|The geographical knowledge of Western Europe changed almost beyond recognition between 1470 and 1520. For while the spherical shape and approximate size of the globe had been known since classical times, and had not been lost in the Middle Ages, what lay one thousand miles beyond Europe and the Mediterranean was largely speculative or second-hand. But the great European voyages of discovery after c.1470, using the new three-masted sailing ships, transformed that.
Consequently mapping the world became a subject of great scholarly and practical importance, and the Low Countries at Antwerp and Louvain in particular, became world leaders: seizing the initiative from the hitherto pre-eminent Venetians, and by 1600, losing it to the Dutch. And crucial to this development was the new ability to print books and maps to widely disseminate geographical ideas.
Sebastian Munster’s Cosmographia is part of this tradition and conspicuously draws upon the foremost Belgian cartographer and mathematician of the previous generation, Gemma Frisius, as well as Petrus Apianus (Peter Apian), and on to Martin Waldseemüller of 1507.
What Munster and his predecessors were trying to do was to find accurate geometrical projection techniques whereby the three-dimensional Earth could be accurately projected upon a flat sheet of paper. (No easy task, and not really solved until the Dutchman, Gerard Mercator in 1569). But Munster’s book is a sustained essay on mathematical practice and surveying: how to use the stars, solar shadows, and eclipses of the sun and moon to fix co-ordinate points on the surface of the Earth; to relate Panama, South Africa, or Indonesia to a known European location, such as Antwerp.
And as these Belgian cartographers were working nearly a century before logarithms and algebra greatly eased the business of doing spherical trigonometry calculations, a variety of empirical devices are inserted and described within the text. These include cut-out-and-assemble paper mathematical instruments to be stitched into the pages by the original purchaser: very familiar teaching aids by the 16th century, and going back to the manuscript vellum prototypes used in medieval mathematical books - teaching devices known as ‘volvelles’, as they included rotating parts.
Cosmographia also contained a detailed section on land surveying, calculating the heights of towers and the distances of objects; all of which would become part of the skills needed for the emerging professions of deep-sea navigation (as opposed to old-fashioned coastal pilots), civil and military engineers, cartographers and mathematical teachers.
Munster’s book is opened to the fold-out world map. It provides an excellent account of what was known about the globe by the mid-16th century. For by this time, and contra the classical cartographers such as Ptolemy and Strabo, it was known that water, and not land, covered most of the Earth’s surface. The outlines of Africa, South America, the Caribbean, India and Asia were “correct” to an astonishing degree, although the western seaboard of North America was still vague. Notice, however, that the supposed great Southern Continent – “Terra Incognita Australis” – was believed to occupy a large part of the southern hemisphere, and to join almost on to the tip of South America, though Ferdinand Magellan had discovered a sea-passage between the Atlantic and the Pacific around 1518. It would be Sir Francis Drake, however, in 1578, who would sail further south and realise that a vast ocean flowed beyond Tierra del Fuego, and that America was not joined to a southern continent.
Note the artistic licence of placing a Greek oared warship in the Pacific! Such a craft could never have survived the rough seas. Only the new, powerfully-built Carracks and Galleons of the 16th century could hope to survive in the mountainous seas of the South Atlantic and Pacific.