1.
Silver
–
Silver is a metallic element with symbol Ag and atomic number 47. The symbol Ag stems from Latin argentum, derived from the Greek ὰργὀς, a soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earths crust in the pure, free form, as an alloy with gold and other metals. Most silver is produced as a byproduct of copper, gold, lead, Silver is more abundant than gold, but it is much less abundant as a native metal. Its purity is measured on a per mille basis, a 94%-pure alloy is described as 0.940 fine. As one of the seven metals of antiquity, silver has had a role in most human cultures. Silver has long valued as a precious metal. Silver metal is used in many premodern monetary systems in bullion coins, Silver is used in numerous applications other than currency, such as solar panels, water filtration, jewelry, ornaments, high-value tableware and utensils, and as an investment medium. Silver is used industrially in electrical contacts and conductors, in specialized mirrors, window coatings, Silver compounds are used in photographic film and X-rays. Dilute silver nitrate solutions and other compounds are used as disinfectants and microbiocides, added to bandages and wound-dressings, catheters. Silver is similar in its physical and chemical properties to its two neighbours in group 11 of the periodic table, copper and gold. This distinctive electron configuration, with an electron in the highest occupied s subshell over a filled d subshell. Silver is a soft, ductile and malleable transition metal. Silver crystallizes in a cubic lattice with bulk coordination number 12. Unlike metals with incomplete d-shells, metallic bonds in silver are lacking a covalent character and are relatively weak and this observation explains the low hardness and high ductility of single crystals of silver. Silver has a brilliant white metallic luster that can take a polish. Protected silver has greater optical reflectivity than aluminium at all wavelengths longer than ~450 nm, at wavelengths shorter than 450 nm, silvers reflectivity is inferior to that of aluminium and drops to zero near 310 nm. The electrical conductivity of silver is the greatest of all metals, greater even than copper, during World War II in the US,13540 tons of silver were used in electromagnets for enriching uranium, mainly because of the wartime shortage of copper
2.
White
–
White is an achromatic color, a color without hue. An incoming light to the eye that stimulates all its three types of color sensitive cone cells in nearly equal amounts results in white. White is one of the most common colors in nature, the color of sunlight, snow, milk, chalk, limestone, in many cultures white represents or signifies purity, innocence, and light, and is the symbolic opposite of black, or darkness. According to surveys in Europe and the United States, white is the color most often associated with perfection, the good, honesty, cleanliness, the beginning, the new, neutrality, and exactitude. In ancient Egypt and ancient Rome, priestesses wore white as a symbol of purity, in the Middle Ages and Renaissance a white unicorn symbolized chastity, and a white lamb sacrifice and purity, the widows of kings dressed in white rather than black as the color of mourning. It was also used in 20th century modern architecture as a symbol of modernity, simplicity. White is an important color for almost all world religions, the Pope, the head of the Roman Catholic Church, has worn white since 1566, as a symbol of purity and sacrifice. In Islam, and in the Shinto religion of Japan, it is worn by pilgrims, in Western cultures and in Japan, white is the most common color for wedding dresses, symbolizing purity and virginity. In many Asian cultures, white is also the color of mourning, the white color on television screens and computer monitors is created with the RGB color model by mixing red, green and blue light at equal intensities. The word white continues Old English hwīt, ultimately from a Common Germanic *χwītaz also reflected in OHG wîz, ON hvítr, the root is ultimately from Proto-Indo-European language *kwid-, surviving also in Sanskrit śveta to be white or bright and Slavonic světŭ light. The Icelandic word for white, hvítur, is derived from the Old Norse form of the word hvítr. Common Germanic also had the word *blankaz, borrowed into Late Latin as *blancus, the antonym of white is black. Some non-European languages have a variety of terms for white. The Inuit language has seven different words for seven different nuances of white, Japanese has six different words, depending upon brilliance or dullness, or if the color is inert or dynamic. White was one of the first colors used in art, the Lascaux Cave in France contains drawings of bulls and other animals drawn by paleolithic artists between 18,000 and 17,000 years ago. Paleolithic artists used calcite or chalk, they sometimes as a background, sometimes as a highlight, along with charcoal and red, in ancient Egypt, white was connected with the goddess Isis. The priests and priestesses of Isis dressed only in white linen, in Greece and other ancient civilizations, white was often associated with mothers milk. In Greek mythology, the chief god Zeus was nourished at the breast of the nymph Amalthea, in the Talmud, milk was one of four sacred substances, along with wine, honey, and the rose
3.
Moon
–
The Moon is an astronomical body that orbits planet Earth, being Earths only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, following Jupiters satellite Io, the Moon is second-densest satellite among those whose densities are known. The average distance of the Moon from the Earth is 384,400 km, the Moon is thought to have formed about 4.51 billion years ago, not long after Earth. It is the second-brightest regularly visible celestial object in Earths sky, after the Sun and its surface is actually dark, although compared to the night sky it appears very bright, with a reflectance just slightly higher than that of worn asphalt. Its prominence in the sky and its cycle of phases have made the Moon an important cultural influence since ancient times on language, calendars, art. The Moons gravitational influence produces the ocean tides, body tides, and this matching of apparent visual size will not continue in the far future. The Moons linear distance from Earth is currently increasing at a rate of 3.82 ±0.07 centimetres per year, since the Apollo 17 mission in 1972, the Moon has been visited only by uncrewed spacecraft. The usual English proper name for Earths natural satellite is the Moon, the noun moon is derived from moone, which developed from mone, which is derived from Old English mōna, which ultimately stems from Proto-Germanic *mǣnōn, like all Germanic language cognates. Occasionally, the name Luna is used, in literature, especially science fiction, Luna is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of our moon. The principal modern English adjective pertaining to the Moon is lunar, a less common adjective is selenic, derived from the Ancient Greek Selene, from which is derived the prefix seleno-. Both the Greek Selene and the Roman goddess Diana were alternatively called Cynthia, the names Luna, Cynthia, and Selene are reflected in terminology for lunar orbits in words such as apolune, pericynthion, and selenocentric. The name Diana is connected to dies meaning day, several mechanisms have been proposed for the Moons formation 4.51 billion years ago, and some 60 million years after the origin of the Solar System. These hypotheses also cannot account for the angular momentum of the Earth–Moon system. This hypothesis, although not perfect, perhaps best explains the evidence, eighteen months prior to an October 1984 conference on lunar origins, Bill Hartmann, Roger Phillips, and Jeff Taylor challenged fellow lunar scientists, You have eighteen months. Go back to your Apollo data, go back to computer, do whatever you have to. Dont come to our conference unless you have something to say about the Moons birth, at the 1984 conference at Kona, Hawaii, the giant impact hypothesis emerged as the most popular. Afterward there were only two groups, the giant impact camp and the agnostics. Giant impacts are thought to have been common in the early Solar System, computer simulations of a giant impact have produced results that are consistent with the mass of the lunar core and the present angular momentum of the Earth–Moon system
4.
Pearl
–
A pearl is a hard object produced within the soft tissue of a living shelled mollusk or another animal, such as a conulariid. Just like the shell of a clam, a pearl is composed of calcium carbonate. in minute crystalline form, the ideal pearl is perfectly round and smooth, but many other shapes, known as baroque pearls, can occur. The finest quality natural pearls have been valued as gemstones. Because of this, pearl has become a metaphor for something rare, fine, the most valuable pearls occur spontaneously in the wild, but are extremely rare. These wild pearls are referred to as natural pearls, cultured or farmed pearls from pearl oysters and freshwater mussels make up the majority of those currently sold. Imitation pearls are widely sold in inexpensive jewelry, but the quality of their iridescence is usually very poor and is easily distinguished from that of genuine pearls. Pearls have been harvested and cultivated primarily for use in jewelry and they have also been crushed and used in cosmetics, medicines and paint formulations. Whether wild or cultured, gem-quality pearls are almost always nacreous and iridescent, however, almost all species of shelled mollusks are capable of producing pearls of lesser shine or less spherical shape. The English word pearl comes from the French perle, originally from the Latin perna meaning leg, nacreous pearls, the best-known and most commercially significant, are primarily produced by two groups of molluskan bivalves or clams. A nacreous pearl is made from layers of nacre, by the same living process as is used in the secretion of the mother of pearl which lines the shell, natural pearls, formed without human intervention, are very rare. Cultured pearls are formed in pearl farms, using human intervention as well as natural processes, saltwater pearls can grow in several species of marine pearl oysters in the family Pteriidae. Freshwater pearls grow within certain species of mussels in the order Unionida. The unique luster of pearls depends upon the reflection, refraction, the thinner and more numerous the layers in the pearl, the finer the luster. The iridescence that pearls display is caused by the overlapping of successive layers, in addition, pearls can be dyed yellow, green, blue, brown, pink, purple, or black. The very best pearls have a metallic mirror-like luster, because pearls are made primarily of calcium carbonate, they can be dissolved in vinegar. Calcium carbonate is susceptible to even a weak acid solution because the crystals of calcium carbonate react with the acid in the vinegar to form calcium acetate. Freshwater and saltwater pearls may sometimes look quite similar, but they come from different sources, Freshwater pearls form in various species of freshwater mussels, family Unionidae, which live in lakes, rivers, ponds and other bodies of fresh water. These freshwater pearl mussels occur not only in hotter climates, most freshwater cultured pearls sold today come from China
5.
Heraldry
–
The beauty and pageantry of heraldic designs allowed them to survive the gradual abandonment of armour on the battlefield during the seventeenth century. Heraldry has been described poetically as the handmaid of history, the shorthand of history, in modern times, heraldry is used by individuals, public and private organizations, corporations, cities, towns, and regions to symbolize their heritage, achievements, and aspirations. Various symbols have been used to represent individuals or groups for thousands of years, similar emblems and devices are found in ancient Mesopotamian art of the same period, and the precursors of heraldic beasts such as the griffin can also be found. In the Bible, the Book of Numbers refers to the standards and ensigns of the children of Israel, the Greek and Latin writers frequently describe the shields and symbols of various heroes, and units of the Roman army were sometimes identified by distinctive markings on their shields. The Book of Saint Albans, compiled in 1486, declares that Christ himself was a gentleman of coat armour, the medieval heralds also devised arms for various knights and lords from history and literature. Notable examples include the toads attributed to Pharamond, the cross and martlets of Edward the Confessor, and the arms attributed to the Nine Worthies. These too are now regarded as an invention, rather than evidence of the antiquity of heraldry. The development of the modern heraldic language cannot be attributed to an individual, time. Yet no individual is depicted twice bearing the arms, nor are any of the descendants of the various persons depicted known to have borne devices resembling those in the tapestry. A Spanish manuscript from 1109 describes both plain and decorated shields, none of which appears to have been heraldic, in England, from the time of the Norman conquest, official documents had to be sealed. A notable example of an armorial seal is attached to a charter granted by Philip I, Count of Flanders. Seals from the part of the eleventh and early twelfth centuries show no evidence of heraldic symbolism. One of the earliest known examples of armory as it came to be practiced can be seen on the tomb of Geoffrey Plantagenet, Count of Anjou. An enamel, probably commissioned by Geoffreys widow between 1155 and 1160, depicts him carrying a shield decorated with six golden lions rampant. He wears a helmet adorned with another lion, and his cloak is lined in vair. A medieval chronicle states that Geoffrey was given a shield of this description when he was knighted by his father-in-law, Henry I, in 1128, but this account probably dates to about 1175. Since Henry was the son of Geoffrey Plantagenet, it seems reasonable to suppose that the adoption of lions as an emblem by Henry or his sons might have been inspired by Geoffreys shield. Richard is also credited with having originated the English crest of a lion statant and it is from this garment that the phrase coat of arms is derived
6.
Metal
–
A metal is a material that is typically hard, opaque, shiny, and has good electrical and thermal conductivity. Metals are generally malleable—that is, they can be hammered or pressed permanently out of shape without breaking or cracking—as well as fusible and ductile, about 91 of the 118 elements in the periodic table are metals, the others are nonmetals or metalloids. Some elements appear in both metallic and non-metallic forms, astrophysicists use the term metal to collectively describe all elements other than hydrogen and helium, the simplest two, in a star. The star fuses smaller atoms, mostly hydrogen and helium, to larger ones over its lifetime. In that sense, the metallicity of an object is the proportion of its matter made up of all chemical elements. Many elements and compounds that are not normally classified as metals become metallic under high pressures, the atoms of metallic substances are typically arranged in one of three common crystal structures, namely body-centered cubic, face-centered cubic, and hexagonal close-packed. In bcc, each atom is positioned at the center of a cube of eight others, in fcc and hcp, each atom is surrounded by twelve others, but the stacking of the layers differs. Some metals adopt different structures depending on the temperature, atoms of metals readily lose their outer shell electrons, resulting in a free flowing cloud of electrons within their otherwise solid arrangement. This provides the ability of metallic substances to easily transmit heat, while this flow of electrons occurs, the solid characteristic of the metal is produced by electrostatic interactions between each atom and the electron cloud. This type of bond is called a metallic bond, Metals are usually inclined to form cations through electron loss, reacting with oxygen in the air to form oxides over various timescales. Examples,4 Na + O2 →2 Na2O2 Ca + O2 →2 CaO4 Al +3 O2 →2 Al2O3, the transition metals are slower to oxidize because they form a passivating layer of oxide that protects the interior. Others, like palladium, platinum and gold, do not react with the atmosphere at all, some metals form a barrier layer of oxide on their surface which cannot be penetrated by further oxygen molecules and thus retain their shiny appearance and good conductivity for many decades. The oxides of metals are generally basic, as opposed to those of nonmetals, exceptions are largely oxides with very high oxidation states such as CrO3, Mn2O7, and OsO4, which have strictly acidic reactions. Painting, anodizing or plating metals are good ways to prevent their corrosion, however, a more reactive metal in the electrochemical series must be chosen for coating, especially when chipping of the coating is expected. Water and the two form an electrochemical cell, and if the coating is less reactive than the coatee. Metals in general have high conductivity, high thermal conductivity. Typically they are malleable and ductile, deforming under stress without cleaving, in terms of optical properties, metals are shiny and lustrous. Sheets of metal beyond a few micrometres in thickness appear opaque, although most metals have higher densities than most nonmetals, there is wide variation in their densities, lithium being the least dense solid element and osmium the densest
7.
Portuguese heraldry
–
Portuguese heraldry encompasses modern and historic heraldic achievements in Portugal and in the former Portuguese Empire. Heraldry has been in use in Portugal at least since the 12th century, most of its present general characteristics were fixed in the 16th century by the heraldic ordinances of King Manuel I of Portugal. Unlike the highly stylized and macaronic language used in the heraldry of other countries. Portuguese heraldry was born within the Iberian heraldry tradition, itself a constituent part of the Latin heraldry family, in the late 14th century it came under significant influence from English heraldry, also absorving part of its features. Portuguese heraldry then evolved autonomously, and by the 16th century had many features of its own and these reached their peak with the ordinances of King Manuel I of 1521, which defined strict heraldic rules and established the statutes for the officers of arms. Heraldry declined in Portugal from the 17th to the 19th century, however, in the late 19th century, and especially in the 20th, it had a strong revival, mainly driven by the high development of the civic, corporate and military heraldries. However, Portuguese heraldry departs from tradition in that almost all armorial bearings are granted with a crest. Additionally, it is characterized by the rarity of the granting of armorial bearings that include supporters, with the beginning of the Age of Discovery in the 15th century, many coats of arms came to include charges related to Portuguese overseas expansion. These included padrões, ships, flags and weapons, Moor and African heads, exotic animals, another feature of Portuguese heraldry is that when an achievement of arms includes a coronet, it is represented over the helm - when it is represented - and not below it. In Portuguese heraldry works, it is common to represent family coats of arms without the helmets, with the respective torses and crests seating directly on the shields. Since the very early, the round bottom shield has been the preferred shape to display the coat of arms in Portugal, causing this shape to often be referred as the Portuguese shield. In 1911, it was adopted as the shield shape for the national coat of arms. Womens coats of arms are represented in a lozenge, with the single exception of those of the Portuguese queens. The Portuguese system of heraldic cadency originates in the regulations of King Manuel I and these regulations state that the head of a lineage, whether royal or common, is the only person to have the right to bear the full arms of the lineage without defacement. No other person can bear such full and undifferentiated arms, not even the heir apparent of the lineage. The system of cadency for the family has the same features of similar systems of other European countries. However, the system of cadency of non-royal lineages is unlike any other, although it is true that the brisure personalizes the arms, in Portugal anyone is entitled to choose their surname and coat of arms from any of ancestors, not necessarily the same ancestor for both. It was common for Portuguese monarchs to grant augmentations of honour to the achievements of arms as a reward or recognition to their bearers
8.
Portugal
–
Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. It is the westernmost country of mainland Europe, to the west and south it is bordered by the Atlantic Ocean and to the east and north by Spain. The Portugal–Spain border is 1,214 kilometres long and considered the longest uninterrupted border within the European Union, the republic also includes the Atlantic archipelagos of the Azores and Madeira, both autonomous regions with their own regional governments. The territory of modern Portugal has been settled, invaded. The Pre-Celts, Celts, Carthaginians and the Romans were followed by the invasions of the Visigothic, in 711 the Iberian Peninsula was invaded by the Moors, making Portugal part of Muslim Al Andalus. Portugal was born as result of the Christian Reconquista, and in 1139, Afonso Henriques was proclaimed King of Portugal, in the 15th and 16th centuries, Portugal established the first global empire, becoming one of the worlds major economic, political and military powers. Portugal monopolized the trade during this time, and the Portuguese Empire expanded with military campaigns led in Asia. After the 1910 revolution deposed the monarchy, the democratic but unstable Portuguese First Republic was established, democracy was restored after the Portuguese Colonial War and the Carnation Revolution in 1974. Shortly after, independence was granted to almost all its overseas territories, Portugal has left a profound cultural and architectural influence across the globe and a legacy of over 250 million Portuguese speakers today. Portugal is a country with a high-income advanced economy and a high living standard. It is the 5th most peaceful country in the world, maintaining a unitary semi-presidential republican form of government and it has the 18th highest Social Progress in the world, putting it ahead of other Western European countries like France, Spain and Italy. Portugal is a pioneer when it comes to drug decriminalization, as the nation decriminalized the possession of all drugs for use in 2001. The early history of Portugal is shared with the rest of the Iberian Peninsula located in South Western Europe, the name of Portugal derives from the joined Romano-Celtic name Portus Cale. Other influences include some 5th-century vestiges of Alan settlements, which were found in Alenquer, Coimbra, the region of present-day Portugal was inhabited by Neanderthals and then by Homo sapiens, who roamed the border-less region of the northern Iberian peninsula. These were subsistence societies that, although they did not establish prosperous settlements, neolithic Portugal experimented with domestication of herding animals, the raising of some cereal crops and fluvial or marine fishing. Chief among these tribes were the Calaicians or Gallaeci of Northern Portugal, the Lusitanians of central Portugal, the Celtici of Alentejo, a few small, semi-permanent, commercial coastal settlements were also founded in the Algarve region by Phoenicians-Carthaginians. Romans first invaded the Iberian Peninsula in 219 BC, during the last days of Julius Caesar, almost the entire peninsula had been annexed to the Roman Republic. The Carthaginians, Romes adversary in the Punic Wars, were expelled from their coastal colonies and it suffered a severe setback in 150 BC, when a rebellion began in the north
9.
Portuguese Air Force
–
The Portuguese Air Force is the aerial warfare force of Portugal. Locally, it is referred to by the acronym FAP, and it is the youngest of the three branches of the Portuguese Armed Forces. The Portuguese Air Force was formed on July 1,1952, the CEMFA is the only officer in the Air Force with the rank of general. Presently, the FAP is a professional force made of career personnel. As 2015, the FAP employed a total of 5957 military personnel, the Air Force further included 842 civilian employees. Besides its warfare role, the FAP has also public service roles, namely assuring the Portuguese Air Search, until 2014, the FAP also integrated the National Aeronautical Authority. The AAN is now a body, but continues to be headed by the Chief of Staff of the Air Force, with the Air Force assuring most of its activities. Its aerobatic display teams are the Asas de Portugal jet aircraft display team, the remote origins of the Portuguese Air Force lay in the origins of the Portuguese military aeronautics. Portugal was directly linked with the history of the aeronautics since its early beginnings, in 1709, the Portuguese priest Bartolomeu de Gusmão requested a patent for a device to move through the air, which consisted in a kind of hot air balloon. The patent was granted on the 19 April 1709 and small models of this device were tested with success in several occasions. Accordingly, with some opinions, a real device would have performed a crewed flight over Lisbon, taking off from the São Jorge Castle. This may have been the first manned flight in history, the AeCP becomes one of the major boosters of the development of the aviation in Portugal in the early 20th century, including of its military use. Despite the previous use of balloons by the Portuguese Army, its first air unit was created in 1911. This unit was the Aerostation Company, which was part of the Army Telegraphic Service and was intended to operate observation aerostats and this unit would later receive a handful of airplanes. In 1912, the Portuguese Government receives its first airplane, a Deperdussin B, the Government further receives a Maurice Farman MF4 offered by the O Comércio do Porto newspaper and an Avro 500 offered by the Portuguese Republican Party. These aircraft would be integrated in the Aerostation Company, but remained years without use because of the inexistence of pilots, still in 1912, midshipman Miguel Freitas Homem of the naval purser branch applied for admission to any course that would qualify him as an aviator. He was so the first so the first member of the Portuguese Military to formally request to be an aircraft pilot. In the same year, by request of the AeCP, the legislator António José de Almeida presents a bill to the Portuguese Parliament for the creation of a Military Aviation Institute
10.
Oxford University Press
–
Oxford University Press is the largest university press in the world, and the second oldest after Cambridge University Press. It is a department of the University of Oxford and is governed by a group of 15 academics appointed by the known as the delegates of the press. They are headed by the secretary to the delegates, who serves as OUPs chief executive, Oxford University has used a similar system to oversee OUP since the 17th century. The university became involved in the print trade around 1480, and grew into a printer of Bibles, prayer books. OUP took on the project became the Oxford English Dictionary in the late 19th century. Moves into international markets led to OUP opening its own offices outside the United Kingdom, by contracting out its printing and binding operations, the modern OUP publishes some 6,000 new titles around the world each year. OUP was first exempted from United States corporation tax in 1972, as a department of a charity, OUP is exempt from income tax and corporate tax in most countries, but may pay sales and other commercial taxes on its products. The OUP today transfers 30% of its surplus to the rest of the university. OUP is the largest university press in the world by the number of publications, publishing more than 6,000 new books every year, the Oxford University Press Museum is located on Great Clarendon Street, Oxford. Visits must be booked in advance and are led by a member of the archive staff, displays include a 19th-century printing press, the OUP buildings, and the printing and history of the Oxford Almanack, Alice in Wonderland and the Oxford English Dictionary. The first printer associated with Oxford University was Theoderic Rood, the first book printed in Oxford, in 1478, an edition of Rufinuss Expositio in symbolum apostolorum, was printed by another, anonymous, printer. Famously, this was mis-dated in Roman numerals as 1468, thus apparently pre-dating Caxton, roods printing included John Ankywylls Compendium totius grammaticae, which set new standards for teaching of Latin grammar. After Rood, printing connected with the university remained sporadic for over half a century, the chancellor, Robert Dudley, 1st Earl of Leicester, pleaded Oxfords case. Some royal assent was obtained, since the printer Joseph Barnes began work, Oxfords chancellor, Archbishop William Laud, consolidated the legal status of the universitys printing in the 1630s. Laud envisaged a unified press of world repute, Oxford would establish it on university property, govern its operations, employ its staff, determine its printed work, and benefit from its proceeds. To that end, he petitioned Charles I for rights that would enable Oxford to compete with the Stationers Company and the Kings Printer and these were brought together in Oxfords Great Charter in 1636, which gave the university the right to print all manner of books. Laud also obtained the privilege from the Crown of printing the King James or Authorized Version of Scripture at Oxford and this privilege created substantial returns in the next 250 years, although initially it was held in abeyance. The Stationers Company was deeply alarmed by the threat to its trade, under this, the Stationers paid an annual rent for the university not to exercise its full printing rights – money Oxford used to purchase new printing equipment for smaller purposes
11.
Book
–
A book is a set of written, printed, illustrated, or blank sheets, made of paper, parchment, or other materials, fastened together to hinge at one side, with text and/or images printed in ink. A single sheet within a book is a leaf, and each side of a leaf is a page, a set of text-filled or illustrated pages produced in electronic format for reading on a computer screen, smartphone or e-reader device is known as an electronic book, or e-book. The term books may refer the body of works of literature. In library and information science, a book is called a monograph, to distinguish it from serial periodicals such as magazines, journals, in novels and sometimes other types of books, a book may be divided into several large sections, also called books. An avid reader or collector of books or a lover is a bibliophile or colloquially. A shop where books are bought and sold is a bookshop or bookstore, Books are also sold in some department stores, drugstores and newspaper vendors. Books can also be borrowed from libraries, google has estimated that as of 2010, approximately 130,000,000 distinct titles had been published. In some wealthier nations, printed books are giving way to the usage of electronic or e-books, the word book comes from Old English bōc, which in turn comes from the Germanic root *bōk-, cognate to beech. Similarly, in Slavic languages буква is cognate with beech, in Russian and in Serbian and Macedonian, the word букварь or буквар refers specifically to a primary school textbook that helps young children master the techniques of reading and writing. It is thus conjectured that the earliest Indo-European writings may have been carved on beech wood, similarly, the Latin word codex, meaning a book in the modern sense, originally meant block of wood. When writing systems were created in ancient civilizations, a variety of objects, such as stone, clay, tree bark, metal sheets, the study of such inscriptions forms a major part of history. The study of inscriptions is known as epigraphy, the Ancient Egyptians would often write on papyrus, a plant grown along the Nile River. At first the words were not separated from other and there was no punctuation. Texts were written right to left, left to right. The technical term for that last type of writing is boustrophedon, a tablet might be defined as a physically robust writing medium, suitable for casual transport and writing. See also stylus, the instrument used to write on a tablet, clay tablets were flattened and mostly dry pieces of clay that could be easily carried, and impressed with a stylus. They were used as a medium, especially for writing in cuneiform, throughout the Bronze Age. Tablets were used by traders to record sales of such as bushels of grain
