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Stained Glass
Stained glass refers to coloured glass as a material or art and architectural works created from it. Although it is traditionally made in flat panels and used as windows, the creations of modern stained glass artists also include three-dimensional structures and sculpture. Modern vernacular usage has often extended the term "stained glass" to include domestic leadlight, lead light and ''objet d'art, objets d'art'' created from glasswork, for example in the famous lamps of Louis Comfort Tiffany. As a material ''stained glass'' is glass that has been coloured by adding Salt (chemistry), metallic salts during its manufacture. It may then be further decorated in various ways. The coloured glass may be crafted into a stained-glass window, say, in which small pieces of glass are arranged to form patterns or pictures, held together (traditionally) by strips of lead, called cames or calms, and supported by a rigid frame. Painted details and yellow-coloured Silver staining, silver stain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chartres RosetteNord 121 DSC08241
Chartres () is the prefecture of the Eure-et-Loir department in the Centre-Val de Loire region in France. It is located about southwest of Paris. At the 2019 census, there were 170,763 inhabitants in the metropolitan area of Chartres (as defined by the INSEE), 38,534 of whom lived in the city ( commune) of Chartres proper. Chartres is famous worldwide for its cathedral. Mostly constructed between 1193 and 1250, this Gothic cathedral is in an exceptional state of preservation. The majority of the original stained glass windows survive intact, while the architecture has seen only minor changes since the early 13th century. Part of the old town, including most of the library associated with the School of Chartres, was destroyed by Allied bombs in 1944. History Chartres was one of the principal towns in Gaul of the Carnutes, a Celtic tribe. In the Gallo-Roman period, it was called ''Autricum'', name derived from the river ''Autura'' (Eure), and afterwards ''civitas Carnutum'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Life Of Christ In Art
The life of Christ as a narrative cycle in Christian art comprises a number of different subjects showing events from the life of Jesus on Earth. They are distinguished from the many other subjects in art showing the eternal life of Christ, such as Christ in Majesty, and also many types of portrait or devotional subjects without a narrative element. They are often grouped in series or cycles of works in a variety of media, from book illustrations to large cycles of wall paintings, and most of the subjects forming the narrative cycles have also been the subjects of individual works, though with greatly varying frequency. By around 1000, the choice of scenes for the remainder of the Middle Ages became largely settled in the Western and Eastern churches, and was mainly based on the major feasts celebrated in the church calendars. The most common subjects were grouped around the birth and childhood of Jesus, and the Passion of Christ, leading to his Crucifixion and Resurrection ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pontil Mark
A pontil mark or punt mark is the scar where the pontil, punty or punt was broken from a work of blown glass. The presence of such a scar indicates that a glass bottle or bowl was blown freehand, while the absence of a punt mark suggests either that the mark has been obliterated or that the work was mold-blown. Note: not all glass with a pontil scar was blown. Some non-blown, free-form glass items were attached to a pontil rod in order to do finishing work on the item; such as crimping the rims, swinging the item upside down to form a swung vase etc., applying glass decorative elements, (rigaree) fire polishing the rims or re-striking, (re-heating) the items made of heat sensitive glass that changes color on the area that has been reheated. Some glassblowers grind a hollow into the base of their work, obliterating the natural punt scar. Where the base of the work is sufficiently heavy, the entire natural base can be sawed or ground flat. Where the base of the work is concav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centrifugal Force
Centrifugal force is a fictitious force in Newtonian mechanics (also called an "inertial" or "pseudo" force) that appears to act on all objects when viewed in a rotating frame of reference. It appears to be directed radially away from the axis of rotation of the frame. The magnitude of the centrifugal force ''F'' on an object of mass ''m'' at the perpendicular distance ''ρ'' from the axis of a rotating frame of reference with angular velocity is F = m\omega^2 \rho. This fictitious force is often applied to rotating devices, such as centrifuges, centrifugal pumps, centrifugal governors, and centrifugal clutches, and in centrifugal railways, planetary orbits and banked curves, when they are analyzed in a non–inertial reference frame such as a rotating coordinate system. The term has sometimes also been used for the '' reactive centrifugal force'', a real frame-independent Newtonian force that exists as a reaction to a centripetal force in some scenarios. History F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potter's Wheel
In pottery, a potter's wheel is a machine used in the shaping (known as throwing) of clay into round ceramic ware. The wheel may also be used during the process of trimming excess clay from leather-hard dried ware that is stiff but malleable, and for applying incised decoration or rings of colour. Use of the potter's wheel became widespread throughout the Old World but was unknown in the Pre-Columbian New World, where pottery was handmade by methods that included coiling and beating. A potter's wheel may occasionally be referred to as a "potter's lathe". However, that term is better used for another kind of machine that is used for a different shaping process, turning, similar to that used for shaping of metal and wooden articles. The pottery wheel is an important component to create arts and craft products. The techniques of jiggering and jolleying can be seen as extensions of the potter's wheel: in jiggering, a shaped tool is slowly brought down onto the plastic clay bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Glass (window)
Crown glass was an early type of window glass. In this process, glass was blown into a "crown" or hollow globe. This was then transferred from the blowpipe to a punty and then flattened by reheating and spinning out the bowl-shaped piece of glass (bullion) into a flat disk by centrifugal force, up to 5 or 6 feet (1.5 to 1.8 metres) in diameter. The glass was then cut to the size required. The thinnest glass was in a band at the edge of the disk, with the glass becoming thicker and more opaque toward the center. Known as a bullseye, the thicker center area around the pontil mark was used for less expensive windows. To fill large window spaces with the best glass, many small diamond shapes were cut from the edge of the disk, and then some might be halved into triangles. These were mounted in a lead lattice work and fitted into the window frame. Crown glass was one of the two most common processes for making window glass until the 19th century. The other was blown plate. Crown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annealing (glass)
Annealing is a process of slowly cooling hot glass objects after they have been formed, to relieve residual internal stresses introduced during manufacture. Especially for smaller, simpler objects, annealing may be incidental to the process of manufacture, but in larger or more complex products it commonly demands a special process of annealing in a temperature-controlled kiln known as a lehr. Annealing of glass is critical to its durability. Glass that has not been properly annealed retains thermal stresses caused by quenching, which will indefinitely decrease the strength and reliability of the product. Inadequately annealed glass is likely to crack or shatter when subjected to relatively small temperature changes or to mechanical shock or stress. It even may fail spontaneously. To anneal glass, it is necessary to heat it to its annealing temperature, at which its viscosity, η, drops to 1013 Poise (1013 dyne-second/cm2). For most kinds of glass, this annealing temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glassblowing
Glassblowing is a glassforming technique that involves inflating molten glass into a bubble (or parison) with the aid of a blowpipe (or blow tube). A person who blows glass is called a ''glassblower'', ''glassmith'', or ''gaffer''. A '' lampworker'' (often also called a glassblower or glassworker) manipulates glass with the use of a torch on a smaller scale, such as in producing precision laboratory glassware out of borosilicate glass. Technology Principles As a novel glass forming technique created in the middle of the 1st century BC, glassblowing exploited a working property of glass that was previously unknown to glassworkers; inflation, which is the expansion of a molten blob of glass by introducing a small amount of air into it. That is based on the liquid structure of glass where the atoms are held together by strong chemical bonds in a disordered and random network,Frank, S 1982. Glass and Archaeology. Academic Press: London. Freestone, I. (1991). "Looking into Glass". ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flashed Glass
Flashed glass, or flash glass, is a type of glass created by coating a colorless gather of glass with one or more thin layers of colored glass. This is done by placing a piece of melted glass of one color into another piece of melted glass of a different color and then blowing the glass. As well as its use for glass vessels, it has been very widely used in making stained glass since medieval times, often in combination with " pot metal glass", made by colouring molten glass, giving colour all through the sheet. The colored glass can be partly or completely etched away (through exposure to acid or via sandblasting), resulting in colorless spots where the colored glass has been removed. Flashed glass can be made from various colors of glass. A finished piece of flashed glass appears translucent. See also * Cased glass * Glass engraving * Satsuma Kiriko cut glass * Stained glass Stained glass refers to coloured glass as a material or art and architectural works create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lime (material)
Lime is an Inorganic compound, inorganic material composed primarily of calcium oxides and hydroxides. It is also the name for calcium oxide which is used as an industrial mineral and is made by heating calcium carbonate in a kiln. Calcium oxide can occur as a product of coal-seam fires and in altered limestone xenoliths in volcanic ejecta. The International Mineralogical Association recognizes lime as a mineral with the chemical formula of CaO. The word ''lime'' originates with its earliest use as building mortar and has the sense of ''sticking or adhering''. These materials are still used in large quantities in the manufacture of steel and as building and engineering materials (including limestone products, cement, concrete, and mortar (masonry), mortar), as chemical feedstocks, for sugar refining, and other uses. Lime industries and the use of many of the resulting products date from prehistoric times in both the Old World and the New World. Lime is used extensively for was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead
Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable nuclide, stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its Amphoterism, amphoteric nature; lead and lead oxides react with acids and base (chemistry), bases, and it tends to form covalent bonds. Lead compounds, Compounds of lead are usually found in the +2 oxidation state rather than the +4 state common with lighter members of the carbon group. Exceptions are mostly limited ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Carbonate
Sodium carbonate (also known as washing soda, soda ash, sal soda, and soda crystals) is the inorganic compound with the formula and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, and because the ashes of these sodium-rich plants were noticeably different from ashes of wood (once used to produce potash), sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the chloralkali process. Hydrates Sodium carbonate is obtained as three hydrates and as the anhydrous salt: * sodium carbonate decahydrate ( natron), Na2CO3·10H2O, which readily effloresces to form the monohydrate. * sodium carbonate heptahydrate (not known in mineral form), Na2CO3·7H2O. * sodium carbonate monohydrate ( thermonatr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
