Holländsk bokhandlarfirma, grundlagd i Amsterdam 1678 av Joannes van Keulen (se denne). Denne handlade med sjökort samt matematiska och nautiska böcker och instrument som han till viss del gjorde förarbetet till. Som förläggare gav han ut en rad stora sjökartverk som 'De lichtende Zeefaakkel' (1680-84), 'Zee Atlas' (1680) och 'De groote nieuwe vermeerderde Zee Atlas ofte water werelt' (1695). Dessa verk kom i flera nyutgåvor. - Hans son, Gerard van Keulen, fortsatte verksamheten, reviderade de gamla kartorna och kompletterade med nya. Efter hans död 1726 fortsatte företaget under ledning av Johannes van Keulen d.y. (d. 1755). 1728 utkom en fransk utgåva, 'Flambeau de la mer' i 4 band, och 1753 en reviderad utgåva, 'De nieuwe groote lichtende Zee fakkel'. Från 1779 var Gerard Hulst van Keulen (se denne) innehavare av företaget och ombesörjde flera nyutgåvor av firmans atlaser. 1802 hade 'Zee-Fakkel' (med text på holländska, franska och spanska) kommit ut i 26 utgåvor, och 'Zee-Atlas' (utan text) i 15 utgåvor....
Bland arbeten.
De lichtende Zeefaakkel.
Zee Atlas.
De groote nieuwe vermeerderde Zee Atlas ofte water werelt.
Flambeau de la mer.
De nieuwe groote lichtende Zee fakkel.
Nissen. - Nouv. biogr. gen. - Phillips. - Wieder.
1661-97.
Kartograf, från 1687 styrmansdirektör vid amiralitetet, en befattning närmast motsv. såväl generallotsdirektörens som chefens för sjökarteverket i vår tid. G. utarbetade nya författningar rörande lotsväsendet, vilka sedaan länge förblevo gällande, och upprättade och utgav tills. med sin företrädare W. v. Rosenfeldt den första svenska sjöatlasen 1694, 'General hydrographisk chart-book öfwer Östersiön', vilken s.å. även utkom i engelsk och holländsk uppl. Genom detta kartarbete tillvann sig G. en framstående plats inom den svenska kartografiens historia.
Worked at the Survey office, from 1681 in marine measurement and production of maps under Admiral Werner von Rosenfeldt. In 1681 appointed principal at the Admiralty. In 1687 Gedda was appointed director of pilots, taking over von Rosenfeldt's responsibilities for the pilots and hydrographical surveying. They continued collaborating, and in 1695 produced the first printed Swedish marine atlas to provide a correct, albeit very general, view of the Kattega...
Bland arbeten.
General hydrographisk chart-book öfwer Östersiön.
Svensk Uppslagsbok. Sveriges sjökartor – A. Hedin.
Gravör av titelbladet till Atlas Novus av Tobias Conrad Lotter.
Bland arbeten.
Atlas Novus.
RdeT.
Vägvisare för XI Olympiaden i Berlin - 1936
Edebo - Väddö och Häverö Skeppslag - 1910.
Cassini de Thury, César-François
Biografiska uppgifter:17 June 1714 – 4 September 1784
César-François Cassini de Thury (17 June 1714 – 4 September 1784), also called Cassini III or Cassini de Thury, was a French astronomer and cartographer.
Cassini de Thury was born in Thury-sous-Clermont (Oise), the second son of Jacques Cassini and Suzanne Françoise Charpentier de Charmois. He was a grandson of Giovanni Domenico Cassini, and would become the father of Jean-Dominique Cassini, Comte de Cassini.
In 1735, he became a member of the French Academy of Sciences as a supernumerary adjunct astronomer, in 1741 as an adjunct astronomer, and in 1745 as a full member astronomer.
In January, 1751 he was elected a Fellow of the Royal Society.
He succeeded to his father’s official position in 1756 and continued the hereditary surveying operations. In 1744, he began the construction of a great topographical map of France, one of the landmarks in the history of cartography. Completed by his son Jean-Dominique, Cassini IV and published by the Académie des Sciences from 1744 to 1793, its 180 plates are known as the Cassini map(fr).
The post of director of the Paris observatory was created for his benefit in 1771 when the establishment ceased to be a dependency of the French Academy of Sciences.
His chief works are: La méridienne de l’Observatoire Royal de Paris (1744), a correction of the Paris meridian; Description géométrique de la terre (1775); and Description géométrique de la France (1784), which was completed by his son ('Cassini IV').
César-François Cassini de Thury died of smallpox in Paris on 4 September 1784,
The Cassini projection is a map projection described by César-François Cassini de Thury in 1745. It is the transverse aspect of theequirectangular projection, in that the globe is first rotated so the central meridian becomes the 'equator', and then the normal equirectangular projection is applied.
In practice, the projection has always been applied to models of the earth as an ellipsoid, which greatly complicates the mathematical development but is suitable for surveying. Nevertheless the use of the Cassini projection has largely been superseded by the Transverse Mercator projection, at least with central mapping agencies.
Areas along the central meridian, and at right angles to it, are not distorted. Elsewhere, the distortion is largely in a north-south direction, and varies by the square of the distance from the central meridian. As such, the greater the longitudinal extent of the area, the worse the distortion becomes.
Due to this, the Cassini projection works best on long, narrow areas, and worst on wide areas.
