Gerardus Mercator

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Dutch cartographer and geographer (1512–1594)

Mercator, originally named Kremer, was born at Rupelmonde, now in Belgium. At the University of Louvain (1530–32) he was a pupil of Gemma Frisius. After learning the basic skills of an instrument maker and engraver, he founded his own studio in Louvain in 1534. Despite accusations of heresy and imprisonment in 1544, he remained in Louvain until 1552, when he moved to Duisburg and opened a cartographic workshop.

Mercator first made his international reputation as a cartographer in 1554 with his map of Europe in which he reduced the size of the Mediterranean from the 62° of Ptolemy to a more realistic, but still excessive, 52°. He produced his world map in 1569 and his edition of Ptolemy in 1578, while his Atlas, begun in 1569, was only published by his son after his death. It was intended to be a whole series of publications describing both the creation of the world and its subsequent history. Mercator was the first to use the term ‘atlas’ for such works, the book having as its frontispiece an illustration of Atlas supporting the world.

The value of Mercator's work lies not just in his skills as an engraver, but also in the introduction of his famous projection in his 1569 map of the world. Navigators wished to be able to sail on what was called a rhumb-line course, or a loxodrome, i.e., to sail between two points on a constant bearing, charting their course with a straight line. On the surface of a globe such lines are curves; to project them onto a plane chart Mercator made the meridians (the lines of longitude) parallel instead of converging at the Poles. This made it straightforward for a navigator to plot his course but it also produced the familiar distortion of the Mercator projection – exaggeration of east–west distances and areas in the high latitudes.

The big difference, apart from projection, between Mercator's and classical maps was in the representation of the Americas. He was not the first to use the name America on a map, that distinction belonging to Martin Waldseemüller in 1507, but he was the first to divide the continent into two named parts – Americae pars septentrionalis (northern part of America) and Americae pars meridionalis (southern part of America).

The Flemish cartographer Gerhardus Mercator (1512-1594) was among the first makers of modern atlases and is best known for his great world map, or chart, using the projection that has acquired his name.

In the history of cartography the work of Gerhardus Mercator illustrated a significant departure (though by no means a complete break) with the geographical traditions of the Middle Ages and those established by the revived Ptolemaic geography. It also signaled the late Renaissance convergence of academic cartography with the practical needs of navigators, an important step in the creation of that dynamic unity between science and technology that is one of the signal characteristics of the modern world.

Mercator was born Gerhard Kremer in Rupelmonde, Flanders, on March 5, 1512. He studied with the cosmographer Gemma Phyrisius at the University of Louvain and gained practical experience as an instrument maker and surveyor. His early successes brought him into close contact with the court of Emperor Charles V; but under growing pressure for his Protestant beliefs, he emigrated to the German Rhineland in 1552. There he settled permanently with his workshop in Duisburg, and in 1564 he became cosmographer to the court of the Duke of Jülich, Cleve, and Berg.

Mercator's early works prepared the way for his world map of 1569. These included maps of the Holy Land (1537), the world (1538), Flanders (1540), Europe (1554; rev. ed. 1572), and Britain (1564). He also constructed terrestrial and celestial globes (1541 and 1551). These maps reflected the critical compilation and rendition of a growing body of data that were typical of the cartographical methods of the time. The 1554 map of Europe showed Mercator's willingness to abandon the theories of Ptolemy and other predecessors in the light of further advances in knowledge. The length of the Mediterranean was shortened by 10 degrees (though remaining disproportionately long), and the stretch of land between the Baltic and the Black seas was widened.

Others may have experimented with the "Mercator projection" before Mercator; he was the first, however, to give cartographical rendition to the solution to the problem for which the projection was designed. This was the problem of plotting loxodromes (rhumb lines, or lines of constant bearing) as straight lines on a navigator's chart. Meridians of longitude converge at the poles, but if lines of constant bearing are plotted as cutting across them at constant angles, they must appear as parallel on the flat map, or chart. This requirement in turn necessitates a proportional increase in parallels of latitude from the Equator to the poles (proportional to the increasing east-west distances between the meridians). The shape of sectional areas is preserved, and the loxodromes can now be plotted as straight lines, although this is achieved at the expense of distortion of the world map as a whole (that is, the radical increase in relative proportions from Equator to poles, hence the apparent gigantism of land masses like Australia and Greenland on a Mercator projection map). This was the solution rendered in the 1569 world map, but it was not fully accepted by navigators until small area charts based on the projection began to be published in the next century.

The rest of Mercator's life was taken up with a three-part publishing project. He planned to print maps based on Ptolemy's Geography, maps of the ancient world, and an atlas of modern maps. The Ptolemaic maps were published in 1578, and the modern atlas appeared in three sections between 1585 and 1595. The entire work (mainly maps of western and southern Europe), totaling 107 maps, was published in 1595. Mercator, however, had died the year before at Duisburg, on Dec. 2, 1594.

Further Reading

Mercator's place in the history of cartography is discussed in Lloyd Arnold Brown, The Story of Maps (1949), and Gerald Roe Crone, Maps and Their Makers: An Introduction to the History of Cartography (1953; 4th rev. ed. 1968). His relation to the new geographical knowledge is examined in the appropriate chapters of Boies Penrose, Travel and Discovery in the Renaissance, 1420-1620 (1952), and John Horace Parry, The Age of Reconnaissance (1963).

Additional Sources

Blondeau, R. A., Mercator van Rupelmonde, Tielt: Lannoo, 1993.

Gerardus Mercator

Gerardus Mercator (5 March 1512 – 2 December 1594) was a Flemish cartographer. He was born in Rupelmonde in the County of Flanders. He is remembered for the Mercator projection world map, which is named after him. This proved very useful to many later explorers.

Contents 1 Life and works 2 See also 3 Further reading 4 References 5 External links

Life and works

Mercator was born Gheert Cremer (or Gérard de Crémère) in the Flemish town of Rupelmonde to parents from Gangelt in the Duchy of Jülich. "Mercator" is the Latinized form of his name. It means "merchant". He was educated in 's-Hertogenbosch by the famous humanist Macropedius and at the Catholic University of Leuven. Despite Mercator's fame as a cartographer, his main source of income came through his craftsmanship of mathematical instruments. In Leuven, he worked with Gemma Frisius and Gaspar Myrica from 1535 to 1536 to construct a terrestrial globe, although the role of Mercator in the project was not primarily as a cartographer, but rather as a highly skilled engraver of brass plates. Mercator's own independent map-making began only when he produced a map of Palestine in 1537; this map was followed by another -- a map of the world (1538) -- and a map of Flanders (1540). During this period he learned Italic script because it was the most suitable type of script for copper engraving of maps. He wrote the first instruction book of Italic script published in northern Europe.

Mercator map of Europe

Mercator was charged with heresy in 1544 on the basis of his sympathy for Protestant beliefs and suspicions about his frequent travels. He was in prison for seven months before the charges were dropped -- possibly because of intervention from the university authorities. ^[1]

In 1552, he moved to Duisburg, one of the major cities in the Duchy of Cleves, and opened a cartographic workshop where he completed a six-panel map of Europe in 1554. He worked also as a surveyor for the city. His motives for moving to Duisburg are not clear. Mercator might have left the Netherlands for religious reasons or because he was informed about the plans to found a university. He taught mathematics at the academic college of Duisburg. After producing several maps, he was appointed Court Cosmographer to Wilhelm, Duke of Jülich-Cleves-Berg in 1564. He constructed a new chart and first used it in 1569. It had parallel lines of longitude to aid navigation by sea, as compass courses could be marked as straight lines.

Rumold's world map, drawn in 1587 after his father's map of 1567 (published in 1595)

Mercator took the word atlas to describe a collection of maps, and encouraged Abraham Ortelius to compile the first modern world atlas --Theatrum Orbis Terrarum -- in 1570. He produced his own atlas in a number of parts, the first of which was published in 1578 and consisted of corrected versions of the maps of Ptolemy (though introducing a number of new errors). Maps of France, Germany and the Netherlands were added in 1585 and of the Balkans and Greece in 1588; further maps were published by Mercator's son Rumold Mercator in 1595 after the death of his father.

Mercator devised a technique to produce globes — celestial as well as terrestrial — by techniques of relative mass production. Globes at the time were laboriously produced by engraving upon a sphere of wood or gilded brass. Mercator moulded globes of papier-mâché on a wooden mould, then cut them along the equator; once reassembled, the globes were coated with gesso, a white mixture of thin plaster and sizing. Mercator engraved and printed sets of world maps on twelve tapering gores, with curved edges that narrowed towards the poles. These twelve gores were cut out and applied to the globe. Circular engraved caps covered the ends at the poles. After the globes were hand-tinted with watercolors, they were set in wooden stands with calibrated brass horizon rings. Twenty-two such pairs of Mercator globes have survived.

Following his move to Duisburg, Mercator never left the city and died there, a respected and wealthy citizen. He is buried in the city's main cathedral of Saint Salvatorus. Exhibits of his works can be seen in the Mercator treasury located in the city.

More exhibits about Mercator's life and work are featured at the Mercator Museum in Sint-Niklaas, Belgium.

See also

Atlas portal

• History of cartography

Further reading

• Nicholas Crane: Mercator: the man who mapped the planet, London: Phoenix, 2003, ISBN 075381692X

References

1. ^ "Gerardus Mercator", Britannica Online Encyclopedia. Accessed 25 January 2008.

External links

• Turn the pages of the British Library's Mercator Atlas of Europe (c.1570)
• Mercator's Atlas
• India Tertia and the mapping of the colonial imaginary by Siddharth Varadarajan
• O'Connor, John J.; Robertson, Edmund F., "Gerardus Mercator", MacTutor History of Mathematics archive .

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