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Donaghmore Souterrain
Donaghmore Souterrain is a souterrain and National Monument located in County Louth, Ireland. Location Donaghmore Souterrain is located west of Dundalk, near a cluster of houses. Donaghmore Souterrain is found in a village named Kilkerley (translates to rulya fein). History Souterrains are cave-like structures built as places of refuge and storage, and in Ireland they date between the 8th and 12th centuries. The souterrain was discovered in 1960 during the construction of a Louth County Council cottage. It was excavated by Etienne Rynne who found trenches, a pit, two post-holes. sherds of souterrain ware, a bronze pin, a whetstone and iron slag. Description The souterrain at Donaghmore is a complex of tunnels lined with dry stone walls, floors and ceilings, with corbels and lintels. The ceilings are over in height and the total length of tunnel is . It is largely dug into boulder clay but also into Silurian The Silurian ( ) is a geologic period and system spanning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Wright (astronomer)
Thomas Wright (22 September 171125 February 1786) was an English astronomer, mathematician, instrument maker, architect and garden designer. He was the first to describe the shape of the Milky Way and to speculate that faint nebulæ were distant galaxies. Early life Wright was born at Byers Green in County Durham being the third son of John and Margaret Wright of Pegg's Poole House. His father was a carpenter. He was educated at home as he suffered from speech impediment and then at King James I Academy. In 1725 he entered into clock-making apprenticeship to Bryan Stobart of Bishop Auckland, continuing to study on his own. He also took courses on mathematics and navigation at a free school in the parish of Gateshead founded by Dr. Theophilus Pickering. Then, he went to London to study mathematical instrument-making with Heath and Sisson and made a trial sea voyage to Amsterdam. In 1730, he set up a school in Sunderland, where he taught mathematics and navigation. He later moved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronze
Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals, such as phosphorus, or metalloids such as arsenic or silicon. These additions produce a range of alloys that may be harder than copper alone, or have other useful properties, such as ultimate tensile strength, strength, ductility, or machinability. The three-age system, archaeological period in which bronze was the hardest metal in widespread use is known as the Bronze Age. The beginning of the Bronze Age in western Eurasia and India is conventionally dated to the mid-4th millennium BCE (~3500 BCE), and to the early 2nd millennium BCE in China; elsewhere it gradually spread across regions. The Bronze Age was followed by the Iron Age starting from about 1300 BCE and reaching most of Eurasia by about 500 BCE, although bronze continued to be much more widely used than it is in mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gritstone
Gritstone or grit is a hard, coarse-grained, siliceous sandstone. This term is especially applied to such sandstones that are quarried for building material. British gritstone was used for millstones to mill flour, to grind wood into pulp for paper and for grindstones to sharpen blades. "Grit" is often applied to sandstones composed of angular sand grains. It may commonly contain small pebbles. " Millstone Grit" is an informal term for a succession of gritstones which are to be found in the Pennines (including the Peak District) of northern England. These sediments were laid down in the late (upper) Paleozoic era, in the Carboniferous period, in deltaic conditions. The Millstone Grit Group is a formal stratigraphic term for this sequence of rocks. The gritstone edges of the Peak District are an important climbing area and the rock is much relished by English climbers, among whom it has almost cult status and is often referred to as "God's own rock". The rough surface provide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silurian
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods (myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boulder Clay
Boulder clay is an unsorted agglomeration of clastic sediment that is unstratified and structureless and contains gravel of various sizes, shapes, and compositions distributed at random in a fine-grained matrix. The fine-grained matrix consists of stiff, hard, pulverized clay or rock flour. Boulder clay is also know as either known as drift clay; till; unstratified drift, geschiebelehm (German); argile á blocaux (French); and keileem (Dutch).Charlesworth, J. K., 1957. ''Chap 18, Boulder Clay''. In ''The Quaternary Era, with Special Reference to its Glaciation''. v. 1, London, United Kingdom, Edward Arnold, p. 376-388.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. The term ''boulder clay'' is infreqently used for gravelly sedimentary deposits of nonglacial origin. These deposits include submarine slump and slide deposits along continental margins,Reineck, H.E. and Si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lintel
A lintel or lintol is a type of beam (a horizontal structural element) that spans openings such as portals, doors, windows and fireplaces. It can be a decorative architectural element, or a combined ornamented structural item. In the case of windows, the bottom span is instead referred to as a sill, but, unlike a lintel, does not serve to bear a load to ensure the integrity of the wall. Modern day lintels are made using prestressed concrete and are also referred to as beams in beam and block slabs or ribs in rib and block slabs. These prestressed concrete lintels and blocks are components that are packed together and propped to form a suspended floor concrete slab. Structural uses In worldwide architecture of different eras and many cultures, a lintel has been an element of post and lintel construction. Many different building materials have been used for lintels. In classical Western architecture and construction methods, by ''Merriam-Webster'' definition, a lintel is a l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corbel
In architecture, a corbel is a structural piece of stone, wood or metal jutting from a wall to carry a superincumbent weight, a type of bracket. A corbel is a solid piece of material in the wall, whereas a console is a piece applied to the structure. A piece of timber projecting in the same way was called a "tassel" or a "bragger" in England. The technique of corbelling, where rows of corbels deeply keyed inside a wall support a projecting wall or parapet, has been used since Neolithic (New Stone Age) times. It is common in medieval architecture and in the Scottish baronial style as well as in the vocabulary of classical architecture, such as the modillions of a Corinthian cornice. The corbel arch and corbel vault use the technique systematically to make openings in walls and to form ceilings. These are found in the early architecture of most cultures, from Eurasia to Pre-Columbian architecture. A console is more specifically an "S"-shaped scroll bracket in the classic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dry Stone
Dry stone, sometimes called drystack or, in Scotland, drystane, is a building method by which structures are constructed from stones without any mortar to bind them together. Dry stone structures are stable because of their construction method, which is characterized by the presence of a load-bearing façade of carefully selected interlocking stones. Dry stone construction is best known in the context of stone walls, traditionally used for the boundaries of fields and churchyards, or as retaining walls for terracing, but dry stone sculptures, buildings, bridges, and other structures also exist. The term tends not to be used for the many historic styles which used precisely-shaped stone, but did not use mortar, for example the Greek temple and Inca architecture. The art of dry stone walling was inscribed in 2018 on the UNESCO representative list of the intangible cultural heritage of humanity, for dry stone walls in countries such as France, Greece, Italy, Slovenia, Cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slag
Slag is a by-product of smelting (pyrometallurgical) ores and used metals. Broadly, it can be classified as ferrous (by-products of processing iron and steel), ferroalloy (by-product of ferroalloy production) or non-ferrous/base metals (by-products of recovering non-ferrous materials like copper, nickel, zinc and phosphorus). Within these general categories, slags can be further categorized by their precursor and processing conditions (e.g., Blast furnace (BF) slags, air-cooled blast furnace (ACBF) slag, basic oxygen furnace (BOF) slag, and electric arc furnace (EAF) slag) . Due to the large demand for these materials, slag production has also significantly increased throughout the years despite recycling (most notably in the iron and steelmaking industries) and upcycling efforts. The World Steel Association (WSA) estimates that 600 kg of by-products (~90 wt% is slags) are generated per tonne of steel produced. Composition Slag is usually a mixture of metal oxides and sili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sharpening Stone
Sharpening stones, or whetstones, are used to sharpen the edges of steel tools such as knives through grinding and honing. Such stones come in a wide range of shapes, sizes, and material compositions. They may be flat, for working flat edges, or shaped for more complex edges, such as those associated with some wood carving or woodturning tools. They may be composed of natural quarried material or from man-made material. They come in various grades, which refer to the grit size of the abrasive particles in the stone. (Grit size is given as a number, which indicates the spatial density of the particles; a higher number denotes a higher density and therefore smaller particles, which give a finer finish to the surface of the sharpened object.) Stones intended for use on a workbench are called bench stones, while small, portable ones, whose size makes it hard to draw large blades uniformly over them, especially “in the field,” are called pocket stones. Often whetstones are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sherds
This page is a glossary of archaeology, the study of the human past from material remains. A B C D E F G H I K L M N O P Q R S T U V W X Y Z See also * Outline of archaeology * Table of years in archaeology * Glossary of history References Bibliography * * * * * * * External links About.com Archaeology Glossary {{Glossaries of science and engineering Archaeology Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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