These additions produce a range of alloys that may be harder than copper alone, or have other useful properties, such as stiffness, ductility, or machinability. The archeological period where bronze was the hardest metal in use is known as the Bronze Age. In the ancient Near East this began with the rise of Sumer in the 4th millennium BC, with India and China starting to use bronze around the same time, everywhere it gradually spread across regions. The Bronze Age was followed by the Iron Age starting from about 1300 BC and reaching most of Eurasia by about 500 BC, the discovery of bronze enabled people to create metal objects which were harder and more durable than previously possible. Bronze tools, weapons and building such as decorative tiles were harder and more durable than their stone. It was only that tin was used, becoming the major ingredient of bronze in the late 3rd millennium BC. Tin bronze was superior to arsenic bronze in that the process could be more easily controlled. Also, unlike arsenic, metallic tin and fumes from tin refining are not toxic, the earliest tin-alloy bronze dates to 4500 BCE in a Vinča culture site in Pločnik.
Other early examples date to the late 4th millennium BC in Africa and some ancient sites in China, ores of copper and the far rarer tin are not often found together, so serious bronze work has always involved trade. Tin sources and trade in ancient times had a influence on the development of cultures. In Europe, a source of tin was the British deposits of ore in Cornwall. In many parts of the world, large hoards of bronze artefacts are found, suggesting that bronze represented a store of value, in Europe, large hoards of bronze tools, typically socketed axes, are found, which mostly show no signs of wear. With Chinese ritual bronzes, which are documented in the inscriptions they carry and from other sources and these were made in enormous quantities for elite burials, and used by the living for ritual offerings. Pure iron is soft, and the process of beating and folding sponge iron to wrought iron removes from the metal carbon. Careful control of the alloying and tempering eventually allowed for wrought iron with properties comparable to modern steel, Bronze was still used during the Iron Age, and has continued in use for many purposes to the modern day.
Among other advantages, it does not rust, the weaker wrought iron was found to be sufficiently strong for many uses. Archaeologists suspect that a disruption of the tin trade precipitated the transition. The population migrations around 1200–1100 BC reduced the shipping of tin around the Mediterranean, limiting supplies, there are many different bronze alloys, but typically modern bronze is 88% copper and 12% tin
It extends from the earliest known use of stone tools, probably by Homo habilis initially,2.6 million years ago, to the end of the Pleistocene around 10,000 BP. The Paleolithic era is followed by the Mesolithic, the date of the Paleolithic–Mesolithic boundary may vary by locality as much as several thousand years. During the Paleolithic period, humans grouped together in small societies such as bands, the Paleolithic is characterized by the use of knapped stone tools, although at the time humans used wood and bone tools. Other organic commodities were adapted for use as tools, including leather and vegetable fibers, due to their nature, surviving artifacts of the Paleolithic era are known as paleoliths. About 50,000 years ago, there was a increase in the diversity of artifacts. For the first time in Africa, bone artifacts and the first art appear in the archaeological record, the first evidence of human fishing is noted, from artifacts in places such as Blombos cave in South Africa. The new technology generated an explosion of modern humans which is believed to have led to the extinction of the Neanderthals.
Humankind gradually evolved from members of the genus Homo—such as Homo habilis. The climate during the Paleolithic consisted of a set of glacial and interglacial periods in which the climate periodically fluctuated between warm and cool temperatures, by c. 50,000 – c. 40,000 BP, the first humans set foot in Australia. By c. 45,000 BP, humans lived at 61°N latitude in Europe, by c. 30,000 BP, Japan was reached, and by c. 27,000 BP humans were present in Siberia, above the Arctic Circle. At the end of the Upper Paleolithic, a group of humans crossed Beringia, the term Paleolithic was coined by archaeologist John Lubbock in 1865. It derives from Greek, παλαιός, old, and λίθος, stone, human evolution is the part of biological evolution concerning the emergence of anatomically modern humans as a distinct species. The Paleolithic Period coincides almost exactly with the Pleistocene epoch of geologic time and this epoch experienced important geographic and climatic changes that affected human societies.
During the preceding Pliocene, continents had continued to drift from possibly as far as 250 km from their present locations to positions only 70 km from their current location. South America became linked to North America through the Isthmus of Panama, most of Central America formed during the Pliocene to connect the continents of North and South America, allowing fauna from these continents to leave their native habitats and colonize new areas. Africas collision with Asia created the Mediterranean Sea, cutting off the remnants of the Tethys Ocean, climates during the Pliocene became cooler and drier, and seasonal, similar to modern climates. The formation of an Arctic ice cap around 3 million years ago is signaled by a shift in oxygen isotope ratios and ice-rafted cobbles in the North Atlantic. Mid-latitude glaciation probably began before the end of the epoch, the global cooling that occurred during the Pliocene may have spurred on the disappearance of forests and the spread of grasslands and savannas
Civil engineering is traditionally broken into a number of sub-disciplines. It is the second-oldest engineering discipline after military engineering, and it is defined to distinguish non-military engineering from military engineering, Civil engineering takes place in the public sector from municipal through to national governments, and in the private sector from individual homeowners through to international companies. Engineering has been an aspect of life since the beginnings of human existence, during this time, transportation became increasingly important leading to the development of the wheel and sailing. The construction of pyramids in Egypt were some of the first instances of large structure constructions, the Romans developed civil structures throughout their empire, including especially aqueducts, harbors, bridges and roads. In the 18th century, the civil engineering was coined to incorporate all things civilian as opposed to military engineering. The first self-proclaimed civil engineer was John Smeaton, who constructed the Eddystone Lighthouse, in 1771 Smeaton and some of his colleagues formed the Smeatonian Society of Civil Engineers, a group of leaders of the profession who met informally over dinner.
Though there was evidence of some meetings, it was little more than a social society. In 1818 the Institution of Civil Engineers was founded in London, the institution received a Royal Charter in 1828, formally recognising civil engineering as a profession. The first private college to teach engineering in the United States was Norwich University. The first degree in engineering in the United States was awarded by Rensselaer Polytechnic Institute in 1835. The first such degree to be awarded to a woman was granted by Cornell University to Nora Stanton Blatch in 1905, throughout ancient and medieval history most architectural design and construction was carried out by artisans, such as stonemasons and carpenters, rising to the role of master builder. Knowledge was retained in guilds and seldom supplanted by advances, structures and infrastructure that existed were repetitive, and increases in scale were incremental. Brahmagupta, an Indian mathematician, used arithmetic in the 7th century AD, based on Hindu-Arabic numerals, Civil engineers typically possess an academic degree in civil engineering.
The length of study is three to five years, and the degree is designated as a bachelor of engineering. The curriculum generally includes classes in physics, project management, after taking basic courses in most sub-disciplines of civil engineering, they move onto specialize in one or more sub-disciplines at advanced levels. In most countries, a degree in engineering represents the first step towards professional certification. After completing a degree program, the engineer must satisfy a range of requirements before being certified. Once certified, the engineer is designated as a engineer, a chartered engineer
Water jet cutter
Waterjet cutting is often used during fabrication of machine parts. It is the method when the materials being cut are sensitive to the high temperatures generated by other methods. Waterjet cutting is used in industries, including mining and aerospace, for cutting, shaping. These early applications were at a low pressure and restricted to soft materials like paper, Waterjet technology evolved in the post-war era as researchers around the world searched for new methods of efficient cutting systems. In 1958, Billie Schwacha of North American Aviation developed a system using ultra-high-pressure liquid to cut hard materials and this system used a 100,000 psi pump to deliver a hypersonic liquid jet that could cut high strength alloys such as PH15-7-MO stainless steel. Used as a honeycomb laminate on the Mach 3 North American XB-70 Valkyrie, while not effective for the XB-70 project, the concept was valid and further research continued to evolve waterjet cutting. In 1962, Philip Rice of Union Carbide explored using a pulsing waterjet at up to 50,000 psi to cut metals, research by S. J.
Leach and G. L.002 inches that operated at pressures up to 70,000 psi. High-pressure vessels and pumps became affordable and reliable with the advent of steam power, by the mid-1800s, steam locomotives were common and the first efficient steam-driven fire engine was operational. By the turn of the century, high-pressure reliability improved, with research leading to a sixfold increase in boiler pressure. Most high-pressure pumps at this time, operated around 500–800 psi, high-pressure systems were further shaped by the aviation and oil industries. Aircraft manufacturers such as Boeing developed seals for hydraulically boosted control systems in the 1940s, higher pressures in hydraulic systems in the oil industry led to the development of advanced seals and packing to prevent leaks. These advances in technology, plus the rise of plastics in the post-war years. The invention of Marlex by Robert Banks and John Paul Hogan of the Phillips Petroleum company required a catalyst to be injected into the polyethylene, mcCartney Manufacturing Company in Baxter Springs, began manufacturing these high-pressure pumps in 1960 for the polyethylene industry.
Flow Industries combined the high-pressure pump research with their waterjet nozzle research, while cutting with water is possible for soft materials, the addition of an abrasive turned the waterjet into a modern machining tool for all materials. This began in 1935 when the idea of adding an abrasive to the stream was developed by Elmo Smith for the liquid abrasive blasting. The March 1984 issue of the Mechanical Engineering magazine showed more details and materials cut with AWJ such as titanium, glass, dr. Mohamed Hashish, was awarded a patent on forming AWJ in 1987. Current work on AWJ nozzles is on micro abrasive waterjet so cutting with jets smaller than 0.015 inches in diameter can be commercialized. By January,1985, that system was being run 24 hours a day producing titanium parts for the B-1B largely at Rockwells North American Aviation facility in Newark, as waterjet cutting moved into traditional manufacturing shops, controlling the cutter reliably and accurately was essential
Iron is a chemical element with symbol Fe and atomic number 26. It is a metal in the first transition series and it is by mass the most common element on Earth, forming much of Earths outer and inner core. It is the fourth most common element in the Earths crust, like the other group 8 elements and osmium, iron exists in a wide range of oxidation states, −2 to +6, although +2 and +3 are the most common. Elemental iron occurs in meteoroids and other low oxygen environments, but is reactive to oxygen, fresh iron surfaces appear lustrous silvery-gray, but oxidize in normal air to give hydrated iron oxides, commonly known as rust. Unlike the metals that form passivating oxide layers, iron oxides occupy more volume than the metal and thus flake off, Iron metal has been used since ancient times, although copper alloys, which have lower melting temperatures, were used even earlier in human history. Pure iron is soft, but is unobtainable by smelting because it is significantly hardened and strengthened by impurities, in particular carbon. A certain proportion of carbon steel, which may be up to 1000 times harder than pure iron.
Crude iron metal is produced in blast furnaces, where ore is reduced by coke to pig iron, further refinement with oxygen reduces the carbon content to the correct proportion to make steel. Steels and iron alloys formed with metals are by far the most common industrial metals because they have a great range of desirable properties. Iron chemical compounds have many uses, Iron oxide mixed with aluminium powder can be ignited to create a thermite reaction, used in welding and purifying ores. Iron forms binary compounds with the halogens and the chalcogens, among its organometallic compounds is ferrocene, the first sandwich compound discovered. Iron plays an important role in biology, forming complexes with oxygen in hemoglobin and myoglobin. Iron is the metal at the site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants. A human male of average height has about 4 grams of iron in his body and this iron is distributed throughout the body in hemoglobin, muscles, bone marrow, blood proteins, ferritin and transport in plasma.
The mechanical properties of iron and its alloys can be evaluated using a variety of tests, including the Brinell test, Rockwell test, the data on iron is so consistent that it is often used to calibrate measurements or to compare tests. An increase in the content will cause a significant increase in the hardness. Maximum hardness of 65 Rc is achieved with a 0. 6% carbon content, because of the softness of iron, it is much easier to work with than its heavier congeners ruthenium and osmium. Because of its significance for planetary cores, the properties of iron at high pressures and temperatures have been studied extensively
Rock or stone is a natural substance, a solid aggregate of one or more minerals or mineraloids. For example, granite, a rock, is a combination of the minerals quartz, feldspar. The Earths outer solid layer, the lithosphere, is made of rock, rock has been used by mankind throughout history. The minerals and metals found in rocks have been essential to human civilization, three major groups of rocks are defined, igneous and metamorphic. The scientific study of rocks is called petrology, which is a component of geology. At a granular level, rocks are composed of grains of minerals, the aggregate minerals forming the rock are held together by chemical bonds. The types and abundance of minerals in a rock are determined by the manner in which the rock was formed, many rocks contain silica, a compound of silicon and oxygen that forms 74. 3% of the Earths crust. This material forms crystals with other compounds in the rock, the proportion of silica in rocks and minerals is a major factor in determining their name and properties.
Rocks are geologically classified according to such as mineral and chemical composition, the texture of the constituent particles. These physical properties are the end result of the processes that formed the rocks, over the course of time, rocks can transform from one type into another, as described by the geological model called the rock cycle. These events produce three general classes of rock, igneous and metamorphic, the three classes of rocks are subdivided into many groups. However, there are no hard and fast boundaries between allied rocks, hence the definitions adopted in establishing rock nomenclature merely correspond to more or less arbitrary selected points in a continuously graduated series. Igneous rock forms through the cooling and solidification of magma or lava and this magma can be derived from partial melts of pre-existing rocks in either a planets mantle or crust. Typically, the melting of rocks is caused by one or more of three processes, an increase in temperature, a decrease in pressure, or a change in composition, igneous rocks are divided into two main categories, plutonic rock and volcanic.
Plutonic or intrusive rocks result when magma cools and crystallizes slowly within the Earths crust, a common example of this type is granite. Volcanic or extrusive rocks result from magma reaching the surface either as lava or fragmental ejecta, the chemical abundance and the rate of cooling of magma typically forms a sequence known as Bowens reaction series. Most major igneous rocks are found along this scale, about 64. 7% of the Earths crust by volume consists of igneous rocks, making it the most plentiful category. Of these, 66% are basalts and gabbros, 16% are granite, only 0. 6% are syenites and 0. 3% peridotites and dunites
Petroglyphs are images created by removing part of a rock surface by incising, carving, or abrading, as a form of rock art. Outside North America, scholars often use such as carving, engraving. Petroglyphs are found world-wide, and are associated with prehistoric peoples. The word comes from the Greek word petro-, theme of the word meaning stone, and glyphein meaning to carve. The term petroglyph should not be confused with petrograph, which is an image drawn or painted on a rock face, both types of image belong to the wider and more general category of rock art or parietal art. Petroforms, or patterns and shapes made by large rocks. Inukshuks are unique, and found only in the Arctic and they are a category of rock art, and sometimes found in conjunction with rock-cut architecture. However, they tend to be omitted in most works on rock art, a few such works exploit the natural contours of the rock and use them to define an image, but they do not amount to man-made reliefs. Rock reliefs have been made in many cultures, and were important in the art of the Ancient Near East.
Rock reliefs are generally large, as they need to be to make an impact in the open air. Most have figures that are over life-size, and in many the figures are multiples of life-size, the vertical relief is most common, but reliefs on essentially horizontal surfaces are found. The term typically excludes relief carvings inside caves, whether natural or themselves man-made, natural rock formations made into statues or other sculpture in the round, most famously at the Great Sphinx of Giza, are usually excluded. Reliefs on large boulders left in their location, like the Hittite İmamkullu relief, are likely to be included. Some petroglyphs are dated to approximately the Neolithic and late Upper Paleolithic boundary, about 10,000 to 12,000 years ago, if not earlier. Sites in Australia have petroglyphs that are estimated to be as much as 27,000 years old, around 7,000 to 9,000 years ago, other precursors of writing systems, such as pictographs and ideograms, began to appear. Petroglyphs were still common though, and some cultures continued using them much longer, petroglyphs have been found in all parts of the globe except Antarctica with highest concentrations in parts of Africa, Siberia, southwestern North America and Australia.
There are many theories to explain their purpose, depending on their location, some petroglyphs are thought to be astronomical markers and other forms of symbolic communication, including a form of pre-writing. Petroglyph maps may show trails, symbols communicating time and distances traveled, as well as the terrain in the form of rivers, landforms
Crazy Horse Memorial
The Crazy Horse Memorial is a mountain monument under construction on privately held land in the Black Hills, in Custer County, South Dakota, United States. It will depict the Oglala Lakota warrior, Crazy Horse, riding a horse, the memorial was commissioned by Henry Standing Bear, a Lakota elder, to be sculpted by Korczak Ziolkowski. It is operated by the Crazy Horse Memorial Foundation, a private non-profit organization, the memorial consists of the mountain carving, the Indian Museum of North America, and the Native American Cultural Center. The monument is being carved out of Thunderhead Mountain, on land considered sacred by some Oglala Lakota, the sculptures final dimensions are planned to be 641 feet wide and 563 feet high. The head of Crazy Horse will be 87 feet high, by comparison, the monument has been in progress since 1948 and is far from completion. If completed, it may become the worlds largest sculpture as well as the first non-religious statue to hold this record since 1967, Crazy Horse was a Native American war leader of the Oglala Lakota.
He took up arms against the U. S. Federal government to fight against encroachments on the territories and his most famous actions against the U. S. military included the Fetterman Fight and the Battle of the Little Bighorn. He surrendered to U. S. troops under General Crook in May 1877 and was wounded by a military guard. He ranks among the most notable and iconic of Native American tribal members and was honored by the U. S. Postal Service in 1982 with a 13¢ postage stamp, that is part of its Great Americans series. In October 1931, Luther Standing Bear, Henrys older brother, wrote sculptor Gutzon Borglum, Luther suggested that it would be most fitting to have the face of Crazy Horse sculpted there. Crazy Horse is the real patriot of the Sioux tribe and the one worthy to place by the side of Washington. Thereafter, Henry Standing Bear began a campaign to have Borglum carve an image of Crazy Horse on Mt. Rushmore, on November 7,1939, Henry Standing Bear wrote to the Polish-American sculptor Korczak Ziolkowski, who worked on Mount Rushmore under Gutzon Borglum.
He informed the sculptor, My fellow chiefs and I would like the man to know that the red man has great heroes. The government responded positively, and the National Forest Service, responsible for the land, agreed to grant a permit for the use of the land, with a commission to oversee the project. Standing Bear chose not to government funds and relied instead upon influential Americans interested in the welfare of the American Indian to privately fund the project. In the spring of 1940, Ziolkowski spent three weeks with Standing Bear at Pine Ridge, South Dakota, discussing land issues and learning about Crazy Horse. According to Ziolkowski, Standing Bear grew very angry when he spoke of the broken Treaty of Fort Laramie and that was the one Id read about in which the President promised the Black Hills would belong to the Indians forever. I remember how his old eyes flashed out of dark mahogany face, he would shake his head
Sculpture is the branch of the visual arts that operates in three dimensions. It is one of the plastic arts, a wide variety of materials may be worked by removal such as carving, assembled by welding or modelling, or molded, or cast. However, most ancient sculpture was painted, and this has been lost. Those cultures whose sculptures have survived in quantities include the cultures of the ancient Mediterranean and China, the Western tradition of sculpture began in ancient Greece, and Greece is widely seen as producing great masterpieces in the classical period. During the Middle Ages, Gothic sculpture represented the agonies and passions of the Christian faith, the revival of classical models in the Renaissance produced famous sculptures such as Michelangelos David. Relief is often classified by the degree of projection from the wall into low or bas-relief, high relief, sunk-relief is a technique restricted to ancient Egypt. Relief sculpture may decorate steles, upright slabs, usually of stone, techniques such as casting and moulding use an intermediate matrix containing the design to produce the work, many of these allow the production of several copies.
The term sculpture is used mainly to describe large works. The very large or colossal statue has had an enduring appeal since antiquity, another grand form of portrait sculpture is the equestrian statue of a rider on horse, which has become rare in recent decades. The smallest forms of life-size portrait sculpture are the head, showing just that, or the bust, small forms of sculpture include the figurine, normally a statue that is no more than 18 inches tall, and for reliefs the plaquette, medal or coin. Sculpture is an important form of public art, a collection of sculpture in a garden setting can be called a sculpture garden. One of the most common purposes of sculpture is in form of association with religion. Cult images are common in cultures, though they are often not the colossal statues of deities which characterized ancient Greek art. The actual cult images in the innermost sanctuaries of Egyptian temples, of which none have survived, were rather small. The same is true in Hinduism, where the very simple.
Some undoubtedly advanced cultures, such as the Indus Valley civilization, appear to have had no monumental sculpture at all, though producing very sophisticated figurines, the Mississippian culture seems to have been progressing towards its use, with small stone figures, when it collapsed. Other cultures, such as ancient Egypt and the Easter Island culture, from the 20th century the relatively restricted range of subjects found in large sculpture expanded greatly, with abstract subjects and the use or representation of any type of subject now common. Today much sculpture is made for intermittent display in galleries and museums, small sculpted fittings for furniture and other objects go well back into antiquity, as in the Nimrud ivories, Begram ivories and finds from the tomb of Tutankhamun
The craft of stonemasonry has existed since humanity could use and make tools - creating buildings and sculpture using stone from the earth. These materials have been used to construct many of the long-lasting, ancient monuments, cathedrals, quarrymen split veins, or sheets of rock, and extract the resulting blocks of stone from the ground. Sawyers cut these rough blocks into cuboids, to required size with diamond-tipped saws, the resulting block if ordered for a specific component is known as sawn six sides. Banker masons are workshop-based, and specialize in working the stones into the shapes required by a design, this set out on templets. They can produce anything from stones with simple chamfers to tracery windows, detailed mouldings and the more classical architectural building masonry. When working a stone from a block, the mason ensures that the stone is bedded in the right way. Occasionally though some stones need to be orientated correctly for the application, the basic tools and skills of the banker mason have existed as a trade for thousands of years.
Carvers cross the line from craft to art, and use their ability to carve stone into foliage, figures. Fixer masons specialize in the fixing of stones onto buildings, using lifting tackle, sometimes modern cements and epoxy resins are used, usually on specialist applications such as stone cladding. Metal fixings, from simple dowels and cramps to specialised single application fixings, are used, the precise tolerances necessary make this a highly skilled job. Memorial masons or monumental masons carve gravestones and inscriptions, the modern stonemason undergoes comprehensive training, both in the classroom and in the working environment. Hands-on skill is complemented by intimate knowledge of each type, its application and best uses. The mason may be skilled and competent to carry out one or all of the branches of stonemasonry. In some areas the trend is towards specialization, in other areas towards adaptability, stonemasons use all types of natural stone, igneous and sedimentary, while some use artificial stone as well.
Igneous stones, Granite is one of the hardest stones, with great persistence, simple mouldings can and have been carved into granite, for example in many Cornish churches and the city of Aberdeen. Generally, however, it is used for purposes that require its strength and durability, such as kerbstones, flooring, igneous stone ranges from very soft rocks such as pumice and scoria to somewhat harder rocks such as tuff and hard rocks such as granite and basalt. Metamorphic, Marble is a fine stone easily workable, that comes in various colours and it has traditionally been used for carving statues, and for facing many Byzantine and Renaissance Italian buildings. Their work was preceded by older sculptors from Mesopotamia and Egypt, the famous Acropolis of Athens is said to be constructed using the Pentelicon marble
Milos or Melos is a volcanic Greek island in the Aegean Sea, just north of the Sea of Crete. Milos is the southwesternmost island in the Cyclades group, the island is famous for the statue of Aphrodite, and for statues of the Greek god Asclepius, the Poseidon and an archaic Apollo in Athens. Milos is a popular tourist destination during the summer, the Municipality of Milos includes the uninhabited offshore islands of Antimilos and Akradies. The combined land area is 160.147 square kilometres and the 2011 census population was 4,977 inhabitants, obsidian from Milos was a commodity as early as 15,000 years ago. The mining of obsidian did not lead to the development of permanent habitation or manufacturing on the island, those in search of obsidian arrived by boat, beaching it in a suitable cove and cutting pieces of the volcanic glass from the quarries. The position of Milos, between mainland Greece and Crete, and its possession of obsidian, made it an important centre of early Aegean civilisation, Milos lost its arms-making importance when bronze became the preferred material for the manufacture of weapons.
The first settlement at Phylakopi arose in the Bronze Age, flourishing as the extraction of obsidian was in the decline, the first settlers were tuna fishermen. The famous fresco of the fish was found in the ruins of the Pillar room and was executed with delicate colouring. Stylistic similarities to Minoan frescoes are suggested, and it could perhaps have been the work of a Cretan artist, part of the site has been washed away by the sea. The antiquities found at the site covered three major periods, from the Early Cycladic period to the Mycenaean period, at the site much pottery was excavated, with several changing styles and influences over the sites long occupation. In the early occupation of the site, there are similarities and imports from other Cycladic islands. The quantities found at the Cycladic sites have taken to suggest a Minoan control over the region. At Phylakopi a Megaron structure, which is associated with the Mycenaean palaces, such as those at Tiryns, Pylos. This has been taken to suggest that the Mycenaeans conquered the settlement, the evidence is not clear, though again it could be a legacy of the islanders adopting foreign elements into their culture.
Particularly unexpected was the discovery in the 1970s of a shrine at the site, the shrine is unprecedented in the Bronze Age Cyclades and has provided a valuable insight ito the beliefs and rituals of the inhabitants of Phylakopi. The site was abandoned and was never reoccupied. The first Dorian settlement on Melos was established no earlier than the 1st millennium BC, dorians are the ethnic group to which the Spartans belonged, but the Dorian settlers of Melos made themselves independent. They eventually established a city whose site lies on the shore of the bay
A file is a tool used to remove fine amounts of material from a workpiece. It is common in woodworking and other similar trade, most are hand tools, made of a case hardened steel bar of rectangular, triangular, or round cross-section, with one or more surfaces cut with sharp, generally parallel teeth. A narrow, pointed tang is common at one end, to which a handle may be fitted, a rasp is a form of file with distinct, individually cut teeth used for coarsely removing large amounts of material. Files have developed with abrasive surfaces, such as natural or synthetic diamond grains or silicon carbide, allowing removal of material that would dull or resist metal. Relatedly, lapping is ancient, with wood and beach sand offering a natural pair of lap. The Disston authors state, To abrade, or file, ancient man used sand, coral, fish skin, the Bronze Age and the Iron Age had various kinds of files and rasps. Archaeologists have discovered rasps made from bronze in Egypt, dating back to the years 1200–1000 BC, archaeologists have discovered rasps made of iron used by the Assyrians, dating back to the 7th Century BC.
During the Middle Ages files were already advanced, thanks to the extensive talents of blacksmiths. By the 11th century, there already existed hardened files that would seem quite modern even to todays eyes. For example, in the 13th century, ornamental iron work at Paris was done skillfully with the aid of files, but the process was a secret known only to a master craftsman. The Disston authors state, It was not until the fourteenth century, that those who practiced art in ironwork began to use tools, besides heat. This statement could mislead in the sense that stoning and lapping have never been rare activities among humans, but by the late Middle Ages, the transition was extensive. The Disston authors mention Nuremberg and Remscheid as leading centers of production for files as well as tools in general, the activity in Remscheid reflects the metalworking spirit of the Rhine-Ruhr region in general rather than representing a single village of geniuses in isolation. Most files of the period were smithed by hand in a sequence in which the iron was forged, the teeth were cut with a chisel, among the drawings of Leonardo da Vinci is a sketch of a machine tool for the cutting of files.
Prior to the industrialization of machining and the development of parts during the 19th century. Component parts were roughly shaped by forging, and by primitive machining operations and these components were individually hand-fit for assembly by careful and deliberate filing. The potential precision of fitting is much higher than generally assumed. Locks and firearms were manufactured in this way for centuries before the Industrial Revolution, machining in the mid-19th century was heavily dependent on filing, because milling practice was slowly evolving out of its infancy