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Paris Meridian
The Paris meridian is a meridian line running through the Paris Observatory in Paris, France – now longitude 2°20′14.02500″ East. It was a long-standing rival to the Greenwich meridian as the prime meridian of the world. The "Paris meridian arc" or "French meridian arc" (French: ''la Méridienne de France'') is the name of the meridian arc measured along the Paris meridian. The French meridian arc was important for French cartography, inasmuch as the triangulations of France began with the measurement of the French meridian arc. Moreover, the French meridian arc was important for geodesy as it was one of the meridian arcs which were measured to determine the figure of the Earth via the arc measurement method. The determination of the figure of the Earth was a problem of the highest importance in astronomy, inasmuch as the diameter of the Earth was the unit to which all celestial distances had to be referred. History French cartography and the figure of the Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptolemy's World Map
The Ptolemy world map is a map of the world known to Greco-Roman societies in the 2nd century. It is based on the description contained in Ptolemy's book '' Geography'', written . Based on an inscription in several of the earliest surviving manuscripts, it is traditionally credited to Agathodaemon of Alexandria. Notable features of Ptolemy's map is the first use of longitudinal and latitudinal lines as well as specifying terrestrial locations by celestial observations. The ''Geography'' was translated from Greek into Arabic in the 9th century and played a role in the work of al-Khwārizmī before lapsing into obscurity. The idea of a global coordinate system revolutionized European geographical thought, however, and inspired more mathematical treatment of cartography. Ptolemy's work probably originally came with maps, but none have been discovered. Instead, the present form of the map was reconstructed from Ptolemy's coordinates by Byzantine monks under the direction of Max ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amiens
Amiens (English: or ; ; pcd, Anmien, or ) is a city and commune in northern France, located north of Paris and south-west of Lille. It is the capital of the Somme department in the region of Hauts-de-France. In 2021, the population of Amiens was 135,429. A central landmark of the city is Amiens Cathedral, the largest Gothic cathedral in France. Amiens also has one of the largest university hospitals in France, with a capacity of 1,200 beds. The author Jules Verne lived in Amiens from 1871 until his death in 1905, and served on the city council for 15 years. Incumbent French president Emmanuel Macron was born in Amiens. The town was fought over during both World Wars, suffering significant damage, and was repeatedly occupied by both sides. The 1918 Battle of Amiens was the opening phase of the Hundred Days Offensive which directly led to the Armistice with Germany. The Royal Air Force heavily bombed the town during the Second World War. In the aftermath, the city was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sourdon
Sourdon (; pcd, Sordon) is a commune in the Somme department in the Hauts-de-France region of France. Geography Sourdon is situated south of Amiens, on the D14 road Population See also *Communes of the Somme department The following is a list of the 772 communes of the Somme department of France. The communes cooperate in the following intercommunalities (as of 2020):Communes of Somme (department) {{Montdidier-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triangulation Network
In surveying, triangulation is the process of determining the location of a point by measuring only angles to it from known points at either end of a fixed baseline by using trigonometry, rather than measuring distances to the point directly as in trilateration. The point can then be fixed as the third point of a triangle with one known side and two known angles. Triangulation can also refer to the accurate surveying of systems of very large triangles, called triangulation networks. This followed from the work of Willebrord Snell in 1615–17, who showed how a point could be located from the angles subtended from ''three'' known points, but measured at the new unknown point rather than the previously fixed points, a problem called resectioning. Surveying error is minimized if a mesh of triangles at the largest appropriate scale is established first. Points inside the triangles can all then be accurately located with reference to it. Such triangulation methods were used for accur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toise
A toise (; symbol: T) is a unit of measure for length, area and volume originating in pre-revolutionary France. In North America, it was used in colonial French establishments in early New France, French Louisiana (''Louisiane''), Acadia (''Acadie'') and Quebec. The related () was used in Portugal, Brazil, and other parts of the Portuguese Empire until the adoption of the metric system. Definition Unit of length * 1 toise was divided in 6 feet (french: pieds) or 72 inches () or 864 lines () in France until 1812. : In 1799 the metre was defined to be exactly 443.296 or toise, with the intention that the metre should equal of the distance from the pole to the equator. This had the effect of making the toise approximately 1949.03631 mm. : According to an article written in 1866, during measurement of various standard length artefacts from several countries, the toise was measured as 1,949.03632 mm. :Since before 1394, the standard for the toise of Paris was an iro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baseline (surveying)
In surveying, a baseline is a line between two points on the earth's surface and the direction and distance between them. In a triangulation network, at least one baseline between two stations needs to be measured to calculate the size of the triangles by trigonometry. In the United States Public Land Survey System, a baseline is the principal east-west line (i.e., a parallel) upon which all rectangular surveys in a defined area are based. The baseline meets its corresponding principal meridian at the point of origin, or ''initial point'', for the land survey. For example, the baseline for Nebraska and Kansas is shared as the border for both states, at the 40th parallel north. More specifically a baseline may be the line that divides a survey township between north and south. "Baseline Road" in the United States Many communities in the United States have roads that run along survey baselines, many of which are named to reflect that fact. Some examples: * In Little Rock, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picard's Arc Measurement
Jean Picard (21 July 1620 – 12 July 1682) was a French astronomer and priest born in La Flèche, where he studied at the Jesuit Collège Royal Henry-Le-Grand. He is principally notable for his accurate measure of the size of the Earth, based on a careful survey of one degree of latitude along the Paris Meridian. Geodesy Picard was the first person to measure the size of the Earth to a reasonable degree of accuracy in an arc measurement survey conducted in 1669–70, for which he is honored with a pyramid at Juvisy-sur-Orge. Guided by Maurolycus's methodology and Snellius's mathematics for doing so, Picard achieved this by measuring one degree of latitude along the Paris Meridian using triangulation along thirteen triangles stretching from Paris to the clocktower of Sourdon, near Amiens. His measurements produced a result of 110.46 km for one degree of latitude, which gives a corresponding terrestrial radius of 6328.9 km. Isaac Newton was to use this value ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Size Of The Earth
Figure of the Earth is a term of art in geodesy that refers to the size and shape used to model Earth. The size and shape it refers to depend on context, including the precision needed for the model. A sphere is a well-known historical approximation of the figure of the Earth that is satisfactory for many purposes. Several models with greater accuracy (including ellipsoid) have been developed so that coordinate systems can serve the precise needs of navigation, surveying, cadastre, land use, and various other concerns. Motivation Earth's topographic surface is apparent with its variety of land forms and water areas. This topographic surface is generally the concern of topographers, hydrographers, and geophysicists. While it is the surface on which Earth measurements are made, mathematically modeling it while taking the irregularities into account would be extremely complicated. The Pythagorean concept of a spherical Earth offers a simple surface that is easy to deal with ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latitude
In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pole, with 0° at the Equator. Lines of constant latitude, or ''parallels'', run east–west as circles parallel to the equator. Latitude and '' longitude'' are used together as a coordinate pair to specify a location on the surface of the Earth. On its own, the term "latitude" normally refers to the ''geodetic latitude'' as defined below. Briefly, the geodetic latitude of a point is the angle formed between the vector perpendicular (or '' normal'') to the ellipsoidal surface from the point, and the plane of the equator. Background Two levels of abstraction are employed in the definitions of latitude and longitude. In the first step the physical surface is modeled by the geoid, a surface which approximates the mean sea level over t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean Picard
Jean Picard (21 July 1620 – 12 July 1682) was a French astronomer and priest born in La Flèche, where he studied at the Jesuit Collège Royal Henry-Le-Grand. He is principally notable for his accurate measure of the size of the Earth, based on a careful survey of one degree of latitude along the Paris Meridian. Geodesy Picard was the first person to measure the size of the Earth to a reasonable degree of accuracy in an arc measurement survey conducted in 1669–70, for which he is honored with a pyramid at Juvisy-sur-Orge. Guided by Maurolycus's methodology and Snellius's mathematics for doing so, Picard achieved this by measuring one degree of latitude along the Paris Meridian using triangulation along thirteen triangles stretching from Paris to the clocktower of Sourdon, near Amiens. His measurements produced a result of 110.46 km for one degree of latitude, which gives a corresponding terrestrial radius of 6328.9 km. Isaac Newton was to use this va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Port-Royal Abbey, Paris
Port-Royal Abbey was an abbey in Paris that was a stronghold of Jansenism. It was first built in 1626 to relieve pressure of numbers on the mother house at Port-Royal-des-Champs. History Famous people who stayed at the Port-Royal Abbey include Marie de Rohan, intriguer during the Fronde; Jeanne Baptiste d'Albert de Luynes, future mistress of a duke of Savoy; Marie Angélique de Fontanges, mistress of Louis XIV, died here giving birth to his child who also died. It was closed down in 1790, at the beginning of the French Revolution and from 1793 used as a prison under the name Prison de Port-libre or Prison de la Bourbe. Chrétien Guillaume de Lamoignon de Malesherbes (lawyer for Louis XVI during his trial) and Madame de Tourzel, former governess of the " children of France", were held here. Today its main cloister (''illustration'') forms part of the modern Hôpital Cochin. Notable patrons *Blaise Pascal *Jacqueline Pascal, sister of Blaise Pascal *Madame du ValoisMary An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
