A chain-link fence is a type of woven fence usually made from galvanized or LLDPE-coated steel wire. The wires run vertically and are bent into a zig-zag pattern so that each zig hooks with the wire immediately on one side and this forms the characteristic diamond pattern seen in this type of fence. In the United Kingdom, the firm of Barnard, Bishop & Barnard was established in Norwich to produce chain-link fencing by machine, the process was developed by Charles Barnard in 1844 based on cloth weaving machines. The Anchor Post Fence Co. established in 1891, bought the rights to the machine and was the first company to manufacture chain-link fencing in the United States. Anchor Fence holds the first United States patent for chain-link, the machine was purchased from a man in 1845 from Belgium who originally invented the wire bending machine. In the United States, fencing usually comes in 20 rod and 50 ft rolls, which can be joined by unscrewing one of the end wires and screwing it back in so that it hooks both pieces.
Common heights include 3 ft,3 ft 6 in,4 ft,5 ft,6 ft,7 ft,8 ft,10 ft, common mesh gauges are 9,11, and 11.5. Mesh length can vary based on need, with the standard mesh length being 2. For tennis courts and ball parks, the most popular height is 10 ft, the popularity of chain-link fence is from its relatively low cost and that the open weave does not obscure sunlight from either side of the fence. One can make a chain-link fence semi-opaque by inserting slats into the mesh, the installation of chain-link fence involves setting posts into the ground and attaching the fence to them. The posts may be steel tubing, timber or concrete and may be driven into the ground or set in concrete. End, corner or gate posts, commonly referred to as terminal posts, posts set between the terminal posts are called line posts and are set at intervals not to exceed 10 feet. The installer attaches the fence at one end, stretches it, the installer ties the fence to the line posts with aluminum wire. Top horizontal rails are used on most chain-link fences, although not necessary, bottom rails may be added in lieu of bottom tension wires, and for taller fences,10 feet or more, intermediate horizontal rails are often added.
Once stretched, a bottom wire should be secured to the line posts, one generally installs this wire before installing the chain-link mesh. The manufacturing of chain-link fencing is called weaving, a metal wire, often galvanized to reduce corrosion, is pulled along a rotating long and flat blade, thus creating a somewhat flattened spiral. The spiral continues to rotate past the blade and winds its way through the spiral that is already part of the fence. When the spiral reaches the far end of the fence, the spiral is cut near the blade, the spiral is pressed flat and the entire fence is moved up, ready for the next cycle
The Magura Cave is located in north-western Bulgaria close to the village of Rabisha,25 km from the town of Belogradchik in Vidin Province. Guided visits are conducted by the staff of Belogradchik municipality, to which the management of the cave was transferred in 2012 by the Bulgarian Council of Ministers, in 1984 the site was induced into UNESCOs tentative list of World Heritage. The total length of the 15 million year old cave is 2.5 km, the average annual temperature of the cave is 12 °C, except for one room where the temperature is always 15 °C. The air humidity reaches 80% and the displacement -56 m, the Magura cave was formed in the limestone Rabisha Hill. The morphology of the consists of one main gallery with six various-sized halls. The very spacious site allows for music concerts to be held during Christmas, the inner temperature is constantly 11-12 °C. During the summers of 1974 and 1975 the cave was used for speleotherapy. Thirty patients slept in the cave for twelve nights, taking advantage of allergens absence, constant humidity.
A part of the cave is now used for ageing sparkling and red wines, labelled Magura, bones from different prehistoric species like cave bear, cave hyena, wolf, wild cat and otter have been discovered in the Magura Cave. Today, constant inhabitants of the cave is the collembola, as well as four types of bats, Cave paintings dating from the Epipaleolithic, late Neolithic and early Bronze Age decorate some of the caves walls. The paintings have been estimated to be made between 10.000 and 8.000 years ago, the drawings represent important events of the society that had occupied the Magura cave, religious ceremonies, hunting scenes and depictions of deities which are unique on the Balkan peninsula. The Fertility Dance and the Hunting Ceremony rank among the most noteworthy paintings, one grouping from the Bronze Age has been interpreted as a solar calendar. The cave paintings allowed storing information about regional solar calendar, religious festivals, contemporary imitations of possible fertility rites are reported — inscriptions in Latin and paintings made by treasure-hunters.
The medium used to create the art was bat guano, more than 750 images have been identified. Painted signs can be organised into four groups, zoomorphic, geometric. For the first group, there are bitriangular silhouettes with raised rounded arms, ithyphallic figures, regarding zoomorpic items, there are caprids, dogs, ostrich-like animals and schematic linear quadrupeds. Few rayed circle figures, mainly the two unica of the so-called calendar scene, likely represent a sun depiction, taking count of some associated figures, it is possible to recognize dancing and mating scenes. In the so-called Cult Hall a large dance and hunting scene is depicted, arranged in two main rows, these are the best known and most reproduced Magura Cave images
Bulgaria, officially the Republic of Bulgaria, is a country in southeastern Europe. It is bordered by Romania to the north and Macedonia to the west and Turkey to the south, with a territory of 110,994 square kilometres, Bulgaria is Europes 16th-largest country. Organised prehistoric cultures began developing on current Bulgarian lands during the Neolithic period and its ancient history saw the presence of the Thracians, Persians, Romans, Goths and Huns. With the downfall of the Second Bulgarian Empire in 1396, its territories came under Ottoman rule for five centuries. The Russo-Turkish War of 1877–78 led to the formation of the Third Bulgarian State, the following years saw several conflicts with its neighbours, which prompted Bulgaria to align with Germany in both world wars. In 1946 it became a one-party socialist state as part of the Soviet-led Eastern Bloc, in December 1989 the ruling Communist Party allowed multi-party elections, which subsequently led to Bulgarias transition into a democracy and a market-based economy.
Bulgarias population of 7.2 million people is predominantly urbanised, most commercial and cultural activities are centred on the capital and largest city, Sofia. The strongest sectors of the economy are industry, power engineering. The countrys current political structure dates to the adoption of a constitution in 1991. Bulgaria is a parliamentary republic with a high degree of political, administrative. Human activity in the lands of modern Bulgaria can be traced back to the Paleolithic, animal bones incised with man-made markings from Kozarnika cave are assumed to be the earliest examples of symbolic behaviour in humans. Organised prehistoric societies in Bulgarian lands include the Neolithic Hamangia culture, Vinča culture, the latter is credited with inventing gold working and exploitation. Some of these first gold smelters produced the coins and jewellery of the Varna Necropolis treasure and this site offers insights for understanding the social hierarchy of the earliest European societies.
Thracians, one of the three primary groups of modern Bulgarians, began appearing in the region during the Iron Age. In the late 6th century BC, the Persians conquered most of present-day Bulgaria, and kept it until 479 BC. After the division of the Roman Empire in the 5th century the area fell under Byzantine control, by this time, Christianity had already spread in the region. A small Gothic community in Nicopolis ad Istrum produced the first Germanic language book in the 4th century, the first Christian monastery in Europe was established around the same time by Saint Athanasius in central Bulgaria. From the 6th century the easternmost South Slavs gradually settled in the region, in 680 Bulgar tribes under the leadership of Asparukh moved south across the Danube and settled in the area between the lower Danube and the Balkan, establishing their capital at Pliska
In archaeology, excavation is the exposure and recording of archaeological remains. An excavation site or dig is a site being studied, such a site excavation concerns itself with a specific archaeological site or a connected series of sites, and may be conducted over as little as several weeks to over a number of years. Numerous specialized techniques each with its features are used. Resources and other practical issues do not allow archaeologists to carry out excavations whenever and wherever they choose and these constraints mean many known sites have been deliberately left unexcavated. This is with the intention of preserving them for generations as well as recognising the role they serve in the communities that live near them. Excavation involves the recovery of types of data from a site. These data include artifacts, ecofacts and, most importantly, data from the excavation should suffice to reconstruct the site completely in three-dimensional space. The presence or absence of remains can often be suggested by remote sensing.
Indeed, grosser information about the development of the site may be drawn from this work, the history of excavation began with a crude search for treasure and for artifacts which fell into the category of curio. These curios were the subject of interest of antiquarians and it was appreciated that digging on a site destroyed the evidence of earlier peoples lives which it had contained. Once the curio had been removed from its context, most of the information it held was lost and it was from this realization that antiquarianism began to be replaced by archaeology, a process still being perfected. Archaeological material tends to accumulate in events, a gardener swept a pile of soil into a corner, laid a gravel path or planted a bush in a hole. A builder built a wall and back-filled the trench, years later, someone built a pig sty onto it and drained the pig sty into the nettle patch. Later still, the original wall blew over and so on, each event, which may have taken a short or long time to accomplish, leaves a context.
This layer cake of events is referred to as the archaeological sequence or record. It is by analysis of sequence or record that excavation is intended to permit interpretation. As he remarked, waiting for animals to hunt represented 24% of the total man-hours of activity recorded, no tools left on the site were used, and there were no immediate material byproducts of the primary activity. All of the activities conducted at the site were essentially boredom reducers
The Middle Paleolithic is the second subdivision of the Paleolithic or Old Stone Age as it is understood in Europe and Asia. The term Middle Stone Age is used as an equivalent or a synonym for the Middle Paleolithic in African archeology, the Middle Paleolithic broadly spanned from 300,000 to 30,000 years ago. There are considerable dating differences between regions, the Middle Paleolithic was succeeded by the Upper Paleolithic subdivision which first began between 50,000 and 40,000 years ago. Activities such as catching fish and hunting large game animals with specialized tools connote increased group-wide cooperation. Both Neandertal and modern human societies took care of the members of their societies during the Middle Paleolithic. Typically, it has assumed that women gathered plants and firewood. Anthropologists such as Tim D. Cannibalism in the Middle Paleolithic may have occurred because of food shortages, around 200,000 BP Middle Paleolithic Stone tool manufacturing spawned a tool-making technique known as the prepared-core technique, that was more elaborate than previous Acheulean techniques.
Wallace and Shea split the core artifacts into two different types, formal cores and expedient cores, formal cores are designed to extract the maximum amount from the raw material while expedient cores are more based on function need. This method increased efficiency by permitting the creation of more controlled and this method allowed Middle Paleolithic humans correspondingly to create stone-tipped spears, which were the earliest composite tools, by hafting sharp, pointy stone flakes onto wooden shafts. The use of fire became widespread for the first time in human prehistory during the Middle Paleolithic, some scientists have hypothesized that hominids began cooking food to defrost frozen meat which would help ensure their survival in cold regions
Quartz is the second most abundant mineral in Earths continental crust, behind feldspar. There are many different varieties of quartz, several of which are semi-precious gemstones, since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. The word quartz is derived from the German word Quarz and its Middle High German ancestor twarc, the Ancient Greeks referred to quartz as κρύσταλλος derived from the Ancient Greek κρύος meaning icy cold, because some philosophers apparently believed the mineral to be a form of supercooled ice. Today, the rock crystal is sometimes used as an alternative name for the purest form of quartz. Quartz belongs to the crystal system. The ideal crystal shape is a six-sided prism terminating with six-sided pyramids at each end, well-formed crystals typically form in a bed that has unconstrained growth into a void, usually the crystals are attached at the other end to a matrix and only one termination pyramid is present.
However, doubly terminated crystals do occur where they develop freely without attachment, a quartz geode is such a situation where the void is approximately spherical in shape, lined with a bed of crystals pointing inward. α-quartz crystallizes in the crystal system, space group P3121 and P3221 respectively. β-quartz belongs to the system, space group P6222 and P6422. These space groups are truly chiral, both α-quartz and β-quartz are examples of chiral crystal structures composed of achiral building blocks. The transformation between α- and β-quartz only involves a comparatively minor rotation of the tetrahedra with respect to one another, although many of the varietal names historically arose from the color of the mineral, current scientific naming schemes refer primarily to the microstructure of the mineral. Color is an identifier for the cryptocrystalline minerals, although it is a primary identifier for the macrocrystalline varieties. Pure quartz, traditionally called rock crystal or clear quartz, is colorless and transparent or translucent, common colored varieties include citrine, rose quartz, smoky quartz, milky quartz, and others.
The most important distinction between types of quartz is that of macrocrystalline and the microcrystalline or cryptocrystalline varieties, the cryptocrystalline varieties are either translucent or mostly opaque, while the transparent varieties tend to be macrocrystalline. Chalcedony is a form of silica consisting of fine intergrowths of both quartz, and its monoclinic polymorph moganite. Other opaque gemstone varieties of quartz, or mixed rocks including quartz, often including contrasting bands or patterns of color, are agate, carnelian or sard, heliotrope, amethyst is a form of quartz that ranges from a bright to dark or dull purple color. The worlds largest deposits of amethysts can be found in Brazil, Uruguay, France, sometimes amethyst and citrine are found growing in the same crystal. It is referred to as ametrine, an amethyst is formed when there is iron in the area where it was formed
Kozarnika or Peshtera Kozarnika is a cave in northwestern Bulgaria that was used as a hunters’ shelter as early as the Lower Paleolithic. It marks an older route of human migration from Africa to Europe via the Balkans. The cave probably keeps the earliest evidence of symbolic behaviour. Kozarnika cave is located 6 km from the town of Belogradchik in northwestern Bulgaria, on the slopes of the Balkan Mountains. It is opened to the south, at 85 m above the valley, with its length of 210 m, the cave is among the small-sized in the Belogradchick karst region. The Kozarnika cave project started in 1984, since 1996, it has been headed by Dr. Prof. Nikolay Sirakov and Dr. Jean-Luc Guadelli. In the ground layers, dated to 1. 6–1, the findings from Middle Paleolithic layers, rather bifacial points, dating from 300, 000–50,000 BP prove presence of hunters’ groups possibly of Homo neanderthalensis. Upper Paleolithic layers consist flint assemblages from the earliest European Gravette complex dating from 43,000 up to 39,000 BP belonging to Homo sapiens sapiens, magura Cave Bacho Kiro cave Sićevo Gorge Peștera cu Oase Vértesszőlős Proto-Indo-Europeans Campanian Ignimbrite Eruption Rincon, Paul
Neolithic flint mines of Spiennes
The mines were active during the mid and late Neolithic between 4,300 and 2,200 BC. Declared to be remarkable for the diversity of technological solutions used for extraction the site, discovered in 1843, the first excavations were undertaken during railway construction in 1867 and intermittent excavations have been carried out up to the present day. The Mines of Spiennes cover some 100 ha of downland four miles south-east of the city of Mons, the site is dotted with millions of scraps of worked flint and numerous mining pits, that Neolithic settlers have gradually turned into vertical mine shafts to depths of over 10 m. Research has illustrated Neolithic techniques for the cutting of the flint and the extraction of large slabs of flint, the nodules were extracted using flint picks. The stones were knapped into rough-out shapes of axes, the SILEXS Interpretive Centre has opened in spring 2015. The rough-outs were exchanged over an area, about 150 km. Polishing strengthens the product, making the axe- or adze-head last longer.
The smooth surface aids the cutting action by lowering friction with the wood, the axes were used initially for forest clearance during the Neolithic period, and for shaping wood for structural applications, such as timber for huts and canoes. The site has been compared with Grimes Graves and Cissbury in the United Kingdom, and Krzemionki in Poland, different hard rocks were used for the polished stone axes. Examples include the Langdale axe industry and Tievebulliagh, guillaume, Ph. Lipinski & A. Masson, Les mines de silex néolithiques de la Meuse dans le contexte européen. Musées de la Meuse, Sampigny 1987, F. Gosselin, Un site dexploitation du silex à Spiennes, au lieu-dit Petit-Spiennes. F. Hubert, Une minière néolithique à silex au Camp-à-Cayaux de Spiennes, F. Hubert, Lexploitation préhistorique du silex à Spiennes. Ministère de la Région wallonne, Direction générale de lAménagement du Territoire, du Logement et du Patrimoine, R. Shepherd, Prehistoric Mining and Allied Industries. Société de recherches préhistoriques en Hainaut, Minières néolithiques à Spiennes,1997 ICOMOS evaluation Collet, H.
Les mines néolithiques de Spiennes, état des connaissances et perspectives de recherche. Section 10, The Neolithic in the Near East and Europe, actes du XIVème congrès UISPP, Université de Liège, Belgique,2 –8 septembre 2001 H. Collet, A. Hauzeur & J. Lech,2008. The prehistoric flint mining complex at Spiennes on the occasion of its discovery 140 years ago In P. Allard, F. Bostyn, flint mining in Prehistoric Europe, Interpreting the archaeological records. European Association of Archaeologists, 12th Annual Meeting, Poland, 19–24 September 2006, H. Collet,2014. Les minières néolithiques de silex de Spiennes
An ice age is a period of long-term reduction in the temperature of Earths surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Within a long-term ice age, individual pulses of cold climate are termed glacial periods, in the terminology of glaciology, ice age implies the presence of extensive ice sheets in both northern and southern hemispheres. In 1742 Pierre Martel, an engineer and geographer living in Geneva, two years he published an account of his journey. He reported that the inhabitants of that valley attributed the dispersal of erratic boulders to the glaciers, similar explanations were reported from other regions of the Alps. In 1815 the carpenter and chamois hunter Jean-Pierre Perraudin explained erratic boulders in the Val de Bagnes in the Swiss canton of Valais as being due to glaciers previously extending further. An unknown woodcutter from Meiringen in the Bernese Oberland advocated a similar idea in a discussion with the Swiss-German geologist Jean de Charpentier in 1834, comparable explanations are known from the Val de Ferret in the Valais and the Seeland in western Switzerland and in Goethes scientific work.
Such explanations could be found in parts of the world. When the Bavarian naturalist Ernst von Bibra visited the Chilean Andes in 1849–1850, European scholars had begun to wonder what had caused the dispersal of erratic material. From the middle of the 18th century, some discussed ice as a means of transport, the Swedish mining expert Daniel Tilas was, in 1742, the first person to suggest drifting sea ice in order to explain the presence of erratic boulders in the Scandinavian and Baltic regions. In 1795, the Scottish philosopher and gentleman naturalist, James Hutton, two decades later, in 1818, the Swedish botanist Göran Wahlenberg published his theory of a glaciation of the Scandinavian peninsula. He regarded glaciation as a regional phenomenon, only a few years later, the Danish-Norwegian geologist Jens Esmark argued a sequence of worldwide ice ages. In a paper published in 1824, Esmark proposed changes in climate as the cause of those glaciations and he attempted to show that they originated from changes in Earths orbit.
During the following years, Esmarks ideas were discussed and taken over in parts by Swedish, Scottish, at the University of Edinburgh Robert Jameson seemed to be relatively open to Esmarks ideas, as reviewed by Norwegian professor of glaciology Bjørn G. Andersen. Jamesons remarks about ancient glaciers in Scotland were most probably prompted by Esmark, in Germany, Albrecht Reinhard Bernhardi, a geologist and professor of forestry at an academy in Dreissigacker, since incorporated in the southern Thuringian city of Meiningen, adopted Esmarks theory. In a paper published in 1832, Bernhardi speculated about former polar ice caps reaching as far as the zones of the globe. When he read his paper before the Schweizerische Naturforschende Gesellschaft, most scientists remained sceptical, Venetz convinced his friend Jean de Charpentier. De Charpentier transformed Venetzs idea into a theory with a limited to the Alps. In fact, both men shared the same volcanistic, or in de Charpentiers case rather plutonistic assumptions, about the Earths history, in 1834, de Charpentier presented his paper before the Schweizerische Naturforschende Gesellschaft
Finnish Museum of Natural History
The Finnish Museum of Natural History, established in 1988, is a research institution under the University of Helsinki in Finland, based in Helsinki, Finland. It is a history museum responsible for the national botanical, zoological and paleontological collections. The collections serve scientific, public informational and educational purposes, in regard to locations and buildings, the Museum is divided into three, The Natural History Museum, the Kaisaniemi Botanic Garden, and the Kumpula Botanic Garden. From 1869 to 2014 it included an independent geological department, botany Unit Botanical Museum maintains the national herbarium of Finland containing 3,3 million specimens of plants and fungi. Botanic Gardens maintain a collection of living plants for education and research, is responsible for international seed exchange, zoology Unit Zoological Museum maintains a collection of 8 million animal specimens, performs research mainly on systematics and zoogeography. Bird ringing centre and monitoring of bird populations Natural Sciences Unit Laboratory of Chronology performs age determination of samples with physical methods, geological Museum maintains collections of rock and ore samples and fossils
The Areni-1 cave complex is located near the Areni village in southern Armenia along the Arpa River. In 2010, it was announced that the earliest known shoe was found at the site, in January 2011, the earliest known winery in the world was announced to have been found. Also in 2011, the discovery of a straw skirt dating to 3900 BC was reported, in 2009, the oldest brain was discovered