He had bought a large map representing the sea,
Without the least vestige of land:
And the crew were much pleased when they found it to be
A map they could all understand.
‘What’s the good of Mercator’s North Poles and Equators,
Tropics, Zones, and Meridian Lines?’
So the Bellman would cry: and the crew would reply
‘They are merely conventional signs!
‘Other maps are such shapes, with their islands and capes!
But we’ve got our brave Captain to thank:’
(So the crew would protest) ‘that he’s bought us the best –
A perfect and absolute blank!’
Lewis Carroll, The Hunting of the Snark
Well, what is the good of Mercator’s famous world map of 1569? It’s riddled with distortions and full of countries many times larger than they really are. And yet, astonishingly, it’s still essentially the map we use today. Countries have been added of course, and the shapes of coasts and borders have been corrected and politically adjusted, but the map that shaped the end of the Renaissance, saw in the Enlightenment and adorned Victorian classrooms remains the display of choice, right through to the latest Google Maps. It is the definitive icon of our world and to mess with it looks like terrorism. Not that people haven’t tried.
We aren’t looking at one map, of course, but a projection of the world – a template for all maps. Which is perhaps a little ironic for Gerardus Mercator, born in Flanders and working at the time in Duisburg, on the Rhine, was not himself a prodigious cartographer. When he laid out his famous world projection in 1569, at the age of fifty-seven, he had produced less than ten maps. But his new one was an undoubted wonder – mathematically meticulous and constructed with startling scale and ambition. It measured roughly 2 × 1.25 metres over eighteen printed sheets and must have stunned all who saw it.
The things that look wrong to us now – Greenland the size of Australia rather than a third of it, an Antarctic continent that bumps raggedly and indefinitely along the base – were not the strangest things then, for exact proportionate sizes were not yet known and the polar regions were but dismal myth. The strangest thing to his contemporaries was that Mercator, a man who had never been to sea (and would never go), would so effectively help the mariner plot a true course across the oceans after so many centuries of intuitive guesswork. The military would also have cause to be grateful to him: he helped them more accurately fire their cannons.
The Mercator map’s main attribute was technical: it provided a solution to a puzzle that had been troubling map-makers since the world was recognised as a sphere, which is to say back to Aristotle. The problem was: how does one represent the curved surface of the globe on a flat chart? The strict and well-established grid of latitude and longitude was all very well for theoretical coordinates, but the navigator pursuing a constant course sailed on an endless curve. Mercator had already displayed this curving course on his globes through his rings or ‘rhumb’ lines, and now he wanted to convert them to a map, and enable any navigator to swiftly locate his position and find his way to any destination.
Mercator had struggled with the problem for a while. You can too: take a nice furry tennis ball, draw a few shapes representing countries on it and slice it in two. Then make some more nicks on the cut sides and flatten it out. The countries will bulge up in the middle, and in order for the tennis ball map to lie flat the middle must be shrunk and the edges expanded. Now try to do this accurately, so that sailors bring their cargo home. Mercator’s quest was to find a way of doing so by mathematical formula.
In 1546 he wrote to a friend that the same journey by sea between two places would often be described in ships’ logs with very different latitudes. The maps were simply misleading: ‘I saw that all nautical charts … would not serve their purpose.’ He wasn’t the first one to see this, but the problem only really presented itself in the sixteenth century with the refinement of the compass and the classic voyages of discovery that tacked their way across new oceans. In the space of a few decades there were numerous new and often cranky projections of the world: the Azimuthal and the Azimuthal Equidistant, the Orthographic, Gnomic, Stereographic, Cordiform, Pseudocordiform, Globular, Trapezoidal and Oval.
Almost all of these projections depended on the graticule system of latitude and longitude, and most marked the Tropics and the Equator. Not all of them were aimed at seafarers; some were better suited to celestial or polar mapping, while others were illustrative and impressionistic. Leonardo da Vinci and Albrecht Durer had also had artistic shots at the problem.
Inevitably Ptolemy had already tackled the issue first – twice. He named one projection ‘inferior and easier’ and one ‘superior and more troublesome’. The former, his by now classical grid system, was naturally limited: in the first projection, for example, his latitude began at his equator (pitched at 16˙25° south to 63° north), while longitude, extending to a mere 180 degrees of the sphere, had a zero meridian beginning at the Blessed Isles, a land now regarded as either the Canary Islands or Cape Verde. Nonetheless, given the limitations posed by an inadequate supply of coordinates, the area covered by his projection is a remarkably good approximation of the true relationship between countries that we recognise today.
The way the world looks, then and now: Mercator’s 1569 classic, printed over eighteen sheets and demanding a double page of any book.
Mercator’s map drew heavily on Ptolemy’s gazetteer and refined it with recent discoveries, notably the outline of North America, which was fully realised, indeed almost plump. But his enduring breakthrough was his new Conformal projection, the method by which he manoeuvred his latitudinal rings to keep all the angles straight (the lines of latitude became further apart as they moved from the Equator). Mariners would thus be able to navigate across the map in straight lines, in keeping with the desired direction of their flickering compass.
Mercator used the blank space on the unexplored interior of North America and his empty oceans to justify his new device to all who might find his projection unfamiliar. He explained that he intended ‘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.’ In so doing, Mercator had created a grid which, in the words of his recent biographer Nicholas Crane, ‘would prove as timeless as the planetary theory of Copernicus. In seeking the essence of spatial truth, he had become the father of modern mapmaking.’
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What has happened to Mercator’s projection since? It has inevitably been modified and improved.
This process began almost as soon as his world map was first published (most notably by Edward Wright, Edmund Halley and Johann Heinrich Lambert), and has continued up to Google – which, extraordinarily, found Mercator’s neat and symmetrical rectangles perfectly suited to the pixelated tiles that make up a digital map.
The projection’s resilience is even more remarkable when one considers the forces that have raged against it for the last four hundred and fifty years. In 1745 a Frenchman named César-François Cassini de Thury suggested using a cylindrical projection, sometimes shown as two hemispheres placed on top of each other with their centres at the poles. This showed a true scale along its central meridian and all places at right angles to it, but a varying level of distortion elsewhere. A more radical transformation was proposed by the Scottish astronomer James Gall at a meeting in Glasgow in 1855. Gall highlighted the essential fault with the Mercator projection – the shapes of the land masses were vaguely right, but their sizes were wrong. Applying his new ‘stereographic cylindrical’ theory first to the constellations and then to earth, he found a way of flattening the earth to a more compact scale, while also decreasing some of Mercator’s distortions (although introducing others).
Without due acknowledgement, many of the attributes of Gall’s work were picked up by the German Arno Peters in the mid-1970s and turned into a hot political quarrel that has still not entirely subsided. The argument was relatively simple: because of its high-latitude distortions, the Mercator map over-emphasised the size and significance of the developed world at the expense of the under-developed (which tended to be closer to the Equator). Peters’ cylindrical projection (now generally known as the Gall-Peters projection) was therefore put forward as both an anatomically and politically correct alternative, and even though its claims were not novel (and it was often compared to a washing line on which countries had been hung out to dry), its alternative to the ‘cartographic imperialism’ and ‘Euro-centric ethnic bias’ of Mercator’s map took on a voguish momentum.
The screenwriter Aaron Sorkin summarised it caustically in an episode of The West Wing in 2001, a scene in which the Press Secretary C.J. Cregg and Deputy Chief of Staff Josh Lyman attend a briefing by members of the fictional Organisation of Cartographers for Social Equality. The OCSE were pushing for the President to ‘aggressively’ support legislation that would make it mandatory for every school to use Peters rather than Mercator. ‘Are you saying the map is wrong?’ Cregg asks. ‘Oh dear yes,’ the OCSE representative replies as the slideshow behind him displays same-size images of Africa and Greenland. ‘Would it blow your mind if I told you that in reality Africa is fourteen times larger?’
Another OCSE member then explains that Mercator’s Europe is drawn considerably larger than South America, whereas in reality South America’s 6.9m square miles is almost double Europe’s 3.8m square miles. Then there is Germany. Germany appears in the middle of the map, whereas in fact it should be in the northernmost quarter. ‘Wait,’ Josh Lyman says. ‘Relative size is one thing, but you’re telling me that Germany isn’t where we think it is?’
The Peters-Gall Projection: a ‘washing line’ of countries
‘Nothing’s where you think it is,’ the chief OCSE man says. He then clicks up the Peters Projection and the OCSE propose that the world map should be flipped so that the northern hemisphere is put on the bottom. A new slide shows what it will look like.
‘Yeah, but you can’t do that,’ C.J. Cregg reasons … ‘Because it’s freaking me out.’
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Peters died a year after the episode was broadcast, his projection ridiculed as much for the smug superiority of its proponents as for itself. In fact, the principal objections often centred on the fact that the supporters of Peters exaggerated both their claims and their outrage, perpetuating the myth that two thirds of Mercator’s map is dedicated to the northern hemisphere and only one third to the southern. And the Gall-Peters has its own distortions (particularly severe between 35° north and 35° south, and between 65° and the poles), rendering some African countries and Indonesia twice as long north-south as they really are. The Royal Geographical Society’s quarterly journal began its review of Arno Peters’ book The New Cartography (1983) thus: ‘Having read this book many times in German and English, I still marvel that the author, any author, could write such nonsense.’
Other projections have also found favour, including one produced by the American cartographer Arthur Robinson which combined elements of Mercator and Gall-Peters, and was adopted by the US map-making company Rand McNally. It first appeared at the height of the Cold War in the early 1960s, but argued against the perceived menace of the USSR by greatly reducing its surface size.
There are so many possible projections, each with their own particular political agenda and limitations, that there is a way of measuring their spatial prejudices as a chart, known as the Tissot Indicatrix of Distortion. This could take, say, the Winkel Tripel Projection of 1921 (yes, this is a real thing) and overlay it with a pattern of stretched circles to show the degree of corruption over any one area (a perfect circle showing true unity, an oval stretched north-south reflecting a north-south distortion).
Will one projection emerge victorious? It’s already happened. Mercator’s map casts its shadow over the digital world just as it did in the world of those navigators opening up new trade routes half a millennium ago, and the possibilities for its future manipulation are therefore limitless. It is the projection used not only by Google Maps, but also (with a spherical interpretation) by its rivals, Microsoft’s Bing and OpenStreetMap. Even in the virtual age it is the ocean-crossing of least resistance. Any alternative would have to be imposed centrally by a court bigger than the United Nations, whose logo, incidentally, is a projection of a globe centred on the Arctic Circle and wreathed in olive branches that first appeared twelve years after Mercator’s.
Yes indeed: the Postel Azimuthal Equidistant of 1581 still has its influential supporters.
When in 1580 Francis Drake returned triumphant from his unintentional circumnavigation of the world, Elizabeth I declared two things: her delight at the fact that his cargo had enabled her to pay off the national debt (she knighted him the following year); and her wish that Drake’s route to the world’s untapped riches remain secret by staying off the maps. Nervous of their necks if they disobeyed, the nation’s cartographers upheld her decree, at least on paper. When one of them finally broke cover after nine years, the map that emerged was intricate, accurate, and struck as a solid silver medallion to be worn around the neck.
There are nine known copies of the Silver Map of Drake’s Voyage, two of them in the British Museum, one in the Library of Congress. Eight of the medallions are almost identical, with a diameter of 69mm, and a small tang at the top, which can be pierced to take a chain. But only the Library of Congress medallion has a tiny oval addition on one side with details of its date, maker, and origination: Michael Mercator, 1589, London.
Michael Mercator was a grandson of Gerardus Mercator, and the world displayed on his Silver Map was drawn from various Dutch, Flemish and English sources. Significantly, it was based on his grandfather’s famous projection. But precisely how he obtained the details of Drake’s route (which he shows with a dotted line) is unclear. Several accounts of Drake’s great voyage were published shortly before the Silver Map was cast, most notably by the English geographer Richard Hakluyt, but any new discovery that appeared on a map was certainly not credited to Drake before 1589, the year after the defeat of the Armada.
How hard must it have been for Drake and his crew to keep the details of their circumnavigation concealed for nine years? Columbus had been under no such restraint in 1492, and nor was Juan Sebastian Elcano, who completed Magellan’s circumnavigation in 1522. Drake had only his riches, valued at some £1000, to console him.
The world around your neck: Drake’s silver medal, enlarged to show the impressive detail of his ragged circumnavigation.
Inevitably, secrecy spawns speculation. And no one speculated more than the two most famous map-makers of the age, Gerardus Mercator and Abraham Ortelius. Drake reached Plymouth at the end of September 1580, and only ten weeks later Mercator wrote to ‘Master Ortelius, the best of friends’ that ‘I am persuaded that there can be no reason for so carefully concealing the course followed during this voyage, nor for putting out differing accounts of the route taken and the areas visited, other than that they must have found very wealthy regions never yet discovered by Europeans …’ But he got it wrong: he assumed that Drake’s expedition ‘pretend[ed] they secured through plunder’ their ‘huge treasure in silver and precious stones’. But, in fact, that was precisely what had happened.
Mercator and Ortelius were intrigued not only by Drake’s haul but also by rumours of two sightings that, if true, would once again transform the look of the world. And these rumours were true: Drake and his men had landed in the upper parts of California (which he named Nova Albion), and sailed past the islands of Tierra del Fuego, which were thought previously to be part of the giant unmapped southern continent of Terra Australis.*
That all this appeared credited to Drake for the first time on a fancy piece of jewellery designed to be hung around the neck of privileged Elizabethans was remarkable in itself, but the medallion offered even more: it is without doubt the smallest map to document so much geographical significance on one side, and conceal so much ruthless piratical history on the other.
The map contains 110 place names. Europe includes the recognisable landmarks of Hibernia, Scotia, Moscouia and Gallia, while Africa boasts Aegypt, Maroco, Mozambique and Serra Lione. China and Japan are present without further detail. On the western side, North America shows both Nova Albion and Californea, while South America features Panama, Lima, Chili and Peru. Frisland still sits mythically in the Atlantic, while there are also the enticing Pacific possibilities of Cazones (Santa Domingo), I. d. los Reyes (possibly Christmas Island) and Infortunates Insules (conceivably Easter Island).
Drake’s route through this world was shown as a dotted line, already an established technique in the sixteenth century (Magellan and his crew, who predated Drake’s circumnavigation by sixty years, had their journey dotted on several globes and maps). In addition to the line, eight inscriptions provide an unexpectedly large amount of additional information about his voyage, including departure and arrival dates, the passage through the Strait of Magellan and the discovery of New Albion. But the map cannot show everything.
The historian Miller Christy published a study of the Silver Map in 1900 and it became clear as he traced Drake’s route on the medallion that it relied almost entirely on opportunism. All sailors are reliant on fair winds, clear skies and suitable weather, but in the sixteenth century other obstacles were just as likely to throw out what passed for planning. Navigational instruments were unreliable; other explorers from other dominions wanted the same things you did and thus had to be engaged; and the maps beyond Europe were both incomplete and wrong. Drake’s passage was affected by all these factors. He left Plymouth on 13 December 1577 with five ships, gave Spain a wide berth to avoid detection, and struck the north-west coast of Africa a fortnight later. He reached the Cape Verde Islands, sailed down the coast of Brazil, and entered the Strait of Magellan in August; the medallion shows his newly named Elizabeth Island. But he was then forced south against his will by a two-month storm, which enabled him to recognise Tierra del Fuego as an archipelago and, beneath it, the latterly named Drake Passage, the strip of ocean connecting the Atlantic and Pacific (Drake did not sail through this notoriously stomach-churning passage himself).
The rest of Drake’s route depicted on the map was equally eventful. Two ships in his convoy foundered in storms (two others had already been broken up after crossing the Atlantic); then sailing northward up the coast of South America he encountered his biggest hauls of silver from the Spanish, and, just as valuable, some of their maps. His hull full and glistening (the Silver Map may have been made from his haul), Drake feared revenge if he returned home by doubling back, so he kept going, towards what he hoped would be the famed Northwest Passage from the Atlantic to the Pacific around the north of North America. Instead he sailed into the area described ominously only two years before by Sir Martin Frobisher as ‘The Mistaken Strait’ (renamed Hudson Strait in 1609), and thereafter resolved with his crew to return home from San Francisco, through the Indian Ocean and round the Cape of Good Hope. Miller Christy contends that ‘it is probable that he had never, up to this point, contemplated a circumnavigation of the Globe.’