1.
Michelangelo
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Michelangelo di Lodovico Buonarroti Simoni was an Italian sculptor, painter, architect, and poet of the High Renaissance who exerted an unparalleled influence on the development of Western art. Considered to be the greatest living artist during his lifetime, he has since described as one of the greatest artists of all time. A number of Michelangelos works of painting, sculpture, and architecture rank among the most famous in existence and he sculpted two of his best-known works, the Pietà and David, before the age of thirty. As an architect, Michelangelo pioneered the Mannerist style at the Laurentian Library, at the age of 74, he succeeded Antonio da Sangallo the Younger as the architect of St. Peters Basilica. Michelangelo transformed the plan so that the end was finished to his design, as was the dome, with some modification. Michelangelo was unique as the first Western artist whose biography was published while he was alive, in his lifetime he was often called Il Divino. One of the qualities most admired by his contemporaries was his terribilità, the attempts by subsequent artists to imitate Michelangelos impassioned and highly personal style resulted in Mannerism, the next major movement in Western art after the High Renaissance. Michelangelo was born on 6 March 1475 in Caprese near Arezzo, at the time of Michelangelos birth, his father was the Judicial administrator of the small town of Caprese and local administrator of Chiusi. Michelangelos mother was Francesca di Neri del Miniato di Siena, the Buonarrotis claimed to descend from the Countess Mathilde of Canossa, this claim remains unproven, but Michelangelo himself believed it. Several months after Michelangelos birth, the returned to Florence. There Michelangelo gained his love for marble, as Giorgio Vasari quotes him, If there is good in me. Along with the milk of my nurse I received the knack of handling chisel and hammer, as a young boy, Michelangelo was sent to Florence to study grammar under the Humanist Francesco da Urbino. The young artist, however, showed no interest in his schooling, preferring to copy paintings from churches, the city of Florence was at that time the greatest centre of the arts and learning in Italy. Art was sponsored by the Signoria, by the merchant guilds and by patrons such as the Medici. The Renaissance, a renewal of Classical scholarship and the arts, had its first flowering in Florence, the sculptor Lorenzo Ghiberti had laboured for fifty years to create the bronze doors of the Baptistry, which Michelangelo was to describe as The Gates of Paradise. The exterior niches of the Church of Orsanmichele contained a gallery of works by the most acclaimed sculptors of Florence – Donatello, Ghiberti, Andrea del Verrocchio, and Nanni di Banco. The interiors of the churches were covered with frescos, begun by Giotto. During Michelangelos childhood, a team of painters had been called from Florence to the Vatican, among them was Domenico Ghirlandaio, a master in fresco painting, perspective, figure drawing, and portraiture who had the largest workshop in Florence at that period
2.
Sistine Chapel
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The Sistine Chapel is a chapel in the Apostolic Palace, the official residence of the Pope, in Vatican City. Originally known as the Cappella Magna, the chapel takes its name from Pope Sixtus IV, since that time, the chapel has served as a place of both religious and functionary papal activity. Today it is the site of the Papal conclave, the process by which a new pope is selected, the fame of the Sistine Chapel lies mainly in the frescos that decorate the interior, and most particularly the Sistine Chapel ceiling and The Last Judgment by Michelangelo. In a different climate after the Sack of Rome, he returned, the fame of Michelangelos paintings has drawn multitudes of visitors to the chapel ever since they were revealed five hundred years ago. At the time of Pope Sixtus IV in the late 15th century, there were 50 occasions during the year on which it was prescribed by the Papal Calendar that the whole Papal Chapel should meet. Of these 50 occasions,35 were masses, of which 8 were held in Basilicas, in general St. Peters and these included the Christmas Day and Easter masses, at which the Pope himself was the celebrant. The other 27 masses could be held in a smaller, less public space, the Cappella Maggiore derived its name, the Greater Chapel, from the fact that there was another chapel also in use by the Pope and his retinue for daily worship. At the time of Pope Sixtus IV, this was the Chapel of Pope Nicholas V, the Cappella Maggiore is recorded as existing in 1368. The proportions of the present chapel appear to follow those of the original. The first mass in the Sistine Chapel was celebrated on 15 August 1483, the Sistine Chapel has maintained its function to the present day, and continues to host the important services of the Papal Calendar, unless the Pope is travelling. There is a permanent choir, the Sistine Chapel Choir, for whom much original music has been written, one of the functions of the Sistine Chapel is as a venue for the election of each successive pope in a conclave of the College of Cardinals. On the occasion of a conclave, a chimney is installed in the roof of the chapel, if white smoke appears, created by burning the ballots of the election, a new Pope has been elected. The conclave also provided for the cardinals a space in which they can hear mass, and in which they can eat, sleep, and pass time attended by servants. From 1455, conclaves have been held in the Vatican, until the Great Schism, canopies for each cardinal-elector were once used during conclaves—a sign of equal dignity. After the new Pope accepts his election, he would give his new name, at this time, until reforms instituted by Saint Pius X, the canopies were of different colours to designate which Cardinals had been appointed by which Pope. Its exterior is unadorned by architectural or decorative details, as is common in many Italian churches of the Medieval, subsidence and cracking of masonry such as must also have affected the Cappella Maggiore has necessitated the building of very large buttresses to brace the exterior walls. The accretion of other buildings has further altered the appearance of the Chapel. The building is divided into three stories of which the lowest is a tall basement level with several utilitarian windows
3.
Vatican City
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Vatican City, officially Vatican City State or the State of Vatican City, is a walled enclave within the city of Rome. With an area of approximately 44 hectares, and a population of 842, however, formally it is not sovereign, with sovereignty being held by the Holy See, the only entity of public international law that has diplomatic relations with almost every country in the world. It is an ecclesiastical or sacerdotal-monarchical state ruled by the Bishop of Rome – the Pope, the highest state functionaries are all Catholic clergy of various national origins. Vatican City is distinct from the Holy See, which dates back to early Christianity and is the episcopal see of 1.2 billion Latin. According to the terms of the treaty, the Holy See has full ownership, exclusive dominion, within Vatican City are religious and cultural sites such as St. Peters Basilica, the Sistine Chapel and the Vatican Museums. They feature some of the worlds most famous paintings and sculptures, the unique economy of Vatican City is supported financially by the sale of postage stamps and tourist mementos, fees for admission to museums, and the sale of publications. The name Vatican City was first used in the Lateran Treaty, signed on 11 February 1929, the name is taken from Vatican Hill, the geographic location of the state. Vatican is derived from the name of an Etruscan settlement, Vatica or Vaticum meaning garden, located in the area the Romans called vaticanus ager. The official Italian name of the city is Città del Vaticano or, more formally, Stato della Città del Vaticano, although the Holy See and the Catholic Church use Ecclesiastical Latin in official documents, the Vatican City officially uses Italian. The Latin name is Status Civitatis Vaticanæ, this is used in documents by not just the Holy See. The name Vatican was already in use in the time of the Roman Republic for an area on the west bank of the Tiber across from the city of Rome. Under the Roman Empire, many villas were constructed there, after Agrippina the Elder drained the area and laid out her gardens in the early 1st century AD. In AD40, her son, Emperor Caligula built in her gardens a circus for charioteers that was completed by Nero, the Circus Gaii et Neronis, usually called, simply. Even before the arrival of Christianity, it is supposed that this originally uninhabited part of Rome had long considered sacred. A shrine dedicated to the Phrygian goddess Cybele and her consort Attis remained active long after the Constantinian Basilica of St. Peter was built nearby, the particularly low quality of Vatican water, even after the reclamation of the area, was commented on by the poet Martial. The Vatican Obelisk was originally taken by Caligula from Heliopolis in Egypt to decorate the spina of his circus and is thus its last visible remnant and this area became the site of martyrdom of many Christians after the Great Fire of Rome in AD64. Ancient tradition holds that it was in this circus that Saint Peter was crucified upside-down, opposite the circus was a cemetery separated by the Via Cornelia. Peters in the first half of the 4th century, the Constantinian basilica was built in 326 over what was believed to be the tomb of Saint Peter, buried in that cemetery
4.
Mural
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A mural is any piece of artwork painted or applied directly on a wall, ceiling or other permanent surface. A distinguishing characteristic of painting is that the architectural elements of the given space are harmoniously incorporated into the picture. Some wall paintings are painted on canvases, which are then attached to the wall. Whether these works can be accurately called murals is a subject of controversy in the art world. Murals of sorts date to Upper Paleolithic times such as the paintings in the Chauvet Cave in Ardèche department of southern France, many ancient murals have been found within ancient Egyptian tombs, the Minoan palaces and in Pompeii. During the Middle Ages murals were executed on dry plaster. The huge collection of Kerala mural painting dating from the 14th century are examples of fresco secco, in Italy, circa 1300, the technique of painting of frescos on wet plaster was reintroduced and led to a significant increase in the quality of mural painting. In modern times, the became more well-known with the Mexican muralism art movement. There are many different styles and techniques, the best-known is probably fresco, which uses water-soluble paints with a damp lime wash, a rapid use of the resulting mixture over a large surface, and often in parts. The colors lighten as they dry, the marouflage method has also been used for millennia. Murals today are painted in a variety of ways, using oil or water-based media, the styles can vary from abstract to trompe-lœil. Initiated by the works of artists like Graham Rust or Rainer Maria Latzke in the 1980s, trompe-loeil painting has experienced a renaissance in private. The buon fresco technique consists of painting in pigment mixed with water on a layer of wet, fresh. The pigment is absorbed by the wet plaster, after a number of hours. After this the painting stays for a time up to centuries in fresh. Fresco-secco painting is done on dry plaster, the pigments thus require a binding medium, such as egg, glue or oil to attach the pigment to the wall. By the end of the century this had largely displaced the buon fresco method. This technique had, in reduced form, the advantages of a secco work, in Greco-Roman times, mostly encaustic colors applied in a cold state were used
5.
Lime plaster
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Lime plaster is a type of plaster composed of sand, water, and lime, usually non-hydraulic hydrated lime. Ancient lime plaster often contained horse hair for reinforcement and pozzolan additives to reduce the working time, traditional non-hydraulic hydrated lime only sets through carbonatation when the plaster is kept moist and access of CO2 from the air is possible. It will not set when submersed in water, when a very thick layer or several layers are applied the lime can remain soft for weeks. The curing time of lime plaster can be shortened by using lime or adding pozzolan additives. In ancient times, Roman lime plaster incorporated pozzolanic volcanic ash, in modern times, non-hydraulic lime plaster can also be made to set faster by adding gypsum. Lime plaster sets up to a mass that is durable yet relatively flexible. Hydraulic lime plaster can be almost as hard as cement plaster, when cured lime plaster is unaffected by water and will not soften or dissolve like drywall and earthen or gypsum plaster. Unlike gypsum or clay plaster, lime plaster is sufficiently durable, compared to cement plaster, plaster made from hydrated lime is less brittle and less prone to cracking, requiring no expansion joints. It will not detach from the wall when subjected to stress due to expansion inflicted by solar radiation. Unlike cement plaster it will shield softer materials from shear stresses otherwise possibly causing the deterioration of the underlaying surface and it is usually not recommended to replace more than 20% of the lime content with cement when rendering the facade. Lime plaster is permeable and allows for the diffusion and evaporation of moisture, the elevated pH of the lime in the plaster will act as a fungicide, mold will not grow in lime plaster. Non-hydraulic lime plaster sets slowly and is quite caustic while wet, plasterers must take care to protect themselves or use mild acids as vinegar or lemon juice to neutralize chemical burn. When the plaster is dry, the pH falls to about 8.6, non-hydraulic lime plaster requires moisture to set and has to be prevented from drying for several days. The number of qualified tradesmen capable of plastering with lime is in due to widespread adoption of drywall. One of the earliest examples of lime plaster dates back to the end of the eighth millennium BC, three statues were discovered in a buried pit at Ain Ghazal in Jordan that were sculpted with lime plaster over armatures of reeds and twine. They were made in the neolithic period, around 7200 BC. The fact that these sculptures have lasted so long is a testament to the durability of lime plaster, lime plaster was found to have been a multi-purpose material at the archaeological site of Ain Ghazal in modern-day Jordan. The site dates human occupation from 7200 BC to 5000 BC, lime plaster is believed to have coated internal walls of buildings and to have been used as the main component of some anthropomorphical figurines discovered at the site
6.
Water
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Water is a transparent and nearly colorless chemical substance that is the main constituent of Earths streams, lakes, and oceans, and the fluids of most living organisms. Its chemical formula is H2O, meaning that its molecule contains one oxygen, Water strictly refers to the liquid state of that substance, that prevails at standard ambient temperature and pressure, but it often refers also to its solid state or its gaseous state. It also occurs in nature as snow, glaciers, ice packs and icebergs, clouds, fog, dew, aquifers, Water covers 71% of the Earths surface. It is vital for all forms of life. Only 2. 5% of this water is freshwater, and 98. 8% of that water is in ice and groundwater. Less than 0. 3% of all freshwater is in rivers, lakes, and the atmosphere, a greater quantity of water is found in the earths interior. Water on Earth moves continually through the cycle of evaporation and transpiration, condensation, precipitation. Evaporation and transpiration contribute to the precipitation over land, large amounts of water are also chemically combined or adsorbed in hydrated minerals. Safe drinking water is essential to humans and other even though it provides no calories or organic nutrients. There is a correlation between access to safe water and gross domestic product per capita. However, some observers have estimated that by 2025 more than half of the population will be facing water-based vulnerability. A report, issued in November 2009, suggests that by 2030, in developing regions of the world. Water plays an important role in the world economy, approximately 70% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a source of food for many parts of the world. Much of long-distance trade of commodities and manufactured products is transported by boats through seas, rivers, lakes, large quantities of water, ice, and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a variety of chemical substances, as such it is widely used in industrial processes. Water is also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, Water is a liquid at the temperatures and pressures that are most adequate for life. Specifically, at atmospheric pressure of 1 bar, water is a liquid between the temperatures of 273.15 K and 373.15 K
7.
Italian language
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By most measures, Italian, together with Sardinian, is the closest to Latin of the Romance languages. Italian is a language in Italy, Switzerland, San Marino, Vatican City. Italian is spoken by minorities in places such as France, Montenegro, Bosnia & Herzegovina, Crimea and Tunisia and by large expatriate communities in the Americas. Many speakers are native bilinguals of both standardized Italian and other regional languages, Italian is the fourth most studied language in the world. Italian is a major European language, being one of the languages of the Organisation for Security and Cooperation in Europe. It is the third most widely spoken first language in the European Union with 65 million native speakers, including Italian speakers in non-EU European countries and on other continents, the total number of speakers is around 85 million. Italian is the working language of the Holy See, serving as the lingua franca in the Roman Catholic hierarchy as well as the official language of the Sovereign Military Order of Malta. Italian is known as the language of music because of its use in musical terminology and its influence is also widespread in the arts and in the luxury goods market. Italian has been reported as the fourth or fifth most frequently taught foreign language in the world, Italian was adopted by the state after the Unification of Italy, having previously been a literary language based on Tuscan as spoken mostly by the upper class of Florentine society. Its development was influenced by other Italian languages and to some minor extent. Its vowels are the second-closest to Latin after Sardinian, unlike most other Romance languages, Italian retains Latins contrast between short and long consonants. As in most Romance languages, stress is distinctive, however, Italian as a language used in Italy and some surrounding regions has a longer history. What would come to be thought of as Italian was first formalized in the early 14th century through the works of Tuscan writer Dante Alighieri, written in his native Florentine. Dante is still credited with standardizing the Italian language, and thus the dialect of Florence became the basis for what would become the language of Italy. Italian was also one of the recognised languages in the Austro-Hungarian Empire. Italy has always had a dialect for each city, because the cities. Those dialects now have considerable variety, as Tuscan-derived Italian came to be used throughout Italy, features of local speech were naturally adopted, producing various versions of Regional Italian. Even in the case of Northern Italian languages, however, scholars are not to overstate the effects of outsiders on the natural indigenous developments of the languages
8.
Fresco-secco
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Fresco-secco is a wall painting technique where pigments mixed with an organic binder and/or lime are applied onto a dry plaster. The paints used can e. g. be casein paint, tempera, oil paint, if the pigments are mixed with lime water or lime milk and applied to a dry plaster the technique is called lime secco painting. The secco technique contrasts with the technique, where the painting is executed on a layer of wet plaster. Because the pigments do not become part of the wall, as in buon fresco, fresco-secco paintings are less durable, the colors may flake off the painting as time goes by, but this technique has the advantages of a longer working time and retouchability. In Italy, fresco technique was reintroduced around 1300 and led to an increase in the quality of mural painting. This technological change coincided with the turn in Western art. The treatise Silparatna by Kumaradeva gives an account of the Fresco-secco painting technology in detail, according to this text, a picture should be painted with appropriate colours, along with proper forms and sentiments, and moods and actions. White, yellow, red, black and terre - verte are pointed out in the text as pure colors, different shades were also prepared from these original colors. Five types of brushes with various shapes and size made of animal hair, specialist painter and decorators still use this technique to great effect in the world of interior design e. g. faux marble. Steve Bogdanoff Giotto June McEwan, Scottish artist who recreates historic Scottish interiors, beohar Rammanohar Sinha, artist from India whose frescoes ornamentate the walls and gigantic dome of the Shaheed-Smarak or Indias Martyrs Memorial Auditorium. Episodes, accomplishments and landmark-events in Indias struggle for independence are depicted. Rudolph F. Zallinger - whose Age of Mammals, a 60 by 5 feet mural painted from 1961 to 1967 on the wall of the Yale Peabody Museum of Natural History, is painted in this style. The fresco technique Recommended reading, Cennino Cenninis Il Libro dellArte, a New English Translation and Commentary with Italian Transcription, Archetype 2015, ISBN 978-1-909492-28-8
9.
Italian Renaissance painting
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The city of Florence in Tuscany is renowned as the birthplace of the Renaissance, and in particular of Renaissance painting. A detailed background is given in the companion articles Renaissance and Renaissance architecture, Italian Renaissance painting can be divided into four periods, the Proto-Renaissance, the Early Renaissance, the High Renaissance, and Mannerism. These dates are approximations rather than specific points because the lives of individual artists, the Proto-Renaissance begins with the professional life of the painter Giotto and includes Taddeo Gaddi, Orcagna and Altichiero. The Early Renaissance was marked by the work of Masaccio, Fra Angelico, Paolo Uccello, Piero della Francesca, the High Renaissance period was that of Leonardo da Vinci, Michelangelo, Raphael and Titian. The Mannerist period included Andrea del Sarto, Pontormo and Tintoretto, Mannerism is dealt with in a separate article. The influences upon the development of Renaissance painting in Italy are those also affected Philosophy, Literature, Architecture, Theology, Science, Government. The following is a summary of points dealt with more fully in the articles that are cited above. A number of Classical texts, that had been lost to Western European scholars for centuries and these included Philosophy, Poetry, Drama, Science, a thesis on the Arts and Early Christian Theology. The resulting interest in Humanist philosophy meant that mans relationship with humanity, a revived interest in the Classics brought about the first archaeological study of Roman remains by the architect Brunelleschi and sculptor Donatello. Simultaneous with gaining access to the Classical texts, Europe gained access to advanced mathematics which had its provenance in the works of Byzantine and Islamic scholars. The advent of movable type printing in the 15th century meant that ideas could be disseminated easily, the development of oil paint and its introduction to Italy had lasting effects on the art of painting. The establishment of the Medici Bank and the subsequent trade it generated brought unprecedented wealth to a single Italian city, Cosimo de Medici set a new standard for patronage of the arts, not associated with the church or monarchy. A similar heritage of artistic achievement occurred in Venice through the talented Bellini family, their influential inlaw Mantegna, Giorgione, Titian, much painting of the Renaissance period was commissioned by or for the Catholic Church. These works were often of large scale and were frequently painted in fresco of the Life of Christ. There were also many paintings on the theme of Salvation. Churches also commissioned altarpieces, which were painted in tempera on panel, apart from large altarpieces, small devotional pictures were produced in very large numbers, both for churches and for private individuals, the most common theme being the Madonna and Child. Throughout the period, civic commissions were also important, during the 15th century portraiture became common, initially often formalised profile portraits but increasingly three-quarter face, bust-length portraits. Portraiture was to become a subject for High Renaissance painters such as Raphael and Titian
10.
Pigment
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A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, many materials selectively absorb certain wavelengths of light. Materials that humans have chosen and developed for use as pigments usually have properties that make them ideal for coloring other materials. A pigment must have a high tinting strength relative to the materials it colors and it must be stable in solid form at ambient temperatures. For industrial applications, as well as in the arts, permanence, pigments that are not permanent are called fugitive. Fugitive pigments fade over time, or with exposure to light, pigments are used for coloring paint, ink, plastic, fabric, cosmetics, food, and other materials. Most pigments used in manufacturing and the arts are dry colorants. This powder is added to a binder, a neutral or colorless material that suspends the pigment. A distinction is made between a pigment, which is insoluble in its vehicle, and a dye, which either is itself a liquid or is soluble in its vehicle. A colorant can act as either a pigment or a dye depending on the vehicle involved, in some cases, a pigment can be manufactured from a dye by precipitating a soluble dye with a metallic salt. The resulting pigment is called a lake pigment, the term biological pigment is used for all colored substances independent of their solubility. In 2006, around 7.4 million tons of inorganic, organic, asia has the highest rate on a quantity basis followed by Europe and North America. By 2020, revenues will have risen to approx, the global demand on pigments was roughly US$20.5 billion in 2009, around 1. 5-2% up from the previous year. It is predicted to increase in a growth rate in the coming years. The worldwide sales are said to increase up to US$24.5 billion in 2015, pigments appear the colors they are because they selectively reflect and absorb certain wavelengths of visible light. White light is an equal mixture of the entire spectrum of visible light with a wavelength in a range from about 375 or 400 nanometers to about 760 or 780 nm. When this light encounters a pigment, parts of the spectrum are absorbed by the molecules or ions of the pigment, in organic pigments such as diazo or phthalocyanine compounds the light is absorbed by the conjugated systems of double bonds in the molecule. Some of the inorganic pigments such as vermilion or cadmium yellow absorb light by transferring an electron from the ion to the positive ion
11.
Temperature
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A temperature is an objective comparative measurement of hot or cold. It is measured by a thermometer, several scales and units exist for measuring temperature, the most common being Celsius, Fahrenheit, and, especially in science, Kelvin. Absolute zero is denoted as 0 K on the Kelvin scale, −273.15 °C on the Celsius scale, the kinetic theory offers a valuable but limited account of the behavior of the materials of macroscopic bodies, especially of fluids. Temperature is important in all fields of science including physics, geology, chemistry, atmospheric sciences, medicine. The Celsius scale is used for temperature measurements in most of the world. Because of the 100 degree interval, it is called a centigrade scale.15, the United States commonly uses the Fahrenheit scale, on which water freezes at 32°F and boils at 212°F at sea-level atmospheric pressure. Many scientific measurements use the Kelvin temperature scale, named in honor of the Scottish physicist who first defined it and it is a thermodynamic or absolute temperature scale. Its zero point, 0K, is defined to coincide with the coldest physically-possible temperature and its degrees are defined through thermodynamics. The temperature of zero occurs at 0K = −273. 15°C. For historical reasons, the triple point temperature of water is fixed at 273.16 units of the measurement increment, Temperature is one of the principal quantities in the study of thermodynamics. There is a variety of kinds of temperature scale and it may be convenient to classify them as empirically and theoretically based. Empirical temperature scales are historically older, while theoretically based scales arose in the middle of the nineteenth century, empirically based temperature scales rely directly on measurements of simple physical properties of materials. For example, the length of a column of mercury, confined in a capillary tube, is dependent largely on temperature. Such scales are only within convenient ranges of temperature. For example, above the point of mercury, a mercury-in-glass thermometer is impracticable. A material is of no use as a thermometer near one of its phase-change temperatures, in spite of these restrictions, most generally used practical thermometers are of the empirically based kind. Especially, it was used for calorimetry, which contributed greatly to the discovery of thermodynamics, nevertheless, empirical thermometry has serious drawbacks when judged as a basis for theoretical physics. Theoretically based temperature scales are based directly on theoretical arguments, especially those of thermodynamics, kinetic theory and they rely on theoretical properties of idealized devices and materials
12.
Plaster
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Plaster is a building material used for the protective and/or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English plaster usually means a material used for the interiors of buildings, another imprecise term used for the material is stucco, which is also often used for plasterwork that is worked in some way to produce relief decoration, rather than flat surfaces. The most common types of plaster mainly contain either gypsum, lime, or cement, the plaster is manufactured as a dry powder and is mixed with water to form a stiff but workable paste immediately before it is applied to the surface. The reaction with water liberates heat through crystallization and the hydrated plaster then hardens, plaster can be relatively easily worked with metal tools or even sandpaper, and can be moulded, either on site or to make pre-formed sections in advance, which are put in place with adhesive. Plaster is not a material, it is suitable for finishing, rather than load-bearing. Forms of plaster have several other uses, in medicine plaster orthopedic casts are still often used for supporting set broken bones. In dentistry plaster is used to make dental models, various types of models and moulds are made with plaster. In art, lime plaster is the matrix for fresco painting. Gypsum plaster, or plaster of Paris, is produced by heating gypsum to about 300 °F, when the dry plaster powder is mixed with water, it re-forms into gypsum. The setting of unmodified plaster starts about 10 minutes after mixing and is complete in about 45 minutes, if plaster or gypsum is heated above 266 °F, hemihydrate is formed, which will also re-form as gypsum if mixed with water. On heating to 180 °C, the nearly water-free form, called γ-anhydrite is produced, γ-Anhydrite reacts slowly with water to return to the dihydrate state, a property exploited in some commercial desiccants. On heating above 250 °C, the anhydrous form called β-anhydrite or dead burned plaster is formed. A large gypsum deposit at Montmartre in Paris led calcined gypsum to be known as plaster of Paris. Plasterers often use gypsum to simulate the appearance of surfaces of wood, stone, or metal, on movie, nowadays, theatrical plasterers often use expanded polystyrene, although the job title remains unchanged. Plaster of Paris can be used to impregnate gauze bandages to make a material called plaster bandages. It is used similarly to clay, as it is shaped when wet, yet sets into a resilient. This is the material that was used to make classic plaster orthopedic casts to protect limbs with broken bones, set Modroc is an early example of a composite material. The hydration of plaster of Paris relies on the reaction of water with the dehydrated or partially hydrated calcium sulfate present in the plaster, lime plaster is a mixture of calcium hydroxide and sand
13.
Calcination
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Authorities differ on the meaning of calcination. The IUPAC defines it as heating to temperatures in air or oxygen. A calciner is a cylinder that rotates inside a heated furnace. The product of calcination is usually referred to in general as calcine, calcination is carried out in furnaces or reactors of various designs including shaft furnaces, rotary kilns, multiple hearth furnaces, and fluidized bed reactors. Calcination reactions usually take place at or above the decomposition temperature or the transition temperature. This temperature is defined as the temperature at which the standard Gibbs free energy for a particular calcination reaction is equal to zero. For example, in limestone calcination, a process, the chemical reaction is CaCO3 → CaO + CO2 The standard Gibbs free energy of reaction is approximated as ΔG°r =177,100 −158 T. The standard free energy of reaction is 0 in this case when the temperature, T, is equal to 1121 K, see also calcination equilibrium of calcium carbonate In some cases, calcination of a metal results in oxidation of the metal. Jean Rey noted that lead and tin when calcinated gained weight, in alchemy, calcination was believed to be one of the 12 vital processes required for the transformation of a substance. Alchemists distinguished two kinds of calcination, actual and potential, actual calcination is that brought about by actual fire, from wood, coals, or other fuel, raised to a certain temperature
14.
Limestone
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Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate, about 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, most cave systems are through limestone bedrock. The first geologist to distinguish limestone from dolomite was Belsazar Hacquet in 1778, like most other sedimentary rocks, most limestone is composed of grains. Most grains in limestone are skeletal fragments of organisms such as coral or foraminifera. Other carbonate grains comprising limestones are ooids, peloids, intraclasts and these organisms secrete shells made of aragonite or calcite, and leave these shells behind when they die. Limestone often contains variable amounts of silica in the form of chert or siliceous skeletal fragment, some limestones do not consist of grains at all, and are formed completely by the chemical precipitation of calcite or aragonite, i. e. travertine. Secondary calcite may be deposited by supersaturated meteoric waters and this produces speleothems, such as stalagmites and stalactites. Another form taken by calcite is oolitic limestone, which can be recognized by its granular appearance, the primary source of the calcite in limestone is most commonly marine organisms. Some of these organisms can construct mounds of rock known as reefs, below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly, so limestone typically does not form in deeper waters. Limestones may also form in lacustrine and evaporite depositional environments, calcite can be dissolved or precipitated by groundwater, depending on several factors, including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits a characteristic called retrograde solubility, in which it becomes less soluble in water as the temperature increases. Impurities will cause limestones to exhibit different colors, especially with weathered surfaces, Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Crystals of calcite, quartz, dolomite or barite may line small cavities in the rock, when conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures. Travertine is a banded, compact variety of limestone formed along streams, particularly there are waterfalls. Calcium carbonate is deposited where evaporation of the leaves a solution supersaturated with the chemical constituents of calcite. Tufa, a porous or cellular variety of travertine, is found near waterfalls, coquina is a poorly consolidated limestone composed of pieces of coral or shells. During regional metamorphism that occurs during the building process, limestone recrystallizes into marble
15.
Lime kiln
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A lime kiln is a kiln used for the calcination of limestone to produce the form of lime called quicklime. The chemical equation for this reaction is CaCO3 + heat → CaO + CO2 This reaction takes place at 900 °C, excessive temperature is avoided because it produces unreactive, dead-burned lime. Slaked lime can be formed by mixing water with quicklime, the earliest descriptions of lime kilns differ little from those used for small-scale manufacture a century ago. Because land transportation of minerals like limestone and coal was difficult in the era, they were distributed by sea. Many preserved kilns are still to be seen on quaysides around the coasts of Britain, permanent lime kilns fall into two broad categories, flare kilns also known as intermittent or periodic kilns, and draw kilns also known as perpetual or running kilns. In a flare kiln, a layer of coal was built up. The fire was alight for several days, and then the entire kiln was emptied of the lime, in a draw kiln, the chalk was layered with coke and lit. As it burnt through, lime was extracted from the bottom of the kiln and further layers of chalk, the common feature of early kilns was an egg-cup shaped burning chamber, with an air inlet at the base, constructed of brick. Limestone was crushed to fairly uniform 20–60 mm lumps – fine stone was rejected, successive dome-shaped layers of limestone and wood or coal were built up in the kiln on grate bars across the eye. When loading was complete, the kiln was kindled at the bottom, when burnt through, the lime was cooled and raked out through the base. Fine ash dropped out and was rejected with the riddlings, only lump stone could be used, because the charge needed to breathe during firing. This also limited the size of kilns and explains why kilns were all much the same size, above a certain diameter, the half-burned charge would be likely to collapse under its own weight, extinguishing the fire. So kilns always made 25–30 tonnes of lime in a batch, typically the kiln took a day to load, three days to fire, two days to cool and a day to unload, so a one-week turnaround was normal. The degree of burning was controlled by trial and error from batch to batch by varying the amount of fuel used. Because there were large temperature differences between the center of the charge and the close to the wall, a mixture of underburned, well-burned and dead-burned lime was normally produced. Typical fuel efficiency was low, with 0.5 tonnes or more of coal being used per tonne of finished lime, lime production was sometimes carried out on an industrial scale. Sets of seven kilns were common, a loading gang and an unloading gang would work the kilns in rotation through the week. A rarely used kiln was known as a lazy kiln, the large kiln at Crindledykes near Haydon Bridge, Northumbria, was one of more than 300 in the county
16.
Calcium carbonate
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Calcium carbonate is a chemical compound with the formula CaCO3. It is a substance found in rocks as the minerals calcite and aragonite and is the main component of pearls and the shells of marine organisms, snails. Calcium carbonate is the ingredient in agricultural lime and is created when calcium ions in hard water react with carbonate ions to create limescale. It is medicinally used as a supplement or as an antacid. Calcium carbonate shares the properties of other carbonates. CaCO3 + CO2 + H2O → Ca2 This reaction is important in the erosion of rock, forming caverns. An unusual form of calcium carbonate is the hexahydrate, ikaite, ikaite is stable only below 6 °C. The vast majority of calcium used in industry is extracted by mining or quarrying. Pure calcium carbonate, can be produced from a quarried source. Alternatively, calcium carbonate is prepared from calcium oxide, other forms can be prepared, the denser, orthorhombic λ-CaCO3 and μ-CaCO3, occurring as the mineral vaterite. The aragonite form can be prepared by precipitation at temperatures above 85 °C, calcite contains calcium atoms coordinated by 6 oxygen atoms, in aragonite they are coordinated by 9 oxygen atoms. The vaterite structure is not fully understood, magnesium carbonate MgCO3 has the calcite structure, whereas strontium and barium carbonate adopt the aragonite structure, reflecting their larger ionic radii. Calcite, aragonite and vaterite are pure calcium carbonate minerals, industrially important source rocks which are predominantly calcium carbonate include limestone, chalk, marble and travertine. Eggshells, snail shells and most seashells are predominantly calcium carbonate, oyster shells have enjoyed recent recognition as a source of dietary calcium, but are also a practical industrial source. While not practical as a source, dark green vegetables such as broccoli. Beyond Earth, strong evidence suggests the presence of Calcium carbonate on Mars, signs of Calcium Carbonate have been detected at more than one location. This provides some evidence for the past presence of liquid water, Carbonate is found frequently in geologic settings and constitute an enormous carbon reservoir. Calcium carbonate occurs as aragonite, calcite and dolomite, the carbonate minerals form the rock types, limestone, chalk, marble, travertine, tufa, and others
17.
Calcium oxide
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Calcium oxide, commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline, crystalline solid at room temperature, the broadly used term lime connotes calcium-containing inorganic materials, in which carbonates, oxides and hydroxides of calcium, silicon, magnesium, aluminium, and iron predominate. By contrast, quicklime specifically applies to the chemical compound calcium oxide. Calcium oxide that survives processing without reacting in building such as cement is called free lime. Both it and a chemical derivative are important commodity chemicals, Calcium oxide is usually made by the thermal decomposition of materials, such as limestone or seashells, that contain calcium carbonate in a lime kiln. This is accomplished by heating the material to above 825 °C, annual worldwide production of quicklime is around 283 million tonnes. China is by far the worlds largest producer, with a total of around 170 million tonnes per year, the United States is the next largest, with around 20 million tonnes per year. Approximately 1.8 t of limestone is required per 1.0 t of quicklime, quicklime has a high affinity for water and is a more efficient desiccant than silica gel. The reaction of quicklime with water is associated with an increase in volume by a factor of at least 2.5, the major use of quicklime is in the Basic oxygen steelmaking process. Its usage varies from about 30–50 kg/t of steel, the quicklime neutralizes the acidic oxides, SiO2, Al2O3, and Fe2O3, to produce a basic molten slag. Ground quicklime is used in the production of aerated concrete blocks, quicklime and hydrated lime can considerably increase the load carrying capacity of clay-containing soils. They do this by reacting with finely divided silica and alumina to produce calcium silicates and aluminates, small quantities of quicklime are used in other processes, e. g. the production of glass, calcium aluminate cement, and organic chemicals. The hydrate can be reconverted to quicklime by removing the water by heating it to redness to reverse the hydration reaction, one litre of water combines with approximately 3.1 kilograms of quicklime to give calcium hydroxide plus 3.54 MJ of energy. This process can be used to provide a convenient portable source of heat, light, When quicklime is heated to 2,400 °C, it emits an intense glow. This form of illumination is known as a limelight, and was used broadly in theatrical productions prior to the invention of electric lighting, cement, Calcium oxide is a key ingredient for the process of making cement. As a cheap and widely available alkali, about 50% of the total quicklime production is converted to calcium hydroxide before use. Both quick- and hydrated lime are used in the treatment of drinking water, petroleum industry, Water detection pastes contain a mix of calcium oxide and phenolphthalein. Should this paste come into contact with water in a storage tank
18.
Calcium hydroxide
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Calcium hydroxide, traditionally called slaked lime, is an inorganic compound with the chemical formula Ca2. It is a crystal or white powder and is obtained when calcium oxide is mixed. It has many names including hydrated lime, caustic lime, builders lime, slack lime, cal, Calcium hydroxide is used in many applications, including food preparation. Limewater is the name for a saturated solution of calcium hydroxide. Calcium hydroxide is insoluble in water, with a solubility product Ksp of 5.5 × 10−6.4. Calcium hydroxide solutions can cause chemical burns, at high pH value, its solubility drastically decreases. This behavior is relevant to cement pastes, Ca2 → CaO + H2O Calcium hydroxide adopts a polymeric structure, as do all metal hydroxides. The structure is identical to that of Mg2, i. e. the cadmium iodide motif, strong hydrogen bonds exist between the layers. Calcium hydroxide is produced commercially by treating lime with water, CaO + H2O → Ca2 In the laboratory it can be prepared by mixing solutions of calcium chloride. The mineral form, portlandite, is rare but can be found in some volcanic, plutonic. It has also known to arise in burning coal dumps. CaOH has been detected in the atmosphere of S-type stars, one significant application of calcium hydroxide is as a flocculant, in water and sewage treatment. It forms a fluffy charged solid that aids in the removal of particles from water. This application is enabled by the low cost and low toxicity of calcium hydroxide and this conversion is part of the causticizing step in the Kraft process for making pulp. In Spanish, calcium hydroxide is called cal, corn cooked with cal becomes hominy, which significantly increases the bioavailability of niacin, and it is also considered tastier and easier to digest. In chewing coca leaves, calcium hydroxide is usually chewed alongside to keep the alkaloid stimulants chemically available for absorption by the body, similarly, Native Americans traditionally chewed tobacco leaves with calcium hydroxide derived from burnt mollusk shells to enhance the effects. It has also used by some indigenous American tribes as an ingredient in yopo. Calcium hydroxide is added to a bundle of areca nut
19.
Roman art
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Roman art refers to the visual arts made in Ancient Rome and in the territories of the Roman Empire. Roman art includes architecture, painting, sculpture and mosaic work, sculpture was perhaps considered as the highest form of art by Romans, but figure painting was also very highly regarded. Roman coins were an important means of propaganda, and have survived in enormous numbers, other perishable forms of art have not survived at all. Stylistic eclecticism and practical application are the hallmarks of much Roman art, though very little remains of Greek wall art and portraiture, certainly Greek sculpture and vase painting bears this out. These forms were not likely surpassed by Roman artists in fineness of design or execution. As another example of the lost Golden Age, he singled out Peiraikos, whose artistry is surpassed by only a very few. ”The adjective vulgar is used here in its original meaning, the Greek antecedents of Roman art were legendary. In the mid-5th century BC, the most famous Greek artists were Polygnotos, noted for his murals, and Apollodoros. In sculpture, Skopas, Praxiteles, Phidias, and Lysippos were the foremost sculptors, Ancient Greek treatises on the arts are known to have existed in Roman times though are now lost. Many Roman artists came from Greek colonies and provinces, the high number of Roman copies of Greek art also speaks of the esteem Roman artists had for Greek art, and perhaps of its rarer and higher quality. One exception is the Roman bust, which did not include the shoulders, the traditional head-and-shoulders bust may have been an Etruscan or early Roman form. Where Greek artists were highly revered in their society, most Roman artists were anonymous, there is no recording, as in Ancient Greece, of the great masters of Roman art, and practically no signed works. Roman culture assimilated many cultures and was for the most part tolerant of the ways of conquered peoples, Roman art was commissioned, displayed, and owned in far greater quantities, and adapted to more uses than in Greek times. Wealthy Romans were more materialistic, they decorated their walls with art, their home with decorative objects, when Constantine moved the capital of the empire to Byzantium, Roman art incorporated Eastern influences to produce the Byzantine style of the late empire. When Rome was sacked in the 5th century, artisans moved to, of the vast body of Roman painting we now have only a very few pockets of survivals, with many documented types not surviving at all, or doing so only from the very end of the period. A succession of dated styles have been defined and analysed by modern art historians beginning with August Mau, there are a number of other parts of painted rooms surviving from Rome and elsewhere, which somewhat help to fill in the gaps of our knowledge of wall-painting. Nothing remains of the Greek paintings imported to Rome during the 4th and 5th centuries, in sum, the range of samples is confined to only about 200 years out of the about 900 years of Roman history, and of provincial and decorative painting. Most of this painting was done using the secco method. There is evidence from mosaics and a few inscriptions that some Roman paintings were adaptations or copies of earlier Greek works
20.
Stabiae
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Stabiae was an ancient Roman town which is famous for the magnificent Roman villas found there near to the modern town of Castellammare di Stabia approximately 4.5 km southwest of Pompeii. The beautiful objects and frescoes taken from these villas were sold and distributed. The villas were sited on a 50 m high overlooking the Gulf of Naples. Being only 16 kilometres from Mount Vesuvius, this resort was largely buried by two metres of tephra ash in 79 AD. Originally a small port, by the 6th century BC Stabiae had already overshadowed by the much larger port at Pompeii. The town was destroyed by Lucius Cornelius Sulla on 30 April 89 BC during the Social War, the Roman author and admiral Pliny the Elder recorded that the town was rebuilt and became a popular resort for wealthy Romans. He reported that there were miles of luxury villas built along the edge of the headland. According to the account written by his nephew, Pliny the Elder was at the side of the bay in Misenum when the eruption started. He travelled by ship across the bay, partly to observe the eruption more closely. Pliny died at Stabiae the following day, probably during the arrival of the sixth, the very diluted outer edge of this surge reached Stabiae and left two centimetres of fine ash on top of the immensely thick aerially-deposited tephra which further protected the underlying remains. The archaeological remains of Stabiae were originally discovered in 1749 by Cavaliere Rocco de Alcubierre and these ruins were partially excavated by Alcubierre with help from Karl Weber between 1749–1782. The ruins that had been excavated, however, were reburied and their location was forgotten until 1950, the site was declared an archaeological protected area in 1957, and by 1962 many of the ruins had been again uncovered. The remains of both an Oscan settlement and the later Roman town were discovered, the most famous of the findings at Stabiae are the villas that come from the time between the destruction of Stabiae by Sulla in 89 BC and the eruption of Mount Vesuvius in 79 AD. As described above, Stabiae became a town during this time and was particularly favored for its view of the Bay of Naples. Stabiae was also known for the quality of its spring water. The ideal placement and qualities of this location drew many wealthy Romans to build villas on the ridge overlooking the bay. These villas, which are described below, provide us with some of the most stunning architectural, a great many artifacts which come from Stabiae are preserved in the Naples National Archaeological Museum. Before the age of the villas, however, an Oscan settlement existed in the region of Stabiae, in 1957 three hundred tombs dating from the 7th to the 3rd centuries BC were found in a necropolis associated with this town
21.
Sinopia
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Sinopia is a dark reddish-brown natural earth pigment, whose reddish color comes from hematite, a dehydrated form of iron oxide. It was widely used in antiquity and the Middle Ages for painting. The word came to be used both for the pigment and for the drawing itself. During the Middle Ages synopia in Latin and Italian came to simply a red ochre. It entered the English language as the word sinoper, meaning a red earth color, from Ancient times through the Renaissance, the pigment was mined in Cappadocia, and exported to Europe through the port of Sinop, a Greek colony on the Black Sea. The pigment was valued for its quality and the product was marked with a seal to show its authenticity. In the Renaissance sinopia or sinoper meant any of a range of different shades and hues, the color shown in the box above is one more recent commercial variety of the color. The Italian painter and writer Cennino Cennini described sinopia in his handbook on painting, Il libro dellarte and this pigment has a lean and dry character. It responds well to mulling, as the more it is mulled the finer it becomes and it is good for working on panel or on anconas, or walls, in fresco and in secco. And it is perfect for doing flesh or for making flesh colours for figures on walls. And work in fresco with it, sinopia was often used in the Renaissance to make the preparatory drawing for frescoes directly onto the wall, oe on the levelling coat or on the arriccio. These drawings became known simply as sinopie, the word in Italian for the pigment. Many of these drawings have been discovered and restored, and are on display in the Museum of Sinopie in Pisa, next to the cathedral, baptistry, Cennino Cennini described in detail the process by which a sinopia was made and used. First, the artist covered a wall with a layer of lime plaster. When it dried, he made his first sketch in charcoal, then he brushed off the plaster, and using a small, pointed brush and ochre pigments as thin as water and without tempera, he painted in the figures in light shades. Then he used sinopia, also without tempera, to out the noses, the eyes, the hair. When the under drawing was finished, the artist then applied a new layer of wet plaster. Before the plaster could dry, he filled in the colors into the plaster, to make the faces in the final fresco, Cennini recommended that the artist first paint them with an undercoat of brownish green, called a verdaccio
22.
Carbonatation
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Carbonatation is a slow process that occurs in concrete where lime in the cement reacts with carbon dioxide from the air and forms calcium carbonate. The water in the pores of Portland cement concrete is normally alkaline with a pH in the range of 12.5 to 13.5 and this highly alkaline environment is one in which the steel rebar is passivated and is protected from corrosion. According to the Pourbaix diagram for iron, the metal is passive when the pH is above 9.5, the carbon dioxide in the air reacts with the alkali in the cement and makes the pore water more acidic, thus lowering the pH. Carbon dioxide will start to carbonatate the cement in the concrete from the moment the object is made and this carbonatation process will start at the surface, then slowly move deeper and deeper into the concrete. The rate of carbonatation is dependent on the humidity of the concrete - a 50% relative humidity being optimal. If the object is cracked, the dioxide in the air will be better able to penetrate into the concrete. Eventually this may lead to corrosion of the rebar and structural damage or failure, the carbonatation process is used in the production of sugar from sugar beets. It involves the introduction of limewater and carbon dioxide enriched gas into the raw juice to form carbonate and precipitate impurities that are then removed. The whole process takes place in tanks and processing time varies from 20 minutes to an hour. Carbonatation involves the effects, The increase in alkalinity coagulates proteins in the juice. Calcium carbonate absorbs colourants Alkalinity destroys some monosaccharide sugars, mostly glucose and fructose The target is a particle that naturally settles rapidly to leave a clear juice. The juice at the end is approximately 15 °Bx and 90% sucrose, the pH of the thin juice produced is a balance between removing as much calcium from the solution and the expected pH drop across later processing. The carbon dioxide gas bubbled through the mixture forms calcium carbonate, the non-sugar solids are incorporated into the calcium carbonate particles and removed by natural sedimentation in tanks. There are several systems of carbonatation, named from the companies that first developed them and they differ in how the lime is introduced, the temperature and duration of each stage, and the separation of the solids from the liquid. Dorr - a continuous process using two tanks with recycling to build up particle size for natural flocculation, the recycling ratio is about 7,1. The particles are separated under gravity in a stage in a vessel called a clarifier. The clear juice is then gassed further in another tank and filtered, the concentrated mud from the clarifier is filtered and/or pressed to recover more liquid. The Dorr process is low in maintenance and man-power but susceptible to problems when frost damaged beets are processed
23.
The School of Athens
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The School of Athens is one of the most famous frescoes by the Italian Renaissance artist Raphael. It was painted between 1509 and 1511 as a part of Raphaels commission to decorate the rooms now known as the Stanze di Raffaello, the picture has long been seen as Raphaels masterpiece and the perfect embodiment of the classical spirit of the Renaissance. The School of Athens is one of a group of four main frescoes on the walls of the Stanza that depict distinct branches of knowledge, accordingly, the figures on the walls below exemplify Philosophy, Poetry, Theology, and Law. The traditional title is not Raphaels, indeed, Plato and Aristotle appear to be the central figures in the scene. However, all the philosophers depicted sought knowledge of first causes, many lived before Plato and Aristotle, and hardly a third were Athenians. The architecture contains Roman elements, but the general semi-circular setting having Plato, compounding the problem, Raphael had to invent a system of iconography to allude to various figures for whom there were no traditional visual types. For example, while the Socrates figure is immediately recognizable from Classical busts, aside from the identities of the figures depicted, many aspects of the fresco have been variously interpreted, but few such interpretations are unanimously accepted among scholars. The popular idea that the gestures of Plato and Aristotle are kinds of pointing is very likely. Aristotle, with his four-elements theory, held that all change on Earth was owing to motions of the heavens, in the painting Aristotle carries his Ethics, which he denied could be reduced to a mathematical science. Finally, according to Vasari, the scene includes Raphael himself, however, as Heinrich Wölfflin observed, it is quite wrong to attempt interpretations of the School of Athens as an esoteric treatise. The all-important thing was the motive which expressed a physical or spiritual state. An interpretation of the fresco relating to hidden symmetries of the figures, the identities of some of the philosophers in the picture, such as Plato or Aristotle, are certain. Beyond that, identifications of Raphaels figures have always been hypothetical, to complicate matters, beginning from Vasaris efforts, some have received multiple identifications, not only as ancients but also as figures contemporary with Raphael. Vasari mentions portraits of the young Federico II Gonzaga, Duke of Mantua, leaning over Bramante with his hands raised near the bottom right and he was writing over 40 years after the painting, and never knew Raphael, but no doubt reflects what was believed in his time. Many other popular identifications of portraits are very dubious, luitpold Dussler counts among those who can be identified with some certainty, Plato, Aristotle, Socrates, Pythagoras, Euclid, Ptolemy, Zoroaster, Raphael, Sodoma and Diogenes. Other identifications he holds to be more or less speculative, both figures hold modern, bound copies of their books in their left hands, while gesturing with their right. Plato holds Timaeus, Aristotle his Nicomachean Ethics, Plato is depicted as old, grey, wise-looking, and bare-foot. By contrast Aristotle, slightly ahead of him, is in manhood, handsome, well-shod and dressed with gold
24.
Basilica of Saint Francis of Assisi
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The basilica is one of the most important places of Christian pilgrimage in Italy. With its accompanying friary, Sacro Convento, the basilica is a landmark to those approaching Assisi. It has been a UNESCO World Heritage Site since 2000, the interior of the Upper Church is an important early example of the Gothic style in Italy. The range and quality of the works gives the basilica a unique importance in demonstrating the development of Italian art of this period. The Franciscan friary and the Lower and Upper Basilicas of Francis of Assisi were begun in honor of this local saint, immediately after his canonization in 1228. Simone di Pucciarello donated the land for the church, a hill at the west side of Assisi, today, this hill is called Hill of Paradise. On 16 July 1228, Francis was canonized by Pope Gregory IX in Assisi, the construction having been begun at his order, the Pope declared the church to be the property of the papacy. The church was designed by Maestro Jacopo Tedesco, who was in those days the most famous architect, the construction was supervised by Brother Elias of Cortona, one of the first followers of Saint Francis and the former Vicar General of the Order under Saint Francis. The Lower Basilica was finished in 1230, the burial place was concealed for fear that St Francis remains might be stolen and dispersed. The construction of the Upper Basilica was begun after 1239 and was completed in 1253, both churches were consecrated by Pope Innocent IV in 1253. Pope Nicholas IV, a former Minister-General of the Order of Franciscans, the Piazza del Loge, the square leading to the church, is surrounded by colonnades constructed in 1474. They housed the numerous pilgrims flocking to this church, in 1818, the remains of Saint Francis were rediscovered beneath the floor of the Lower Basilica. In the reign of Pope Pius IX the crypt was built so that the faithful visit the burial place of the saint. On 27 October 1986 and January 2002, Pope John Paul II gathered in Assisi with more than 120 representatives of different religions and Christian denominations for a World Day of Prayer for Peace. On the morning of September 26,1997, two earthquakes hit that region of Italy in rapid succession, registering 5.5 and 6.1 respectively on the Richter Scale, there was widespread devastation and many ancient buildings were destroyed or damaged. While a group of specialists and friars were inspecting the damage to the Basilica of Saint Francis, Two Franciscan friars who were among the group and two of the specialists were killed. The church was closed for two years for restoration, the collapse was filmed on tape. The church was designed by Maestro Jacopo Tedesco on two levels, each of which is consecrated as a church and they are known as the Basilica superiore, generally called The Upper Church and the Basilica inferiore, generally called The Lower Church
25.
Assisi
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Assisi is a town and comune of Italy in the Province of Perugia in the Umbria region, on the western flank of Monte Subasio. The 19th-century Saint Gabriel of Our Lady of Sorrows was also born in Assisi, around 1000 BC a wave of immigrants settled in the upper Tiber valley as far as the Adriatic Sea, and also in the neighborhood of Assisi. These were the Umbrians, living in fortified settlements on high ground. From 450 BC these settlements were taken over by the Etruscans. The Romans took control of central Italy after the Battle of Sentinum in 295 BC and they built the flourishing municipium Asisium on a series of terraces on Monte Subasio. Roman remains can still be found in Assisi, city walls, the forum, a theatre, an amphitheatre, in 1997, the remains of a Roman villa were also discovered containing several well-preserved rooms with frescoes and mosaics in a condition rarely found outside sites such as Pompei. In 238 AD Assisi was converted to Christianity by bishop Rufino, according to tradition, his remains rest in the Cathedral Church of San Rufino in Assisi. The Ostrogoths of king Totila destroyed most of the town in 545, Assisi then came under the rule of the Lombards as part of the Lombard and then Frankish Duchy of Spoleto. The thriving commune became an independent Ghibelline commune in the 11th century, the city, which had remained within the confines of the Roman walls, began to expand outside these walls in the 13th century. In this period the city was under papal jurisdiction, the city went into a deep decline through the plague of the Black Death in 1348. The city came again under papal jurisdiction under the rule of Pope Pius II, in 1569 construction was started of the Basilica of Santa Maria degli Angeli. During the Renaissance and in later centuries, the city continued to develop peacefully, as the 17th-century palazzi of the Bernabei, now the site of many a pilgrimage, Assisi is linked in legend with its native son, St. Francis. The gentle saint founded the Franciscan order and shares honors with St. Catherine of Siena as the saint of Italy. He is remembered by many, even non-Christians, as a lover of nature, Assisi was hit by two devastating earthquakes, that shook Umbria in September 1997. But the recovery and restoration have been remarkable, although much remains to be done, massive damage was caused to many historical sites, but the major attraction, the Basilica di San Francesco, reopened less than 2 years later. UNESCO collectively designated the Franciscan structures of Assisi as a World Heritage Site in 2000, the Basilica of San Francesco dAssisi. The Franciscan monastery, il Sacro Convento, and the lower and upper church of St Francis were begun immediately after his canonization in 1228, and completed in 1253. The Basilica was badly damaged by an earthquake on 26 September 1997, during part of the vault collapsed, killing four people inside the church
26.
Ancient Rome
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In its many centuries of existence, the Roman state evolved from a monarchy to a classical republic and then to an increasingly autocratic empire. Through conquest and assimilation, it came to dominate the Mediterranean region and then Western Europe, Asia Minor, North Africa and it is often grouped into classical antiquity together with ancient Greece, and their similar cultures and societies are known as the Greco-Roman world. Ancient Roman civilisation has contributed to modern government, law, politics, engineering, art, literature, architecture, technology, warfare, religion, language and society. Rome professionalised and expanded its military and created a system of government called res publica, the inspiration for modern republics such as the United States and France. By the end of the Republic, Rome had conquered the lands around the Mediterranean and beyond, its domain extended from the Atlantic to Arabia, the Roman Empire emerged with the end of the Republic and the dictatorship of Augustus Caesar. 721 years of Roman-Persian Wars started in 92 BC with their first war against Parthia and it would become the longest conflict in human history, and have major lasting effects and consequences for both empires. Under Trajan, the Empire reached its territorial peak, Republican mores and traditions started to decline during the imperial period, with civil wars becoming a prelude common to the rise of a new emperor. Splinter states, such as the Palmyrene Empire, would divide the Empire during the crisis of the 3rd century. Plagued by internal instability and attacked by various migrating peoples, the part of the empire broke up into independent kingdoms in the 5th century. This splintering is a landmark historians use to divide the ancient period of history from the pre-medieval Dark Ages of Europe. King Numitor was deposed from his throne by his brother, Amulius, while Numitors daughter, Rhea Silvia, because Rhea Silvia was raped and impregnated by Mars, the Roman god of war, the twins were considered half-divine. The new king, Amulius, feared Romulus and Remus would take back the throne, a she-wolf saved and raised them, and when they were old enough, they returned the throne of Alba Longa to Numitor. Romulus became the source of the citys name, in order to attract people to the city, Rome became a sanctuary for the indigent, exiled, and unwanted. This caused a problem for Rome, which had a large workforce but was bereft of women, Romulus traveled to the neighboring towns and tribes and attempted to secure marriage rights, but as Rome was so full of undesirables they all refused. Legend says that the Latins invited the Sabines to a festival and stole their unmarried maidens, leading to the integration of the Latins, after a long time in rough seas, they landed at the banks of the Tiber River. Not long after they landed, the men wanted to take to the sea again, one woman, named Roma, suggested that the women burn the ships out at sea to prevent them from leaving. At first, the men were angry with Roma, but they realized that they were in the ideal place to settle. They named the settlement after the woman who torched their ships, the Roman poet Virgil recounted this legend in his classical epic poem the Aeneid
27.
Pompeii
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Pompeii was an ancient Roman town-city near modern Naples, in the Campania region of Italy, in the territory of the comune of Pompei. Pompeii, along with Herculaneum and many villas in the area, was mostly destroyed and buried under 4 to 6 m of volcanic ash. Researchers believe that the town was founded in the seventh or sixth century BC by the Osci or Oscans. It came under the domination of Rome in the 4th century BC, by the time of its destruction,160 years later, its population was estimated at 11,000 people, and the city had a complex water system, an amphitheatre, gymnasium, and a port. The eruption destroyed the city, killing its inhabitants and burying it under tons of ash, the site was lost for about 1,500 years until its initial rediscovery in 1599 and broader rediscovery almost 150 years later by Spanish engineer Rocque Joaquin de Alcubierre in 1748. The objects that lay beneath the city have been preserved for centuries because of the lack of air and these artefacts provide an extraordinarily detailed insight into the life of a city during the Pax Romana. During the excavation, plaster was used to fill in the voids in the ash layers that once held human bodies and this allowed archaeologists to see the exact position the person was in when he or she died. Pompeii has been a tourist destination for over 250 years, today it has UNESCO World Heritage Site status and is one of the most popular tourist attractions in Italy, with approximately 2.5 million visitors every year. Pompeii in Latin is a second declension plural, the ruins of Pompeii are located near the modern suburban town of Pompei. It stands on a formed by a lava flow to the north of the mouth of the Sarno River. Today it is some distance inland, but in ancient times was nearer to the coast, Pompeii is about 8 km away from Mount Vesuvius. It covered a total of 64 to 67 hectares and was home to approximately 11,000 to 11,500 people on the basis of household counts and it was a major city in the region of Campania. Three sheets of sediment have been found on top of the lava that lies below the city and, mixed in with the sediment, archaeologists have found bits of bone, pottery shards. Carbon dating has placed the oldest of these layers from the 8th–6th centuries BC, the other two strata are separated either by well-developed soil layers or Roman pavement, and were laid in the 4th century BC and 2nd century BC. It is theorized that the layers of the sediment were created by large landslides. The town was founded around the 7th-6th century BC by the Osci or Oscans and it had already been used as a safe port by Greek and Phoenician sailors. According to Strabo, Pompeii was also captured by the Etruscans, and in recent excavations have shown the presence of Etruscan inscriptions. Pompeii was captured for the first time by the Greek colony of Cumae, allied with Syracuse, in the 5th century BC, the Samnites conquered it, the new rulers imposed their architecture and enlarged the town
28.
Egg as food
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Eggs are laid by female animals of many different species, including birds, reptiles, amphibians, mammals, and fish, and have been eaten by humans for thousands of years. Bird and reptile eggs consist of an eggshell, albumen. The most popular choice for egg consumption are chicken eggs, other popular choices for egg consumption are duck, quail, roe, and caviar. Egg yolks and whole eggs store significant amounts of protein and choline, due to their protein content, the United States Department of Agriculture categorizes eggs as Meats within the Food Guide Pyramid. Despite the nutritional value of eggs, there are potential health issues arising from egg quality, storage. Chickens and other egg-laying creatures are widely kept throughout the world, in 2009, an estimated 62.1 million metric tons of eggs were produced worldwide from a total laying flock of approximately 6.4 billion hens. There are issues of variation in demand and expectation, as well as current debates concerning methods of mass production. In 2012, the European Union banned battery husbandry of chickens, bird eggs have been valuable foodstuffs since prehistory, in both hunting societies and more recent cultures where birds were domesticated. The chicken was probably domesticated for its eggs before 7500 BCE, chickens were brought to Sumer and Egypt by 1500 BCE, and arrived in Greece around 800 BCE, where the quail had been the primary source of eggs. In Thebes, Egypt, the tomb of Haremhab, built about 1420 BCE, shows a depiction of a man carrying bowls of ostrich eggs and other large eggs, presumably those of the pelican, as offerings. In ancient Rome, eggs were preserved using a number of methods, the Romans crushed the shells in their plates to prevent evil spirits from hiding there. In the Middle Ages, eggs were forbidden during Lent because of their richness, the word mayonnaise possibly was derived from moyeu, the medieval French word for the yolk, meaning center or hub. Egg scrambled with acidic fruit juices were popular in France in the 17th century, the dried egg industry developed in the 19th century, before the rise of the frozen egg industry. In 1878, a company in St. Louis, Missouri started to transform egg yolk and white into a light-brown, the production of dried eggs significantly expanded during World War II, for use by the United States Armed Forces and its allies. In 1911, the egg carton was invented by Joseph Coyle in Smithers, British Columbia, early egg cartons were made of paper. Bird eggs are a food and one of the most versatile ingredients used in cooking. They are important in many branches of the food industry. The most commonly used bird eggs are those from the chicken, duck and goose eggs, and smaller eggs, such as quail eggs, are occasionally used as a gourmet ingredient in western countries
29.
Tempera
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Tempera, also known as egg tempera, is a permanent, fast-drying painting medium consisting of colored pigments mixed with a water-soluble binder medium. Tempera also refers to the paintings done in this medium, Tempera paintings are very long lasting, and examples from the 1st centuries AD still exist. Egg tempera was a method of painting until after 1500 when it was superseded by the invention of oil painting. Tempera painting has been found on early Egyptian sarcophagi decorations, many of the Fayum mummy portraits use tempera, sometimes in combination with encaustic. A related technique has been used also in ancient and early medieval paintings found in several caves, high-quality art with the help of tempera was created in Bagh Caves between the late 4th and 10th centuries AD and in the 7th century AD in Ravan Chhaya rock shelter, Orissa. Tempera painting was the panel painting medium for nearly every painter in the European Medieval. For example, every surviving panel painting by Michelangelo is egg tempera, oil paint, which may have originated in Afghanistan between the 5th and 9th centuries and migrated westward in the Middle Ages eventually superseded tempera. Oil replaced tempera as the medium used for creating artwork during the 15th century in Early Netherlandish painting in northern Europe. Around 1500, oil paint replaced tempera in Italy, in the 19th and 20th centuries, there were intermittent revivals of tempera technique in Western art, among the Pre-Raphaelites, Social Realists, and others. Tempera painting continues to be used in Greece and Russia where it is the medium for Orthodox icons. Tempera is traditionally created by hand-grinding dry powdered pigments into an agent or medium, such as egg, glue, honey, water, milk. Tempera painting starts with placing an amount of the powdered pigment onto a palette, dish or bowl and adding about an equal volume of the binder. Some pigments require slightly more binder, some require less, a few drops of distilled water are added, then the binder is added in small increments to the desired transparency. The more egg emulsion, the more transparent the paint, the most common form of classical tempera painting is egg tempera. For this form most often only the contents of the egg yolk is used, the white of the egg and the membrane of the yolk are discarded. Egg yolk is never used by itself with pigment, it dries almost immediately, some agent is always added, in variable proportions. One recipe calls for vinegar, other recipes suggest white wine, some schools of egg tempera use various mixtures of egg yolk and water. The paint mixture has to be adjusted to maintain a balance between a greasy and watery consistency by adjusting the amount of water and yolk
30.
Oil painting
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Oil painting is the process of painting with pigments with a medium of drying oil as the binder. Commonly used drying oils include linseed oil, poppy seed oil, walnut oil, the choice of oil imparts a range of properties to the oil paint, such as the amount of yellowing or drying time. Certain differences, depending on the oil, are visible in the sheen of the paints. An artist might use different oils in the same painting depending on specific pigments and effects desired. The paints themselves also develop a particular consistency depending on the medium, the oil may be boiled with a resin, such as pine resin or frankincense, to create a varnish prized for its body and gloss. Its practice may have migrated westward during the Middle Ages, Oil paint eventually became the principal medium used for creating artworks as its advantages became widely known. In recent years, water miscible oil paint has come to prominence and, to some extent, water-soluble paints contain an emulsifier that allows them to be thinned with water rather than paint thinner, and allows very fast drying times when compared with traditional oils. Traditional oil painting techniques often begin with the artist sketching the subject onto the canvas with charcoal or thinned paint, Oil paint is usually mixed with linseed oil, artist grade mineral spirits, or other solvents to make the paint thinner, faster or slower-drying. A basic rule of oil paint application is fat over lean and this means that each additional layer of paint should contain more oil than the layer below to allow proper drying. If each additional layer contains less oil, the painting will crack. This rule does not ensure permanence, it is the quality and type of oil leads to a strong. There are many media that can be used with the oil, including cold wax, resins. These aspects of the paint are closely related to the capacity of oil paint. Traditionally, paint was transferred to the surface using paintbrushes. Oil paint remains wet longer than other types of artists materials, enabling the artist to change the color. At times, the painter might even remove a layer of paint. This can be done with a rag and some turpentine for a time while the paint is wet, Oil paint dries by oxidation, not evaporation, and is usually dry to the touch within a span of two weeks. It is generally dry enough to be varnished in six months to a year, art conservators do not consider an oil painting completely dry until it is 60 to 80 years old
31.
Alkaline
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Alkalinity is the name given to the quantitative capacity of an aqueous solution to neutralize an acid. Measuring alkalinity is important in determining a streams ability to neutralize acidic pollution from rainfall or wastewater and it is one of the best measures of the sensitivity of the stream to acid inputs. There can be changes in the alkalinity of streams and rivers in response to human disturbances. Alkalinity is related to the pH of a solution, but measures a different property, roughly, the alkalinity of a solution is a measure of how strong the bases are in a solution, whereas the pH measures the amount of chemical bases. A good example is a solution, which can have many available bases despite having only a moderate pH level. Alkalinity roughly refers to the amount of bases in a solution that can be converted to uncharged species by a strong acid. The cited author, James Drever, provides an equation expressed in terms of molar equivalents, which means the number of moles of each ion type multiplied by the charge of the ion. For example,1 mole of HCO31− in solution represents 1 molar equivalent, the total charge of a solution always equals zero. On the left-hand side of the equation is the sum of conservative cations minus the sum of conservative anions, balancing this on the right side is the sum of the anions that could be neutralized by added H+ ions minus H+ ions already present, as indicated by the pH. This right side term is called total alkalinity and it is, quoting Drever, formally defined as the equivalent sum of the bases that are titratable with strong acid. The listing of ions shown on the right in Drever was mHCO3− + 2mCO32− + mB4− + mH34− + mHS− + morganic anions + mOH− - mH+, total alkalinity is measured by adding a strong acid until all the anions listed above are converted to uncharged species. The total alkalinity is not affected by temperature, pressure, or pH, though the values of individual constituents are, Drever further notes that in most natural waters, all ions except HCO3− and CO3−2 have low concentrations. Thus carbonate alkalinity, which is equal to mHCO3− + 2mCO3−2 is also equal to the total alkalinity. Alkalinity or AT measures the ability of a solution to neutralize acids to the point of carbonate or bicarbonate. The alkalinity is equal to the sum of the bases in solution. Other common natural components that can contribute to alkalinity include borate, hydroxide, phosphate, silicate, dissolved ammonia, the bases of some organic acids. Solutions produced in a laboratory may contain a virtually limitless number of bases that contribute to alkalinity, Alkalinity is usually given in the unit mEq/L. Commercially, as in the pool industry, alkalinity might also be given in parts per million of equivalent calcium carbonate
32.
Azurite
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Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits. It is also known as Chessylite after the locality at Chessy-les-Mines near Lyon. The mineral, a carbonate, has known since ancient times, and was mentioned in Pliny the Elders Natural History under the Greek name kuanos. The blue of azurite is exceptionally deep and clear, and for that reason the mineral has tended to be associated since antiquity with the blue color of low-humidity desert. Azurite is one of the two basic copper carbonate minerals, the other being bright green malachite, simple copper carbonate is not known to exist in nature. Azurite has the formula Cu322, with the copper cations linked to two different anions, carbonate and hydroxide, small crystals of azurite can be produced by rapidly stirring a few drops of copper sulfate solution into a saturated solution of sodium carbonate and allowing the solution to stand overnight. Large crystals are blue, often prismatic. Azurite specimens can be massive to nodular and they are often stalactitic in form. Specimens tend to lighten in color over time due to weathering of the surface into malachite. Azurite is soft, with a Mohs hardness of only 3.5 to 4, the specific gravity of azurite is 3.77 to 3.89. Azurite is destroyed by heat, losing carbon dioxide and water to form black, characteristic of a carbonate, specimens effervesce upon treatment with hydrochloric acid. The optical properties of such as azurite and malachite are characteristic of copper. Many coordination complexes of copper exhibit similar colors, as explained within the context of ligand field theory, the colors result from low energy d-d transitions associated with the d9 metal center. Azurite is unstable in air with respect to malachite. Azurite is also incompatible with media, such as saltwater aquariums. Azurite is not a useful pigment because it is unstable in air and it was however used as a blue pigment in antiquity. Azurite is naturally occurring in Sinai and the Eastern Desert of Egypt and it was reported by F. C. J. Depending on the degree of fineness to which it was ground and it has been known as mountain blue or Armenian stone, in addition it was formerly known as Azurro Della Magna
33.
Lapis lazuli
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Lapis lazuli, or lapis for short, is a deep blue, semi-precious stone prized since antiquity for its intense color. As early as the 7th millennium BC, lapis lazuli was mined in the Sar-i Sang mines, in Shortugai, Lapis was highly valued by the Indus Valley Civilisation. Lapis beads have been found at burials in Mehrgarh, the Caucasus. It was used in the mask of Tutankhamun. At the end of the Middle Ages, lapis lazuli began to be exported to Europe, where it was ground into powder and made into ultramarine, today, mines in northeast Afghanistan and Pakistan are still the major source of lapis lazuli. Important amounts are produced from mines west of Lake Baikal in Russia. Smaller quantities are mined in Italy, Mongolia, the United States, the name Lapis lazuli came to be associated with its color. The English word azure, French azur, Italian azzurro, Polish lazur, Romanian azur and azuriu, Portuguese and Spanish azul, the most important mineral component of lapis lazuli is lazurite, a feldspathoid silicate mineral with the formula 861-2. Most lapis lazuli also contains calcite, sodalite, and pyrite, some samples of lapis lazuli contain augite, diopside, enstatite, mica, hauynite, hornblende, nosean, and sulfur-rich löllingite geyerite. Lapis lazuli usually occurs in marble as a result of contact metamorphism. The intense blue color is due to the presence of the radical anion in the crystal. An electronic excitation of one electron from the highest doubly filled molecular orbital into the lowest singly occupied orbital results in an intense absorption line at λmax ~617 nm. Lapis lazuli is found in limestone in the Kokcha River valley of Badakhshan province in northeastern Afghanistan, Afghanistan was the source of lapis for the ancient Egyptian and Mesopotamian civilizations, as well as the later Greeks and Romans. Ancient Egyptians obtained this material through trade from Afghanistan, during the height of the Indus Valley Civilisation about 2000 BC, the Harappan colony now known as Shortugai was established near the lapis mines. In addition to the Afghan deposits, lapis is also extracted in the Andes and it is mined in smaller amounts in Angola, Argentina, Burma, Pakistan, Canada, Italy, India, and in the United States in California and Colorado. Lapis takes an excellent polish and can be made into jewelry, carvings, boxes, mosaics, ornaments, small statues, during the Renaissance, Lapis was ground and processed to make the pigment ultramarine for use in frescoes and oil painting. Its usage as a pigment in oil paint largely ended in the early 19th century when a chemically identical synthetic variety became available, Lapis lazuli is commercially synthesized or simulated by the Gilson process, which is used to make artificial ultramarine and hydrous zinc phosphates. It may also be substituted by spinel or sodalite, or by dyed jasper or howlite, Lapis lazuli has been mined in Afghanistan and exported to the Mediterranean world and South Asia since the Neolithic age
34.
Giovanni Battista Tiepolo
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Giovanni Battista Tiepolo, also known as Gianbattista or Giambattista Tiepolo, was an Italian painter and printmaker from the Republic of Venice. He was prolific, and worked not only in Italy, but also in Germany, Giovan Battista Tiepolo, together with Giambattista Pittoni, Canaletto, Giovan Battista Piazzetta, Giuseppe Maria Crespi and Francesco Guardi forms the traditional great Old Masters of that period. Successful from the beginning of his career, he has described by Michael Levey as the greatest decorative painter of eighteenth-century Europe. Born in Venice, he was the youngest of six children of Domenico and his father was a small shipping merchant who belonged to a family that bore the prestigious patrician name of Tiepolo without claiming any noble descent. Some of the children acquired noble godparents, and Giambattista was originally named after his godfather and he was baptised on 16 April 1696 in the local church, San Pietro di Castello. His father died about a later, leaving his mother to bring up a family of young children. In 1710 he became a pupil of Gregorio Lazzarini, a painter with an eclectic style. A biography of his teacher, published in 1732, says that Tiepolo departed from studied manner of painting and his earliest known works are depictions of the apostles, painted in spandrels as part of the decoration of the church of the Ospedoletto in Venice in 1715–6. He painted his first fresco in 1716, on the ceiling of a church at Biadene and he probably left Lazzarinis studio in 1717, the year he was received into the Fraglia or guild of painters. In around 1719–20 he painted a scheme of frescoes for the wealthy, Tiepolo depicted the Triumph of Aurora on the ceiling, and the Myth of Phaethon on the walls, creating the kind of fluid spatial illusion which was to become a recurring theme in his work. In 1722 he was one of twelve artists commissioned to contribute a painting on canvas of one of the apostles as part of a scheme for the nave of San Stae in Venice. The other artists involved included Ricci, Piazetta, and Pellegrini, in 1719, Tiepolo married noblewoman Maria Cecilia Guardi, sister of two contemporary Venetian painters Francesco and Giovanni Antonio Guardi. Together, Tiepolo and his wife had nine children, four daughters and three sons survived childhood. Two of his sons, Domenico and Lorenzo, painted with him as his assistants and his children painted figures with a design similar to that of their father, but with distinctive, including genre, styles. His third son became a priest, fabio Canal, Francesco Lorenzi, Domenico Pasquini were among his pupils. Some major commissions came from the patrician Dolfin family, Tiepolo used a much cooler palette than previous Venetian painters, in order to create a convincing effect of daylight. These early masterpieces, innovative amongst Venetian frescoes for their luminosity, dominic Instituting the Rosary, Palazzo Clerici, Milan, decorations for Villa Cordellini at Montecchio Maggiore and for the ballroom of the Palazzo Labia in Venice, showing the Story of Cleopatra. Tiepolo produced two sets of etchings, the Capricci and the Scherzi di fantasia, the ten capricci were first published by Anton Maria Zanetti, incorporated into the third edition of a compilation of woodcuts after Parmigiano
35.
Fourth Dynasty of Egypt
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The Fourth Dynasty of ancient Egypt is characterized as a golden age of the Old Kingdom. Dynasty IV lasted from c. 2613 to 2494 BC and it was a time of peace and prosperity as well as one during which trade with other countries is documented. Dynasties III, IV, V and VI are often combined under the title the Old Kingdom. The capital at time was Memphis. The Fourth Dynasty heralded the height of the pyramid-building age, the relative peace of the Third Dynasty allowed the Dynasty IV rulers the leisure to explore more artistic and cultural pursuits. Sneferu’s building experiments led to the evolution from the mastaba styled step pyramids to the smooth sided “true” pyramids, no other period in Egypt’s history equaled Dynasty IV’s architectural accomplishments. Each of the rulers of this dynasty commissioned at least one pyramid to serve as a tomb or cenotaph, the pharaohs of the Fourth Dynasty ruled for approximately 120 years, from c. 2613 to 2494 BC. The names in the table are taken from Dodson and Hilton and he also constructed a number of smaller step pyramids, making him the most prolific pyramid builder of the era. It is said that Sneferu had more stone and brick moved than any other pharaoh, sneferus chief wife was Hetepheres I, his half-sister and the mother of his son Khufu. His other two wives bore him more children, a well-liked ruler, Sneferu bolstered the power of the ruling family line by giving official titles and positions to relatives. He maintained control over the nobility by keeping a tight rein on lands and he conducted military excursions into Sinai, Nubia, Libya, and began trade arrangements with Lebanon for the acquisition of cedar. Surviving from this era are the records of Egyptian contact with her neighbors. They are recorded on the Palermo stone, information carved on the stone pre-dates and antedates this dynasty. Objects dating to the reign of Khafre have been found farther away, at Ebla. Khufu is the ruler who is known in Greek as Χέοψ = Cheops and his son is Khafre and his grandson is Menkaure. All of these rulers achieved lasting fame in the construction of their pyramids at Giza. In fact, recent excavations outside the Wall of the Crow by Dr. Mark Lehner have uncovered a city which seems to have housed, fed. Some records indicate that each household was responsible for providing a worker for civic projects, civic duties were not necessarily building projects, there were duties for the temples, libraries, and festivals as well, and both men and women filled some of the positions
36.
Old Kingdom of Egypt
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The term itself was coined by eighteenth-century historians and the distinction between the Old Kingdom and the Early Dynastic Period is not one which would have been recognized by Ancient Egyptians. The Old Kingdom is most commonly regarded as the period from the Third Dynasty through to the Sixth Dynasty, many Egyptologists also include the Memphite Seventh and Eighth Dynasties in the Old Kingdom as a continuation of the administration centralized at Memphis. During the Old Kingdom, the king of Egypt became a god who ruled absolutely and could demand the services. Under King Djoser, the first king of the Third Dynasty of the Old Kingdom, the capital of Egypt was moved to Memphis. A new era of building was initiated at Saqqara under his reign, King Djosers architect, Imhotep is credited with the development of building with stone and with the conception of the new architectural form—the Step Pyramid. Indeed, the Old Kingdom is perhaps best known for the number of pyramids constructed at this time as burial places for Egypts kings. For this reason, the Old Kingdom is frequently referred to as the Age of the Pyramids, the first king of the Old Kingdom was Djoser of the third dynasty, who ordered the construction of a pyramid in Memphis necropolis, Saqqara. An important person during the reign of Djoser was his vizier and it was in this era that formerly independent ancient Egyptian states became known as nomes, under the rule of the king. The former rulers were forced to assume the role of governors or otherwise work in tax collection, Egyptians in this era worshipped their king as a god, believing that he ensured the annual flooding of the Nile that was necessary for their crops. Egyptian views on the nature of time during this period held that the worked in cycles. They also perceived themselves as a specially selected people, the Old Kingdom and its royal power reached a zenith under the Fourth Dynasty, which began with Sneferu. Using more stones than any king, he built three pyramids, a now collapsed pyramid in Meidum, the Bent Pyramid at Dahshur. However, the development of the pyramid style of building was reached not at Saqqara. Sneferu was succeeded by his son, Khufu who built the Great Pyramid of Giza, after Khufus death, his sons Djedefra and Khafra may have quarrelled. The latter built the pyramid and the Sphinx in Giza. Recent reexamination of evidence has led Egyptologist Vassil Dobrev to propose that the Sphinx had been built by Djedefra as a monument to his father Khufu, alternatively, the Sphinx has been proposed to be the work of Khafra and Khufu himself. There were military expeditions into Canaan and Nubia, with Egyptian influence reaching up the Nile into what is today the Sudan, the later kings of the Fourth Dynasty were king Menkaure, who built the smallest pyramid in Giza, Shepseskaf and, perhaps, Djedefptah. The Fifth Dynasty began with Userkaf and was marked by the importance of the cult of sun god Ra
37.
Investiture of Zimri-Lim
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The Investiture of Zimri-Lim is a large colorful mural discovered at the Royal Palace of the ancient city-state of Mari in eastern Syria. The fresco, which dates back to the 18th century BC, depicts Zimri-Lim, king of Mari, the painting was discovered in situ on its original wall located opposite the grand doorway to the podium which leads to the throne room of the palace. It was discovered by French archaeologist André Parrot during excavations at Mari in 1935–1936, the painting is now displayed at the Musée du Louvre in Paris, France. The painting is composed of three vertical panels arranged symmetrically, with the two outer sections framing the central one, the middle panel is divided horizontally into two rectangular registers framed by six parallel lines of different colors. The paintings symmetry facilitates the reconstruction of the part on the left panel. The painting is said to reflect the architecture of the palace in which the mural was located. The lower register of the panel reflects the podium room in which the body of a statue of a goddess similar to the goddess Lama depicted in the mural was discovered. The statue had a vase from which water flowed. The podium room opens up to the room, where the investiture takes place. The palm trees depicted in the side panels represent actual trees that were planted in the palaces courtyard, the upper register of the middle panel is the center of the mural and depicts the solemn scene of investiture. It is composed of five people standing against a blank background, Ishtar is depicted wearing her divine crown, with weapons sprouting from her shoulders and a sickle-sword in her left hand, and presenting the king with the symbols of authority. The king is extending his hand to the goddess, while his right hand is depicted against his mouth in a symbol of prayer. On either side of the king and Ishtar stands a Lama deity, to the right stands Ninshubur, the vassal of Ishtar. The lower register is symmetrical, and symbolizes the fertility and prosperity of the reign of Zimri-Lim. It shows the goddess Lama dispensing water from a round vase, plants are shown sprouting from the vase, and fish swimming in the flowing stream. The outer panels depict a garden of palms and another tree with a red trunk. A Lama deity is standing in the garden, on side of the central scene. Three mythic animals, a lion, a sphinx and a bull with a head, are depicted each on a ground line
38.
Minoan civilization
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The Minoan civilization was an Aegean Bronze Age civilization on the island of Crete and other Aegean islands which flourished from about 2600 to 1100 BC. It preceded the Mycenaean civilization of Ancient Greece, the civilization was rediscovered at the beginning of the 20th century through the work of British archaeologist Arthur Evans. It has been described as the earliest of its kind in Europe, the term Minoan, which refers to the mythical King Minos, originally described the pottery of the period. Minos was associated in Greek mythology with the labyrinth and the Minotaur, according to Homer, Crete once had 90 cities. The Minoan period saw trade between Crete and Aegean and Mediterranean settlements, particularly the Near East, traders and artists, the Minoan cultural influence reached beyond Crete to the Cyclades, Egypts Old Kingdom, copper-bearing Cyprus, Canaan and the Levantine coast, and Anatolia. Some of its best art is preserved in the city of Akrotiri on the island of Santorini, although the Minoan language and writing systems remain undecipherable and are subjects of academic dispute, they apparently conveyed a language entirely different from the later Greek. The reason for the end of the Minoan period is unclear, theories include Mycenaean invasions from mainland Greece, the term Minoan refers to the mythical King Minos of Knossos. Its origin is debated, but it is attributed to archeologist Arthur Evans. Minos was associated in Greek mythology with the labyrinth, which Evans identified with the site at Knossos. However, Karl Hoeck had already used the title Das Minoische Kreta in 1825 for volume two of his Kreta, this appears to be the first known use of the word Minoan to mean ancient Cretan, Evans said that applied it, not invented it. Hoeck, with no idea that the archaeological Crete had existed, had in mind the Crete of mythology, although Evans 1931 claim that the term was unminted before he used it was called a brazen suggestion by Karadimas and Momigliano, he coined its archaeological meaning. Instead of dating the Minoan period, archaeologists use two systems of relative chronology, the first, created by Evans and modified by later archaeologists, is based on pottery styles and imported Egyptian artifacts. Evans system divides the Minoan period into three eras, early, middle and late. These eras are subdivided—for example, Early Minoan I, II and III, another dating system, proposed by Greek archaeologist Nicolas Platon, is based on the development of architectural complexes known as palaces at Knossos, Phaistos, Malia and Kato Zakros. Platon divides the Minoan period into pre-, proto-, neo-, the relationship between the systems in the table includes approximate calendar dates from Warren and Hankey. The Thera eruption occurred during a phase of the LM IA period. Efforts to establish the volcanic eruptions date have been controversial, the eruption is identified as a natural event catastrophic for the culture, leading to its rapid collapse. Although stone-tool evidence exists that hominins may have reached Crete as early as 130,000 years ago, evidence for the first anatomically-modern human presence dates to 10, the oldest evidence of modern human habitation on Crete are pre-ceramic Neolithic farming-community remains which date to about 7000 BC
39.
Bronze Age
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The Bronze Age is a historical period characterized by the use of bronze, proto-writing, and other early features of urban civilization. The Bronze Age is the principal period of the three-age Stone-Bronze-Iron system, as proposed in modern times by Christian Jürgensen Thomsen. An ancient civilization is defined to be in the Bronze Age either by smelting its own copper and alloying with tin, arsenic, or other metals, or by trading for bronze from production areas elsewhere. Copper-tin ores are rare, as reflected in the fact there were no tin bronzes in Western Asia before trading in bronze began in the third millennium BC. Worldwide, the Bronze Age generally followed the Neolithic period, with the Chalcolithic serving as a transition, although the Iron Age generally followed the Bronze Age, in some areas, the Iron Age intruded directly on the Neolithic. Bronze Age cultures differed in their development of the first writing, according to archaeological evidence, cultures in Mesopotamia and Egypt developed the earliest viable writing systems. The overall period is characterized by use of bronze, though the place and time of the introduction. Human-made tin bronze technology requires set production techniques, tin must be mined and smelted separately, then added to molten copper to make bronze alloy. The Bronze Age was a time of use of metals. The dating of the foil has been disputed, the Bronze Age in the ancient Near East began with the rise of Sumer in the 4th millennium BC. Societies in the region laid the foundations for astronomy and mathematics, the usual tripartite division into an Early, Middle and Late Bronze Age is not used. Instead, a division based on art-historical and historical characteristics is more common. The cities of the Ancient Near East housed several tens of thousands of people, ur in the Middle Bronze Age and Babylon in the Late Bronze Age similarly had large populations. The earliest mention of Babylonia appears on a tablet from the reign of Sargon of Akkad in the 23rd century BC, the Amorite dynasty established the city-state of Babylon in the 19th century BC. Over 100 years later, it took over the other city-states. Babylonia adopted the written Semitic Akkadian language for official use, by that time, the Sumerian language was no longer spoken, but was still in religious use. Elam was an ancient civilization located to the east of Mesopotamia, in the Old Elamite period, Elam consisted of kingdoms on the Iranian plateau, centered in Anshan, and from the mid-2nd millennium BC, it was centered in Susa in the Khuzestan lowlands. Its culture played a role in the Gutian Empire and especially during the Achaemenid dynasty that succeeded it
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Akrotiri (Santorini)
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Akrotiri is a Minoan Bronze Age settlement on the volcanic Greek island of Santorini. The settlement was destroyed in the Theran eruption about 1627 BC and buried in volcanic ash, the settlement has been suggested as a possible inspiration for Platos story of Atlantis. The site has been excavated since 1967, the earliest evidence for human habitation of Akrotiri can be traced back as early as the fifth millennium BC, when it was a small fishing and farming village. By the end of the millennium, this community developed and expanded significantly. One factor for Akrotiri’s growth may be the relations it established with other cultures in the Aegean. This all came to an end, however, in the late 17th century BC with the eruption of Thera. The excavation is named for a village situated on a hill nearby. The name of the site in antiquity is unknown, Akrotiri was buried by the massive Theran eruption in the middle of the second millennium BC, as a result, like the Roman ruins of Pompeii after it, it is remarkably well-preserved. Frescoes, pottery, furniture, advanced drainage systems and three-story buildings have been discovered at the site, the earliest excavations on Santorini were conducted by French geologist F. Fouque in 1867, after some local people found old artifacts at a quarry. Later, in 1895-1900, the digs by German archeologist Baron Friedrich Hiller von Gaertringen revealed the ruins of ancient Thera on Mesa Vouno. Also, a later, R. Zahn excavated in the locality of Potamos, near Akrotiri. Extensive modern excavation was started in 1967 by Spyridon Marinatos, Spyridon Marinatos choice of site proved to be correct, and just a few hours into the excavation, the remains of the buried city began to be discovered. The next step was to determine the extent of the city and he experimented with tunneling into the pumice, but this technique was later abandoned. Excavated artifacts have been installed in a museum distant from the site, with many objects, only a single gold object has been found, hidden beneath flooring, and no uninterred human skeletal remains have been found. This indicates that an evacuation was performed with little or no loss of life. An ambitious modern roof structure, meant to protect the site, collapsed just prior to its completion in 2005, no damage was caused to the antiquities. As a result, the site was closed to visitors until April 2012, all of the pigments used by the artists at Akrotiri for painting the frescoes look as though they are all mineral based, and thus have resulted in the great preservation of the pieces. The colors used in Theran painting includes white, yellow, red, brown, blue, as a result, often on the same fresco, the paint has penetrated the plaster in some areas but flakes off easily in others
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Aegean Sea
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The Aegean Sea is an elongated embayment of the Mediterranean Sea located between the Greek and Anatolian peninsulas, i. e. between the mainlands of Greece and Turkey. In the north, it is connected to the Marmara Sea and Black Sea by the Dardanelles, the Aegean Islands are within the sea and some bound it on its southern periphery, including Crete and Rhodes. The sea was known as Archipelago, but in English this words meaning has changed to refer to the Aegean Islands and, generally. In ancient times, there were various explanations for the name Aegean, a possible etymology is a derivation from the Greek word αἶγες – aiges = waves, hence wavy sea, cf. also αἰγιαλός, hence meaning sea-shore. The Venetians, who ruled many Greek islands in the High and Late Middle Ages, popularized the name Archipelago, in some South Slavic languages the Aegean is often called White Sea. The Aegean Sea covers about 214,000 square kilometres in area, the seas maximum depth is 3,543 metres, east of Crete. The Aegean Islands are found within its waters, with the following islands delimiting the sea on the south, Kythera, Antikythera, Crete, Kasos, Karpathos, many of the Aegean Islands, or chains of islands, are actually extensions of the mountains on the mainland. One chain extends across the sea to Chios, another extends across Euboea to Samos, the International Hydrographic Organization defines the limits of the Aegean Sea as follows, On the South. In the Dardanelles. A line joining Kum Kale and Cape Helles, the dense Mediterranean water sinks below the Black Sea inflow to a depth of 23–30 metres, then flows through the Dardanelles Strait and into the Sea of Marmara at velocities of 5–15 cm/s. The Black Sea outflow moves westward along the northern Aegean Sea, Aegean Sea Intermediate Water – Aegean Sea Intermediate Water extends from 40–50 m to 200–300 metres with temperatures ranging from 11–18 °C. Aegean Sea Bottom Water – occurring at depths below 500–1000 m with a uniform temperature. The current coastline dates back to about 4000 BC, before that time, at the peak of the last ice age sea levels everywhere were 130 metres lower, and there were large well-watered coastal plains instead of much of the northern Aegean. When they were first occupied, the islands including Milos with its important obsidian production were probably still connected to the mainland. The present coastal arrangement appeared c.7000 BC, with post-ice age sea levels continuing to rise for another 3,000 years after that, the subsequent Bronze Age civilizations of Greece and the Aegean Sea have given rise to the general term Aegean civilization. In ancient times, the sea was the birthplace of two ancient civilizations – the Minoans of Crete and the Mycenean Civilization of the Peloponnese, later arose the city-states of Athens and Sparta among many others that constituted the Athenian Empire and Hellenic Civilization. Plato described the Greeks living round the Aegean like frogs around a pond, the Aegean Sea was later invaded by the Persians and the Romans, and inhabited by the Byzantine Empire, the Bulgarians, the Venetians, the Genoese, the Seljuq Turks, and the Ottoman Empire. The Aegean was the site of the democracies, and its seaways were the means of contact among several diverse civilizations of the Eastern Mediterranean. Many of the islands in the Aegean have safe harbours and bays, in ancient times, navigation through the sea was easier than travelling across the rough terrain of the Greek mainland
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Santorini
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Santorini, classically Thera, and officially Thira, is an island in the southern Aegean Sea, about 200 km southeast of Greeces mainland. It is the largest island of a small, circular archipelago which bears the name and is the remnant of a volcanic caldera. It forms the southernmost member of the Cyclades group of islands, with an area of approximately 73 km2, the municipality of Santorini includes the inhabited islands of Santorini and Therasia and the uninhabited islands of Nea Kameni, Palaia Kameni, Aspronisi, and Christiana. The total land area is 90.623 km2, Santorini is part of the Thira regional unit. Santorini is essentially what remains after a volcanic eruption that destroyed the earliest settlements on a formerly single island. A giant central, rectangular lagoon, which measures about 12 by 7 km, is surrounded by 300 m high, the main island slopes downward to the Aegean Sea. On the fourth side, the lagoon is separated from the sea by another smaller island called Therasia. The islands principal port is Athinios, the capital, Fira, clings to the top of the cliff looking down on the lagoon. The volcanic rocks present from the prior eruptions feature olivine, and have a presence of hornblende. It is the most active volcanic centre in the South Aegean Volcanic Arc, the volcanic arc is approximately 500 km long and 20 to 40 km wide. The island is the site of one of the largest volcanic eruptions in recorded history, the Minoan eruption, another popular theory holds that the Thera eruption is the source of the legend of Atlantis. Before then, it was known as Kallístē, Strongýlē, or Thēra, the name Thera was revived in the nineteenth century as the official name of the island and its main city, but the colloquial name Santorini is still in popular use. During the Ottoman Empires domination of the Aegean Sea, the Turkish exonym for the island was Santurin or Santoron, Oia is now called a Κοινότητα, within the municipality of Thera, and it consists of the local subdivisions of Therasia and Oia. The two main sources of wealth in Santorini are agriculture and tourism, in recent years, Santorini has been voted one of the worlds most beautiful islands. Santorini remains the home of a small, but flourishing wine industry, white varieties also include Athiri and Aidani, whereas red varieties include mavrotragano and mandilaria. The Cyclades are part of a complex that is known as the Cycladic Massif. The complex formed during the Miocene and was folded and metamorphosed during the Alpine orogeny around 60 million years ago, Thera is built upon a small, non-volcanic basement that represents the former non-volcanic island, which was approximately 9 by 6 km. The basement rock is composed of metamorphosed limestone and schist
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Radiocarbon dating
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Radiocarbon dating is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed by Willard Libby in the late 1940s, Libby received the Nobel Prize for his work in 1960. The radiocarbon dating method is based on the fact that radiocarbon is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting radiocarbon combines with oxygen to form radioactive carbon dioxide. When the animal or plant dies, it stops exchanging carbon with its environment, and from that point onwards the amount of 14C it contains begins to decrease as the 14C undergoes radioactive decay. Measuring the amount of 14C in a sample from a plant or animal such as a piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died. The idea behind radiocarbon dating is straightforward, but years of work were required to develop the technique to the point where accurate dates could be obtained. Research has been ongoing since the 1960s to determine what the proportion of 14C in the atmosphere has been over the past fifty thousand years. The resulting data, in the form of a curve, is now used to convert a given measurement of radiocarbon in a sample into an estimate of the samples calendar age. Other corrections must be made to account for the proportion of 14C in different types of organisms, additional complications come from the burning of fossil fuels such as coal and oil, and from the above-ground nuclear tests done in the 1950s and 1960s. Conversely, nuclear testing increased the amount of 14C in the atmosphere, measurement of radiocarbon was originally done by beta-counting devices, which counted the amount of beta radiation emitted by decaying 14C atoms in a sample. The development of dating has had a profound impact on archaeology. In addition to permitting more accurate dating within archaeological sites than previous methods, histories of archaeology often refer to its impact as the radiocarbon revolution. Radiocarbon dating has allowed key transitions in prehistory to be dated, such as the end of the last ice age, and they synthesized 14C using the laboratorys cyclotron accelerator and soon discovered that the atoms half-life was far longer than had been previously thought. This was followed by a prediction by Serge A. Korff, then employed at the Franklin Institute in Philadelphia and it had previously been thought that 14C would be more likely to be created by deuterons interacting with 13C. At some time during World War II, Willard Libby, who was then at Berkeley, learned of Korffs research, in 1945, Libby moved to the University of Chicago where he began his work on radiocarbon dating. He published a paper in 1946 in which he proposed that the carbon in living matter might include 14C as well as non-radioactive carbon, by contrast, methane created from petroleum showed no radiocarbon activity because of its age. The results were summarized in a paper in Science in 1947, Libby and James Arnold proceeded to test the radiocarbon dating theory by analyzing samples with known ages
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Minoan eruption
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It devastated the island of Thera, including the Minoan settlement at Akrotiri and communities and agricultural areas on nearby islands and the coast of Crete with a related earthquake or tsunami. There are no clear ancient records of the eruption, which may have inspired certain Greek myths, caused turmoil in Egypt, geological evidence shows the Thera volcano erupted numerous times over several hundred thousand years before the Minoan eruption. In a repeating process, the volcano would erupt, then eventually collapse into a roughly circular seawater-filled caldera. The caldera would slowly refill with magma, building a new volcano, immediately prior to the Minoan eruption, the walls of the caldera formed a nearly continuous ring of islands with the only entrance lying between Thera and the tiny island of Aspronisi. This cataclysmic eruption was centered on an island just north of the existing island of Nea Kameni in the centre of the then-existing caldera. The northern part of the caldera was refilled by the ash and lava. With an estimated DRE in excess of 60 km3, the volume of ejecta was approximately 100 km3, if so, the eruptions Volcanic Explosivity Index was 7. The volcano ejected up to four times as much as the eruption by Krakatoa in 1883. The Thera volcanic events and subsequent ashfall probably sterilized the island, on Santorini, there is a 60 m thick layer of white tephra that overlies the soil clearly delineating the ground level prior to the eruption. This layer has three bands that indicate the different phases of the eruption. Studies have identified four major phases, and one minor precursory tephra fall. Since no human remains have been found at the Akrotiri site and it is also suggested that several months before the eruption, Santorini experienced one or more earthquakes, which damaged the local settlements. Intense magmatic activity of the first major phase of the eruption deposited up to 7 m of pumice and ash, with a minor lithic component, archaeological evidence indicated burial of man-made structures with limited damage. The second and third eruption phases involved pyroclastic flow and lava fountain activity, man-made structures not buried during Minoan A were completely destroyed. The third phase was characterized by the initiation of caldera collapse. The fourth, and last, major phase was marked by varied activity, lithic-rich base surge deposits, lahars, debris flows and this phase was characterized by the completion of caldera collapse, which produced megatsunamis. Although the fracturing process is not yet known, the statistical analysis indicates that the caldera had formed just before the eruption. The area of the island was smaller, and the southern and eastern coastlines appeared regressed, during the eruption, the landscape was covered by the pumice sediments
. PMID 10049836.
