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Reeding
Reeding is a technique wherein a number of narrow ridges called "reeds" are carved or milled into a surface. __NOTOC__ Numismatics In numismatics, reeded edges are often referred to as "ridged" or "grooved" (American usage), or "milled" (British usage). Some coins, such as United States quarters and dimes, 1 euro, Australian 5, 10, 20 cents, 1 and 2 dollars, as well many other current coins, have reeded edges. One reason for having reeded edges was to prevent counterfeiting. Some gold and silver coins were reeded to discourage clipping, i.e. scraping off the precious metals from the edge of the coin, to maintain its stated value in precious metal. This practice was made more difficult through the implementation of reeding by Isaac Newton in 1698, during his time as warden of the Royal Mint. Another benefit of certain coins having reeded edges is that it helps the visually impaired identify different coin denominations by sense of touch alone. This dual purpose of reeding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluting (architecture)
Fluting in architecture consists of shallow grooves running along a surface. The term typically refers to the grooves (flutes) running vertically on a column shaft or a pilaster, but need not necessarily be restricted to those two applications. If the hollowing out of material meets in a point, the point (sharp ridge) is called an arris. If the raised ridge between two flutes is blunt, the ridge is a . Purpose Fluting promotes a play of light on a column which helps the column appear more perfectly round than a smooth column. As a strong vertical element it also has the visual effect of minimizing any horizontal joints. Greek architects viewed rhythm as an important design element. As such, fluting was often used on buildings and temples to increase the sense of rhythm. It may also be incorporated in columns to make them look thinner, lighter, and more elegant. There is debate as to whether fluting was originally used in imitation of ancient woodworking practices, mimicking ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milled Coinage
In numismatics, the term milled coinage (also known as machine-struck coinage) is used to describe coins which are produced by some form of machine, rather than by manually hammering coin blanks between two dies ( hammered coinage) or casting coins from dies. Introduction Until 1550, coinage techniques used in European mints had not progressed from the hammered coinage of Ancient Greece. This was problematic because an increase in the supply of bullion from central Europe and America was overworking mints. That led to low quality coins which were easily forged or clipped, i.e. precious metal was shaved from the edges of the coins. In accordance with Gresham's law, the clipped and forged coins drove good coins out of circulation, depreciating the currency. Leonardo da Vinci's notebooks showed there was a better way and Donato Bramante, the architect who made the initial plans for St. Peter's Basilica, developed a screw press to make the lead bullae attached to Papal docum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coins Of The Australian Dollar
Coins of the Australian dollar were introduced on 14 February 1966, although they did not at that time include the one-dollar or two-dollar coins. The dollar was equivalent in value to 10 shillings (half a pound) in the former currency. Regular coinage Produced by the Royal Australian Mint, all current coins have featured four versions of the effigy of Her Majesty Elizabeth II, former Queen of Australia, on the obverse. The first effigy was designed by Arnold Machin, the second effigy by Raphael Maklouf, the third effigy by Ian Rank-Broadley and the fourth effigy by artist Jody Clark. They have all been matched with designs by the Australian-born artist Stuart Devlin on the reverse. The set now comprises a 50c, 20c, 10c and 5c coin, all still referred to as "silver", although they consist of 75% copper and 25% nickel. For many years there were also 2c and 1c coins, traditionally called "copper" coins, although they are actually an alloy of copper and zinc. The original ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spline (mechanical)
Splines are ridges or teeth on a drive shaft that matches with grooves in a mating piece and transfer torque to it, maintaining the angular correspondence between them. For instance, a gear mounted on a shaft might use a male spline on the shaft that matches the female spline on the gear. The splines on the pictured drive shaft match with the female splines in the center of the clutch plate, while the smooth tip of the axle is supported in the pilot bearing in the flywheel. An alternative to splines is a keyway and key, though splines provide a longer fatigue life, and can carry significantly greater torques for the size. Types There are several types of splines: ;Parallel key spline: where the sides of the equally spaced grooves are parallel in both directions, radial and axial. ;Involute spline: where the sides of the equally spaced grooves are involute, as with an involute gear, but not as tall. The curves increase strength by decreasing stress concentrations. ;Crow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
King George VI Hong Kong 50 Cents 1951 Security Edge
King is the title given to a male monarch in a variety of contexts. The female equivalent is queen, which title is also given to the consort of a king. *In the context of prehistory, antiquity and contemporary indigenous peoples, the title may refer to tribal kingship. Germanic kingship is cognate with Indo-European traditions of tribal rulership (c.f. Indic ''rājan'', Gothic '' reiks'', and Old Irish '' rí'', etc.). *In the context of classical antiquity, king may translate in Latin as '' rex'' and in Greek as ''archon'' or '' basileus''. *In classical European feudalism, the title of ''king'' as the ruler of a ''kingdom'' is understood to be the highest rank in the feudal order, potentially subject, at least nominally, only to an emperor (harking back to the client kings of the Roman Republic and Roman Empire). *In a modern context, the title may refer to the ruler of one of a number of modern monarchies (either absolute or constitutional). The title of ''king'' is u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furniture
Furniture refers to movable objects intended to support various human activities such as seating (e.g., stools, chairs, and sofas), eating ( tables), storing items, eating and/or working with an item, and sleeping (e.g., beds and hammocks). Furniture is also used to hold objects at a convenient height for work (as horizontal surfaces above the ground, such as tables and desks), or to store things (e.g., cupboards, shelves, and drawers). Furniture can be a product of design and can be considered a form of decorative art. In addition to furniture's functional role, it can serve a symbolic or religious purpose. It can be made from a vast multitude of materials, including metal, plastic, and wood. Furniture can be made using a variety of woodworking joints which often reflects the local culture. People have been using natural objects, such as tree stumps, rocks and moss, as furniture since the beginning of human civilization and continues today in some households/campsite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metalworking
Metalworking is the process of shaping and reshaping metals to create useful objects, parts, assemblies, and large scale structures. As a term it covers a wide and diverse range of processes, skills, and tools for producing objects on every scale: from huge ships, buildings, and bridges down to precise engine parts and delicate jewelry. The historical roots of metalworking predate recorded history; its use spans cultures, civilizations and millennia. It has evolved from shaping soft, native metals like gold with simple hand tools, through the smelting of ores and hot forging of harder metals like iron, up to highly technical modern processes such as machining and welding. It has been used as an industry, a driver of trade, individual hobbies, and in the creation of art; it can be regarded as both a science and a craft. Modern metalworking processes, though diverse and specialized, can be categorized into one of three broad areas known as forming, cutting, or joining processes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodworking
Woodworking is the skill of making items from wood, and includes cabinet making (cabinetry and furniture), wood carving, joinery, carpentry, and woodturning. History Along with stone, clay and animal parts, wood was one of the first materials worked by early humans. Microwear analysis of the Mousterian stone tools used by the Neanderthals show that many were used to work wood. The development of civilization was closely tied to the development of increasingly greater degrees of skill in working these materials. Among early finds of wooden tools are the worked sticks from Kalambo Falls, Clacton-on-Sea and Lehringen. The spears from Schöningen (Germany) provide some of the first examples of wooden hunting gear. Flint tools were used for carving. Since Neolithic times, carved wooden vessels are known, for example, from the Linear Pottery culture wells at Kückhofen and Eythra. Examples of Bronze Age wood-carving include tree trunks worked into coffins from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Numismatics
Numismatics is the study or collection of currency, including coins, tokens, paper money, medals and related objects. Specialists, known as numismatists, are often characterized as students or collectors of coins, but the discipline also includes the broader study of money and other means of payment used to resolve debts and exchange goods. The earliest forms of money used by people are categorised by collectors as "Odd and Curious", but the use of other goods in barter exchange is excluded, even where used as a circulating currency (e.g., cigarettes or instant noodles in prison). As an example, the Kyrgyz people used horses as the principal currency unit, and gave small change in lambskins; the lambskins may be suitable for numismatic study, but the horses are not. Many objects have been used for centuries, such as cowry shells, precious metals, cocoa beans, large stones, and gems. Etymology First attested in English 1829, the word ''numismatics'' comes from the adje ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Architectural Elements
:''The following Outline (list), outline is an overview and topical guide to architecture:'' Architecture – the process and the product of designing and constructing buildings. Architectural works with a certain indefinable combination of design quality and external circumstances may become cultural symbols and / or be considered works of art. What ''type'' of thing is architecture? Architecture can be described as all of the following: * Academic discipline – focused study in one academic field or profession. A discipline incorporates expertise, people, projects, communities, challenges, studies, inquiry, and research areas that are strongly associated with the given discipline. * Buildings – buildings and similar structures, the product of architecture, are referred to as architecture. * One of the arts – as an art form, architecture is an outlet of human expression, that is usually influenced by culture and which in turn helps to change culture. Ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knurling
Knurling is a manufacturing process, typically conducted on a lathe, whereby a pattern of straight, angled or crossed lines is rolled into the material. Etymology The terms ''knurl'' and ''knurled'' are from an earlier ''knur'' ‘knot in wood’ and the diminutive ''-le'', from Middle English ''knaur'' or ''knarre'' ‘knot in wood; twisted rock; crag’. This descends from Old English ''cnearra'' but the vowel in Middle English may have been influenced by Old Norse ''knǫrr'' ‘merchant ship’ which was known as ''cnearr'' in Old English. The modern ''gnarl'' is a back-formation of ''gnarled'' which itself is first attested in Shakespeare’s works and is apparently a variant of ''knurled''. Uses The operation is performed for producing indentations on a part of a workpiece. Knurling allows hands or fingers to get a better grip on the knurled object than would be provided by the originally smooth metal surface. Occasionally, the knurled pattern is a series of straig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gadrooning
Gadrooning is a decorative motif consisting of convex curves in a series. In furniture and other decorative arts, it is an ornamental carved band of tapered, curving and sometimes alternating concave and convex sections, usually diverging obliquely either side of a central point, often with rounded ends vaguely reminiscent of flower petals. Gadrooning, derived from Roman art, Roman sarcophagi and other antiquities, was widely used during the Italian Renaissance, and in the classicising phases of 18th- and 19th-century design. In medieval European metalwork, gadroons on circular dishes are often tapering, ending in a point on a central circular zone, and run diagonally across the surface in a spiral. Similar – but typically not tapered – designs were popular in Rococo porcelain and metalwork. In Renaissance or Neoclassical works, they are normally thinner and straighter. The term may also be applied to spiraling stop-fluting running up a classical column. Gallery Three or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
