Wool is the textile fiber obtained from sheep and other animals, including cashmere and mohair from goats, qiviut from muskoxen, from hide and fur clothing from bison, angora from rabbits, other types of wool from camelids. Wool consists of protein together with a few percent lipids. In this regard it is chemically quite distinct from the more dominant textile, cellulose. Wool is produced by follicles; these follicles are located in the upper layer of the skin called the epidermis and push down into the second skin layer called the dermis as the wool fibers grow. Follicles can be classed as either secondary follicles. Primary follicles produce three types of fiber: kemp, medullated fibers, true wool fibers. Secondary follicles only produce true wool fibers. Medullated fibers share nearly identical characteristics to hair and are long but lack crimp and elasticity. Kemp fibers are coarse and shed out. Wool's scaling and crimp make it easier to spin the fleece by helping the individual fibers attach to each other, so they stay together.
Because of the crimp, wool fabrics have greater bulk than other textiles, they hold air, which causes the fabric to retain heat. Wool has a high specific thermal resistance, so it impedes heat transfer in general; this effect has benefited desert peoples, as Tuaregs use wool clothes for insulation. Felting of wool occurs upon hammering or other mechanical agitation as the microscopic barbs on the surface of wool fibers hook together. Wool has several qualities that distinguish it from hair/fur: it is crimped and elastic; the amount of crimp corresponds to the fineness of the wool fibers. A fine wool like Merino may have up to 100 crimps per inch, while coarser wool like karakul may have as few as one or two. In contrast, hair has little if any scale and no crimp, little ability to bind into yarn. On sheep, the hair part of the fleece is called kemp; the relative amounts of kemp to wool vary from breed to breed and make some fleeces more desirable for spinning, felting, or carding into batts for quilts or other insulating products, including the famous tweed cloth of Scotland.
Wool fibers absorb moisture, but are not hollow. Wool can absorb one-third of its own weight in water. Wool absorbs sound like many other fabrics, it is a creamy white color, although some breeds of sheep produce natural colors, such as black, brown and random mixes. Wool ignites at a higher temperature than some synthetic fibers, it has a lower rate of flame spread, a lower rate of heat release, a lower heat of combustion, does not melt or drip. Wool carpets are specified for high safety environments, such as trains and aircraft. Wool is specified for garments for firefighters and others in occupations where they are exposed to the likelihood of fire. Wool causes an allergic reaction in some people. Sheep shearing is the process. After shearing, the wool is separated into four main categories: fleece, broken and locks; the quality of fleeces is determined by a technique known as wool classing, whereby a qualified person, called a wool classer, groups wools of similar gradings together to maximize the return for the farmer or sheep owner.
In Australia before being auctioned, all Merino fleece wool is objectively measured for micron, staple length, staple strength, sometimes color and comfort factor. Wool straight off a sheep, known as "greasy wool" or "wool in the grease", contains a high level of valuable lanolin, as well as the sheep's dead skin and sweat residue, also contains pesticides and vegetable matter from the animal's environment. Before the wool can be used for commercial purposes, it must be scoured, a process of cleaning the greasy wool. Scouring may be as simple as a bath in warm water or as complicated as an industrial process using detergent and alkali in specialized equipment. In north west England, special potash pits were constructed to produce potash used in the manufacture of a soft soap for scouring locally produced white wool. In commercial wool, vegetable matter is removed by chemical carbonization. In less-processed wools, vegetable matter may be removed by hand and some of the lanolin left intact through the use of gentler detergents.
This semigrease wool can be worked into yarn and knitted into water-resistant mittens or sweaters, such as those of the Aran Island fishermen. Lanolin removed from wool is used in cosmetic products, such as hand creams. Raw wool has many impurities; the sheep's body yields many types of wool with differing strengths, length of staple and impurities. The raw wool is processed into'top'.'Worsted top' requires strong straight and parallel fibres. The quality of wool is determined by its fiber diameter, yield and staple strength. Fiber diameter is the single most important wool characteristic determining price. Merino wool is 3–5 inches in length and is fine; the finest and most valuable wool comes from Merino hoggets. Wool taken from sheep produced for meat is more coarse, has fibers 1.5 to 6 in in length. Damage or breaks in the wool can occur if the sheep is stressed whil
Sister cities or twin towns are a form of legal or social agreement between towns, counties, prefectures, regions and countries in geographically and politically distinct areas to promote cultural and commercial ties. The modern concept of town twinning, conceived after the Second World War in 1947, was intended to foster friendship and understanding among different cultures and between former foes as an act of peace and reconciliation, to encourage trade and tourism. By the 2000s, town twinning became used to form strategic international business links among member cities. In the United Kingdom, the term "twin towns" is most used. In mainland Europe, the most used terms are "twin towns", "partnership towns", "partner towns", "friendship towns"; the European Commission uses the term "twinned towns" and refers to the process as "town twinning". Spain uses the term "ciudades hermanadas", which means "sister cities". Germany and the Czech Republic use Partnerstadt / miasto partnerskie / partnerské město, which translate as "partner town or city".
France uses ville jumelée, Italy has gemellaggio and comune gemellato. In the Netherlands, the term is stedenband. In Greece, the word αδελφοποίηση has been adopted. In Iceland, the terms vinabæir and vinaborgir are used. In the former Soviet Bloc, "twin towns" and "twin cities" are used, along with города-побратимы; the Americas, South Asia, Australasia use the term "sister cities" or "twin cities". In China, the term is 友好城市. Sometimes, other government bodies enter into a twinning relationship, such as the agreement between the provinces of Hainan in China and Jeju-do in South Korea; the douzelage is a town twinning association with one town from each of the member states of the European Union. Despite the term being used interchangeably, with the term "friendship city", this may mean a relationship with a more limited scope in comparison to a sister city relationship, friendship city relationships are mayor-to-mayor agreements. In recent years, the term "city diplomacy" has gained increased usage and acceptance as a strand of paradiplomacy and public diplomacy.
It is formally used in the workings of the United Cities and Local Governments and the C40 Cities Climate Leadership Group and recognised by the USC Center on Public Diplomacy. A March 2014 debate in the British House of Lords acknowledged the evolution of town twinning into city diplomacy around trade and tourism, but in culture and post-conflict reconciliation; the importance of cities developing "their own foreign economic policies on trade, foreign investment and attracting foreign talent" has been highlighted by the World Economic Forum. The earliest known town twinning in Europe was between Paderborn, Le Mans, France, in 836. Starting in 1905, Keighley in West Yorkshire, had a twinning arrangement with French communities Suresnes and Puteaux; the first recorded modern twinning agreement was between Keighley and Poix-du-Nord in Nord, France, in 1920 following the end of the First World War. This was referred to as an adoption of the French town; the practice was continued after the Second World War as a way to promote mutual understanding and cross-border projects of mutual benefit.
For example, Coventry twinned with Stalingrad and with Dresden as an act of peace and reconciliation, all three cities having been bombed during the war. The City of Bath formed an "Alkmaar Adoption committee" in March 1945, when the Dutch city was still occupied by the German Army in the final months of the war, children from each city took part in exchanges in 1945 and 1946. In 1947, Bristol Corporation sent five'leading citizens' on a goodwill mission to Hanover. Reading in 1947 was the first British town to form links with a former "enemy" city – Düsseldorf; the link still exists. Since 9 April 1956 Rome and Paris have been and reciprocally twinned with each other, following the motto: "Only Paris is worthy of Rome; the support scheme was established in 1989. In 2003 an annual budget of about €12 million was allocated to about 1,300 projects; the Council of European Municipalities and Regions works with the Commission to promote modern, high quality twinning initiatives and exchanges that involve all sections of the community.
It has launched a website dedicated to town twinning. As of 1995, the European Union had more than 7,000 bilateral relationships involving 10,000 European municipalities French and German. Public art has been used to celebrate twin town links, for instance in the form of seven mural paintings in the centre of the town of Sutton, Greater London; the five main paintings show a number of the main features of the London Borough of Sutton and its four twin towns, along with the heraldic shield of each above the other images. Each painting features a plant as a visual representation of its town's environmental awareness. In the case of Sutton this is in a separate smaller painting showing a beech tree, intended as a symbol of prosperity and from whi
Christian Democratic Union of Germany
The Christian Democratic Union of Germany is a Christian-democratic, liberal-conservative political party in Germany. It is the major catch-all party of the centre-right in German politics; the CDU forms the CDU/CSU grouping known as the Union, in the Bundestag with its Bavarian counterpart the Christian Social Union in Bavaria. The party is considered an effective successor of the Centre Party, although it has a broader base; the leader of the CDU is Annegret Kramp-Karrenbauer. She is the successor of the former party leader Angela Merkel, the current Chancellor of Germany; the CDU is a member of the Centrist Democrat International, International Democrat Union and European People's Party. Following the collapse of the Nazi dictatorship at the end of World War II, the need for a new political order in Germany was paramount. Simultaneous yet unrelated meetings began occurring throughout Germany, each with the intention of planning a Christian-democratic party; the CDU was established in Berlin on 26 June 1945 and in Rheinland and Westfalen in September of the same year.
The founding members of the CDU consisted of former members of the Centre Party, the German Democratic Party, the German National People's Party and the German People's Party. Many of these individuals, including CDU-Berlin founder Andreas Hermes, were imprisoned for the involvement in the German Resistance during the Nazi dictatorship. In the Cold War years after World War II up to the 1960s, the CDU attracted conservative, anti-communist former Nazis and Nazi collaborators into its higher ranks. A prominent anti-Nazi member was theologian Eugen Gerstenmaier, who became Acting Chairman of the Foreign Board. One of the lessons learned from the failure of the Weimar Republic was that disunity among the democratic parties allowed for the rise of the Nazi Party, it was therefore crucial to create a unified party of Christian democrats—a Christian Democratic Union. The result of these meetings was the establishment of an interconfessional party influenced by the political tradition of liberal conservatism.
The CDU experienced considerable success gaining support from the time of its creation in Berlin on 26 June 1945 until its first convention on 21 October 1950, at which Chancellor Konrad Adenauer was named the first Chairman of the party. In the beginning, it was not clear which party would be favored by the victors of World War II, but by the end of the 1940s the governments of the United States and of Britain began to lean toward the CDU and away from the Social Democratic Party of Germany; the latter was more nationalist and sought German reunification at the expense of concessions to the Soviet Union, depicting Adenauer as an instrument of both the Americans and the Vatican. The Western powers appreciated the CDU's moderation, its economic flexibility and its value as an oppositional force to the communists which appealed to European voters at the time. Adenauer was trusted by the British; the party was split over issues of rearmament within the Western alliance and German unification as a neutral state.
Adenauer staunchly outmanoeuvred some of his opponents. He refused to consider the SPD as a party of the coalition until he felt sure that they shared his anti-communist position; the principled rejection of a reunification that would alienate Germany from the Western alliance made it harder to attract Protestant voters to the party as most refugees from the former German territories east of the Oder were of that faith as were the majority of the inhabitants of East Germany. The CDU was the dominant party for the first two decades following the establishment of West Germany in 1949. Adenauer remained the party's leader until 1963, at which point the former minister of economics Ludwig Erhard replaced him; as the Free Democratic Party withdrew from the governing coalition in 1966 due to disagreements over fiscal and economic policy, Erhard was forced to resign. A grand coalition with the SPD took over government under CDU Chancellor Kurt Georg Kiesinger; the SPD gained popularity and succeeded in forming a social-liberal coalition with the FDP following the 1969 federal election, forcing the CDU out of power for the first time in their history.
The CDU continued its role as opposition until 1982, when the FDP's withdrawal from the coalition with the SPD allowed the CDU to regain power. CDU Chairman Helmut Kohl became the new Chancellor of West Germany and his CDU–FDP coalition was confirmed in the 1983 federal election. Public support for the coalition's work in the process of German reunification was reiterated in the 1990 federal election in which the CDU–FDP governing coalition experienced a clear victory. After the collapse of the East German government in 1989, Kohl—supported by the governments of the United States and reluctantly by those of France and the United Kingdom—called for German reunification. On 3 October 1990, the government of East Germany was abolished and its territory acceded to the scope of the Basic Law in place in West Germany; the East German CDU merged with its West German counterpart and elections were held for the reunified country. Although Kohl was re-elected, the party began losing much of its popularity because of an economic recession in the former GDR and increased taxes in the west.
The CDU was nonetheless able to win the 1994 federal election by a narrow margin due to an economic recovery. Kohl served as chairman until the party's electoral defeat in 1998, when he was su
Hungary is a country in Central Europe. Spanning 93,030 square kilometres in the Carpathian Basin, it borders Slovakia to the north, Ukraine to the northeast, Austria to the northwest, Romania to the east, Serbia to the south, Croatia to the southwest, Slovenia to the west. With about 10 million inhabitants, Hungary is a medium-sized member state of the European Union; the official language is Hungarian, the most spoken Uralic language in the world, among the few non-Indo-European languages to be spoken in Europe. Hungary's capital and largest city is Budapest; the territory of modern Hungary was for centuries inhabited by a succession of peoples, including Celts, Germanic tribes, West Slavs and the Avars. The foundations of the Hungarian state were established in the late ninth century CE by the Hungarian grand prince Árpád following the conquest of the Carpathian Basin, his great-grandson Stephen I ascended the throne in 1000, converting his realm to a Christian kingdom. By the 12th century, Hungary became a regional power, reaching its cultural and political height in the 15th century.
Following the Battle of Mohács in 1526, Hungary was occupied by the Ottoman Empire. It came under Habsburg rule at the turn of the 18th century, joined Austria to form the Austro–Hungarian Empire, a major European power; the Austro-Hungarian Empire collapsed after World War I, the subsequent Treaty of Trianon established Hungary's current borders, resulting in the loss of 71% of its territory, 58% of its population, 32% of ethnic Hungarians. Following the tumultuous interwar period, Hungary joined the Axis Powers in World War II, suffering significant damage and casualties. Hungary became a satellite state of the Soviet Union, which contributed to the establishment of a socialist republic spanning four decades; the country gained widespread international attention as a result of its 1956 revolution and the seminal opening of its previously-restricted border with Austria in 1989, which accelerated the collapse of the Eastern Bloc. On 23 October 1989, Hungary became a democratic parliamentary republic.
Hungary is an OECD high-income economy and has the world's 58th largest economy by PPP. It ranks 45th on the Human Development Index, owing in large part to its social security system, universal health care, tuition-free secondary education. Hungary's rich cultural history includes significant contributions to the arts, literature, sports and technology, it is the 13th most popular tourist destination in Europe, attracting 15.8 million international tourists in 2017, owing to attractions such as the largest thermal water cave system in the world, second largest thermal lake, the largest lake in Central Europe and the largest natural grasslands in Europe. Hungary's cultural and academic prominence classify it as a middle power in global affairs. Hungary joined the European Union in 2004 and has been part of the Schengen Area since 2007, it is a member of numerous international organizations, including the United Nations, NATO, WTO, World Bank, the AIIB, the Council of Europe, the Visegrád Group.
The "H" in the name of Hungary is most due to early founded historical associations with the Huns, who had settled Hungary prior to the Avars. The rest of the word comes from the Latinized form of Byzantine Greek Oungroi. According to an explanation,the Greek name was borrowed from Old Bulgarian ągrinŭ, in turn borrowed from Oghur-Turkic Onogur. Onogur was the collective name for the tribes who joined the Bulgar tribal confederacy that ruled the eastern parts of Hungary after the Avars; the Hungarian endonym is Magyarország, composed of ország. The word magyar is taken from the name of one of the seven major semi-nomadic Hungarian tribes, magyeri; the first element magy is from Proto-Ugric *mäńć-'man, person' found in the name of the Mansi people. The second element eri,'man, lineage', survives in Hungarian férj'husband', is cognate with Mari erge'son', Finnish archaic yrkä'young man'; the Roman Empire conquered the territory west of the Danube between 35 and 9 BC. From 9 BC to the end of the 4th century, Pannonia was part of the Roman Empire, located within part of Hungary's territory.
Around AD 41–54, a 500-strong cavalry unit created the settlement of Aquincum and a Roman legion of 6,000 men was stationed here by AD 89. A civil city grew in the neighbourhood of the military settlement and in AD 106 Aquincum became the focal point of the commercial life of this area and the capital city of the province of Pannonia Inferior; this area now corresponds to the Óbuda district of Budapest, with the Roman ruins now forming part of the modern Aquincum museum. Came the Huns, a Central Asian tribe who built a powerful empire. After Hunnish rule, the Germanic Ostrogoths and Gepids, the Avar Khaganate, had a presence in the Carpathian Basin. In the 9th century, East Francia, the First Bulgarian Empire and Great Moravia ruled the territory of the Carpathian Basin; the freshly unified Hungarians led by Árpád, settled in the Carpathian Basin starting in 895. According to linguistic evidence, they originated from an ancient Uralic-speaking population that inhabited the forested area between the Volga River and the Ural Mountains.
As a federation of united tribes, Hungary was established in 895, some 50 years after the division of the Carolingian Empire at the Treaty of Verdun in 843, before the unification of the Anglo-Saxon king
A factory or manufacturing plant is an industrial site consisting of buildings and machinery, or more a complex having several buildings, where workers manufacture goods or operate machines processing one product into another. Factories arose with the introduction of machinery during the Industrial Revolution when the capital and space requirements became too great for cottage industry or workshops. Early factories that contained small amounts of machinery, such as one or two spinning mules, fewer than a dozen workers have been called "glorified workshops". Most modern factories have large warehouses or warehouse-like facilities that contain heavy equipment used for assembly line production. Large factories tend to be located with access to multiple modes of transportation, with some having rail and water loading and unloading facilities. Factories may either make discrete products or some type of material continuously produced such as chemicals and paper, or refined oil products. Factories manufacturing chemicals are called plants and may have most of their equipment – tanks, pressure vessels, chemical reactors and piping – outdoors and operated from control rooms.
Oil refineries have most of their equipment outdoors. Discrete products may be final consumer goods, or parts and sub-assemblies which are made into final products elsewhere. Factories may make them from raw materials. Continuous production industries use heat or electricity to transform streams of raw materials into finished products; the term mill referred to the milling of grain, which used natural resources such as water or wind power until those were displaced by steam power in the 19th century. Because many processes like spinning and weaving, iron rolling, paper manufacturing were powered by water, the term survives as in steel mill, paper mill, etc. Max Weber considered production during ancient times as never warranting classification as factories, with methods of production and the contemporary economic situation incomparable to modern or pre-modern developments of industry. In ancient times, the earliest production limited to the household, developed into a separate endeavour independent to the place of inhabitation with production at that time only beginning to be characteristic of industry, termed as "unfree shop industry", a situation caused under the reign of the Egyptian pharaoh, with slave employment and no differentiation of skills within the slave group comparable to modern definitions as division of labour.
According to translations of Demosthenes and Herodotus, Naucratis was a, or the only, factory in the entirety of ancient Egypt. A source of 1983, states the largest factory production in ancient times was of 120 slaves within 4th century BC Athens. An article within the New York Times article dated 13 October 2011 states: "In African Cave, Signs of an Ancient Paint Factory" –... discovered at Blombos Cave, a cave on the south coast of South Africa where 100,000-year-old tools and ingredients were found with which early modern humans mixed an ochre-based paint. Although The Cambridge Online Dictionary definition of factory states: a building or set of buildings where large amounts of goods are made using machines elsewhere:... the utilization of machines presupposes social cooperation and the division of labour The first machine is stated by one source to have been traps used to assist with the capturing of animals, corresponding to the machine as a mechanism operating independently or with little force by interaction from a human, with a capacity for use with operation the same on every occasion of functioning.
The wheel was invented c. 3000 BC, the spoked wheel c. 2000 BC. The Iron Age began 1200–1000 BC. However, other sources define machinery as a means of production. Archaeology provides a date for the earliest city as 5000 BC as Tell Brak, therefore a date for cooperation and factors of demand, by an increased community size and population to make something like factory level production a conceivable necessity. According to one text the water-mill was first made in 555 A. D. by Belisarius, although according to another they were known to Pliny the Elder and Vitruvius in the first century B. C. By the time of the 4th century A. D. mills with a capacity to grind 3 tonnes of cereal an hour, a rate sufficient to meet the needs of 80,000 persons, were in use by the Roman Empire. The Venice Arsenal provides one of the first examples of a factory in the modern sense of the word. Founded in 1104 in Venice, Republic of Venice, several hundred years before the Industrial Revolution, it mass-produced ships on assembly lines using manufactured parts.
The Venice Arsenal produced nearly one ship every day and, at its height, employed 16,000 people. One of the earliest factories was John Lombe's water-powered silk mill at Derby, operational by 1721. By 1746, an integrated brass mill was working at Warmley near Bristol. Raw material went in at one end, was smelted into brass and was turned into pans, pins and other goods. Housing was provided for workers on site. Josiah Wedgwood in Staffordshire and Matthew Boulton at his Soho Manufactory were other prominent early industrialists, who employed the factory system; the factory system began widespread use somewhat when cotton spinning was mechanized. Richard Arkwright is the person credited with inventing the prototype of the modern factory. After he patented his water frame in 1769, he established Cromford Mill, in Derbyshire, England expanding the village of Cromford to accommodate the migrant workers new to the area; the factory system was a new way of organizing labour made necessary by the developm
Leather is a natural durable and flexible material created by tanning animal rawhides and skins. The most common raw material is cattle hide, it can be produced at manufacturing scales ranging from artisan to modern industrial scale. Leather is used to make a variety of articles, including footwear, automobile seats, bags, book bindings, fashion accessories, furniture, it is decorated by a wide range of techniques. The earliest record of leather artifacts dates back to 2200 BC; the leather manufacturing process is divided into three fundamental subprocesses: preparatory stages and crusting. A further subprocess, can be added into the leather process sequence, but not all leathers receive finishing; the preparatory stages are. Preparatory stages may include: soaking, liming, bating and pickling. Tanning is a process that stabilizes the proteins collagen, of the raw hide to increase the thermal and microbiological stability of the hides and skins, making it suitable for a wide variety of end applications.
The principal difference between raw and tanned hides is that raw hides dry out to form a hard, inflexible material that, when rewetted, will putrefy, while tanned material dries to a flexible form that does not become putrid when rewetted. Many tanning methods and materials exist; the typical process sees tanners load the hides into a drum and immerse them in a tank that contains the tanning "liquor". The hides soak while the drum rotates about its axis, the tanning liquor penetrates through the full thickness of the hide. Once the process achieves penetration, workers raise the liquor's pH in a process called basification, which fixes the tanning material to the leather; the more tanning material fixed, the higher the leather's hydrothermal stability and shrinkage temperature resistance. Crusting is a process that lubricates leather, it includes a coloring operation. Chemicals added during crusting must be fixed in place. Crusting culminates with a drying and softening operation, may include splitting, dyeing, whitening or other methods.
For some leathers, tanners apply a surface coating, called "finishing". Finishing operations can include oiling, buffing, polishing, glazing, or tumbling, among others. Leather can be oiled to improve its water resistance; this currying process after tanning supplements the natural oils remaining in the leather itself, which can be washed out through repeated exposure to water. Frequent oiling of leather, with mink oil, neatsfoot oil, or a similar material keeps it supple and improves its lifespan dramatically. Tanning processes differ in which chemicals are used in the tanning liquor; some common types include: Vegetable-tanned leather is tanned using tannins extracted from vegetable matter, such as tree bark prepared in bark mills. It is the oldest known method, it is supple and brown in color, with the exact shade depending on the mix of materials and the color of the skin. The color tan derives its name from the appearance of undyed vegetable-tanned leather. Vegetable-tanned leather is not stable in water.
This is a feature of oak-bark-tanned leather, exploited in traditional shoemaking. In hot water, it shrinks drastically and congeals, becoming rigid and brittle. Boiled leather is an example of this, where the leather has been hardened by being immersed in hot water, or in boiled wax or similar substances, it was used as armor after hardening, it has been used for book binding. Chrome-tanned leather, invented in 1858, is tanned using chromium other chromium salts, it is known as "wet blue" for the pale blue color of the undyed leather. The chrome tanning method takes one day to complete, making it best suited for large-scale industrial use; this is the most common method in modern use. It is more supple and pliable than vegetable-tanned leather and does not discolor or lose shape as drastically in water as vegetable-tanned. However, there are environmental concerns with this tanning method. Aldehyde-tanned leather is tanned using oxazolidine compounds, it is referred to as "wet white" due to its pale cream color.
It is the main type of "chrome-free" leather seen in shoes for infants and automobiles. Formaldehyde has been used for tanning in the past. Chamois leather is a form of aldehyde tanning that produces a porous and water-absorbent leather. Chamois leather is made using marine oils that oxidize to produce the aldehydes that tan the leather. Brain tanned leathers are made by a labor-intensive process that uses emulsified oils those of animal brains such as deer and buffalo, they are known for their exceptional washability. Alum leather is transformed using aluminium salts mixed with a variety of binders and protein sources, such as flour and egg yolk. Alum leather is not tanned. In general, leather is produced in the following grades: Top-grain leather includes the outer layer of the hide, known as the grain, which features finer, more densely packed fibers, resulting in strength and durability. Depending on thickness, it may contain some of the more fibrous under layer, known as the corium. Types of top-grain leather incl
Telecommunication is the transmission of signs, messages, writings and sounds or information of any nature by wire, optical or other electromagnetic systems. Telecommunication occurs when the exchange of information between communication participants includes the use of technology, it is transmitted either electrically over physical media, such as cables, or via electromagnetic radiation. Such transmission paths are divided into communication channels which afford the advantages of multiplexing. Since the Latin term communicatio is considered the social process of information exchange, the term telecommunications is used in its plural form because it involves many different technologies. Early means of communicating over a distance included visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, optical heliographs. Other examples of pre-modern long-distance communication included audio messages such as coded drumbeats, lung-blown horns, loud whistles. 20th- and 21st-century technologies for long-distance communication involve electrical and electromagnetic technologies, such as telegraph and teleprinter, radio, microwave transmission, fiber optics, communications satellites.
A revolution in wireless communication began in the first decade of the 20th century with the pioneering developments in radio communications by Guglielmo Marconi, who won the Nobel Prize in Physics in 1909, other notable pioneering inventors and developers in the field of electrical and electronic telecommunications. These included Charles Wheatstone and Samuel Morse, Alexander Graham Bell, Edwin Armstrong and Lee de Forest, as well as Vladimir K. Zworykin, John Logie Baird and Philo Farnsworth; the word telecommunication is a compound of the Greek prefix tele, meaning distant, far off, or afar, the Latin communicare, meaning to share. Its modern use is adapted from the French, because its written use was recorded in 1904 by the French engineer and novelist Édouard Estaunié. Communication was first used as an English word in the late 14th century, it comes from Old French comunicacion, from Latin communicationem, noun of action from past participle stem of communicare "to share, divide out.
Homing pigeons have been used throughout history by different cultures. Pigeon post had Persian roots, was used by the Romans to aid their military. Frontinus said; the Greeks conveyed the names of the victors at the Olympic Games to various cities using homing pigeons. In the early 19th century, the Dutch government used the system in Sumatra, and in 1849, Paul Julius Reuter started a pigeon service to fly stock prices between Aachen and Brussels, a service that operated for a year until the gap in the telegraph link was closed. In the Middle Ages, chains of beacons were used on hilltops as a means of relaying a signal. Beacon chains suffered the drawback that they could only pass a single bit of information, so the meaning of the message such as "the enemy has been sighted" had to be agreed upon in advance. One notable instance of their use was during the Spanish Armada, when a beacon chain relayed a signal from Plymouth to London. In 1792, Claude Chappe, a French engineer, built the first fixed visual telegraphy system between Lille and Paris.
However semaphore suffered from the need for skilled operators and expensive towers at intervals of ten to thirty kilometres. As a result of competition from the electrical telegraph, the last commercial line was abandoned in 1880. On 25 July 1837 the first commercial electrical telegraph was demonstrated by English inventor Sir William Fothergill Cooke, English scientist Sir Charles Wheatstone. Both inventors viewed their device as "an improvement to the electromagnetic telegraph" not as a new device. Samuel Morse independently developed a version of the electrical telegraph that he unsuccessfully demonstrated on 2 September 1837, his code was an important advance over Wheatstone's signaling method. The first transatlantic telegraph cable was completed on 27 July 1866, allowing transatlantic telecommunication for the first time; the conventional telephone was invented independently by Alexander Bell and Elisha Gray in 1876. Antonio Meucci invented the first device that allowed the electrical transmission of voice over a line in 1849.
However Meucci's device was of little practical value because it relied upon the electrophonic effect and thus required users to place the receiver in their mouth to "hear" what was being said. The first commercial telephone services were set-up in 1878 and 1879 on both sides of the Atlantic in the cities of New Haven and London. Starting in 1894, Italian inventor Guglielmo Marconi began developing a wireless communication using the newly discovered phenomenon of radio waves, showing by 1901 that they could be transmitted across the Atlantic Ocean; this was the start of wireless telegraphy by radio. Voice and music had little early success. World War I accelerated the development of radio for military communications. After the war, commercial radio AM broadcasting began in the 1920s and became an important mass medium for entertainment and news. World War II again accelerated development of radio for the wartime purposes of aircraft and land communication, radio navigation and radar. Development of stereo FM broadcasting of radio