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Georges Oberhaeuser
Georges Oberhaeuser was a German optician working in Paris in the early to middle 19th century. His contributions, and the contributions of his partner and successor, Edmund Hartnack, were part of the early development of the microscope as a scientific tool on the European continent. Birth and education Georges Oberhaeuser was born in Ansbach, Bavaria, in 1798 to Michael Adam Oberhäuser (1755–1814), a master turner. The boy attended a university-preparatory school in Ansbach and then was apprenticed to a University of Würzburg machinist surnamed du Mouceau. After his apprenticeship, he emigrated to France, and in 1816 joined the workshop of Henri Gambey (1787–1847). Microscope and optics workshop Oberhaeuser's first commercial venture was during partnership with Bouquet und Achille Trécourt in 1822. Oberhaeuser produced one of his most successful early microscope designs for the student market. As research in cell biology and botany broadened, students needed a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ansbach
Ansbach (; ; East Franconian: ''Anschba'') is a city in the German state of Bavaria. It is the capital of the administrative region of Middle Franconia. Ansbach is southwest of Nuremberg and north of Munich, on the river Fränkische Rezat, a tributary of the river Main. In 2020, its population was 41,681. Developed in the 8th century as a Benedictine monastery, it became the seat of the Hohenzollern family in 1331. In 1460, the Margraves of Brandenburg-Ansbach lived here. The city has a castle known as Margrafen–Schloss, built between 1704 and 1738. It was not badly damaged during the World Wars and hence retains its original historical baroque sheen. Ansbach is now home to a US military base and to the Ansbach University of Applied Sciences. The city has connections via autobahn A6 and highways B13 and B14. Ansbach station is on the Nürnberg–Crailsheim and Treuchtlingen–Würzburg railways and is the terminus of line S4 of the Nuremberg S-Bahn. Name origin Ans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achromatic Lens
An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus on the same plane. The most common type of achromat is the achromatic doublet, which is composed of two individual lenses made from glasses with different amounts of dispersion. Typically, one element is a negative (concave) element made out of flint glass such as F2, which has relatively high dispersion, and the other is a positive (convex) element made of crown glass such as BK7, which has lower dispersion. The lens elements are mounted next to each other, often cemented together, and shaped so that the chromatic aberration of one is counterbalanced by that of the other. In the most common type (shown), the positive power of the crown lens element is not quite equalled by the negative power of the flint lens element. Together they form a weak positive lens that will b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
German Scientific Instrument Makers
German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Germanic peoples (Roman times) * German language **any of the Germanic languages * German cuisine, traditional foods of Germany People * German (given name) * German (surname) * Germán, a Spanish name Places * German (parish), Isle of Man * German, Albania, or Gërmej * German, Bulgaria * German, Iran * German, North Macedonia * German, New York, U.S. * Agios Germanos, Greece Other uses * German (mythology), a South Slavic mythological being * Germans (band), a Canadian rock band * "German" (song), a 2019 song by No Money Enterprise * ''The German'', a 2008 short film * "The Germans", an episode of ''Fawlty Towers'' * ''The German'', a nickname for Congolese rebel André Kisase Ngandu See also * Germanic (other) * Germa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1868 Deaths
Events January–March * January 2 – British Expedition to Abyssinia: Robert Napier leads an expedition to free captive British officials and missionaries. * January 3 – The 15-year-old Mutsuhito, Emperor Meiji of Japan, declares the ''Meiji Restoration'', his own restoration to full power, under the influence of supporters from the Chōshū and Satsuma Domains, and against the supporters of the Tokugawa shogunate, triggering the Boshin War. * January 5 – Paraguayan War: Brazilian Army commander Luís Alves de Lima e Silva, Duke of Caxias enters Asunción, Paraguay's capital. Some days later he declares the war is over. Nevertheless, Francisco Solano López, Paraguay's president, prepares guerrillas to fight in the countryside. * January 7 – The Arkansas constitutional convention meets in Little Rock. * January 9 – Penal transportation from Britain to Australia ends, with arrival of the convict ship ''Hougoumont'' in Western Australi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1798 Births
Events January–June * January – Eli Whitney contracts with the U.S. federal government for 10,000 muskets, which he produces with interchangeable parts. * January 4 – Constantine Hangerli enters Bucharest, as Prince of Wallachia. * January 22 – A coup d'état is staged in the Netherlands ( Batavian Republic). Unitarian Democrat Pieter Vreede ends the power of the parliament (with a conservative-moderate majority). * February 10 – The Pope is taken captive, and the Papacy is removed from power, by French General Louis-Alexandre Berthier. * February 15 – U.S. Representative Roger Griswold (Fed-CT) beats Congressman Matthew Lyon (Dem-Rep-VT) with a cane after the House declines to censure Lyon earlier spitting in Griswold's face; the House declines to discipline either man.''Harper's Encyclopaedia of United States History from 458 A. D. to 1909'', ed. by Benson John Lossing and, Woodrow Wilson (Harper & Brothers, 1910) p171 * March &ndas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Immersion Objective
In light microscopy, a water immersion objective is a specially designed objective lens used to increase the resolution of the microscope. This is achieved by immersing both the lens and the specimen in water which has a higher refractive index than air, thereby increasing the numerical aperture of the objective lens. Applications Water immersion objectives are used not only at very large magnifications that require high resolving power, but also of moderate power as there are water immersion objectives as low as 4X. Objectives with high power magnification have short focal lengths, facilitating the use of water. The water is applied to the specimen (conventional microscope), and the stage is raised, immersing the objective in water. Sometimes with water dipping objectives, the objective is directly immersed in the solution of water which contains the specimens to look at. Electrophoretic preparations used in the case of comet assay can benefit from the use of water objectives. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Jackson Lister
Joseph Jackson Lister FRS FRMS (11 January 1786 – 24 October 1869) was an amateur British opticist and physicist and the father of The 1st Baron Lister. Ancestry In 1705, Thomas Lister, a farmer and maltster, of Bingley, Yorkshire, England, married Hannah, the daughter of a yeoman (an independent small farmer). They joined the Society of Friends, becoming Quakers, as were most of their descendants. They had a son, Joseph, who left Yorkshire in about 1720 to become a tobacconist in Aldersgate Street in the City of London. Joseph's youngest son, christened John, was born in 1737. He was apprenticed to a watchmaker, Isaac Rogers, in 1752, and followed that trade on his own account in Bell Alley, Lombard Street from 1759 to 1766. He then took over his father's tobacco business, but gave it up in 1769 in favour of his father-in-law Stephen Jackson's business as a wine-merchant in Lothbury. John Lister was made a freeman of the Bakers' company in 1760. He married Mary in 176 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spherical Aberration
In optics, spherical aberration (SA) is a type of optical aberration, aberration found in optical systems that have elements with spherical surfaces. Lens (optics), Lenses and curved mirrors are prime examples, because this shape is easier to manufacture. Light rays that strike a spherical surface off-centre are refraction, refracted or reflection (physics), reflected more or less than those that strike close to the centre. This deviation reduces the quality of images produced by optical systems. Overview A spherical lens has an Optical aberration#Aberration of elements, i.e. smallest objects at right angles to the axis, aplanatic point (i.e., no spherical aberration) only at a radius that equals the radius of the sphere divided by the index of refraction of the lens material. A typical value of refractive index for crown glass is 1.5 (see List of refractive indices, list), which indicates that only about 43% of the area (67% of diameter) of a spherical lens is useful. It is o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Objective (optics)
In optical engineering, the objective is the optical element that gathers light from the object being observed and focuses the light rays to produce a real image. Objectives can be a single lens or mirror, or combinations of several optical elements. They are used in microscopes, binoculars, telescopes, cameras, slide projectors, CD players and many other optical instruments. Objectives are also called object lenses, object glasses, or objective glasses. Microscope objectives The objective lens of a microscope is the one at the bottom near the sample. At its simplest, it is a very high-powered magnifying glass, with very short focal length. This is brought very close to the specimen being examined so that the light from the specimen comes to a focus inside the microscope tube. The objective itself is usually a cylinder containing one or more lenses that are typically made of glass; its function is to collect light from the sample. Magnification One of the most important prope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bavaria
Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total land area of Germany. With over 13 million inhabitants, it is second in population only to North Rhine-Westphalia, but due to its large size its population density is below the German average. Bavaria's main cities are Munich (its capital and largest city and also the third largest city in Germany), Nuremberg, and Augsburg. The history of Bavaria includes its earliest settlement by Iron Age Celtic tribes, followed by the conquests of the Roman Empire in the 1st century BC, when the territory was incorporated into the provinces of Raetia and Noricum. It became the Duchy of Bavaria (a stem duchy) in the 6th century AD following the collapse of the Western Roman Empire. It was later incorporated into the Holy Roman Empire, became an ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giovanni Battista Amici
Giovanni Battista Amici (; 25 March 1786 – 10 April 1863) was an Italian astronomer, microscopist, and botanist. Amici was born in Modena, in present-day Italy. After studying at Bologna, he became professor of mathematics at Modena, and in 1831 was appointed inspector-general of studies in the Duchy of Modena. A few years later he was chosen director of the observatory at Florence, where he also lectured at the museum of natural history. Amici died in Florence in 1863. His name is best known for the improvements he effected in the mirrors of reflecting telescopes and especially in the construction of the microscope. He was also a diligent and skillful observer, and busied himself not only with astronomical subjects, such as the double stars, the satellites of Jupiter and the measurement of the polar and equatorial diameters of the sun, but also with biological studies of the circulation of the sap in plants, the fructification of plants, infusoria etc. He was the first to obse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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