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Étienne Lenoir (instrument Maker)
Étienne Lenoir (1744–1832) was a French scientific instrument maker and inventor of the repeating circle.Chronologie scientifique, technologique et économique de la France - Page 137 Danièle et Jean-Claude Clermontel - 2009 "POIDS ET MESURES : le 9 juin 1795, Étienne Lenoir fabrique le premier mètre étalon, sur la base de la mesure du méridien, effectuée en 1754 par l'abbé de La Caille (soit : 5 129 070 toises de Paris, du pôle à l'équateur)." When hired by Jean-Charles de Borda around 1772 to work on the reflecting circle, he was about thirty years old and nearly illiterate. However, his intelligence and mechanical genius allowed him to perform work that few others could perform. He played a significant role in the improvements to the reflecting circle and later used this experience in inventing the repeating circle. As a result of this work, he became known as the pre-eminent maker of instruments for astronomy, navigation and surveying in France. In 1787, the king ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Repeating Circle
The repeating circle is an instrument for geodetic surveying, developed from the Reflecting instrument#reflecting circle, reflecting circle by Étienne Lenoir (instrument maker), Étienne Lenoir in 1784. He invented it while an assistant of Jean-Charles de Borda, who later improved the instrument. It was notable as being the equal of the Ramsden surveying instruments#great theodolite, great theodolite created by the renowned instrument maker, Jesse Ramsden. It was used to arc measurement, measure the meridian arc from Dunkirk to Barcelona by Jean Baptiste Joseph Delambre, Jean Baptiste Delambre and Pierre Méchain (see: meridian arc of Delambre and Méchain). Construction and operation The repeating circle is made of two telescopes mounted on a shared axis with scales to measure the angle between the two. The instrument combines multiple measurements to increase accuracy with the following procedure: At this stage, the angle on the instrument is double the angle of interest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruler
A ruler, sometimes called a rule, scale, line gauge, or metre/meter stick, is an instrument used to make length measurements, whereby a length is read from a series of markings called "rules" along an edge of the device. Usually, the instrument is rigid and the edge itself is a straightedge ("ruled straightedge"), which additionally allows one to draw straighter lines. Rulers are an important tool in geometry, geography and mathematics. They have been used since at least 2650 BC. Variants Rulers have long been made from different materials and in multiple sizes. Historically, they were mainly wood but plastics have also been used. They can be created with length markings instead of being wikt:scribe, scribed. Metal is also used for more durable rulers for use in the workshop; sometimes a metal edge is embedded into a wooden desk ruler to preserve the edge when used for straight-line cutting. Typically in length, though some can go up to 100 cm, it is useful for a ruler to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Scientific Instrument Makers
French may refer to: * Something of, from, or related to France ** French language, which originated in France ** French people, a nation and ethnic group ** French cuisine, cooking traditions and practices Arts and media * The French (band), a British rock band * "French" (episode), a live-action episode of ''The Super Mario Bros. Super Show!'' * ''Française'' (film), a 2008 film * French Stewart (born 1964), American actor Other uses * French (surname), a surname (including a list of people with the name) * French (tunic), a type of military jacket or tunic * French's, an American brand of mustard condiment * French (catheter scale), a unit of measurement * French Defence, a chess opening * French kiss, a type of kiss See also * France (other) * Franch, a surname * French Revolution (other) * French River (other), several rivers and other places * Frenching (other) * Justice French (other) Justice French may refer to: * C. G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual Climate of Antarctica#Precipitation, precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the Lowest temperature recorded on Earth, lowest measured temperature on Earth, . The coastal regions can reach temperatures over in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lenoir Rock
Lenoir Rock (, ) is the rock off the NW coast of Smith Island in the South Shetland Islands, Antarctica 230 m long in southwest-northeast direction and 85 m wide with a surface area of 1.29 ha. The vicinity was visited by early 19th century sealers.L. IvanovGeneral Geography and History of Livingston Island.In: ''Bulgarian Antarctic Research: A Synthesis''. Eds. C. Pimpirev and N. Chipev. Sofia: St. Kliment Ohridski University Press, 2015. pp. 17–28 The feature is named after Étienne Lenoir (1744-1832), a Belgian-French scientific instrument maker and inventor of the repeating circle; in association with other names in the area deriving from the early development or use of geodetic instruments and methods. Location Lenoir Rock is located at ,Bulgarian Antarctic Gazetteer. Antarctic Place-names Commission which is 380 m southwes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Repeating Circle
The repeating circle is an instrument for geodetic surveying, developed from the Reflecting instrument#reflecting circle, reflecting circle by Étienne Lenoir (instrument maker), Étienne Lenoir in 1784. He invented it while an assistant of Jean-Charles de Borda, who later improved the instrument. It was notable as being the equal of the Ramsden surveying instruments#great theodolite, great theodolite created by the renowned instrument maker, Jesse Ramsden. It was used to arc measurement, measure the meridian arc from Dunkirk to Barcelona by Jean Baptiste Joseph Delambre, Jean Baptiste Delambre and Pierre Méchain (see: meridian arc of Delambre and Méchain). Construction and operation The repeating circle is made of two telescopes mounted on a shared axis with scales to measure the angle between the two. The instrument combines multiple measurements to increase accuracy with the following procedure: At this stage, the angle on the instrument is double the angle of interest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Musée Des Arts Et Métiers
The Musée des Arts et Métiers (; English: Museum of Arts and Crafts) is an industrial design museum in Paris that houses the collection of the Conservatoire national des arts et métiers, which was founded in 1794 as a repository for the preservation of scientific instruments and inventions. History Since its foundation, the museum has been housed in the deserted priory of Saint-Martin-des-Champs on the Rue Réaumur in the 3rd arrondissement of Paris. Today the museum, which underwent major renovations in 1990, includes an additional building adjacent to the abbey, with larger objects remaining in the abbey itself. Collection The museum has over 80,000 objects and 15,000 drawings in its collection, of which about 2,500 are on display in Paris. The rest of the collection is preserved in a storehouse in Saint-Denis, Seine-Saint-Denis, Saint-Denis. Among its collection is an original version of the Foucault pendulum, the original model of ''Liberty Enlightening the World'' (commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflecting Circle
Reflecting instruments are those that use mirrors to enhance their ability to make measurements. In particular, the use of mirrors permits one to observe two objects simultaneously while measuring the angular distance between the objects. While reflecting instruments are used in many professions, they are primarily associated with celestial navigation as the need to solve navigation problems, in particular the problem of the longitude, was the primary motivation in their development. Objectives of the instruments The purpose of reflecting instruments is to allow an observer to measure the altitude of a celestial object or the angular distance between two objects. The driving force behind the developments discussed here was the solution to the problem of finding one's longitude at sea. The solution to this problem was seen to require an accurate means of measuring angles and the accuracy was seen to rely on the observer's ability to measure this angle by simultaneously observing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brass
Brass is an alloy of copper and zinc, in proportions which can be varied to achieve different colours and mechanical, electrical, acoustic and chemical properties, but copper typically has the larger proportion, generally copper and zinc. In use since prehistoric times, it is a substitutional alloy: atoms of the two constituents may replace each other within the same crystal structure. Brass is similar to bronze, a copper alloy that contains tin instead of zinc. Both bronze and brass may include small proportions of a range of other Chemical element, elements including arsenic, lead, phosphorus, aluminium, manganese and silicon. Historically, the distinction between the two alloys has been less consistent and clear, and increasingly museums use the more general term "list of copper alloys, copper alloy". Brass has long been a popular material for its bright gold-like appearance and is still used for drawer pulls and door handle, doorknobs. It has also been widely used to ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinum
Platinum is a chemical element; it has Symbol (chemistry), symbol Pt and atomic number 78. It is a density, dense, malleable, ductility, ductile, highly unreactive, precious metal, precious, silverish-white transition metal. Its name originates from Spanish language, Spanish , a diminutive of "silver". Platinum is a member of the platinum group of elements and group 10 element, group 10 of the periodic table of elements. It has six naturally occurring isotopes. It is one of the Abundance of elements in Earth's crust, rarer elements in Earth's crust, with an average abundance of approximately 5 microgram, μg/kg, making platinum about 30 times rarer than gold. It occurs in some nickel and copper ores along with some Native element mineral, native deposits, with 90% of current production from deposits across Russia's Ural Mountains, Colombia, the Sudbury Basin, Sudbury basin of Canada, and a large reserve in South Africa. Because of its scarcity in Earth's crust, only a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean-Charles De Borda
Jean-Charles, chevalier de Borda (4 May 1733 – 19 February 1799) was a French mathematician, physicist, and Navy officer. Biography Borda was born in the city of Dax to Jean‐Antoine de Borda and Jeanne‐Marie Thérèse de Lacroix. In 1756, Borda wrote ''Mémoire sur le mouvement des projectiles'', a product of his work as a military engineer. For that, he was elected to the French Academy of Sciences in 1764. Borda was a mariner and a scientist, spending time in the Caribbean testing out advances in chronometers. Between 1777 and 1778, he participated in the American Revolutionary War. In 1781, he was put in charge of several vessels in the French Navy. In 1782, he was captured by the English, and was returned to France shortly after. He returned as an engineer in the French Navy, making improvements to waterwheels and pumps. He was appointed as France's Inspector of Naval Shipbuilding in 1784, and with the assistance of the naval architect Jacques-Noël Sané in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meridian Arc
In geodesy and navigation, a meridian arc is the curve (geometry), curve between two points near the Earth's surface having the same longitude. The term may refer either to a arc (geometry), segment of the meridian (geography), meridian, or to its Arc length, length. Both the practical determination of meridian arcs (employing measuring instruments in field campaigns) as well as its theoretical calculation (based on geometry and abstract mathematics) have been pursued for many years. Measurement The purpose of measuring meridian arcs is to determine a figure of the Earth. One or more measurements of meridian arcs can be used to infer the shape of the reference ellipsoid that best approximates the geoid in the region of the measurements. Measurements of meridian arcs at several latitudes along many meridians around the world can be combined in order to approximate a ''geocentric ellipsoid'' intended to fit the entire world. The earliest determinations of the size of a spherical E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
