map, conventionalized representation of spatial phenomena on a plane surface. Unlike photographs, maps are selective and may be prepared to show various quantitative and qualitative facts, including boundaries, physical features, patterns, and distribution. Each point on such a map corresponds to a geographical position in accordance with a definite scale and projection (see map projection). Maps may also represent such comparative data as industrial power, population density, and birth and death rates. The earliest European printed maps (2d half of the 15th cent.) were made from woodcuts; maps are now reproduced by several processes, including photoengraving, wax engraving, and lithography. See also chart.
Cartography, or mapmaking, antedates even the art of writing. Diagrams of areas familiar to them were made by Marshall Islanders, Eskimo, Native Americans, and many other preliterate peoples. Maps drawn by ancient Babylonians, Egyptians, and Chinese have been found. The oldest known map, now on exhibition in the Semitic Museum of Harvard, is a Babylonian clay tablet dating from c.2500 BC Our present system of cartography was established by the Greeks, who remained unexcelled until the 16th cent. Scientific measurements of earth distances by means of meridians and parallels were first made by Eratosthenes (3d cent. BC). Of the ancient scholars, the mathematician and geographer Ptolemy (2d cent. AD), expounded on the principles of cartography; his system was followed for many centuries, although his basic error in underestimating the earth's size was not corrected until the age of Mercator. Only the Mediterranean world was represented with any accuracy in early maps. During the Middle Ages, while European cartographers produced artistic, idealized maps, Arabic mapmakers, notably Idrisi (12th cent.), carried on the work of Ptolemy, and the Chinese produced the first printed maps.
Cartography in the Sixteenth through Eighteenth Centuries
Three major events contributed to the spectacular renaissance of cartography in Europe around 1500—the rediscovery and translation into Latin of Ptolemy's Geographia, the invention of printing and engraving, and the great voyages of discovery. This renaissance was manifested by the work of Gerardus Mercator in the first modern world atlas, published in 1570 by Abraham Ortelius, and by the decorative, paintinglike maps of the French Sanson family (17th cent.). Improvements in the methods of surveying and increased emphasis on accuracy led to the noted work in the 18th cent. of the Frenchmen Guillaume Delisle and J. B. B. d'Anville, the founders of modern cartography. After 1750 many European governments undertook the systematic mapping of their countries. The first important national survey was made in France (published 1756), followed by the Ordnance Survey of Great Britain (published 1801) and the topographic survey of Switzerland (organized 1832). In the United States the U.S. Geological Survey (established 1879) has mapped much of the country on varying scales.
During the Nineteenth and Twentieth Centuries
During the 19th cent. the demand for national maps was fulfilled, and famous world atlases were published. But with the advent of the 20th cent. the need arose for an international map of the world on a uniform scale. Accordingly, at several meetings of the International Geographical Congress (1891, 1909, 1913), the German Albrecht Penck presented and perfected plans for a world map on a scale of 1:1,000,000, to consist of about 1,500 sheets, each covering four degrees of latitude and six degrees of longitude in a modified conic projection. Uniformity of lettering and the use of layer tints to indicate relief were agreed upon. However, only part of the work has been completed. The greatest single contribution to the map of the world was made by the American Geographical Society of New York, which completed (1945) its 107-sheet Map of Hispanic America.
During World Wars I and II the science and art of mapping were greatly advanced. Modern technology, using remote sensing by airborne and satellite radar, as well as devices called multispectral scanners, has made it possible to quickly collect and update information for mapmaking. Computerized geographic information systems, first developed in the 1960s, now are used to link information stored in databases to maps, increasing and varying the amount of information a map can display. Such systems are used to produce maps for business use, law enforcement, natural-disaster prediction, and many other purposes. In recent years the critical cartography movement, led by a group of British scholars, notably the late J. B. Harley, has studied maps as sociopolitical constructs that interpret reality and reflect the historical power structure as well as their makers' ideas about the world.
See T. W. Birch, Maps: Topographical and Statistical (2d ed. 1964); D. Greenhood, Mapping (rev. ed. 1964); F. J. Monkhouse and H. R. Wilkinson, Maps and Diagrams (1971); N. J. W. Thrower, Maps and Man (1972); G. R. Crone, Maps and Their Makers (5th ed. 1978); L. Bagrow and R. A. Skelton, History of Cartography (enl. 2d ed. 1985, repr. 2010); M. Monmonier, How to Lie with Maps (1991); A. H. Robinson et al., Elements of Cartography (6th ed. 1995); J. Black, Maps and Politics (1997); M. H. Edney, Mapping an Empire (1997); J. B. Harley and D. Woodward, ed., History of Cartography (2 vol., 1987–); J. B. Harley, The New Nature of Maps (2001); J. Black, Maps and Politics (2001); S. Schulten, The Geographical Imagination in America, 1880–1950 (2001); P. Whitfield, The Image of the World (upd. ed. 2010).