A paper mill is a factory devoted to making paper from vegetable fibres such as wood pulp, old rags and other ingredients. Prior to the invention and adoption of the Fourdrinier machine and other types of paper machine that use an endless belt, all paper in a paper mill was made by hand, one sheet at a time, by specialized laborers. Historical investigations into the origin of the paper mill are complicated by differing definitions and loose terminology from modern authors: Many modern scholars use the term to refer indiscriminately to all kinds of mills, whether powered by humans, by animals or by water, their propensity to refer to any ancient paper manufacturing centre as a "mill", without further specifying its exact power drive, has increased the difficulty of identifying the efficient and important water-powered type. The use of human and animal powered mills was known to Muslim papermakers. However, evidence for water-powered paper mills is elusive among both prior to the 11th century.
The general absence of the use of water-powered paper mills in Muslim papermaking prior to the 11th century is suggested by the habit of Muslim authors at the time to call a production center not a "mill", but a "paper manufactory". Scholars have identified paper mills in Abbasid-era Baghdad in 794–795; the evidence that waterpower was applied to papermaking at this time is a matter of scholarly debate. In the Moroccan city of Fez, Ibn Battuta speaks of "400 mill stones for paper". Since Ibn Battuta does not mention the use of water-power and such a number of water-mills would be grotesquely high, the passage is taken to refer to human or animal force. An exhaustive survey of milling in Al-Andalus did not uncover water-powered paper mills, nor do the Spanish books of property distribution after the Christian reconquest refer to any. Arabic texts never use the term mill in connection with papermaking and the most thorough account of Muslim papermaking at the time, the one by the Zirid Sultan Al-Muizz ibn Badis, describes the art purely in terms of a handcraft.
Donald Hill has identified a possible reference to a water-powered paper mill in Samarkand, in the 11th-century work of the Persian scholar Abu Rayhan Biruni, but concludes that the passage is "too brief to enable us to say with certainty" that it refers to a water-powered paper mill. This is seen by Leor Halevi as evidence of Samarkand first harnessing waterpower in the production of paper, but notes that it is not known if waterpower was applied to papermaking elsewhere across the Islamic world at the time. Robert I. Burns remains sceptical, given the isolated occurrence of the reference and the prevalence of manual labour in Islamic papermaking elsewhere prior to the 13th century. Hill notes that paper mills appear in early Christian Catalan documentation from the 1150s, which may imply Islamic origins, but that hard evidence is lacking. Burns, has dismissed the case for early Catalan water-powered paper mills, after re-examination of the evidence; the identification of early hydraulic stamping mills in medieval documents from Fabriano, Italy, is completely without substance.
Clear evidence of a water-powered paper mill dates to 1282 in the Spanish Kingdom of Aragon. A decree by the Christian king Peter III addresses the establishment of a royal "molendinum", a proper hydraulic mill, in the paper manufacturing centre of Xàtiva; this early hydraulic paper mill was operated by Muslim Mudéjar in the Moorish quarter of Xàtiva, though it appears to have been resented by sections of the local Muslim papermakering community. The first permanent paper mill north of the Alps was established in Nuremberg by Ulman Stromer in 1390. From the mid-14th century onwards, European paper milling underwent a rapid improvement of many work processes; the size of a paper mill prior to the use of industrial machines was described by counting the number of vats it had. Thus, a "one vat" paper mill had only one vatman, one coucher, other laborers. By the early 20th century, paper mills sprang up around New England and the rest of the world, due to the high demand for paper. At this time, there were many world leaders of the production of paper.
During the year 1907, the Brown Company cut between 30 and 40 million acres of woodlands on their property, which extended from La Tuque, Canada to West Palm, Florida. In the 1920s Nancy Baker Tompkins represented large paper manufacturing companies, like Hammermill Paper Company, Honolulu Paper Company and Appleton Coated Paper Company to promote sales to the distributors of paper products, it was the only business of its kind in the world and was started in 1931 by Tompkins and prospered in spite of the business depression. “Log drives” were conducted on local rivers to send the logs to the mills. By the late 20th and early 21st-century, paper mills began to close and the log drives became a dying craft. Due to the addition of new machinery, many millworkers were laid off and many of the historic paper mills closed. Paper mills can be integrated mills or nonintegrated mills. Integrated mills consist of a paper mill on the same site; such mills produce paper. The modern paper mill uses large amounts of energy and wood pulp in an efficient and complex series of processes, control technology to produce a sheet of paper that can be used in diverse ways.
Modern paper machines can be 500 feet in length, produce a sheet 400 inc
Chaff called Window by the British and Düppel by the Second World War era German Luftwaffe, is a radar countermeasure in which aircraft or other targets spread a cloud of small, thin pieces of aluminium, metallized glass fibre or plastic, which either appears as a cluster of primary targets on radar screens or swamps the screen with multiple returns. Modern armed forces use chaff to distract radar-guided missiles from their targets. Most military aircraft and warships have chaff dispensing systems for self-defense. An intercontinental ballistic missile may release in its midcourse phase several independent warheads as well as penetration aids such as decoy balloons and chaff; the idea of using chaff developed independently in the United Kingdom, the United States and Japan. In 1937, British researcher Gerald Touch, while working with Robert Watson-Watt on radar, suggested that lengths of wire suspended from balloons or parachutes might overwhelm a radar system with false echoes and R. V. Jones had suggested that pieces of metal foil falling through the air might do the same.
In early 1942, a Telecommunications Research Establishment researcher named Joan Curran investigated the idea and came up with a scheme for dumping packets of aluminium strips from aircraft to generate a cloud of false echoes. An early idea was to use sheets the size of a notebook page, it was found that the most effective version was strips of black paper backed with aluminium foil 27 cm × 2 cm and packed into bundles each weighing 1 pound. The head of the TRE, A. P. Rowe, code-named the device "Window". In Germany, similar research had led to the development of Düppel; the German code name came from the estate where the first German tests with chaff took place, circa 1942. Once the British had passed the idea to the US via the Tizard Mission, Fred Whipple developed a system for dispensing strips for the USAAF, but it is not known if this was used; the systems used the same concept of small aluminium strips cut to a half of the target radar's wavelength. When hit by the radar, such lengths of metal re-radiate the signal.
Opposing defences would find it impossible to distinguish the aircraft from the echoes caused by the chaff. Other radar-confusing techniques included Mandrel and Jostle. Ignorance about the extent of knowledge of the principle in the opposing air force led planners to judge that it was too dangerous to use, since the opponent could duplicate it; the British government's leading scientific adviser, Professor Lindemann, pointed out that if the Royal Air Force used it against the Germans, the Luftwaffe would copy it and could launch a new Blitz. This caused concern in RAF Fighter Command and Anti-Aircraft Command, who managed to suppress the use of Window until July 1943, it was felt that the new generation of centimetric radars available to Fighter Command would cope with Luftwaffe retaliation. Examination of the Würzburg radar equipment brought back to the UK during Operation Biting and subsequent reconnaissance revealed to the British that all German radars were operating in no more than three frequency ranges, making them prone to jamming.
"Bomber" Harris, Commander-in-Chief of RAF Bomber Command got approval to use Window as part of Operation Gomorrah, the fire raids against Hamburg. The first aircrew trained to use Window were in 76 Squadron. Twenty-four crews were briefed on how to drop the bundles of aluminised-paper strips, one every minute through the flare chute, using a stopwatch to time them; the results proved spectacular. The radar-guided master searchlights wandered aimlessly across the sky; the anti-aircraft guns fired randomly or not at all and the night fighters, their radar displays swamped with false echoes, utterly failed to find the bomber stream. Over a week of attacks, Allied attacks devastated a vast area of Hamburg, resulting in more than 40,000 civilian deaths, with the loss of only 12 out of the 791 bombers on the first night. Squadrons had special chutes fitted to their bombers to make chaff deployment easier. Seeing this as a development that made it safer to go on operations, many crews got in as many trips as they could before the Germans found a counter-countermeasure.
Although the metal strips puzzled the German civilians at first, German scientists knew what they were - Düppel - but had refrained from using it for the same reasons as Lindemann had pointed out to the British. For over a year the curious situation arose where both sides of the conflict knew how to use chaff to jam the other side's radar but had refrained from doing for fear of their opponent replying in kind. Window rendered the ground-controlled Himmelbett fighters of the Kammhuber Line unable to track their targets in the night sky and the early UHF-band versions of the airborne intercept Lichtenstein radar useless, blinding radar-guided guns and spotlights dependent on the ground-based radar. Oberst Hajo Herrmann developed Wilde Sau to cope with the lack of accurate ground guidance and led to the formation of three new fighter wings to use the tactic, numbered JG 300, JG 301 and JG 302. Ground operators would radio-direct single-seat fighters and night fighters to areas where the concentrations of chaff were greatest (which would indicate the source o
South Africa the Republic of South Africa, is the southernmost country in Africa. It is bounded to the south by 2,798 kilometres of coastline of Southern Africa stretching along the South Atlantic and Indian Oceans. South Africa is the largest country in Southern Africa and the 25th-largest country in the world by land area and, with over 57 million people, is the world's 24th-most populous nation, it is the southernmost country on the mainland of the Eastern Hemisphere. About 80 percent of South Africans are of Sub-Saharan African ancestry, divided among a variety of ethnic groups speaking different African languages, nine of which have official status; the remaining population consists of Africa's largest communities of European and multiracial ancestry. South Africa is a multiethnic society encompassing a wide variety of cultures and religions, its pluralistic makeup is reflected in the constitution's recognition of 11 official languages, the fourth highest number in the world. Two of these languages are of European origin: Afrikaans developed from Dutch and serves as the first language of most coloured and white South Africans.
The country is one of the few in Africa never to have had a coup d'état, regular elections have been held for a century. However, the vast majority of black South Africans were not enfranchised until 1994. During the 20th century, the black majority sought to recover its rights from the dominant white minority, with this struggle playing a large role in the country's recent history and politics; the National Party imposed apartheid in 1948. After a long and sometimes violent struggle by the African National Congress and other anti-apartheid activists both inside and outside the country, the repeal of discriminatory laws began in 1990. Since 1994, all ethnic and linguistic groups have held political representation in the country's liberal democracy, which comprises a parliamentary republic and nine provinces. South Africa is referred to as the "rainbow nation" to describe the country's multicultural diversity in the wake of apartheid; the World Bank classifies South Africa as an upper-middle-income economy, a newly industrialised country.
Its economy is the second-largest in Africa, the 34th-largest in the world. In terms of purchasing power parity, South Africa has the seventh-highest per capita income in Africa; however and inequality remain widespread, with about a quarter of the population unemployed and living on less than US$1.25 a day. South Africa has been identified as a middle power in international affairs, maintains significant regional influence; the name "South Africa" is derived from the country's geographic location at the southern tip of Africa. Upon formation, the country was named the Union of South Africa in English, reflecting its origin from the unification of four separate British colonies. Since 1961, the long form name in English has been the "Republic of South Africa". In Dutch, the country was named Republiek van Zuid-Afrika, replaced in 1983 by the Afrikaans Republiek van Suid-Afrika. Since 1994, the Republic has had an official name in each of its 11 official languages. Mzansi, derived from the Xhosa noun umzantsi meaning "south", is a colloquial name for South Africa, while some Pan-Africanist political parties prefer the term "Azania".
South Africa contains human-fossil sites in the world. Archaeologists have recovered extensive fossil remains from a series of caves in Gauteng Province; the area, a UNESCO World Heritage site, has been branded "the Cradle of Humankind". The sites include one of the richest sites for hominin fossils in the world. Other sites include Gondolin Cave Kromdraai, Coopers Cave and Malapa. Raymond Dart identified the first hominin fossil discovered in Africa, the Taung Child in 1924. Further hominin remains have come from the sites of Makapansgat in Limpopo Province and Florisbad in the Free State Province, Border Cave in KwaZulu-Natal Province, Klasies River Mouth in Eastern Cape Province and Pinnacle Point and Die Kelders Cave in Western Cape Province; these finds suggest that various hominid species existed in South Africa from about three million years ago, starting with Australopithecus africanus. There followed species including Australopithecus sediba, Homo ergaster, Homo erectus, Homo rhodesiensis, Homo helmei, Homo naledi and modern humans.
Modern humans have inhabited Southern Africa for at least 170,000 years. Various researchers have located pebble tools within the Vaal River valley. Settlements of Bantu-speaking peoples, who were iron-using agriculturists and herdsmen, were present south of the Limpopo River by the 4th or 5th century CE, they displaced and absorbed the original Khoisan speakers, the Khoikhoi and San peoples. The Bantu moved south; the earliest ironworks in modern-day KwaZulu-Natal Province are believed to date from around 1050. The southernmost group was the Xhosa people, whose language incorporates certain linguistic traits from the earlier Khoisan people; the Xhosa reached the Great Fish River, in today's Eastern Cape Province. As they migrated, these larger Iron Age populations
New Zealand is a sovereign island country in the southwestern Pacific Ocean. The country geographically comprises two main landmasses—the North Island, the South Island —and around 600 smaller islands. New Zealand is situated some 2,000 kilometres east of Australia across the Tasman Sea and 1,000 kilometres south of the Pacific island areas of New Caledonia and Tonga; because of its remoteness, it was one of the last lands to be settled by humans. During its long period of isolation, New Zealand developed a distinct biodiversity of animal and plant life; the country's varied topography and its sharp mountain peaks, such as the Southern Alps, owe much to the tectonic uplift of land and volcanic eruptions. New Zealand's capital city is Wellington. Sometime between 1250 and 1300, Polynesians settled in the islands that were named New Zealand and developed a distinctive Māori culture. In 1642, Dutch explorer Abel Tasman became the first European to sight New Zealand. In 1840, representatives of the United Kingdom and Māori chiefs signed the Treaty of Waitangi, which declared British sovereignty over the islands.
In 1841, New Zealand became a colony within the British Empire and in 1907 it became a dominion. Today, the majority of New Zealand's population of 4.9 million is of European descent. Reflecting this, New Zealand's culture is derived from Māori and early British settlers, with recent broadening arising from increased immigration; the official languages are English, Māori, NZ Sign Language, with English being dominant. A developed country, New Zealand ranks in international comparisons of national performance, such as quality of life, education, protection of civil liberties, economic freedom. New Zealand underwent major economic changes during the 1980s, which transformed it from a protectionist to a liberalised free-trade economy; the service sector dominates the national economy, followed by the industrial sector, agriculture. Nationally, legislative authority is vested in an elected, unicameral Parliament, while executive political power is exercised by the Cabinet, led by the prime minister Jacinda Ardern.
Queen Elizabeth II is the country's monarch and is represented by a governor-general Dame Patsy Reddy. In addition, New Zealand is organised into 11 regional councils and 67 territorial authorities for local government purposes; the Realm of New Zealand includes Tokelau. New Zealand is a member of the United Nations, Commonwealth of Nations, ANZUS, Organisation for Economic Co-operation and Development, ASEAN Plus Six, Asia-Pacific Economic Cooperation, the Pacific Community and the Pacific Islands Forum. Dutch explorer Abel Tasman sighted New Zealand in 1642 and named it Staten Land "in honour of the States General", he wrote, "it is possible that this land joins to the Staten Land but it is uncertain", referring to a landmass of the same name at the southern tip of South America, discovered by Jacob Le Maire in 1616. In 1645, Dutch cartographers renamed the land Nova Zeelandia after the Dutch province of Zeeland. British explorer James Cook subsequently anglicised the name to New Zealand. Aotearoa is the current Māori name for New Zealand.
It is unknown whether Māori had a name for the whole country before the arrival of Europeans, with Aotearoa referring to just the North Island. Māori had several traditional names for the two main islands, including Te Ika-a-Māui for the North Island and Te Waipounamu or Te Waka o Aoraki for the South Island. Early European maps labelled the islands North and South. In 1830, maps began to use North and South to distinguish the two largest islands and by 1907 this was the accepted norm; the New Zealand Geographic Board discovered in 2009 that the names of the North Island and South Island had never been formalised, names and alternative names were formalised in 2013. This set the names as North Island or Te Ika-a-Māui, South Island or Te Waipounamu. For each island, either its English or Māori name can be used. New Zealand was one of the last major landmasses settled by humans. Radiocarbon dating, evidence of deforestation and mitochondrial DNA variability within Māori populations suggest New Zealand was first settled by Eastern Polynesians between 1250 and 1300, concluding a long series of voyages through the southern Pacific islands.
Over the centuries that followed, these settlers developed a distinct culture now known as Māori. The population was divided into iwi and hapū who would sometimes cooperate, sometimes compete and sometimes fight against each other. At some point a group of Māori migrated to Rēkohu, now known as the Chatham Islands, where they developed their distinct Moriori culture; the Moriori population was all but wiped out between 1835 and 1862 because of Taranaki Māori invasion and enslavement in the 1830s, although European diseases contributed. In 1862 only 101 survived, the last known full-blooded Moriori died in 1933; the first Europeans known to have reached New Zeala
Cambridge is a university city and the county town of Cambridgeshire, England, on the River Cam 50 miles north of London. At the United Kingdom Census 2011, its population was 123,867 including 24,506 students. Cambridge became an important trading centre during the Roman and Viking ages, there is archaeological evidence of settlement in the area as early as the Bronze Age; the first town charters were granted in the 12th century, although modern city status was not conferred until 1951. The world-renowned University of Cambridge was founded in 1209; the buildings of the university include King's College Chapel, Cavendish Laboratory, the Cambridge University Library, one of the largest legal deposit libraries in the world. The city's skyline is dominated by several college buildings, along with the spire of the Our Lady and the English Martyrs Church, the chimney of Addenbrooke's Hospital and St John's College Chapel tower. Anglia Ruskin University, which evolved from the Cambridge School of Art and the Cambridgeshire College of Arts and Technology has its main campus in the city.
Cambridge is at the heart of the high-technology Silicon Fen with industries such as software and bioscience and many start-up companies born out of the university. More than 40% of the workforce have a higher education qualification, more than twice the national average; the Cambridge Biomedical Campus, one of the largest biomedical research clusters in the world, is soon to house premises of AstraZeneca, a hotel and the relocated Papworth Hospital. The first game of association football took place at Parker's Piece; the Strawberry Fair music and arts festival and Midsummer Fair are held on Midsummer Common, the annual Cambridge Beer Festival takes place on Jesus Green. The city is adjacent to the A14 roads. Cambridge station is less than an hour from London King's Cross railway station. Settlements have existed around the Cambridge area since prehistoric times; the earliest clear evidence of occupation is the remains of a 3,500-year-old farmstead discovered at the site of Fitzwilliam College.
Archaeological evidence of occupation through the Iron Age is a settlement on Castle Hill from the 1st century BC relating to wider cultural changes occurring in southeastern Britain linked to the arrival of the Belgae. The principal Roman site is a small fort Duroliponte on Castle Hill, just northwest of the city centre around the location of the earlier British village; the fort was bounded on two sides by the lines formed by the present Mount Pleasant, continuing across Huntingdon Road into Clare Street. The eastern side followed Magrath Avenue, with the southern side running near to Chesterton Lane and Kettle's Yard before turning northwest at Honey Hill, it was converted to civilian use around 50 years later. Evidence of more widespread Roman settlement has been discovered including numerous farmsteads and a village in the Cambridge district of Newnham. Following the Roman withdrawal from Britain around 410, the location may have been abandoned by the Britons, although the site is identified as Cair Grauth listed among the 28 cities of Britain by the History of the Britons.
Evidence exists that the invading Anglo-Saxons had begun occupying the area by the end of the century. Their settlement – on and around Castle Hill – became known as Grantebrycge. Anglo-Saxon grave goods have been found in the area. During this period, Cambridge benefited from good trade links across the hard-to-travel fenlands. By the 7th century, the town was less significant and described by Bede as a "little ruined city" containing the burial site of Etheldreda. Cambridge was on the border between the East and Middle Anglian kingdoms and the settlement expanded on both sides of the river; the arrival of the Vikings was recorded in the Anglo-Saxon Chronicle in 875. Viking rule, the Danelaw, had been imposed by 878 Their vigorous trading habits caused the town to grow rapidly. During this period the centre of the town shifted from Castle Hill on the left bank of the river to the area now known as the Quayside on the right bank. After the Viking period, the Saxons enjoyed a return to power, building churches such as St Bene't's Church, merchant houses and a mint, which produced coins with the town's name abbreviated to "Grant".
In 1068, two years after his conquest of England, William of Normandy built a castle on Castle Hill. Like the rest of the newly conquered kingdom, Cambridge fell under the control of the King and his deputies; the first town charter was granted by Henry I between 1120 and 1131. It recognised the borough court; the distinctive Round Church dates from this period. In 1209, Cambridge University was founded by students escaping from hostile townspeople in Oxford; the oldest existing college, was founded in 1284. In 1349 Cambridge was affected by the Black Death. Few records survive; the town north of the river was affected being wiped out. Following further depopulation after a second national epidemic in 1361, a letter from the Bishop of Ely suggested that two parishes in Cambridge be merged as there were not enough people to fill one church. With more than a third of English clergy dying in the Black Death, four new colleges were established at the university over the following years to train new clergymen, namely Gonville Hall, Trinity Hall, Corpus Christi and Clare.
In 1382 a revised town charter effects a "diminution of the liberties that the community had enjoyed", due to Cambridge's pa
Royal Air Force
The Royal Air Force is the United Kingdom's aerial warfare force. Formed towards the end of the First World War on 1 April 1918, it is the oldest independent air force in the world. Following victory over the Central Powers in 1918 the RAF emerged as, at the time, the largest air force in the world. Since its formation, the RAF has taken a significant role in British military history. In particular, it played a large part in the Second World War where it fought its most famous campaign, the Battle of Britain; the RAF's mission is to support the objectives of the British Ministry of Defence, which are to "provide the capabilities needed to ensure the security and defence of the United Kingdom and overseas territories, including against terrorism. The RAF describes its mission statement as "... an agile and capable Air Force that, person for person, is second to none, that makes a decisive air power contribution in support of the UK Defence Mission". The mission statement is supported by the RAF's definition of air power.
Air power is defined as "the ability to project power from the air and space to influence the behaviour of people or the course of events". Today the Royal Air Force maintains an operational fleet of various types of aircraft, described by the RAF as being "leading-edge" in terms of technology; this consists of fixed-wing aircraft, including: fighter and strike aircraft, airborne early warning and control aircraft, ISTAR and SIGINT aircraft, aerial refueling aircraft and strategic and tactical transport aircraft. The majority of the RAF's rotary-wing aircraft form part of the tri-service Joint Helicopter Command in support of ground forces. Most of the RAF's aircraft and personnel are based in the UK, with many others serving on operations or at long-established overseas bases. Although the RAF is the principal British air power arm, the Royal Navy's Fleet Air Arm and the British Army's Army Air Corps deliver air power, integrated into the maritime and land environments. While the British were not the first to make use of heavier-than-air military aircraft, the RAF is the world's oldest independent air force: that is, the first air force to become independent of army or navy control.
Following publication of the "Smuts report" prepared by Jan Smuts the RAF was founded on 1 April 1918, with headquarters located in the former Hotel Cecil, during the First World War, by the amalgamation of the Royal Flying Corps and the Royal Naval Air Service. At that time it was the largest air force in the world. After the war, the service was drastically cut and its inter-war years were quiet, with the RAF taking responsibility for the control of Iraq and executing a number of minor actions in other parts of the British Empire; the RAF's naval aviation branch, the Fleet Air Arm, was founded in 1924 but handed over to Admiralty control on 24 May 1939. The RAF developed the doctrine of strategic bombing which led to the construction of long-range bombers and became its main bombing strategy in the Second World War; the RAF underwent rapid expansion prior to and during the Second World War. Under the British Commonwealth Air Training Plan of December 1939, the air forces of British Commonwealth countries trained and formed "Article XV squadrons" for service with RAF formations.
Many individual personnel from these countries, exiles from occupied Europe served with RAF squadrons. By the end of the war the Royal Canadian Air Force had contributed more than 30 squadrons to serve in RAF formations approximately a quarter of Bomber Command's personnel were Canadian. Additionally, the Royal Australian Air Force represented around nine percent of all RAF personnel who served in the European and Mediterranean theatres. In the Battle of Britain in 1940, the RAF defended the skies over Britain against the numerically superior German Luftwaffe. In what is the most prolonged and complicated air campaign in history, the Battle of Britain contributed to the delay and subsequent indefinite postponement of Hitler's plans for an invasion of the United Kingdom. In the House of Commons on 20 August, prompted by the ongoing efforts of the RAF, Prime Minister Winston Churchill eloquently made a speech to the nation, where he said "Never in the field of human conflict was so much owed by so many to so few".
The largest RAF effort during the war was the strategic bombing campaign against Germany by Bomber Command. While RAF bombing of Germany began immediately upon the outbreak of war, under the leadership of Air Chief Marshal Harris, these attacks became devastating from 1942 onward as new technology and greater numbers of superior aircraft became available; the RAF adopted night-time area bombing on German cities such as Hamburg and Dresden, developed precision bombing techniques for specific operations, such as the "Dambusters" raid by No. 617 Squadron, or the Amiens prison raid known as Operation Jericho. Following victory in the Second World War, the RAF underwent significant re-organisation, as technological advances in air warfare saw the arrival of jet fighters and bombers. During the early stages of the Cold War, one of the first major operations undertaken by the Royal Air Force was in 1948 and the Berlin Airlift, codenamed Operation Plainfire. Between 26 June and the lifting of the Russian blockade of the city on 2 May, the RAF provided 17% of the total supplies delivered du