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Dovetail Joint
A dovetail joint or simply dovetail is a joinery technique most commonly used in woodworking joinery (carpentry), including furniture, cabinets, log buildings, and traditional timber framing. Noted for its resistance to being pulled apart, also known as tensile strength, the dovetail joint is commonly used to join the sides of a drawer to the front. A series of pins cut to extend from the end of one board interlock with a series of 'tails' cut into the end of another board. The pins and tails have a trapezoidal shape. Once glued, a wooden dovetail joint requires no mechanical fasteners. History The dovetail joint technique probably pre-dates written history. Some of the earliest known examples of the dovetail joint are in ancient Egyptian furniture entombed with mummies dating from First Dynasty, the tombs of Chinese emperors, and a stone pillar at the Vazhappally Maha Siva Temple in India. The dovetail design is an important method of distinguishing various periods of furni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finished Dovetail
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Finished may refer to: * ''Finished'' (novel), a 1917 novel by H. Rider Haggard * ''Finished'' (film), a 1923 British silent romance film * "Finished" (short story), a science fiction short story by L. Sprague de Camp See also * Finishing (other) *Finish (other) Finish may refer to: * Finishing (whisky), in the distillation of Scotch * The aftertaste of an alcoholic beverage, particularly for: ** wine * Finished good, a good that is completed as to manufacturing but not yet sold or distributed to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ironbridge2
Ironbridge is a riverside village in the borough of Telford and Wrekin, Shropshire, England. Located on the bank of the River Severn, at the heart of the Ironbridge Gorge, it lies in the civil parishes in England, civil parish of Ironbridge Gorge#The Gorge parish, The Gorge. Ironbridge developed beside, and takes its name from, the Iron Bridge, a cast iron bridge that was built in 1779. History The area around Ironbridge is described by those promoting it as a tourist destination as the "birthplace of the Industrial Revolution". This description is based on the idea that Abraham Darby I, Abraham Darby perfected the technique of smelting iron with Coke (fuel), coke, in Coalbrookdale, allowing much cheaper Iron making, production of iron. However, the industrial revolution did not begin in any one place. Darby's iron smelting was but one small part of this generalised revolution and was soon superseded by the great iron-smelting areas. However, the bridge – being the fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airgun
An air gun or airgun is a gun that uses energy from compressed air or other gases that are mechanically pressurized and then released to propel and accelerate projectiles, similar to the principle of the primitive blowgun. This is in contrast to a firearm, which shoots projectiles using energy generated via exothermic combustion ( detonation) of chemical propellants, most often black powder or smokeless powder. Air guns come in both long gun (air rifle) and handgun (air pistol) forms. Both types typically propel metallic projectiles that are either diabolo-shaped pellets or spherical shots called BBs, although in recent years Minié ball-shaped cylindro-conoidal projectiles called slugs are gaining more popularity. Certain types of air guns (usually air rifles) may also launch fin-stabilized projectile such as darts (e.g., tranquilizer guns) or hollow-shaft arrows (so-called "airbows"). The first air guns were developed as early as the 16th century, and have s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telescopic Sight
A telescopic sight, commonly called a scope informally, is an optical sighting device based on a refracting telescope. It is equipped with some form of a referencing pattern – known as a ''reticle'' – mounted in a focally appropriate position in its optical system to provide an accurate point of aim. Telescopic sights are used with all types of systems that require magnification in addition to reliable visual aiming, as opposed to non-magnifying iron sights, reflector (reflex) sights, holographic sights or laser sights, and are most commonly found on long-barrel firearms, particularly rifles, usually via a scope mount. Similar devices are also found on other platforms such as artillery, tanks and even aircraft. The optical components may be combined with optoelectronics to add night vision or smart device features. History The first experiments directed to give shooters optical aiming aids go back to the early 17th century. For centuries, different optical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Sights
Iron sights are a system of physical alignment markers used as a sighting device to assist the accurate aiming of ranged weapons such as firearms, airguns, crossbows, and bows, or less commonly as a primitive finder sight for optical telescopes. Iron sights, which are typically made of metal, are the earliest and simplest type of sighting device. Since iron sights neither magnify nor illuminate the target, they rely completely on the viewer's naked eye and the available light by which the target is visible. In this respect, iron sights are distinctly different from optical sight designs that employ optical manipulation or active illumination, such as telescopic sights, reflector (reflex) sights, holographic sights, and laser sights. Iron sights are typically composed of two components mounted perpendicularly above the weapon's bore axis: a 'rear sight' nearer (or 'proximal') to the shooter's eye, and a 'front sight' farther forward (or 'distal') near the muzzle. During ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3D Printing
3D printing, or additive manufacturing, is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer control, with the material being added together (such as plastics, liquids or powder grains being fused), typically layer by layer. In the 1980s, 3D printing techniques were considered suitable only for the production of functional or aesthetic prototypes, and a more appropriate term for it at the time was rapid prototyping. , the precision, repeatability, and material range of 3D printing have increased to the point that some 3D printing processes are considered viable as an industrial-production technology; in this context, the term ''additive manufacturing'' can be used synonymously with ''3D printing''. One of the key advantages of 3D printing is the ability to produce very complex shapes or geometries that would be otherwise infeasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fastnet Lighthouse
Fastnet Lighthouse is a lighthouse situated on the remote Fastnet Rock in the Atlantic Ocean. It is the most southerly point of Ireland and lies southwest of Cape Clear Island and from County Cork on the Irish mainland. The current lighthouse is the second to be built on the rock and is the tallest in Ireland. First lighthouse Construction of the first lighthouse began in 1853, and it first produced a light on 1 January 1854. The lighthouse replaced an early one built on Cape Clear Island in 1818, partly motivated by the loss of an American sailing packet, ''Stephen Whitney'', in thick fog during November 1847 on nearby West Calf Island causing the death of 92 of her 110 passengers and crew. The new lighthouse was constructed of cast iron with an inner lining of brick and was designed by George Halpin. Costing £17,390, the tower was tall with an lantern structure on top, giving a total height of around . It had an oil-burning lamp of 38 kilocandelas; in contrast, moder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eddystone Lighthouse
The Eddystone Lighthouse is a lighthouse on the Eddystone Rocks, south of Rame Head in Cornwall, England. The rocks are submerged below the surface of the sea and are composed of Precambrian gneiss. View at 1:50000 scale The current structure is the fourth to be built on the site. The first lighthouse (Winstanley's) was swept away in a powerful storm, killing its architect and five other men in the process. The second (Rudyard's) stood for fifty years before it burned down. The third (Smeaton's) is renowned because of its influence on Lighthouse, lighthouse design and its importance in the development of concrete for building; its upper portions were re-erected in Plymouth as a monument. The first lighthouse, completed in 1699, was the world's first open ocean lighthouse, although the Cordouan Lighthouse off the western French coast preceded it as the first offshore lighthouse. The need for a light The Eddystone Rocks are an extensive reef approximately SSW off Plymouth S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA Tech Briefs
The National Aeronautics and Space Administration is required by its charter to report to industry any new, commercially significant technologies developed in the course of their R&D. Since the early 1960s, this has been accomplished primarily through the publication of ''NASA Tech Briefs''. ''NASA Tech Briefs'' were first published about 1963 by the Technology Utilization Office at NASA HQ (Washington, D.C.) as single-page documents. Over the years, hundreds of such documents were published and disseminated covering many areas of science and industry. The material for these documents was collected by TU offices in each of the NASA field centers, as well as from all of their contractors. Most work done under NASA contract was presumed to be the property of NASA and was freely disseminated to industry and the public. Compilations of these became available in the 1970s. Since then, it has been a joint publishing venture of NASA and Tech Briefs Media Group, a unit of SAE Internat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbine
A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced can be used for generating electrical power when combined with a generator.Munson, Bruce Roy, T. H. Okiishi, and Wade W. Huebsch. "Turbomachines." Fundamentals of Fluid Mechanics. 6th ed. Hoboken, NJ: J. Wiley & Sons, 2009. Print. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor. Gas, steam, and water turbines have a casing around the blades that contains and controls the working fluid. Modern steam turbines frequently employ both reaction and impulse in the same unit, typically varying the degree of reaction and impulse from the blade root to its periphery. History Hero of Alexandria demonstrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Popular Science
Popular science (also called pop-science or popsci) is an interpretation of science intended for a general audience. While science journalism focuses on recent scientific developments, popular science is more broad ranging. It may be written by professional science journalists or by scientists themselves. It is presented in many forms, including books, film and television documentaries, magazine articles, and web pages. History Before the modern specialization and professionalization of science, there was often little distinction between "science" and "popular science", and works intended to share scientific knowledge with a general reader existed as far back as Greek and Roman antiquity. Without these popular works, much of the scientific knowledge of the era might have been lost. For example, none of the original works of the Greek astronomer Eudoxus (4th century BC) have survived, but his contributions were largely preserved due to the didactic poem '' Phenomena'' writte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Machine Tools
A machine tool is a machine for handling or machining metal or other rigid materials, usually by cutting, boring, grinding, shearing, or other forms of deformations. Machine tools employ some sort of tool that does the cutting or shaping. All machine tools have some means of constraining the workpiece and provide a guided movement of the parts of the machine. Thus, the relative movement between the workpiece and the cutting tool (which is called the toolpath) is controlled or constrained by the machine to at least some extent, rather than being entirely "offhand" or " freehand". It is a power-driven metal cutting machine which assists in managing the needed relative motion between cutting tool and the job that changes the size and shape of the job material. The precise definition of the term ''machine tool'' varies among users. While all machine tools are "machines that help people to make things", not all factory machines are machine tools. Today machine tools are typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
