Mercator map of the world (Nova et Aucta Orbis Terrae Descriptio ad Usum Navigantium Emendate Accommodata). The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator in 1569. It became the standard map projection for nautical purposes because of its ability to represent lines of constant course, known as rhumb lines or loxodromes, as straight segments which conserve the angles with the meridians.Haven, Kendall (2005).
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The first map which identifies and names "Los Chagos" (in about the right position) is that of Pierre Desceliers (Dieppe 1550), although Diego Garcia is not named. An island called "Don Garcia" appears on the Theatrum Orbis Terrarum of Abraham Ortelius (Antwerp 1570), together with "Dos Compagnos", slightly to the north. It may be the case that "Don Garcia" was named after Garcia de Noronha, although no evidence exists to support this. The island is also labelled "Don Garcia" on Mercator's Nova et Aucta Orbis Terrae Descriptio ad Usum Navigatium Emendate (Duisburg 1569).
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Mercator's 1569 World Map (Nova et Aucta Orbis Terrae Descriptio ad Usum Navigantium Emendate Accommodata) World map Theatrum Orbis Terrarum (Theater of the Whole World) by Abraham Ortelius, 1570 This article covers the science, art and industry of cartography by the (especially Dutch-speaking) people of the Low Countries in the early modern period, especially in the early 16th to early 18th centuries. It includes cartography of the Netherlands (i.e. history of surveying and creation of maps of the Netherlands) and cartography of the Low Countries in general (i.e. history of surveying and creation of maps of the Low Countries).
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As a result, the map has a constant width and the parallels are stretched east–west as the poles are approached. Mercator's insight was to stretch the separation of the parallels in a way which exactly compensates for their increasing length, thus preserving shapes of small regions, albeit at the expense of global distortion. Such a conformal map projection necessarily transforms rhumb lines, sailing courses of a constant bearing, into straight lines on the map thus greatly facilitating navigation. That this was Mercator's intention is clear from the title: Nova et Aucta Orbis Terrae Descriptio ad Usum Navigantium Emendate Accommodata which translates as "New and more complete representation of the terrestrial globe properly adapted for use in navigation".
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Mercator's insight was to stretch the separation of the parallels in a way which exactly compensates for their increasing length, thus preserving shapes of small regions, albeit at the expense of global distortion. Such a conformal map projection necessarily transforms rhumb lines, sailing courses of a constant bearing, into straight lines on the map thus greatly facilitating navigation. That this was Mercator's intention is clear from the title: Nova et Aucta Orbis Terrae Descriptio ad Usum Navigantium Emendate Accommodata which translates as "New and more complete representation of the terrestrial globe properly adapted for use in navigation". Although the projection's adoption was slow, by the end of the seventeenth century it was in use for naval charts throughout the world and remains so to the present day.
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While the linear scale is constant in all directions around any point, thus preserving the angles and the shapes of small objects (which makes the projection conformal), the Mercator projection distorts the size and shape of large objects, as the scale increases from the Equator to the poles, where it becomes infinite. The title (Nova et Aucta Orbis Terrae Descriptio ad Usum Navigatium Emendate: "new and augmented description of Earth corrected for the use of navigation") and the map legends show that the map was expressly conceived for the use of marine navigation. The principal feature of the projection is that Rhumb lines, sailing courses at a constant bearing, are mapped to straight lines on the map. The development of the Mercator projection represented a major breakthrough in the nautical cartography of the 16th century although it was only slowly adopted by seafaring nations.
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The Chronologia developed into an even wider project, the Cosmographia, a description of the whole Universe. Mercator's outline was (1) the creation of the world; (2) the description of the heavens (astronomy and astrology); (3) the description of the earth comprising modern geography, the geography of Ptolemy and the geography of the ancients; (4) genealogy and history of the states; and (5) chronology. Of these the chronology had already been accomplished, the account of the creation and the modern maps would appear in the atlas of 1595, his edition of Ptolemy appeared in 1578 but the ancient geography and the description of the heavens never appeared. (Higher- resolution images) As the Chronologia was going to press in 1569, Mercator also published what was to become his most famous map: Nova et Aucta Orbis Terrae Descriptio ad Usum Navigantium Emendate Accommodata ('A new and more complete representation of the terrestrial globe properly adapted for use in navigation').
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