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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, since 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, 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 Earth In the ye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
El Hierro
El Hierro (), nicknamed ''Isla del Meridiano'' (the "Meridian Island"), is the farthest south and west of the Canary Islands (an autonomous community of Spain), in the Atlantic Ocean off the coast of Africa, with a population of 11,659 (2023). Its capital is Valverde. At , it is the second smallest of the eight main islands of the Canaries with La Graciosa being the smallest. Name The name ''El Hierro'', although spelled like the Spanish word for 'iron', is not related to that word. The ''H'' in the name of the metal is derived from the ''F'' of Latin ''ferrum'' (compare ''higo'' for 'fig'), a phonetic mutation that was complete by the end of the Middle Ages. The confusion with the name of the metal had effects on the international naming of the island. As early as the 16th century, maps and texts called the island after the word for 'iron' in other languages: Portuguese ''Ferro'', French ''l'île de Fer'', and Latin '' Insula Ferri''. Nevertheless, the origin of the nam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sourdon
Sourdon (; ) 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 771 communes of the Somme department of France. The communes cooperate in the following intercommunalities (as of 2025):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. The name is derived from the Latin , meaning "outstretched arms". Definition Unit of length Unit of area * 1 toise was about 3.799 square metres, or a square French toise, as a measure for land and masonry area in France before 10 December 1799. Unit of volume * 1 toise = 8.0 cubic metres (20th century Haiti) See also * Units of measurement in France before the French Revolution * Portuguese customary units * Ottoman units of measurement * Fathom and klafter The ''klafter'' is an historical unit of length, volume and area that was used in Central Europe. Unit of length As a unit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baseline (surveying)
In surveying, a baseline is generally a line between two points on the Earth's surface and the direction and/or distance between them. In a triangulation network, at least one distance between two stations needs to be measured to calculate the size of the triangles by trigonometry. In relative Global Navigation Satellite System (GNSS) surveying, a baseline is the line between two GNSS receivers to determine the 3D coordinate difference. United States In the United States Public Land Survey System, a baseline is specifically 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 (north-south line) 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Size Of The Earth
Size in general is the magnitude or dimensions of a thing. More specifically, ''geometrical size'' (or ''spatial size'') can refer to three geometrical measures: length, area, or volume. Length can be generalized to other linear dimensions (width, height, diameter, perimeter). Size can also be measured in terms of mass, especially when assuming a density range. In mathematical terms, "size is a concept abstracted from the process of measuring by comparing a longer to a shorter". Size is determined by the process of comparing or measuring objects, which results in the determination of the magnitude of a quantity, such as length or mass, relative to a unit of measurement. Such a magnitude is usually expressed as a numerical value of units on a previously established spatial scale, such as meters or inches. The sizes with which humans tend to be most familiar are body dimensions (measures of anthropometry), which include measures such as human height and h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latitude
In geography, latitude is a geographic coordinate system, geographic 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. Parallel (latitude), 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 (geometry), normal'') to the ellipsoidal surface from the point, and the equatorial plane, 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 i ... [...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 1669–1670, for which he is honored with a pyramid at Juvisy-sur-Orge. Guided by Maurolycus's methodology and Willebrord 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 for one degree of latitude, which gives a corresponding terrestrial radius of . Isaac Newton was to use this value in his th ... [...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. Cistercian nuns moved from the older abbey, Port-Royal-des-Champs, founded in 1204, to Paris and founded Port-Royal-de-Paris in 1626. There were frequent controversies as the sisters struggled against authorities in the church and at court. Some of the sisters returned to the medieval convent. Until it was dissolved in 1709, the Parisian abbey was highly influential and often in the news. It is today the site of an urban hospital. History Origins of the Abbey The buildings that housed the Abbey began as a private mansion. The ''Hôtel de Clagny'' was built by Pierre Lescot between 1566 and 1569 in the Faubourg Saint-Jacques in Paris. When he died in 1578, Léon Lescot, his nephew, inherited the property. On March 20, 1623, Léon gave Jehan Blondeau, his valet, and his great-nephew Robert de Romain, a cleric in the diocese of Meaux, "the vegetable garden and the gardens commonly called Claigny." By dee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midsummer's Day
Midsummer is a celebration of the season of summer, taking place on or near the date of the summer solstice in the Northern Hemisphere; the longest day of the year. The name "midsummer" mainly refers to summer solstice festivals of European origin. These cultures traditionally regard it as the middle of summer, with the season beginning on May Day. Although the summer solstice falls on 20, 21 or 22 June in the Northern Hemisphere, it was traditionally reckoned to fall on 23–24 June in much of Europe. These dates were Christianized as Saint John's Eve and Saint John's Day. It is usually celebrated with outdoor gatherings that include bonfires and feasting. History There is evidence that the summer solstice has been culturally important since the Neolithic era, with many ancient monuments throughout Eurasia and the Americas aligned with sunrise or sunset on the summer solstice. The name 'midsummer' is attested in Old English as ''midsumor'', and refers to the time aro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
