Gerardus Mercator

1512-1594

Flemish Geographer and Cartographer

The word "atlas" to define a collection of maps was coined by Gerardus Mercator, who is best known for his 1569 invention of a new system of projection for marine charts, called the Mercator projection, which revolutionized cartography as well as nautical navigation.

The son of a shoemaker, Mercator was born Gerhard de Kremer on March 5, 1512, in Rupelmonde, Flanders (now Belgium). His name was later latinized to Gerardus Mercator. Mercator began his education in Hertogenbosch in the Netherlands, where he studied Christian doctrine, dialectics, and Latin. From there, he continued his education at the University of Louvain, studying philosophy and the humanities and graduating in 1532 in geography, geometry, and astronomy. While at university, Mercator was a mathematical pupil and assistant to Gemma Frisius (1508-1555), a physician, astronomer, and mathematician for whom he worked as an instrument-maker and globe-maker after graduating.

Before going to work with Frisius, however, young Mercator spent two years of religious study in Antwerp and Mechelen to reconcile his doubts regarding the biblical account of the origin of the world versus the teachings of the philosopher Aristotle (384-322 b.c.). During this time, he developed a passion for geography and subsequently began pursuing a career as a professional cartographer. In 1534 he was married to Barbara Schellekens (with whom he had six children).

Mercator returned to Louvain and from 1535 to 1536 worked with Frisius and Gaspar à Myrica to construct a terrestrial globe. In 1537 the team completed a celestial globe. The same year, Mercator created his first map, of Palestine, and one year later, had completed his first map of the world, a unique double heart-shaped projection. He began gaining a well-deserved reputation as a cartographer and talented engraver and, in 1540, published his first book, a manual on the italic lettering he had introduced on his maps entitled Literatum Latinarum quas Italicas cursoriasque vocant scribende ratio, for which he created woodblock engravings depicting the lettering.

From 1541 to 1551 Mercator spent much of his time creating globes, interrupted only by a seven-month stint in prison for Lutheran heresy (1544). In 1552 he embarked on a new career as a mapmaker and lecturer at the University of Duisburg in the Duchy of Cleve in Germany. Two years later he published a map of Europe, which perfected earlier maps such as those of Ptolemy (c. 100-c. 170). He followed it, in 1564, with a map of the British Isles. That same year, he became the court cosmographer to Duke Wilhelm of Cleve.

In 1569 Mercator introduced, with the publication of his world map, a new system of projection for marine charts featuring true bearings, or rhumb-lines, between any two points (a ship's course could be found by laying a ruler across the map). His system, mathematically derived in an early form of calculus, allowed for a more accurate representation of the world's continents and resulted in a revolutionary cylindrical projection where a straight line between any two points forms the same angle with all the meridians, which appear as straight, or longitude, lines that are perpendicular to the Equator and parallels, which appear as straight, or latitude, lines that are parallel to the Equator.

Mercator's 1569 world map was one part of his plan of publications that began the same year with the publishing of a chronology of the world from its creation to 1568, followed, in 1578, by the publication of 27 maps originally prepared by the Greek geographer Ptolemy with corrections and commentary by Mercator. He finished the whole work, but it wasn't published until 1595, shortly after his December 2, 1594, death; it carried the title Atlas, the name chosen by Mercator to represent a collection of maps. The Atlas was preceded by the publication of a series of maps—in 1585 Mercator issued new maps of France, Germany, and the Netherlands; in 1589 he published new maps of Italy, Sclavonia (the Balkans), and Greece; and in 1595 the posthumously published Atlas included all his previous maps as well as a new series of maps on the British Isles. After Mercator's death, his Atlas had a new printing (in 1602), and a 1606 edition including new maps by Jodocus Hondius (1563-1612) became known as the Mercator-Hondius Atlas.

ANN T. MARSDEN