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Graphite Pencil
A graphite pencil, also called a lead pencil, is a type of pencil in which a thin graphite core is embedded in a shell of other material. The pencil shell is typically wooden, but can be made of plastic or recycled paper. History A large deposit of graphite was discovered in 1565 on the approach to Grey Knotts from the hamlet of Seathwaite in Borrowdale parish, Cumbria, England. Petroski, 1990, pp. 168, 358 This particular deposit of graphite was extremely pure and solid, and it could easily be sawn into sticks. It remains the only large-scale deposit of graphite ever found in this solid form. Chemistry was in its infancy and the substance was thought to be a form of lead. Consequently, it was called ''plumbago'' (Latin for "lead ore"). Because the pencil core is still referred to as "lead", or a "lead", many people have the misconception that the graphite in the pencil is lead, even though it never contained the element lead. The words for pencil in German (''Bleistift''), Ir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Round Shot
A round shot (also called solid shot or simply ball) is a solid spherical projectile without explosive charge, launched from a gun. Its diameter is slightly less than the bore of the barrel from which it is shot. A round shot fired from a large-caliber gun is also called a cannonball. The cast iron cannonball was introduced by a French artillery engineer Samuel J. Besh after 1450; it had the capacity to reduce traditional English castle wall fortifications to rubble. French armories would cast a tubular cannon body in a single piece, and cannonballs took the shape of a sphere initially made from stone material. Advances in gunpowder manufacturing soon led the replacement of stone cannonballs with cast iron ones. Round shot was made in early times from dressed stone, referred to as gunstone (Middle English: ''gunneston''), but by the 17th century, from iron. It was used as the most accurate projectile that could be fired by a smoothbore cannon, used to batter the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plumbago Drawing
Plumbago drawings are graphite drawings from the 17th and 18th centuries. There was a group of artists whose work in plumbago is remarkable for their portraits drawn with finely pointed pieces of graphite and on vellum. These works were initially prepared as the basis of an engraving. Eventually they would be produced as works in their own right. Early artists in plumbago One of the earliest of this group of workers was Simon Van de Pass (1595–1647), and his pencil drawings were probably either for reproduction on silver tablets or counters or for engraved plates. The earlier miniature painters also drew in this manner, notably Nicholas Hilliard in preparing designs for jewels and seals, and Isaac Oliver and Peter Oliver in portraits. A few pencil portraits by Abraham Blooteling, the Dutch engraver, have been preserved, which appear to have been first sketches, from which plates were afterwards engraved. David Loggan (1635–1700), a pupil of Van de Pass, also left a few port ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaolin
Kaolinite ( ) is a clay mineral, with the chemical composition Al2 Si2 O5( OH)4. It is an important industrial mineral. It is a layered silicate mineral, with one tetrahedral sheet of silica () linked through oxygen atoms to one octahedral sheet of alumina () octahedra. Rocks that are rich in kaolinite are known as kaolin () or china clay. Kaolin is occasionally referred to by the antiquated term lithomarge, from the Ancient Greek ''litho-'' and Latin ''marga'', meaning 'stone of marl'. Presently the name lithomarge can refer to a compacted, massive form of kaolin. The name ''kaolin'' is derived from Gaoling (), a Chinese village near Jingdezhen in southeastern China's Jiangxi Province. The name entered English in 1727 from the French version of the word: , following François Xavier d'Entrecolles's reports on the making of Jingdezhen porcelain. Kaolinite has a low shrink–swell capacity and a low cation-exchange capacity (1–15 meq/100 g). It is a soft, earthy, usu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumberland Pencil Museum
The Derwent Pencil Museum is in Keswick, in the north-west of England. History The museum opened in 1981 and is home to one of the biggest colouring pencils in the world, the idea of technical manager Barbara Murray. The yellow pencil was completed on 28 May 2001, is long, and weighs . The first pencil factory in Keswick opened in 1832. The second and current factory was started in the 1920s and completed in 1950 (it closed in 2007 when the owners moved production to Workington). The museum now receives over 80,000 visitors a year from all around the world. It is particularly popular with visitors from the county of Yorkshire, due to the importance of pencil production for the local economy during the 1930s. The museum features as one of the locations in the 2012 film ''Sightseers''. Storm Desmond In December 2015, the museum was badly damaged by several feet of flood water when the River Greta broke its banks as a result of Storm Desmond and many artefacts were destroye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keswick, Cumbria
Keswick ( ) is a market town and civil parishes in England, civil parish in the Allerdale Borough in Cumbria, England. Historic counties of England, Historically, until 1974, it was part of Cumberland. It lies within the Lake District National Park, Keswick is just north of Derwentwater and is from Bassenthwaite Lake. It had a population of 5,243 at the United Kingdom census, 2011, 2011 census. There is evidence of Prehistoric Cumbria, prehistoric occupation of the area, but the first recorded mention of the town dates from the 13th century, when Edward I of England granted a Royal charter, charter for Keswick's market, which has maintained a continuous 700-year existence. The town was an important Coal mining in the United Kingdom, mining area, and from the 18th century has been known as a holiday centre; tourism has been its principal industry for more than 150 years. Its features include the Moot Hall, Keswick, Moot Hall; a modern theatre, the Theatre by the Lake; one of Br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leather
Leather is a strong, flexible and durable material obtained from the tanning, or chemical treatment, of animal skins and hides to prevent decay. The most common leathers come from cattle, sheep, goats, equine animals, buffalo, pigs and hogs, and aquatic animals such as seals and alligators. Leather can be used to make a variety of items, including clothing, footwear, handbags, furniture, tools and sports equipment, and lasts for decades. Leather making has been practiced for more than 7,000 years and the leading producers of leather today are China and India. Animal rights groups claim that modern commercial leather making and the consumption of its products is unethically killing animals. According to the life-cycle assessment (LCA) report for the United Nations Industrial Development Organization, 99% of the raw hides and skins used in the production of leather derive from animals raised for meat and/or dairy production. Critics of tanneries claim that they engage in uns ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Crown
The Crown is the state in all its aspects within the jurisprudence of the Commonwealth realms and their subdivisions (such as the Crown Dependencies, overseas territories, provinces, or states). Legally ill-defined, the term has different meanings depending on context. It is used to designate the monarch in either a personal capacity, as Head of the Commonwealth, or as the king or queen of their realms (whereas the monarchy of the United Kingdom and the monarchy of Canada, for example, are distinct although they are in personal union). It can also refer to the rule of law; however, in common parlance 'The Crown' refers to the functions of government and the civil service. Thus, in the United Kingdom (one of the Commonwealth realms), the government of the United Kingdom can be distinguished from the Crown and the state, in precise usage, although the distinction is not always relevant in broad or casual usage. A corporation sole, the Crown is the legal embodiment of execut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic viability of investing in the equipment, labor, and energy required to extract, refine and transport the materials found at the mine to manufacturers who can use the material. Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Element
A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler substances by any chemical reaction. The number of protons in the nucleus is the defining property of an element, and is referred to as its atomic number (represented by the symbol ''Z'') – all atoms with the same atomic number are atoms of the same element. Almost all of the baryonic matter of the universe is composed of chemical elements (among rare exceptions are neutron stars). When different elements undergo chemical reactions, atoms are rearranged into new compounds held together by chemical bonds. Only a minority of elements, such as silver and gold, are found uncombined as relatively pure native element minerals. Nearly all other naturally occurring elements occur in the Earth as compounds or mixtures. Air is primarily a mixture o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pencil
A pencil () is a writing or drawing implement with a solid pigment core in a protective casing that reduces the risk of core breakage, and keeps it from marking the user's hand. Pencils create marks by physical abrasion, leaving a trail of solid core material that adheres to a sheet of paper or other surface. They are distinct from pens, which dispense liquid or gel ink onto the marked surface. Most pencil cores are made of graphite powder mixed with a clay binder. Graphite pencils (traditionally known as "lead pencils") produce grey or black marks that are easily erased, but otherwise resistant to moisture, most chemicals, ultraviolet radiation and natural aging. Other types of pencil cores, such as those of charcoal, are mainly used for drawing and sketching. Coloured pencils are sometimes used by teachers or editors to correct submitted texts, but are typically regarded as art supplies, especially those with cores made from wax-based binders that tend to smear when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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