Ever since antiquity, geography and chronology had been regarded as the two eyes of history, and both were now undergoing radical reassessments in the light of the recent voyages of discovery. The encounter with the New World alone required new cosmographies to understand the changing terrestrial space of the known world; its inhabitants and their histories posed equally difficult questions for Christian chronology. Why were such people not mentioned in the Bible? How should their history be assessed within Christian Creation – especially where it threatened to predate it? In the sixteenth century, cosmography and chronology were central to providing answers to some of the most contentious questions of the time.
Both subjects appealed to brilliant, unorthodox and in some cases dissident thinkers. To many, the cosmographer seemed to adopt a divine perspective from which to gaze upon the earth, while also looking up and speculating on the structure and origins of the universe. But as Mercator knew, it also risked accusations of pride, or hubris – or heresy. Nor was chronology immune from such charges. The study of the arrangement of historical events in time, and their assignation to an agreed dateline, had fascinated scholars since classical times, but by the sixteenth century the practical and moral value of establishing such a line had become a preoccupation for scholars.37 ‘What chaos would there be in our present life’, asked Mercator’s contemporary, the astrologer Erasmus Rheingold in 1549, ‘if the sequence of years were unknown?’38 Without accurate chronology, how could you correctly celebrate Easter? And without temporal accuracy, how could you prepare for the predicted end of the world? At a more practical level, from the later fifteenth century people demanded increasingly accurate measurement of both clock and calendrical time. The development of mechanical escapement clocks introduced a new sense of time that drove people to work and to prayer, and these new technologies were supplemented by the publication of ever more complex chronologies, calendars and almanacs.
By the mid-sixteenth century, people also ‘turned to chronology in the hope of finding an order that the chaos of the present denied’.39 But with such hopes and fears came suspicions. Mercator’s near contemporaries, the Catholic Jean Bodin (1530–96) and the Huguenot Joseph Scaliger (1540–1609) both wrote vast, learned chronologies drawing on classical sources which appeared to contradict the biblical account of the Creation. In private, Scaliger worried over everything from Jesus’s genealogy to the date of the crucifixion, and concluded that chronology was not necessarily defined by religion. Both chronologers and cosmographers inevitably came to the attention of Catholic and Protestant authorities. As well as the accusations levelled against cosmographers like Finé, Bodin was accused of heresy, and Scaliger fled religious persecution in France; and many of their works ended up on the papacy’s Index of Prohibited Books.
By reviving his career as a cosmographer, and beginning with chronology, Mercator was trying to find a new way of answering the questions about creation and the origins of the cosmos that had occupied him since he had been a young student in Louvain. It was a more recondite route, but perhaps the secrets of chronology could disclose the past and even more importantly the future, putting the current apocalyptical times into greater perspective; and, as many including Mercator believed, chronology could disclose an imminent eschatology. After the publication of the Chronologia he would write to a friend that ‘I remain convinced that the war which is now being waged, is the one of the Hosts of the Lord, which is mentioned at the end of the seventeenth chapter of the Revelation of St. John; wherein the Lamb and the Elect will prevail, and the Church will flower as never before’.40 Whether this represented an attack on the excesses of reformed religious assaults on Rome is unclear, but it shows that Mercator certainly believed that the end of the world was imminent, and that chronology might reveal its exact date.
Fig. 21 Gerard Mercator, pages from Chronologia, 1569.
In 1569 Mercator’s Chronologia was published in Cologne. It drew on a vast assortment of Babylonian, Hebrew, Greek and Roman sources in an attempt to provide a coherent history of the world in accordance with the Scriptures.41 His solution to the problem of a chronology that could acknowledge all these sources and their divergent temporalities was to plot a table across which it was possible to compare each Christian date with Greek, Hebrew, Egyptian and Roman calendars. Readers could therefore navigate their way across time, slicing through a particular moment to compare it with other moments in world history. On page 147, for example, they could locate Christ’s Crucifixion as the fourth year of the 202nd Greek Olympiad, 780 in the Egyptian calendar, year 53 since the third destruction of the temple of Jerusalem in the Hebrew calendar, 785 in the Roman calendar, and 4,000 years since Creation.42 The problem that Mercator (along with other chronologers) faced was how to arrive at these calculations based on divergent estimates of the passage of time between the Creation and the coming of the Messiah. The Greek text of the Old Testament claimed 5,200 years separated the two events, while the Hebrew text claimed it was 4,000 years. Like many other chronologers, Mercator endorsed the Hebrew version, with slight revisions based on his reading of classic authors like Ptolemy.43
Compared to subsequent chronologers like Scaliger, Mercator’s theological chronology was quite traditional, although because it included references to reformed religious events and individuals it was soon placed on the Index of Prohibited Books. But it was his method of organizing his material that was so significant. In aligning simultaneous historical temporal events on the same pages, Mercator was attempting to establish chronology, and to reconcile apparently incompatible historical data, in the same way that the cartographer was trying to square the spherical globe and project it upon a flat surface.
Mercator’s Chronologia represented part of his wider cosmographic ideal, uniting the study of chronology and geography to rise above contingent, earth-bound behaviour. Its inspirations were Plato, Ptolemy and the Stoic philosophy of Cicero’s ‘Scipio’s Dream’, adopting a transcendent, cosmic gaze, rising up to look down on the world from above, indifferent to its petty terrestrial conflicts.44 This was the immediate context for the creation of the world map on Mercator’s famous projection: just as the Chronologia invited its readers to navigate across time, his world map would offer a spatial navigation across the globe, which also needed the guiding hand of the cosmographer to transform it into a flat surface. Rather than celebrating the virtues of European civilization by placing it at the centre of his work, the map was part of a cosmography that aimed to transcend the theological persecution and division of sixteenth-century Europe. Instead of exhibiting a confident Eurocentrism, Mercator’s world map would provide an oblique rejection of such values and a search for a larger picture of harmony across universal space and time.
The Chronologia was not a great success. Mercator had little if no reputation as a chronologer, and the book’s traditional interpretation of dates and events (notwithstanding its unusual layout) meant that it received little popular or critical attention; indeed, depite the fact that Mercator spent more than a decade writing it, the Chronologia is usually overlooked when compared to his geographical achievements, and in particular the map he was about to publish.
Several months after the printing of his chronology, Mercator released the next instalment of his cosmography: a world map, published in Duisburg, entitled Nova et aucta orbis terrae descriptio ad usum navigantium emendata accommodata, or ‘A New and Enlarged Description of the Earth with Corrections for Use in Navigation’. Mercator’s 1569 projection may be the most influential map in the history of geography, but it was also one of the most peculiar. Nothing prepared Mercator’s contemporaries for such a strange object: not its scale, its appearance, or its claims ‘for use in navigation’. As a cosmographer interested in mapping the heavens onto the earth, Mercator had shown little or no previous interest in the practical applications of maps for the pursuit of accurate navigation; indeed, his only previous attempt at a world map using the
cordiform projection in 1538 reflected a fascination with the theology of the heart more than navigating across the terrestrial globe.
This world map was enormous. Engraved on eighteen sheets, it was intended to hang on a wall, and when assembled it measured more than 2 metres in length, and was nearly 1.3 metres high, similar in size to Waldseemüller’s 1507 world map. But even more surprising was its strange layout. On first inspection it looks more like a work in progress than a triumphant moment in global cartography. Large areas of the map are given over to elaborately decorated cartouches containing extensive legends and complicated diagrams. North America, which on Waldseemüller’s map looked like a modest wedge of cheese, was transformed by Mercator into ‘India Nova’, a sprawling behemoth, with its northern land mass covering more space than Europe and Asia put together. South America, with its inexplicable south-western bulge, bore little resemblance to its presentation by Ribeiro and other mapmakers as an elongated pendulum. Europe covered twice its true area, Africa appeared reduced in size compared with contemporary maps, and South-east Asia was unrecognizable to those brought up on the Ptolemaic overestimations of its shape and size.
Even more peculiar is Mercator’s depiction of the polar regions, which were shown running the full width of the map’s top and bottom, making no apparent concession at all to the earth’s sphericity. Mystified viewers could consult the legend in the map’s bottom left-hand corner, which calmly informed them that Mercator based his conception of the northern polar regions on a mythical voyage undertaken by a fourteenth-century Oxfordshire monk called Nicolas of Lynn, who used his ‘magical arts’ to sail all the way to the North Pole. Mercator concluded that the polar region was composed of a circular land mass, ‘the ocean breaking through by nineteen passages between these isles forms four arms of the sea by which, without cease, it is carried northward there being absorbed into the bowels of the Earth’. On one of the land masses Mercator wrote, ‘Here live pygmies whose length in all is four feet, as are also those who are called Screlingers in Greenland’.45
In its fine detail the map looks more obviously poised between an older cosmographical tradition and a newer mathematical understanding of geography – much like Mercator’s religious beliefs. Mercator’s delineation of Asia is drawn from Marco Polo’s travels, but the map’s legends also record in some detail the recent political manoeuvrings surrounding the voyages of da Gama, Columbus and Magellan. There are long written digressions on the existence of the fabled Christian ruler Prester John, alongside very precise revisions of the Ptolemaic geography of the Nile, Ganges and the location of the ‘Golden Chersonese’. But across Africa and Asia Mercator also reproduces Pliny’s ‘Samogeds, that is the people who devour each other’, ‘Perosite, with narrow mouths, who live on the odour of roast flesh’, and ‘men who unearth the gold of ants’.
Mercator’s map shows the study of cosmography stretched to its furthest limits. In an attempt to combine the synoptic desire of cosmography with the mathematical rigour of the new techniques of surveying and navigation, the map looked backwards to classical and medieval authorities as much as it looked forwards to embrace a new conception of geography. But the great discovery Mercator made in his years of studying chronology alongside geography was a method of plotting a spherical earth on a plane surface, a mathematical projection that would transform mapmaking and signal the beginning of the end of cosmography.
In his address to the reader, contained within the enormous legend conveniently obscuring most of North America, Mercator explained that ‘in making this representation of the world we had three preoccupations’. They were ‘to show which are the parts of the universe which were known to the ancients’, so that ‘the limitations of ancient geography be not unknown and that the honour which is due to past centuries be given to them’. The ancients, and in particular Ptolemy, were being politely given their due and quietly shown the door. Secondly, Mercator aimed ‘to represent the positions and dimensions of the lands, as well as the distances of places, as much as in conformity with very truth as it is possible so to do’. But finally, and most importantly, his intention was
to spread on a plane the surface of the sphere in such a way that the positions of places shall correspond on all sides with each other both in so far as true direction and distance are concerned and as concerns correct longitudes and latitudes; then, that the forms of the parts be retained, so far as is possible, such as they appear on the sphere.
Mercator’s two aims here sound like basic common sense. Most people now would assume that a world map ensures that geographical features on a map have the same shape as on a globe, and that directions and distances are accurately represented. But Mercator knew from thirty years of making globes that it is not possible to retain both features on a plane surface. For the mid-sixteenth-century mapmaker, the problem was compounded by the fact that the representation of large areas was predominantly the domain of the cosmographer, who sought to show continents and seas from an imaginary point located above the earth, while direction and distance was of almost exclusive interest to the sea pilot, navigating across open water, with little or no interest in the shape of land masses.
Prior to the sixteenth century, none of this really mattered. Cosmography pursued its classical ideals, projecting geometrical principles onto the surface of a vaguely defined world. At the other extreme, the portolan sailing charts used in the Mediterranean required extremely basic methods of navigational projection, as they covered such a tiny fraction of the earth’s surface. As a result, they developed geometrical networks of criss-crossing straight lines to sail from one location to another. These were known as ‘rhumb lines’ – from the Portuguese rumbo (‘course’ or ‘direction’), or the Greek rhombus (‘parallelogram’). In reality, rhumb lines were curved due to the sphericity of the earth’s surface. If they were extended over great distances, the distortion would lead to a pilot sailing way off course, but across the relatively short distances of the Mediterranean, such discrepancies were of little serious consequence. Once the Portuguese began sailing longer distances down the coast of Africa and across the Atlantic, one of the many problems they faced was how to draw maps with straight rhumb lines that took into account the earth’s curvature.
Technically, a rhumb line is what later mathematicians would call a loxodrome (taken from the Greek loxos, or ‘oblique’, and dromos, or ‘course’).46 As its root suggests, a loxodrome was a diagonal line of constant direction that intersects all meridians at the same angle. Rhumb lines were not the only method of navigating across the earth’s surface. A navigator could use the traditional portolan-style straight line sailing method (and many navigators, fearful of change, continued on this path for decades), but beyond the Mediterranean it left sailors so far adrift that it soon became unsustainable. The other method was great circle sailing. A great circle is, as its name suggests, the largest circle that can be drawn around the globe, with its plane running through the earth’s centre. The equator and the meridians are all great circles. The advantage of great circle sailing was that great circles always represent the shortest route between any two points on the earth’s surface. But the likelihood of charting a route from one location to another that involved sailing exactly along the equator or a parallel was not only highly unlikely, but also technically very difficult, as the bearing of the curved arc is constantly changing, requiring pilots to repeatedly adjust their direction.
Rhumb lines represented a via media, or ‘middle way’. They were the most likely directions sailed by navigators, particularly once diagonal east–west routes via the Cape of Good Hope and Magellan’s Straits became vital for sixteenth-century European seaborne trade (the kind of routes traced by the ships depicted on Mercator’s map). But another complicated feature of any rhumb line drawn across the earth’s surface was not only that it curved, but that, if followed indefinitely, it traced a spiral that ends up infinitely circling one or other of the poles, because
of the gradual convergence of the meridians. For mathematicians, a loxodrome’s spiral is a beguiling geometrical feature, but for navigators, turning it into a straight line was a frustrating exercise. Mercator confronted the problem as early as 1541, when he traced a series of rhumb lines across the surface of his terrestrial globe. Portuguese cosmographers had already described the loxodrome in the 1530s when trying to explain why pilots navigating across the Atlantic found themselves gradually sailing off course. Unfortunately the Portuguese could offer no solution as to how to flatten out a loxodrome accurately onto a plane surface.
Fig. 22 Model of a spiral loxodrome.
In his address to the reader, Mercator proposed the ingenious solution to the problem that lay at the heart of his new projection, which was the curvature of the meridians. ‘Indeed,’ he wrote, ‘the forms of the meridians, used till now by geographers, on account of their curvature and convergence to each other, are not utilisable for navigation’, because, as he went on, ‘at the extremities they distort the forms and positions of regions so much, on account of the oblique incidence of the meridians to the parallels, that these cannot be recognised nor can the relation of distances be maintained’. Mercator then concluded famously, ‘It is for these reasons that we have progressively increased the degrees of latitude towards each pole in proportion to the lengthening of the parallels with reference to the equator’. How did he reach this conclusion, and how did it work?
A History of the World in 12 Maps Page 31
