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Caves Of The Mendip Hills
The caves of the Mendip Hills are formed by the particular geology of the Mendip Hills: large areas of limestone worn away by water makes it a national centre for caving. The hills conceal the largest underground river system in Britain. Geology The hills consist of anticlines of Carboniferous Limestone lying over Devonian Old Red Sandstone, with the sandstone exposed on the summits. When a surface stream running off the sandstone reaches the limestone it sinks below ground through a " swallet", (also known locally as a "slocker"), continuing on its way down towards sea level by enlarging existing cracks in the rock to form caves, and reappearing at the base of the limestone outcrop. As the water changes route within the hill some caves (or parts of caves) are left dry. There is a characteristic type of Mendip cave, in which there is an initially steep descent, and then a more level stretch ending in a " sump" as the cave reaches and descends below the prevailing water table ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Britain
Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European islands by area, largest European island, and the List of islands by area, ninth-largest island in the world. It is dominated by a maritime climate with narrow temperature differences between seasons. The island of Ireland, with an area 40 per cent that of Great Britain, is to the west – these islands, along with over List of islands of the British Isles, 1,000 smaller surrounding islands and named substantial rocks, comprise the British Isles archipelago. Connected to mainland Europe until 9,000 years ago by a land bridge now known as Doggerland, Great Britain has been inhabited by modern humans for around 30,000 years. In 2011, it had a population of about , making it the world's List of islands by population, third-most-populous islan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheddar Gorge
Cheddar Gorge is a limestone gorge in the Mendip Hills, near the village of Cheddar, Somerset, England. The gorge is the site of the Cheddar show caves, where Britain's oldest complete human skeleton, Cheddar Man, estimated to be 9,000 years old, was found in 1903. Older remains from the Upper Late Palaeolithic era (12,000–13,000 years ago) have been found. The caves, produced by the activity of an underground river, contain stalactites and stalagmites. The gorge is part of a Site of Special Scientific Interest called Cheddar Complex. Cheddar Gorge, including the caves and other attractions, has become a tourist destination. In a 2005 poll of ''Radio Times'' readers, following its appearance on the television programme ''Seven Natural Wonders'' (2005), Cheddar Gorge was named as the second greatest natural wonder in Britain, surpassed only by Dan yr Ogof caves. The gorge attracts about 500,000 visitors per year. Geology Cheddar Gorge is located on the southern edge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mendip Cave Registry And Archive
The Mendip Cave Registry and Archive (MCRA) has the object of recording and indexing all available information on caves, mines, rock shelters and other sites of speleological interest primarily in the area of Bristol, Somerset, Bath and Wiltshire in South West England. History The MCRA was formed as the Mendip Cave Registry in January 1956. In 1969 the Registry ceased to function but it was revived in 1994 by Dave Irwin. In 2007 it was decided to expand the Registry to include archive material and the name was amended to Mendip Cave Registry and Archive. Publications * Related There are also some established cave registers for other parts of the United Kingdom. These are: Mendip cave registry(already mentioned) Welsh Cave Registeroperated by the Cambrian Caving Counciestablished in the 1960The Caves of Scotlandpresented in the form of a comprehensive one-page bibliography Southern Ireland Cave Bibliographyoperated by UBSS * The Derbyshire Cave Registry, which doesn't ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbert E
Herbert may refer to: People * Herbert (musician), a pseudonym of Matthew Herbert * Herbert (given name) * Herbert (surname) Places Antarctica * Herbert Mountains, Coats Land * Herbert Sound, Graham Land Australia * Herbert, Northern Territory, a rural locality * Herbert, South Australia. former government town * Division of Herbert, an electoral district in Queensland * Herbert River, a river in Queensland * County of Herbert, a cadastral unit in South Australia Canada * Herbert, Saskatchewan, Canada, a town * Herbert Road, St. Albert, Canada New Zealand * Herbert, New Zealand, a town * Mount Herbert (New Zealand) United States * Herbert, Illinois, an unincorporated community * Herbert, Michigan, a former settlement * Herbert Creek, a stream in South Dakota * Herbert Island, Alaska Arts, entertainment, and media Fictional entities * Herbert (Disney character) * Herbert Pocket, a character in the Charles Dickens novel ''Great Expectations'' * Herbert West, ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash Powder
Flash powder is a pyrotechnic composition, a mixture of an oxidizer and a metallic fuel, which burns quickly (deflagrates) and produces a loud noise, regardless of confinement in some formulations. It is widely used in theatrical and display pyrotechnics and consumer fireworks (namely firecrackers, professional salutes, and formerly in banned items such as cherry bombs and M-80s) and was once used for flashes in photography. Different varieties of flash powder are made from different compositions; most common are potassium perchlorate and aluminium powder. Early formulations used potassium chlorate instead of potassium perchlorate. Flash powder compositions are also used in military pyrotechnics when production of large amount of noise or light is required, e.g., stun grenades, battle simulator devices, and photoflash bombs. History Lycopodium powder is a yellow-tan dust-like powder historically used as a flash powder. Today, the principal use of the powder is to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Plate
Photographic plates preceded film as the primary medium for capturing images in photography. These plates, made of metal or glass and coated with a light-sensitive emulsion, were integral to early photographic processes such as heliography, daguerreotypes, and photogravure. Glass plates, thinner than standard window glass, became widely used in the late 19th century for their clarity and reliability. Although largely replaced by film during the 20th century, plates continued to be used for specialised scientific and medical purposes until the late 20th century. History Glass plates were far superior to film for research-quality imaging because they were stable and less likely to bend or distort, especially in large-format frames for wide-field imaging. Early plates used the wet collodion process. The wet plate process was replaced late in the 19th century by gelatin dry plates. A view camera nicknamed "The Mammoth" weighing was built by George R. Lawrence in 1899, sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
View Camera
A view camera is a large format, large-format camera in which the large format lens, lens forms an erect image, inverted image on a ground glass, ground-glass screen directly at the film plane. The image is viewed, composed, and focused, then the glass screen is replaced with the photographic film, film to exposure (photography), expose exactly the same image seen on the screen. This type of camera was developed during the era of the daguerreotypeStroebel, L. D. (1986). ''View Camera Technique'', 5th ed., p. 212. Boston: Focal Press. (1840s–1850s) and is still in use, some using drive mechanisms for movement (rather than loosen-move-tighten), more scale markings, and/or more spirit levels. It comprises a flexible bellows (photography), bellows that forms a light-tight seal between two adjustable ''standards'', one of which holds a Photographic lens, lens, and the other a ground glass or a photographic film holder or a digital back.Stroebel (1986). p. 2. There are three gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ochre
Ochre ( ; , ), iron ochre, or ocher in American English, is a natural clay earth pigment, a mixture of ferric oxide and varying amounts of clay and sand. It ranges in colour from yellow to deep orange or brown. It is also the name of the colours produced by this pigment, especially a light brownish-yellow. A variant of ochre containing a large amount of hematite, or dehydrated iron oxide, has a reddish tint known as red ochre (or, in some dialects, ruddle). The word ochre also describes clays coloured with iron oxide derived during the extraction of tin and copper. Earth pigments Ochre is a family of earth pigments, which includes yellow ochre, red ochre, purple ochre, sienna, and umber. The major ingredient of all the ochres is iron(III) oxide-hydroxide, known as limonite, which gives them a yellow colour. A range of other minerals may also be included in the mixture:Krivovichev V. G. Mineralogical glossary. Scientific editor :uk:Булах Андрій Глібович, A. G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Age
The Iron Age () is the final epoch of the three historical Metal Ages, after the Chalcolithic and Bronze Age. It has also been considered as the final age of the three-age division starting with prehistory (before recorded history) and progressing to protohistory (before written history). In this usage, it is preceded by the Stone Age (subdivided into the Paleolithic, Mesolithic and Neolithic) and Bronze Age. These concepts originated for describing Iron Age Europe and the ancient Near East. In the archaeology of the Americas, a five-period system is conventionally used instead; indigenous cultures there did not develop an iron economy in the pre-Columbian era, though some did work copper and bronze. Indigenous metalworking arrived in Australia with European contact. Although meteoric iron has been used for millennia in many regions, the beginning of the Iron Age is defined locally around the world by archaeological convention when the production of Smelting, smelted iron (espe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronze Age
The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of the three-age system, following the Stone Age and preceding the Iron Age. Conceived as a global era, the Bronze Age follows the Neolithic, with a transition period between the two known as the Chalcolithic. The final decades of the Bronze Age in the Mediterranean basin are often characterised as a period of widespread societal collapse known as the Late Bronze Age collapse (), although its severity and scope are debated among scholars. An ancient civilisation is deemed to be part of the Bronze Age if it either produced bronze by smelting its own copper and alloying it with tin, arsenic, or other metals, or traded other items for bronze from producing areas elsewhere. Bronze Age cultures were the first to History of writing, develop writin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neolithic
The Neolithic or New Stone Age (from Ancient Greek, Greek 'new' and 'stone') is an archaeological period, the final division of the Stone Age in Mesopotamia, Asia, Europe and Africa (c. 10,000 BCE to c. 2,000 BCE). It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts of the world. This "Neolithic package" included the History of agriculture, introduction of farming, domestication of animals, and change from a hunter-gatherer lifestyle to one of sedentism, settlement. The term 'Neolithic' was coined by John Lubbock, 1st Baron Avebury, Sir John Lubbock in 1865 as a refinement of the three-age system. The Neolithic began about 12,000 years ago, when farming appeared in the Epipalaeolithic Near East and Mesopotamia, and later in other parts of the world. It lasted in the Near East until the transitional period of the Chalcolithic (Copper Age) from about 6,500 years ago (4500 BCE), marked by the development ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
