Dover Castle is a medieval castle in Dover, England. It was founded in the 11th century and has been described as the "Key to England" due to its defensive significance throughout history, it is the largest castle in England. This site may have been fortified with earthworks in the Iron Age or earlier, before the Romans invaded in AD43; this is suggested on the basis of the unusual pattern of the earthworks which does not seem to be a perfect fit for the medieval castle. Excavations have provided evidence of Iron Age occupation within the locality of the castle, but it is not certain whether this is associated with the hillfort; the site contains one of Dover's two Roman lighthouses, one of only three surviving Roman-era lighthouses in the world, the most complete standing Roman structure in England. Built in the early 2nd century, the 5-level 8-sided tower was made of layers of tufa, Kentish ragstone, red bricks; the castle lighthouse survived after being converted into a belfry in the Saxon era, having a new upper layer added, was renovated in 1913-1915.
The remains of the other are located across the town of Dover. After the Battle of Hastings in October 1066, William the Conqueror and his forces marched to Westminster Abbey for his coronation, they took a roundabout route via Romney, Canterbury and Berkshire. From the Cinque Ports foundation in 1050, Dover has always been a chief member—it may have been this that first attracted William's attention, got Kent the motto of Invicta. In the words of William of Poitiers: Then he marched to Dover, reported impregnable and held by a large force; the English, stricken with fear at his approach had confidence neither in their ramparts nor in the numbers of their troops... While the inhabitants were preparing to surrender unconditionally, greedy for money, set the castle on fire and the great part of it was soon enveloped in flames... having taken possession of the castle, the Duke spent eight days adding new fortifications to it'. The Castle was first built out of clay, it collapsed to the ground and the clay was used as the flooring for many of the ground-floor rooms.
In 1088, eight knights were appointed under tenures to guard Dover Castle, their names were: William d'Albrincis. It was during the reign of Henry II; the inner and outer baileys and the great keep belong to this time. Maurice the Engineer was responsible for building the keep. From 1179 to 1188, the King spent over £6,500 on the castle, an enormous sum, considering that his annual revenue was around £10,000. In 1216, during the First Barons' War, a group of rebel barons invited the future Louis VIII of France to come and take the English crown, he had some success breaching the walls, but was unable to take the castle. The vulnerable north gate, breached in the siege was converted into an underground forward-defence complex, new gates built into the outer curtain wall on the western and eastern sides. During the siege, the English defenders attacked the French. During the time of Stephen de Pencester, a windmill was erected on Tower 22, known as the Mill Tower. By the Tudor age, the defences themselves had been superseded by gunpowder.
They were improved by Henry VIII, who made a personal visit, added to it with the Moat Bulwark. During the English Civil War it was held for the king but taken by a Parliamentarian trick without a shot being fired in 1642. Dover Castle was a crucial observation point for the cross-channel sightings of the Anglo-French Survey, which used trigonometric calculations to link the Royal Greenwich Observatory with the Paris Observatory; this work was overseen by General William Roy. Massive rebuilding took place at the end of the 18th century during the Napoleonic Wars. William Twiss, the Commanding Engineer of the Southern District, as part of his brief to improve the town's defences, completed the remodelling of the outer defences of Dover Castle adding the huge Horseshoe, Hudson's, East Arrow and East Demi-Bastions to provide extra gun positions on the eastern side, constructing the Constable's Bastion for additional protection on the west. Twiss further strengthened the Spur at the northern end of the castle, adding a redan, or raised gun platform.
By taking the roof off the keep and replacing it with massive brick vaults he was able to mount heavy artillery on the top. Twiss constructed Canon's Gateway to link the defences of the castle with those of the town. With Dover becoming a garrison town, there was a need for barracks and storerooms for the additional troops and their equipment; the solution adopted by Twiss and the Royal Engineers was to create a complex of barracks tunnels about 15 metres below the cliff top and the first troops were accommodated in 1803. The windmill on the Mill Tower was demolished during the Anglo-American War of the orders of the Ordnance Board, it was said that the sale of materials from the demolished mill did not cover the cost of the demolition. At the end of the Napoleonic Wars, the tunnels were converted and used by the Coast Blockade Service to combat smuggling; this was a short-term endeavour though, in 1827 the headquarters were moved closer to shore. The tunnels remained abandoned for more than a century.
The outbreak of the Second World War in 1939 saw the tunnels converted first into an ai
Pas-de-Calais is a department in northern France named after the French designation of the Strait of Dover, which it borders. Inhabited since prehistoric times, the Pas-de-Calais region was populated in turn by the Celtic Belgae, the Romans, the Germanic Franks and the Alemanni. During the fourth and fifth centuries, the Roman practice of co-opting Germanic tribes to provide military and defence services along the route from Boulogne-sur-Mer to Cologne created a Germanic-Romance linguistic border in the region that persisted until the eighth century. Saxon colonization into the region from the fifth to the eighth centuries extended the linguistic border somewhat south and west so that by the ninth century most inhabitants north of the line between Béthune and Berck spoke a dialect of Middle Dutch, while the inhabitants to the south spoke Picard, a variety of Romance dialects; this linguistic border is still evident today in the patronyms of the region. Beginning in the ninth century, the linguistic border began a steady move to north and the east, by the end of the 15th century Romance dialects had displaced those of Dutch.
Pas-de-Calais is one of the original 83 departments created during the French Revolution on 4 March 1790. It was created from parts of the former provinces of Calaisis English, Boulonnais and Artois, this last part of the Spanish Netherlands; some of the costliest battles of World War I were fought in the region. The Canadian National Vimy Memorial, eight kilometres from Arras, commemorates the Battle of Vimy Ridge assault during the Battle of Arras and is Canada's most important memorial in Europe to its fallen soldiers. Pas-de-Calais was the target of Operation Fortitude during World War II, an Allied plan to deceive the Germans that the invasion of Europe at D-Day was to occur here, rather than in Normandy. Pas-de-Calais is in the current region of Hauts-de-France and is surrounded by the departments of Nord and Somme, the English Channel, the North Sea, it shares a nominal border with the English county of Kent halfway through the Channel Tunnel. Its principal towns are, on the coast, Boulogne-sur-Mer and Étaples, in Artois, Lens, Liévin and Saint-Omer.
The principal rivers are the following: Authie Canche Ternoise Liane Sensée Scarpe Deûle Lys Aa The economy of the department was long dependent on mining the coal mines near the town of Lens, Pas-de-Calais where coal was discovered in 1849. However, since World War II, the economy has become more diversified; the inhabitants of the department are called Pas-de-Calaisiens. Pas-de-Calais is one of the most densely populated departments of France, yet it has no large cities. Calais has only about 80,000 inhabitants, followed by Arras, Boulogne-sur-Mer, Lens and Liévin; the remaining population is concentrated along the border with the department of Nord in the mining district, where a string of small towns constitutes an urban area with a population of about 1.2 million. The centre and south of the department are more rural, but still quite populated, with many villages and small towns. Although the department saw some of the heaviest fighting of World War I, its population rebounded after both world wars.
However, many of the mining towns have seen dramatic decreases in population, some up to half of their population. In the second round of the French presidential elections of 2017 Pas-de-Calais was one of only two departments in which the candidate of the Front National, Marine Le Pen, received a majority of the votes cast: 52.05%. There are two public universities in the department. Although it is one of the most populous departments of France, Pas-de-Calais did not contain a university until 1991 when the French government created two universities: ULCO on the western part of the department, Université d'Artois on the eastern part. Cantons of the Pas-de-Calais department Communes of the Pas-de-Calais department Arrondissements of the Pas-de-Calais department Battle of Vimy Ridge 7 Valleys Pas de Calais A whole wiki about the Pas-de-Calais Prefecture website General Council website Official Tourist website Short regional tourism guide Coats of arms of the municipalities in Pas-de-Calais
Trigonometry is a branch of mathematics that studies relationships between side lengths and angles of triangles. The field emerged in the Hellenistic world during the 3rd century BC from applications of geometry to astronomical studies. In particular, 3rd-century astronomers first noted that the ratio of the lengths of two sides of a right-angled triangle depends only of one acute angles of the triangle; these dependencies are now called trigonometric functions. Trigonometry is the foundation of all applied geometry, including geodesy, celestial mechanics, solid mechanics, navigation. Trigonometric functions have been extended as functions of a real or complex variable, which are today pervasive in all mathematics. Sumerian astronomers studied angle measure. They, the Babylonians, studied the ratios of the sides of similar triangles and discovered some properties of these ratios but did not turn that into a systematic method for finding sides and angles of triangles; the ancient Nubians used a similar method.
In the 3rd century BC, Hellenistic mathematicians such as Euclid and Archimedes studied the properties of chords and inscribed angles in circles, they proved theorems that are equivalent to modern trigonometric formulae, although they presented them geometrically rather than algebraically. In 140 BC, Hipparchus gave the first tables of chords, analogous to modern tables of sine values, used them to solve problems in trigonometry and spherical trigonometry. In the 2nd century AD, the Greco-Egyptian astronomer Ptolemy constructed detailed trigonometric tables in Book 1, chapter 11 of his Almagest. Ptolemy used chord length to define his trigonometric functions, a minor difference from the sine convention we use today. Centuries passed before more detailed tables were produced, Ptolemy's treatise remained in use for performing trigonometric calculations in astronomy throughout the next 1200 years in the medieval Byzantine and Western European worlds; the modern sine convention is first attested in the Surya Siddhanta, its properties were further documented by the 5th century Indian mathematician and astronomer Aryabhata.
These Greek and Indian works were expanded by medieval Islamic mathematicians. By the 10th century, Islamic mathematicians were using all six trigonometric functions, had tabulated their values, were applying them to problems in spherical geometry; the Persian polymath Nasir al-Din al-Tusi has been described as the creator of trigonometry as a mathematical discipline in its own right. Nasīr al-Dīn al-Tūsī was the first to treat trigonometry as a mathematical discipline independent from astronomy, he developed spherical trigonometry into its present form, he listed the six distinct cases of a right-angled triangle in spherical trigonometry, in his On the Sector Figure, he stated the law of sines for plane and spherical triangles, discovered the law of tangents for spherical triangles, provided proofs for both these laws. Knowledge of trigonometric functions and methods reached Western Europe via Latin translations of Ptolemy's Greek Almagest as well as the works of Persian and Arab astronomers such as Al Battani and Nasir al-Din al-Tusi.
One of the earliest works on trigonometry by a northern European mathematician is De Triangulis by the 15th century German mathematician Regiomontanus, encouraged to write, provided with a copy of the Almagest, by the Byzantine Greek scholar cardinal Basilios Bessarion with whom he lived for several years. At the same time, another translation of the Almagest from Greek into Latin was completed by the Cretan George of Trebizond. Trigonometry was still so little known in 16th-century northern Europe that Nicolaus Copernicus devoted two chapters of De revolutionibus orbium coelestium to explain its basic concepts. Driven by the demands of navigation and the growing need for accurate maps of large geographic areas, trigonometry grew into a major branch of mathematics. Bartholomaeus Pitiscus was the first to use the word, publishing his Trigonometria in 1595. Gemma Frisius described for the first time the method of triangulation still used today in surveying, it was Leonhard Euler who incorporated complex numbers into trigonometry.
The works of the Scottish mathematicians James Gregory in the 17th century and Colin Maclaurin in the 18th century were influential in the development of trigonometric series. In the 18th century, Brook Taylor defined the general Taylor series. If one angle of a triangle is 90 degrees and one of the other angles is known, the third is thereby fixed, because the three angles of any triangle add up to 180 degrees; the two acute angles therefore add up to 90 degrees: they are complementary angles. The shape of a triangle is determined, except for similarity, by the angles. Once the angles are known, the ratios of the sides are determined, regardless of the overall size of the triangle. If the length of one of the sides is known, the other two are determined; these ratios are given by the following trigonometric functions of the known angle A, where a, b and c refer to the lengths of the sides in the accompanying figure: Sine function, defined as the ratio of the side opposite the angle to the hypotenuse.
Sin A = opposite hypotenuse = a c. Cosine funct
Major-General William Roy FRS, FSA FRSE was a Scottish military engineer and antiquarian. He was an innovator who applied new scientific discoveries and newly emerging technologies to the accurate geodetic mapping of Great Britain, his masterpiece is referred to as Roy's Map of Scotland. It was Roy's advocacy and leadership that led to the creation of the Ordnance Survey in 1791, the year after his death, his technical work in the establishment of a surveying baseline won him the Copley Medal in 1785. His maps and drawings of Roman archaeological sites in Scotland were the first accurate and systematic study of the subject, have not been improved upon today. Roy was a member of the Society of Antiquaries of London. Lee Dictionary of National Biography. Close The early years of the Ordnance Survey. First published in 1924. Includes some of Roy's letters. Hewitt Map of a Nation: a biography of the Ordnance Survey. Owen & Pilbeam Ordnance Survey, map makers to Britain since 1791. Available online. Seymour A History of the Ordnance Survey.
The official account. References to original papers. Available online. Porter History of the Corps of Royal Engineers. Available online. Roy was born at Milton Head in Carluke parish in South Lanarkshire on 4 May 1726, his father was a factor in the service of the Gordons/Hamiltons of Hallcraig, as well as an elder of the Kirk. His grandfather had held a similar position as factor, his uncle acted in that capacity for the Lockharts of Lee, thus Roy grew up in an environment where making land surveys and using maps was part of the daily business. He was educated in Carluke parish school and Lanark Grammar School. There is no record of a further education such as that enjoyed by his younger brother James; the next few years of his life are poorly documented. Owen and Pilbeam claim that "Some time after 1738 he moved to Edinburgh and gained experience of surveying and making plans as a civilian draughtsman at the office of the Board of Ordnance at Edinburgh Castle." It is possible that he may have been employed there as a boy because it was normal procedure for the board to employ "cadets" aged ten or eleven who were trained to become civilian surveyors and draughtsmen.
Roy was associated with the board by 1746, for he was the author of an official map of Culloden made soon after the battle. As an employee of the board he would have come to notice of Lieutenant-Colonel David Watson, Deputy Quartermaster-General of the Military District of North Britain for the board, whose headquarters was in Edinburgh; the terms of Roy's employment are unknown but must have some opportunity to undertake private surveys for he was reported as a respected land surveyor employed by the Callander family at their Craigforth estate near Stirling prior to his work for the military. Roy maintained his connections to the people living there. A servant for the Lockharts of Lee recalled his visits there over time, as his national reputation grew, she noted that at first he would dine in the servants hall, in years he would dine with the family, still he would be seated at the right hand of the Laird. In 1747 Lieutenant-Colonel David Watson, Deputy Quartermaster-General, proposed the compilation of a map of the Scottish Highlands to facilitate the subjugation of the clans following the Jacobite rising of 1745.
In response, King George II commissioned a military survey of the Highlands, Watson was placed in charge, under the command of the Duke of Cumberland, but it fell to Roy "to begin, afterwards to have a considerable share in, the execution of that map", now known as The Duke of Cumberland's Map. Roy was without any military rank at this time but Watson appointed him as an assistant to the quartermaster to provide him some seniority over the group of six soldiers who travelled with him: an NCO, two end markers, two chainmen and a batman. From 1749 he was joined by another five junior surveyors for various periods of time: notable among these young assistants were Paul Sandby renowned for his watercolour landscapes, a seventeen-year-old David Dundas Commander-in-Chief of the armed forces. There were six teams conducting surveys by traverses of the country with the objects to the side of the line recorded by sketches and compass directions; the Highlands were covered by 1752, but the survey was extended to the lowlands for another three years, until 1755, when most of the engineer surveyors were posted to war stations.
In the introduction to the 1885 account of the measurement of the Hounslow baseline Roy writes that the map remained "in an unfinished state... and is to be considered as a magnificent military sketch rather than a accurate map of a country... it would have been completed, many of its imperfections no doubt remedied, but for the breaking out of war in 1755." The eighty-four original field sheets and the thirty-eight divisions of the "fair-protraction"are held in the British Museum together with a small index map and a reduced map of the whole country in a single sheet published as "the King's map". It is now possible to view the map online. Throughout the Survey of Scotland, Roy was a civilian assistant to David Watson the deputy quartermaster-general, but in 1755 the survey was terminated by the outbreak of the Seven Years' War with France and the consequent redeployment of personnel to more pressing posts in both the regular army and the Board of Ordnance. In the same year the engineers of the board were formed into the Corps of Engineers.
The board officers were members of both structures, for they would be deployed with the army regi
Cap Gris-Nez is a cape on the Côte d'Opale in the Pas-de-Calais département in northern France. It is in the commune of Audinghen; the cliffs of the cape are the closest point of France to England – 34 km from their English counterparts at Dover. Smothered in sea pinks and thrift, the cliffs are a perfect vantage point to see hundreds of ships, from oil tankers to little fishing trawlers, plying the waters below. On a clear day, the emblematic white cliffs of Dover on the English shore can be seen. Grisnez means "grey nose" in English, it derives from colloquial Dutch Grizenesse "grey cape". The element -nesse is cognate to English -ness, denoting "headland", as in for example Sheerness; the cliffs of Cap Gris-Nez are made of sandstone and chalk. They are grey which gives the cape its name, it is a good place to collect fossils, which are from the Jurassic period. One can find bivalves and wood. In the sandstone layers with small pebbles, one can find teeth of fish and reptiles. Sometimes larger ammonites are found in the sandstones.
The cape is a regular stopover for millions of migratory birds. The proximity of the cape to England led to the frequent destruction of the nearby village of Audinghen in wars between England and France. On the top of the cliff are the ruins of an English fortress, built by Henry VIII at the beginning of the 16th century; the English called a translation of the Dutch name Swartenisse. Napoleonic WarsNapoleon stopped at the cape on 1 July 1803 whilst making an inspection of the coast around Boulogne-sur-Mer and of his invasion troops, he envisioned setting up a cross-Channel optical telegraph, with a semaphore on the cape. The first semaphore of this line was installed on the cape in 1805, without waiting for the planned French invasion of England. On 18 July 1805, a memorable naval battle took place off the cape. A British flotilla with strong numerical superiority pursued Dutch ships that were following the coast and trying to get back into harbour of Ambleteuse. Expecting an attack of this type, Napoleon had stationed a battery of 300 guns on the cape, a barrage from this force obliged the British vessels to withdraw.
World War IICommandant Ducuing and his men died on May 25, 1940 while defending the semaphore, a commemorative stela was placed on the cape to commemorate this sacrifice. The Germans built a blockhouse inside the Tudor ruins; the locality has a cluster of World War II bunkers, part of the Atlantic Wall intended to rebuff the anticipated allied invasion. There are heavy artillery sites – Batterie Grosser Kurfürst with three 170 millimetre guns, Todt Battery, with four 380 mm guns; these covered the approaches to both Calais and Boulogne and they were protected by massive concrete blockhouses and other lesser defensive sites. One of the Todt Battery blockhouses now houses the Atlantic Wall Museum. Units of the 3rd Canadian Infantry Division liberated the area in September 1944. Post-warThe cylindrical concrete lighthouse at Cap Gris-Nez dates from 1958, it is 31 metres high, replaces an earlier structure destroyed in 1944. The lighthouse and its accompanying radar station provide guidance to over 500 ships passing the cape every day.
Itius Portus Cross-Channel guns in the Second World War
England is a country, part of the United Kingdom. It shares land borders with Wales to Scotland to the north-northwest; the Irish Sea lies west of England and the Celtic Sea lies to the southwest. England is separated from continental Europe by the North Sea to the east and the English Channel to the south; the country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Palaeolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century, since the Age of Discovery, which began during the 15th century, has had a significant cultural and legal impact on the wider world; the English language, the Anglican Church, English law – the basis for the common law legal systems of many other countries around the world – developed in England, the country's parliamentary system of government has been adopted by other nations.
The Industrial Revolution began in 18th-century England, transforming its society into the world's first industrialised nation. England's terrain is chiefly low hills and plains in central and southern England. However, there is upland and mountainous terrain in the west; the capital is London, which has the largest metropolitan area in both the United Kingdom and the European Union. England's population of over 55 million comprises 84% of the population of the United Kingdom concentrated around London, the South East, conurbations in the Midlands, the North West, the North East, Yorkshire, which each developed as major industrial regions during the 19th century; the Kingdom of England – which after 1535 included Wales – ceased being a separate sovereign state on 1 May 1707, when the Acts of Union put into effect the terms agreed in the Treaty of Union the previous year, resulting in a political union with the Kingdom of Scotland to create the Kingdom of Great Britain. In 1801, Great Britain was united with the Kingdom of Ireland to become the United Kingdom of Great Britain and Ireland.
In 1922 the Irish Free State seceded from the United Kingdom, leading to the latter being renamed the United Kingdom of Great Britain and Northern Ireland. The name "England" is derived from the Old English name Englaland, which means "land of the Angles"; the Angles were one of the Germanic tribes that settled in Great Britain during the Early Middle Ages. The Angles came from the Anglia peninsula in the Bay of Kiel area of the Baltic Sea; the earliest recorded use of the term, as "Engla londe", is in the late-ninth-century translation into Old English of Bede's Ecclesiastical History of the English People. The term was used in a different sense to the modern one, meaning "the land inhabited by the English", it included English people in what is now south-east Scotland but was part of the English kingdom of Northumbria; the Anglo-Saxon Chronicle recorded that the Domesday Book of 1086 covered the whole of England, meaning the English kingdom, but a few years the Chronicle stated that King Malcolm III went "out of Scotlande into Lothian in Englaland", thus using it in the more ancient sense.
According to the Oxford English Dictionary, its modern spelling was first used in 1538. The earliest attested reference to the Angles occurs in the 1st-century work by Tacitus, Germania, in which the Latin word Anglii is used; the etymology of the tribal name itself is disputed by scholars. How and why a term derived from the name of a tribe, less significant than others, such as the Saxons, came to be used for the entire country and its people is not known, but it seems this is related to the custom of calling the Germanic people in Britain Angli Saxones or English Saxons to distinguish them from continental Saxons of Old Saxony between the Weser and Eider rivers in Northern Germany. In Scottish Gaelic, another language which developed on the island of Great Britain, the Saxon tribe gave their name to the word for England. An alternative name for England is Albion; the name Albion referred to the entire island of Great Britain. The nominally earliest record of the name appears in the Aristotelian Corpus the 4th-century BC De Mundo: "Beyond the Pillars of Hercules is the ocean that flows round the earth.
In it are two large islands called Britannia. But modern scholarly consensus ascribes De Mundo not to Aristotle but to Pseudo-Aristotle, i.e. it was written in the Graeco-Roman period or afterwards. The word Albion or insula Albionum has two possible origins, it either derives from a cognate of the Latin albus meaning white, a reference to the white cliffs of Dover or from the phrase the "island of the Albiones" in the now lost Massaliote Periplus, attested through Avienus' Ora Maritima to which the former served as a source. Albion is now applied to England in a more poetic capacity. Another romantic name for England is Loegria, related to the Welsh word for England and made popular by its use in Arthurian legend; the earliest known evidence of human presence in the area now known as England was that of Homo antecessor, dating to approximate