting the holes closed. The most common type of modern glass bead is the seed bead, a small type of bead less than 6 mm, traditionally monochrome, manufactured in large quantities, they are a modern example of mechanically-drawn glass beads. The micro-bead or "seed bead", are so called due to their regular size. Modern seed beads are extruded by machine and some, such as Miyuki delicas, look like small tubes.
Pressed or molded beads are associated with lower labour costs. These are made in the Czech republic. Thick rods are heated to molten and fed into a complex apparatus that stamps the glass, including a needle that pierces a hole; the beads again are rolled in hot sand to soften seam lines. By making canes striped or otherwise patterned, the resulting beads can be more elaborately colored than seed beads. One `feed' of a hot rod might result in 10–20 beads, a single operator can make thousands in a day. Glass beads are manufactured or moulded using a rotary machine where molten glass is fed in to the centre of a rotary mould and solid or hollow glass beads are formed; the Bohemian glass industry was known for its ability to copy more expensive beads, produced molded glass "lion's teeth", "coral", "shells", which were popular in the 19th and early 20th century Africa trade. A variant of the wound glass beadmaking technique, a labor-intensive one, is what is traditionally called lampworking. In the Venetian industry, where large quantities of beads were produced in the 19th century for the African trade, the core of a decorated bead was produced from molten glass at furnace temperatures, a large-scale industrial process dominated by men.
The delicate multicolored decoration was added by people women, working at home using an oil lamp or spirit lamp to re-heat the cores and the fine wisps of colored glass used to decorate them. These workers were paid on a piecework basis for the resulting lampwork beads. Modern lampwork beads are made by using a gas torch to heat a rod of glass and spinning the resulting thread around a metal rod covered in bead release; when the base bead has been formed, other colors of glass can be added to the surface to create many designs. After this initial stage of the beadmaking process, the bead can be further fired in a kiln to make it more durable. Modern beadmakers use dual fuel torches, so ` flameworked' is replacing the older term. Unlike a metalworking torch, or burner as some people in the trade prefer to call them, a flameworking torch is "surface mix". Unlike metalworking, the torch is fixed, and
Engraving is the practice of incising a design onto a hard flat surface by cutting grooves into it with a burin. The result may be a decorated object in itself, as when silver, steel, or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing images on paper as prints or illustrations. Engraving is one of the oldest and most important techniques in printmaking. Wood engraving is not covered in this article. Engraving was a important method of producing images on paper in artistic printmaking, in mapmaking, for commercial reproductions and illustrations for books and magazines, it has long been replaced by various photographic processes in its commercial applications and because of the difficulty of learning the technique, is much less common in printmaking, where it has been replaced by etching and other techniques. "Engraving" is loosely but incorrectly used for any old black and white print. Many old master prints combine techniques on the same plate, further confusing matters.
Line engraving and steel engraving cover use for reproductive prints, illustrations in books and magazines, similar uses in the 19th century, not using engraving. Traditional engraving, by burin or with the use of machines, continues to be practised by goldsmiths, glass engravers and others, while modern industrial techniques such as photoengraving and laser engraving have many important applications. Engraved gems were an important art in the ancient world, revived at the Renaissance, although the term traditionally covers relief as well as intaglio carvings, is a branch of sculpture rather than engraving, as drills were the usual tools. Other terms used for printed engravings are copper engraving, copper-plate engraving or line engraving. Steel engraving is the same technique, on steel or steel-faced plates, was used for banknotes, illustrations for books and reproductive prints and similar uses from about 1790 to the early 20th century, when the technique became less popular, except for banknotes and other forms of security printing.
In the past, "engraving" was used loosely to cover several printmaking techniques, so that many so-called engravings were in fact produced by different techniques, such as etching or mezzotint. "Hand engraving" is a term sometimes used for engraving objects other than printing plates, to inscribe or decorate jewellery, trophies and other fine metal goods. Traditional engravings in printmaking are "hand engraved", using just the same techniques to make the lines in the plate; each graver has its own use. Engravers use a hardened steel tool called a burin, or graver, to cut the design into the surface, most traditionally a copper plate. However, modern hand engraving artists use burins or gravers to cut a variety of metals such as silver, steel, gold and more, in applications from weaponry to jewellery to motorcycles to found objects. Modern professional engravers can engrave with a resolution of up to 40 lines per mm in high grade work creating game scenes and scrollwork. Dies used in mass production of molded parts are sometimes hand engraved to add special touches or certain information such as part numbers.
In addition to hand engraving, there are engraving machines that require less human finesse and are not directly controlled by hand. They are used for lettering, using a pantographic system. There are versions for the insides of rings and the outsides of larger pieces; such machines are used for inscriptions on rings and presentation pieces. Gravers come in a variety of sizes that yield different line types; the burin produces a unique and recognizable quality of line, characterized by its steady, deliberate appearance and clean edges. The angle tint tool has a curved tip, used in printmaking. Florentine liners are flat-bottomed tools with multiple lines incised into them, used to do fill work on larger areas or to create uniform shade lines that are fast to execute. Ring gravers are made with particular shapes that are used by jewelry engravers in order to cut inscriptions inside rings. Flat gravers are used for fill work on letters, as well as "wriggle" cuts on most musical instrument engraving work, remove background, or create bright cuts.
Knife gravers are for line engraving and deep cuts. Round gravers, flat gravers with a radius, are used on silver to create bright cuts, as well as other hard-to-cut metals such as nickel and steel. Square or V-point gravers are square or elongated diamond-shaped and used for cutting straight lines. V-point can be anywhere depending on purpose and effect; these gravers have small cutting points. Other tools such as mezzotint rockers and burnishers are used for texturing effects. Burnishing tools can be used for certain stone setting techniques. Musical instrument engraving on American-made brass instruments flourished in the 1920s and utilizes a specialized engraving technique where a flat graver is "walked" across the surface of the instrument to make zig-zag lines and patterns; the method for "walking" the graver may be referred to as "wriggle" or "wiggle" cuts. This technique is necessary due to the thinness of metal used to make musical instruments versus firearms or jewelry. Wriggle cuts are found on
Glass mosaic is a traditional Burmese mosaic made with pieces of glass, used to embellish decorative art and furniture. Glass mosaic is divided into two subcategories, hman gyan si and hman nu si; the former is used to decorate the walls and ceilings of pagodas, while the latter is used to embellish furniture and accessories. The art form originated in the 1500s during the Nyaungyan era. Glass mosaic is studded with gems and semi-precious stones. Mosaic Art of Myanmar Glass Mosaics of Burma, 1901
A lathe is a machine that rotates a workpiece about an axis of rotation to perform various operations such as cutting, knurling, deformation and turning, with tools that are applied to the workpiece to create an object with symmetry about that axis. Lathes are used in woodturning, metal spinning, thermal spraying, parts reclamation, glass-working. Lathes can be used to shape the best-known design being the Potter's wheel. Most suitably equipped metalworking lathes can be used to produce most solids of revolution, plane surfaces and screw threads or helices. Ornamental lathes can produce three-dimensional solids of incredible complexity; the workpiece is held in place by either one or two centers, at least one of which can be moved horizontally to accommodate varying workpiece lengths. Other work-holding methods include clamping the work about the axis of rotation using a chuck or collet, or to a faceplate, using clamps or dogs. Examples of objects that can be produced on a lathe include screws, gun barrels, cue sticks, table legs, baseball bats, musical instruments and much more.
The lathe is an ancient tool, with tenuous evidence for its existence at a Mycenaean Greek site, dating back as far as the 13th or 14th century BC. Clear evidence of turned artifacts have been found from the 6th century BC: fragments of a wooden bowl in an Etruscan tomb in Northern Italy as well as two flat wooden dishes with decorative turned rims from modern Turkey. During the Warring States period in China, ca 400 BCE, the ancient Chinese used rotary lathes to sharpen tools and weapons on an industrial scale; the first known painting showing a lathe dates to the 3rd century BC in ancient Egypt. The lathe was important to the Industrial Revolution, it is known as the mother of machine tools, as it was the first machine tool that led to the invention of other machine tools. The first documented, all-metal slide rest lathe was invented by Jacques de Vaucanson around 1751, it was described in the Encyclopédie. An important early lathe in the UK was the horizontal boring machine, installed in 1772 in the Royal Arsenal in Woolwich.
It was horse-powered and allowed for the production of much more accurate and stronger cannon used with success in the American Revolutionary War in the late 18th century. One of the key characteristics of this machine was that the workpiece was turning as opposed to the tool, making it technically a lathe. Henry Maudslay who developed many improvements to the lathe worked at the Royal Arsenal from 1783 being exposed to this machine in the Verbruggen workshop. A detailed description of Vaucanson's lathe was published decades before Maudslay perfected his version, it is that Maudslay was not aware of Vaucanson's work, since his first versions of the slide rest had many errors that were not present in the Vaucanson lathe. During the Industrial Revolution, mechanized power generated by water wheels or steam engines was transmitted to the lathe via line shafting, allowing faster and easier work. Metalworking lathes evolved into heavier machines with more rigid parts. Between the late 19th and mid-20th centuries, individual electric motors at each lathe replaced line shafting as the power source.
Beginning in the 1950s, servomechanisms were applied to the control of lathes and other machine tools via numerical control, coupled with computers to yield computerized numerical control. Today manually controlled and CNC lathes coexist in the manufacturing industries. A lathe may or may not have legs known as a nugget, which sit on the floor and elevate the lathe bed to a working height. A lathe may sit on a workbench or table, not requiring a stand. All lathes have a bed, a horizontal beam. Woodturning lathes specialized for turning large bowls have no bed or tail stock a free-standing headstock and a cantilevered tool rest. At one end of the bed is a headstock; the headstock contains high-precision spinning bearings. Rotating within the bearings is a horizontal axle, with an axis parallel to the bed, called the spindle. Spindles are hollow and have exterior threads and/or an interior Morse taper on the "inboard" by which work-holding accessories may be mounted to the spindle. Spindles may have exterior threads and/or an interior taper at their "outboard" end, and/or may have a hand-wheel or other accessory mechanism on their outboard end.
Spindles are impart motion to the workpiece. The spindle is driven either by foot power from a treadle and flywheel or by a belt or gear drive to a power source. In most modern lathes this power source is an integral electric motor either in the headstock, to the left of the headstock, or beneath the headstock, concealed in the stand. In addition to the spindle and its bearings, the headstock contains parts to convert the motor speed into various spindle speeds. Various types of speed-changing mechanism achieve this, from a cone pulley or step pulley, to a cone pulley with back gear, to an entire gear train similar to that of a manual-shift auto transmission; some motors have electronic rheostat-type speed controls, which obviates cone gears. The counterpoint to the headstock is the tailstock, sometimes referred to as the loose head, as it can be positioned at any convenient point on the bed by
Glass production involves two main methods – the float glass process that produces sheet glass, glassblowing that produces bottles and other containers. Broadly, modern glass container factories are three-part operations: the batch house, the hot end, the cold end; the batch house handles the raw materials. The following table lists common viscosity fixpoints, applicable to large-scale glass production and experimental glass melting in the laboratory: Batch processing is one of the initial steps of the glass-making process; the batch house houses the raw materials in large silos and holds anywhere from 1–5 days of material. Some batch systems include material processing such as raw material screening/sieve, drying, or pre-heating. Whether automated or manual, the batch house measures, assembles and delivers the glass raw material recipe via an array of chutes and scales to the furnace; the batch enters the furnace at the'dog house' or'batch charger'. Different glass types, desired quality, raw material purity / availability, furnace design will affect the batch recipe.
The hot end of a glassworks is where the molten glass is formed into glass products, beginning when the batch is fed into the furnace at a slow, controlled rate by the batch processing system. The furnaces are natural gas- or fuel oil-fired, operate at temperatures up to 1,575 °C; the temperature is limited only by the quality of the furnace’s superstructure material and by the glass composition. Types of furnaces used in container glass making include'end-port','side-port', and'oxy-fuel'. Furnace "size" is classified by metric tons per day production capability. There are two primary methods of making glass containers: the blow & blow method for narrow-neck containers only, the press & blow method used for jars and tapered narrow-neck containers. Figure 1: Steps during Blow&Blow container forming process In both methods, a stream of molten glass, at its plastic temperature, is cut with a shearing blade to form a solid cylinder of glass, called a gob; the gob is of predetermined weight just sufficient to make a bottle.
Both processes start with the gob falling, by gravity, guided, through troughs and chutes, into the blank moulds, two halves of which are clamped shut and sealed by the "baffle" from above. In the blow and blow process, the glass is first blown through a valve in the baffle, forcing it down into the three-piece "ring mould", held in the "neckring arm" below the blanks, to form the "finish", The compressed air is blown through the glass, which results in hollow and formed container. Compressed air is blown again at the second stage to give final shape. Containers are made in two major stages; the first stage moulds all the details around the opening, but the body of the container is made much smaller than its final size. These manufactured containers are called parisons, quite they are blow-molded into final shape. Referring to the mechanism, the "rings" are sealed from below by a short plunger. After the "settleblow" finishes, the plunger retracts to allow the skin that's formed to soften. "Counterblow" air comes up through the plunger, to create the parison.
The baffle rises and the blanks open. The parison is inverted in an arc to the "mould side" by the "neckring arm", which holds the parison by the "finish"; as the neckring arm reaches the end of its arc, two mould halves close around the parison. The neckring arm opens to release its grip on the "finish" reverts to the blank side. Final blow, applied through the "blowhead", blows the glass out, expanding into the mould, to make the final container shape. In the press and blow process, the parison is formed by a long metal plunger which rises up and presses the glass out, in order to fill the ring and blank moulds; the process continues as before, with the parison being transferred to the final-shape mould, the glass being blown out into the mould. The container is picked up from the mould by the "take-out" mechanism, held over the "deadplate", where air cooling helps cool down the still-soft glass; the bottles are swept onto a conveyor by the "push out paddles" that have air pockets to keep the bottles standing after landing on the "deadplate".
The forming machines move the parts that form the container. The machine consist of basic 19 mechanisms in operation to form a bottle and powered by compressed air, the mechanisms are electronically timed to coordinate all movements of the mechanisms; the most used forming machine arrangement is the individual section machine. This machine has a bank of 5–20 identical sections, each of which contains one complete set of mechanisms to make containers; the sections are in a row, the gobs feed into each section via a moving chute, called the gob distributor. Sections make either one, three or four containers simultaneously.. In the case of multiple gobs, the shears cut the gobs and they fall into the blank moulds in parallel. After the forming process, some containers—particularly those intended for alcoholic spirits—undergo a treatment t
Sir Alan Charles Laurence Whistler was a British poet and artist. He devoted himself to glass engraving, on goblets and bowls blown to his own designs, on large-scale panels and windows in churches and private houses, he engraved on three-sided prisms, some of them designed to revolve on a small turntable so that the prism's internal reflections complete the image. The best-known of these was done as a memorial to Rex Whistler, his son, Simon Whistler became a glass engraver. In 1935 Laurence Whistler became the first recipient of the King's Gold Medal for Poetry. However, he turned away from verse to concentrate on glass engraving, his early works include a casket for the Queen Mother, a hinged glass triptych to hold her daily schedule. Other engravings of his can be found, for example, in Salisbury, where his family lived during part of his childhood, including a pair of memorial panels with quotations by T. S. Eliot, the Rex Prism Video on YouTube in the Morning Chapel, both in Salisbury Cathedral.
In 1947, Whistler created one of the wedding gifts for Princess Elizabeth, a glass goblet engraved with the words of a 1613 poem by Thomas Campion, written for the marriage of Elizabeth of Bohemia, daughter of James I. In 1975 he became the first President of the newly founded British Guild of Glass Engravers. In 1939 Laurence Whistler married the actress Jill Furse. In 1950 Laurence Whistler married Jill Furse's younger sister, but the marriage was dissolved, they had another two children Frances. In 1987 he married a third time, but was divorced in 1991. Whistler's many honours included an OBE and a CBE. In 2000, not long before his death at the age of 88, Laurence Whistler was created a Knight Bachelor. Oxford Dictionary of National Biography, Sir Laurence, glass engraver and architectural historian, by Robin Ravilious The Initials in the Heart. Michael Russell Publishing Ltd. ISBN 0-85955-257-8 Point Engraving on Glass. Walker Books Ltd. ISBN 0-7445-1894-6 The Laughter and the Urn: The Life of Rex Whistler.
Weidenfeld & Nicolson Ltd ISBN 0-297-78603-2 The Image on the Glass. Cupid Press, ISBN 0-7195-3275-2 Stowe: Guide to the Gardens. E. N. Hillier & Sons, 3rd edition