Who Drew the Map That Taught Us to Know the World? | This Is How Our Lives Are Designed

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Gerardus Mercator — calligrapher, engraver, maker of scientific instruments, and also a cartographer and geographer. He solved a fundamental problem in mapmaking, and set the standard for modern cartography.

In 2010, Facebook, which then had 500 million users, published a rather strange map of the world. It marked no equator, no lines of latitude or longitude, no North or South Pole. China and Asia were almost entirely missing, and East Africa looked as if it had sunk into the sea.

This was not a map meant to convey geography for its own sake. It was a diagram showing where Facebook's users lived (which is why you can barely see China). The fine, interlacing fluorescent-blue threads stood for the connections between those users around the world.

In the digital age, drawing a map has become effortless. As Facebook did, you can simply count up user data and let something close enough to a world map appear on its own. Faced with a map like that, people rarely bother to argue about whether the Bering Strait between Eurasia and North America has been left out, or whether California has ended up inside the Arctic Circle. In mapmaking, precision is largely a matter of adding and subtracting. What matters is deciding which set of rules you do the arithmetic under.

Facebook's map, for instance, was essentially a marketing exercise — but to make it look at least like a map with some grounding behind it, Facebook still used a mapmaking rule that has been in service since the 16th century: the Mercator projection.

That projection came, of course, from a man named Mercator. Without this Dutchman of the Renaissance, human mapmaking might have taken much longer to reach its "modern" age. Besides forever probing the philosophical question of who I am, we would probably have needed a good many more detours before we could say correctly where I live.

But be clear about this: Mercator did not invent the map, and he was not the first person to draw one. As far as the record goes, there was no single, heroic inventor of the map. Recording where you are, like recording when you are, is a survival skill bred into human beings.

The earliest map found in North America was drawn on a piece of hide. Polynesians could convey newly gathered navigational knowledge with nothing more than a few small sticks.

Indian mapmakers, for their part, were not much troubled by the convention of north up, south down, west left, east right. Early Indian maps are steeped in the beauty of religion: they rendered the whole world as a lotus, each petal a landmass.

The Chinese led the way in early cartography for a time. The "six principles" of mapmaking — six drawing methods — that Pei Xiu set out in 267 CE were the most scientific mapping techniques of their day. But China did not keep the lead for long, and the story of cartography began to unfold, in volume, in Europe.

It is worth noting that although all of humanity took a keen interest in drawing maps, before the Age of Discovery in the 15th century a map did little more than explain the layout of one region. Until humans sent navigators out to measure the earth, the world held far too many unknown territories — some of them labelled, mysteriously, "here be dragons."

Ptolemy of ancient Greece was the first to pull the field together. In 127 CE he wrote a work of geography that laid out a detailed system of geographic calculation, with matching lines of latitude and longitude based on astronomical data. The method could be used to map information about Europe, North Africa and even southern Africa, but given the way the known world was divided at the time, it was not precise enough. That is why the east coast of Africa as he drew it does not match reality, and why he described India as an enclosed inland sea.

Still, because this systematic work of Ptolemy's came so early, his Geographia was in time translated from Greek into Latin. The book usually carried 27 maps, three of them projections. Out of this came a way of observing the world by choosing surfaces from different projection grids — the foundation the Mercator projection would later improve upon.

But for Europeans, Geographia could not keep up with the times, and it could not hold the discoveries they were making in one field after another.

After Ptolemy, the history of cartography entered the Dark Ages along with the rest of Europe. Religion crushed, without mercy, the long human wish to pursue the objective and the true in matters of space. Medieval maps drew the world as a great disc with the holy city of Jerusalem at its center. Across the southern half of the disc lay the Nile and the Don; down the middle ran the Mediterranean; together they formed a T-shaped body of water dividing the world into three continents — Asia, Europe and Africa.

Mercator took the baton from that generation of medieval mapmakers.

He was not only a geographer but a cartographer. Because he poured his interest in mathematics, astronomy, cosmology, geomagnetism, history, philosophy and theology into the drawing of maps, he can also be counted a calligrapher, an engraver and a maker of scientific instruments.

Mercator was born in 1512 in Rupelmonde, a small port near Antwerp, in Belgium. His father was a shoemaker and not well off. Under an uncle's influence, Mercator went to a monastery school at 15, took clerical training, and there honed the calligraphy he would later be known for. To study Christian theology and Latin better, he worked up an elegant italic hand, which he thought suited scholars better than Gothic lettering did. In 1540 he even wrote a pamphlet, How to Write the Latin Letters Which They Call Italic or Cursive, explaining how to use italic script in mapmaking.

This was Mercator's hard-won craft, and it won him his first reputation in cartography.

In the early 16th century, mapmakers all used a heavy Gothic typeface. The letters were large and ate up the surface of the map, so not many place names could be marked. Mercator switched to a new italic — Italian cursive — which freed up room on a globe for labels.

In 1536, Mercator, by then an engraver, made a globe of his own. Nicholas Crane, the modern biographer who wrote Mercator's life, notes that other mapmakers "could mark only 50 American place names on a wall map about as tall as a grown man, whereas Mercator marked 60 place names on a globe only two palms wide."

Later, Mercator took on a field survey of Flanders, using the magnetic meridian Columbus had discovered as the standard line of longitude — the beginning of maps drawn from actual measurement.

In 1537 he also made a map of the Holy Land of the Bible. It let people of the day gain "a clearer understanding of the Hebrew and Greek portions" of the biblical record. In the 16th century, maps of the Holy Land were an unreliable lot: some marked fewer than 30 place names, and errors were plentiful. Mercator's marked more than 400 sites alone. It also traced the route the Israelites took through the wilderness after the exodus from Egypt.

His skilled hand, you could say, made mapmaking more precise. If the standard projection he later invented is what made him remembered, it was his command of calligraphy that made him known in the first place.

None of it, though, matched the atlas he published in 1569, Atlas. In it he used the "Mercator projection" to draw a cylindrical projection of the world. All the meridians run parallel instead of converging at the poles. The lines of longitude widen steadily outward from the poles toward a circle, and that circle is the equator. On a map drawn this way, lines of latitude and longitude cross at right angles everywhere, so the world can be laid out on a rectangle; and because the projection preserves oblique angles, the bearing of every detail on the map is exact. That same year Mercator used the method for his map of the Arctic as well. After 1630 the Mercator projection came into general use, and it mattered greatly to navigation, trade and exploration worldwide.

Mercator did not draw these maps to make himself immortal. Religious faith was one of the main things driving him.

After graduating from Leuven he began studying Aristotle. Before long he found that Aristotle's teaching contradicted the truths of the Bible. It troubled him. "Aristotle, like the other philosophers, did not accept the account of creation Moses wrote down," he said. "What they say differs from Genesis in many respects." He began to doubt whether these philosophers were telling the truth, and resolved to look into the truth about the creation of nature himself.

In Chronology, the first part of the atlas he published in 1569, he gathered up what he called the whole process of creation, "from the beginning of heaven and earth to the present." There Mercator not only arranged events by date but supplied geographic information as well.

In other words, for Mercator, drawing maps was not simply a matter of combining different pieces of geographic knowledge and inventing new ways to draw them. It was a byproduct of his inquiry into the Bible. To a great extent he did something quite rational in order to settle his confusion about religion. The good news is that the method he used to settle it was exact mathematics — which is why the Mercator projection can also be called an accidentally rational thing.

Look at the background he lived in: the mid-to-late 16th century, when medieval thought was beginning to collapse, Italy was leading the Renaissance, Lutheranism had just risen in Europe, and the Reformation was under way. Like every believer of his time, Mercator was still taken in by the Church's indulgences, and he himself was once jailed for getting too close to Lutheranism.

But this sacred way of thinking about religion later changed in him. He may have caught the scent of a strong market.

In the 15th century, the Age of Discovery began. European fleets appeared on oceans everywhere, looking for new trade routes and trading partners to feed Europe's infant capitalism.

In 1492, Queen Isabella funded Christopher Columbus's expedition, hoping he would find a westward route to the Indian Ocean to replace the southern African route that the Treaty of Alcáçovas reserved for the Portuguese. Columbus never reached Asia, but he stumbled on a new continent instead — the Americas.

In 1497, Vasco da Gama, sent by the King of Portugal, sailed from Lisbon in search of a sea route to India, and found the route from Europe around the Cape of Good Hope.

In 1480, Ferdinand Magellan was about to set out on his voyage around the world. The Spanish crown, keenly interested in the East Indies, funded him in the hope that he would find a westward trade route to the Spice Islands (also called the East Indies), which would let Spain profit from the spice trade without breaking the Treaty of Tordesillas.

Commercial competition being what it was, crews treated early sea charts as secrets. The charts were often tied to weights, so that if pirates took the ship the captain could throw them into deep water without hesitating. As Europeans opened new waters everywhere and carved up colonies, nothing mattered more than an accurate map.

That is one big reason Mercator's projection was so welcome at the time: it made sea charts easier to use.

Before it was invented, the projections used in navigation preserved neither angle nor area, and at high latitudes in particular they diverged so far from reality that they were of little practical use.

The projection Mercator published in 1569 improved on the ordinary perspective cylindrical projection. The higher the latitude, the more a parallel is stretched when projected onto the cylinder — so he stretched the corresponding meridians to match, keeping the ratio between the two constant. That is what makes the projection preserve angles.

On a chart drawn with the Mercator projection, a rhumb line is a straight line, which matters a great deal at sea. Sail along a rhumb line and you reach your destination without changing course. To sail from A to B, you take a ruler, join A and B on the Mercator chart, work out the angle that line makes with the meridians, and hold that angle on the compass all the way to B.

Most of Mercator's income, it is said, came from maps and globes. Though he had been jailed over his faith, Catholic customers went on sponsoring his projects and buying his maps. Cardinals were among his patrons too.

In the end it was commercial need that pushed mapmaking forward, and Mercator was only one of the people who drew maps for a living. In that distant scene, the ones who carried news to men like him — the ones who had mastered the craft — included boastful merchants, nitpicking surveyors, philosophers with runaway imaginations, patrons who spent freely, navigators not to be believed too readily, and, of course, conquerors driven by money. Thanks to them, maps could grow finer and finer, and the new information brought back from the sea could be set down on the map as it was.

All of their work rested on Mercator's way of lettering and his way of projecting, and by that standard humanity took one more step toward knowing itself. Next would come triangulation in the late 16th century, longitude settled step by step in the 18th, and observation from the air in the 20th, which gave mapmaking better conditions still.

Some people did complain, of course, that Mercator's map was inaccurate in many places. But because he had solved the question of how a map should be drawn so far ahead of time, the arguments people conducted through maps came to look ever more trivial.

Later still, maps took on the color of national self-interest. One idea people often discuss is that putting your own country at the center makes the world map look different. Another is that the map your eyes see can deceive you; we have reported on many map-related experiments and designs, and every one of them asks you to think again about what is real.

In this sense, although Mercator solved the problem of a single method for drawing the world, he could never solve the parochialism in the human mind. The one thing to be thankful for is that what the world actually looks like is not for people alone to decide.

Some images in this article are from Maps and History by Jeremy Black. Some images in this article are from en.wikipediar and upload.wikimedia.