Geographical maps are a mirror of what we, humans, know about the world around us. They make it possible to contrast the achievements of modern science with the knowledge of our ancestors. The first cartographic images that appeared thousands of years ago were primitive and limited in every way, in terms of both their reliability and the size of the territories depicted on them. Up to the Middle Ages, the geography of the European world had been confined to a tri-continental zone. Most of those maps were works of art rather than navigational tools.
During Medieval times, unknown lands and seas provided fertile soil for mapmakers’ imagination. It was widely believed that in mare incognitum and terra incognita (Latin for “unknown seas” and “unknown lands”) there were bound to be some dangers, and for this reason thanks to the influence of folklore and the Bible, sea monsters and other fictional creatures began to appear on maps.
In the late Middle Ages, two branches of cartography began to develop side by side. On the one hand, cosmographers studied the structure of the Universe in general and produced so-called mappa mundi (Latin for “maps of the world”). Those maps were of theoretical significance, but lacked any practical application. Nonetheless, they helped shape people’s notion of the world.
On the other hand, there were portolans — naval charts that succeeded ancient peripli (descriptions of marine voyages, which seafarers used as guides). Portolans came into use at a time when compasses were already being utilized for naval navigational purposes. Merchants from Italy and Catalan ports frequently enjoyed their benefits. Such maps showed inland areas in a very sketchy fashion, while the coastlines, capes and islands were depicted in great detail. The portolans showed the already explored merchant routes stretching from the Black Sea to the Atlantic Coast.
In the second half of the 16th century, one man appeared on the scene to unify these two branches of geography and he did it very creatively. He produced a map linking the theoretical achievements of cosmographers and real-life eyewitness accounts from his contemporary sailors. The revolution of this innovation was that this map allowed someone to pinpoint their location and to chart a long route using a compass.
In 1512, the family of cobbler Hubert Kremer who had resided in the tiny town of Rupelmonde (then part of the Netherlands) celebrated the birth of his seventh child, a boy named Gerhard. Decades later, he was destined to earn world fame as an outstanding cartographer. In his youth, Gerhard lost his father and means of sustenance, but fortunately his uncle Gisbert stepped in to take his nephew under his wing and became the boy’s guardian, thus letting Gerhard receive a decent education at a gymnasium.
Following the fashion of the era, Gerhard changed his German name Gerhard Kremer (merchant) to its full Latin equivalent of Gerardus Mercator. He moved to Louven, where he graduated from the local university, one of the best in Northern Europe by the standards of those days, and dedicated himself to making globes and geographic charts.
The latter pursuit earned him international distinction. The world-renowned mapmaker, as far as we know, never traveled by sea, but it was Mercator alone that created a groundbreaking map using a principle that would lay the foundation for the entire science of naval navigation. New and More Complete Representation of The Terrestrial Globe Properly Adapted for Use in Navigation was the title of his work in Latin, published in August 1569 that incorporated all the knowledge of geography that was available at that time.
Mercator’s map stands out from other typical cosmographic images of that time. Here the world is rectangular, not oval, round or even heart-shaped. It consists of 18 sheets, which can be bound to make an atlas or glued together into a wall version.
The scale expands from the equator towards the poles. For the equatorial zone, it is 1:21 000 000. The map covers a space stretching from 80˚ North to approximately 67˚ South. The North Pole is greatly distorted and is shown separately. There are no state borders on his map — Mercator’s objective was to create a scientific map of the world known to him, and not a political one.
The original copper sheets that Gerardus Mercator engraved himself have been lost, but today three surviving printed copies of the map are known and are kept in the National Library of France, the Maritime Museum Rotterdam and the Basel University Library. All three sets of sheets are slightly different from one another, quite possibly because Father Time had no mercy on the paper that the map had been printed on. Here in front of you is a collected and processed copy of the chart from the Basel University Library.
Gerardus Mercator used the space of the unexplored territories of North America, the Pacific Ocean and the Southern Hemisphere quite resourcefully. The cartographer filled these voids with his own notes on magnetism and the geography of the polar regions, descriptions of large rivers and also the methods used in making the map and information on the date and place of its publication. All in all, the notes take up nearly a quarter of the map’s space.
It goes without saying that Mercator had no idea of what the North Pole looks like in reality. Nevertheless, he managed to put together a detailed description of the Arctic, the first-ever in the history of cartography.
A picture of four islands — two of them livable — with a whirlpool sucking seas into the Earth must have been prompted by Mercator’s two contemporaries. According to the outline of these lands, the explorers, Frobischer and Davis in reality did not go farther than the islands of northern Canada.
Besides, Mercator was very fortunate to get his hands on a valuable cartographic find: an Inventio Fortunata as they say in Latin, and that incidentally was the book’s title. It was dated around the 14th century, and was said to be a travelogue, which contained firsthand testimony of attempts to reach the North Pole. The original notes were soon lost, so Mercator was only able to rely on a verbal account by a traveler named Jacob Cnoyen. The original text is attributed to a Franciscan monk from Oxford, who is said to have traveled north several times on orders of King Edward III of England. Theoretically, it was quite possible. Quite a few English subjects resided in Norway’s Bergen in those days, so the cleric could have surely joined the locals on their trips to the shores of Greenland, and quite possibly even farther.
Any medieval traveler was able to get to the North Pole by compass, an instrument that had just begun to be used. Still, even then in no way could Mercator have known that the North Pole differed from the magnetic pole, where a compass arrow pointing to the North had brought him.
Mercator must have learned by then that the magnetic pole and the North Pole are two different things. That’s why in addition to the huge black mountain in the center of the whirlpool, he drew another cliff in the area of the Bering Strait, since he thought that the real magnetic pole was there.
Mercator was certain that the location of the magnetic pole was crucial to the position of another geographical parameter — the Prime Meridian. Today, we know that strictly speaking it does not really matter which of the meridians should be considered as the prime one. It is merely a conditional point of reference for calculating the geographic longitude. Mercator assumed that the Prime Meridian is not determined arbitrarily, but could be calculated by drawing a line through two poles — the geographical one, in other words, the one found by the Polar Star, and the magnetic one that any compass points to. The Flemish cartographer did not know that the magnetic pole shifts.
Mercator pointed to two likely spots where the lines towards both poles meet. He found the arguments in favor of the group of the Cape Verde (Cabo Verde) islands (Sal, Boa Vista and Maio) more reasonable. However, just in case, he pointed to another magnetic pole, taking into account the fact that the zero meridian could pass off the island of Corvo in the Azores archipelago, and he hoped that sailors would eventually clarify this information.
The International Meridian Conference held in October 1884 selected the Greenwich Meridian passing through the territory of the Greenwich Observatory in Britain as the international standard for zero degrees longitude. However, in 2015, technologically updated data indicated that the line was slightly off and had to be moved by approximately 102 meters. The cold, hard fact is that the choice of the Prime Meridian came as a result of an international treaty, and not based on the laws of nature, contrary to what cartographers of the 16th century, including Gerardus Mercator postulated.
The existence of a major continent in the south had been foreseen by the great Aristotle. Another ancient Greek geographer and scholar, Strabo, called this hypothetical continent Terra Australis Incognita (Latin for “The Unknown Southern Land”). And the renowned Greek mathematician and scientist, Ptolemy displayed this continent on his map. Although in Mercator’s days, the knowledge of an Unknown Southern Land had already expanded to incorporate more accurate empirical data, the Flemish cartographer preferred to rely on Ptolemy’s works when making his own map.
According to Mercator, the Southern Continent stretches far to the north and includes Antarctica and more than half of the territory of today’s Australia, which still had not been discovered at that time. Mercator’s contemporaries stuck to the old-fashioned view that a large amount of dry land in the Northern Hemisphere had to be “balanced” by an amount not any smaller than that in the Southern Hemisphere, or else the Earth would “flip over”.
Incidentally, this theory runs counter to the eyewitness accounts Mercator himself mentions in his notes. For instance, he quotes Italian voyager Ludovico di Varthema, who discovered a large landmass beyond the Java la Grande island (today’s Java) with a perimeter of more than 2,000 miles, many times smaller than the territories shown on the map.
The Southern Continent is an ideal example of how Mercator managed to blend into his work some sources close to the truth, provided by his contemporaries, and others, hopelessly outdated from antiquity. Occasionally, he relied on the reputation of his predecessors even when the inaccuracies were as large as a whole continent.
If the contours of modern continents are projected onto Mercator’s map of 1569, glaring discrepancies will instantly catch somebody’s attention.
The farther from Europe, the less detailed Mercator’s map is. The Old World — Europe, Asia and Africa — are shown in the most thorough way, but there are certain discrepancies, too. The shape of the Mediterranean Sea, some scientists say, was based on outdated works by Ptolemy. The coast is disproportionately extended from the west to the east. Apparently, Mercator preferred to trust his ancient predecessor, thus ignoring more accurate modern portolans.
The shape of the New World — North America and South America — are greatly deformed. Australia is out of the picture, since it was yet to be discovered. The first-ever documented landing of a European there, Willem Janszoon, would take place later in 1606. The southernmost continent — Antarctica — is absent, too. It would be discovered 250 years after the publication of the map — in 1820. Furthermore, even if Gerardus Mercator had known about Antarctica, the continent would have been below the bottom edge of the image, since the 1569 map covers a space only down to 67˚ South, while most of Antarctica lies further south.
In making the map, the cartographer widely used local legends and tales told by seafarers and adventurers. This explains why in his descriptions of the Earth’s surface one finds trustworthy stories about the world’s first circumnavigation and myths about lands in the polar latitudes, notes about the life and customs of the inhabitants of different countries, and the diversity of wildlife and many other things.
On the 1569 map, there are quite a few minor textual descriptions. We selected 25 of the funniest and most paradoxical ones. Try to find on this map:
The navigational charts (Mercator borrowed their methodology to a certain extent) are also called compass charts or nautical charts. Rhumblines are radial rays extending from one center, with the same angle between two neighboring ones (11.25˚). There are 32 such directions, consistent with the number of a compass’ graduated markings. The beams of such rays are called wind roses (or also compass roses). On Mercator’s map, there are 20 of them. They were used to both draw the charts by means of placing coastline contours over the grid and to map out the routes of sea voyages.
For seafarers, Mercator added a graphic instruction called the Organum Directorium. The author’s idea was this template would make it easier to determine the ship’s direction and course, and to pinpoint its location and even calculate the distance between two points.
On Mercator’s map, just as on the early portolans, navigators charted a route between the port of departure and port of destination consisting of straight lines. For each of these lines, a corresponding direction in the rhumbline network was identified. This is precisely how a ship’s course was determined: the vessel was navigated in such a way that during the voyage, its course, controlled according to compass readings, remained constant. Mercator’s predecessors mistakenly believed that this straight line was the shortest distance between ports. This system of navigation worked well for short-distance voyages, but during long-distance ones, the ship’s deviation from its determined route turned out to be significant.
Gerardus Mercator was the one who found the solution to this problem. He was not the first in the world of mapmaking who used the technique of drawing nautical charts. The trick was the rumblines on his chart enabled seafarers to map out the routes of long voyages.
Several decades before Mercator came up with his map, Portuguese mathematician and cartographer Pedro Nunes had revealed that the portolans of his day were utterly useless on distant voyages. The problem was that maps of those days made no adjustments for the fact that the meridians converged at the poles. In addition, navigation heavily depended on compass readings, the arrow of which in different parts of the world could deviate in different ways from the direction to the north due to a magnetic declination (the difference between the directions towards the magnetic and North poles).
Nunes was the one who coined the term loxodrome — a curved line crossing the meridians at the same angle. The introduction of loxodromes made the navigator’s calculations far simpler and made it possible to plot various courses with a measurement instrument and a protractor. Nunes contrasted loxodrome-guided navigation, along a permanent course and orthodrome-guided navigation, along the shortest possible route (orthodrome-based voyages became possible in the 20th century with the advent of electronic navigation instruments).
The method of portraying loxodromes as straight lines used in Mercator’s map of 1569 was its most valuable feature, which made it unrivaled in marine navigation up to this day.
Medieval rhumbline charts are sometimes mistakenly referred to as loxodrome charts. This is wrong: a straight line can be called a loxodrome only on a map made in the Mercator projection (the projection is an image of the Earth’s surface or some part of it onto a flat surface crucial to making a map).
How exactly was this projection made? To this day, we still do not know. Mercator’s calculations or descriptions of his method, if any had ever existed, have not been passed down to us. He compared his own invention, possibly in a figurative way, to resolving one of the greatest riddles of mathematics, known as the squaring of the circle.
After a very short time, he displayed and set out on a new work, ... projecting the sphere onto the plane by a new and most convenient invention, which would answer to the squaring of the circle so perfectly that nothing seems to be lacking save a proof, as I have heard no few times from his own mouth.Walter Ghim, Mercator’s friend and author of his biography
Many researchers today agree that the Flemish cartographer used an exclusively geographic method for building the grid, without resorting to any complex mathematical calculations for this purpose. As its basis, he used the rhumb tables — sets of coordinates compiled by mariners. Mercator capitalized on the available knowledge of his contemporaries as best as he could. He left no instructions concerning his cartographic method, although he originally promised to do so, and the map’s reproduction and the moment when voyagers began to use it in practice was delayed for several decades.
In 1599, 30 years after the map was out of print, Edward Wright, an English scientist and designer of navigation equipment, and having participated in a pirate expedition, published a work entitled Certain Errors in Navigation. The author set up trigonometric equations that for the first time provided a mathematical basis for Mercator’s projection. In the foreword, the author inserted a special clause in order to ward off any likely accusations of plagiarism:
I must answer, that indeed by occasion of that Map of Mercator, I first thought of correcting so many, and gross errors, and absurdities… But the way how this should be done, I learned neither of Mercator, nor of any man else.Edward Wright, professor of mathematics
Mercator’s greatest achievement is that he created a trustworthy image of the Earth, while Wright takes credit for providing mathematical calculations of the projection, by creating a table and calculating the coefficients of the scale change for each degree of increasing latitude at the corresponding parallel. Wright proved that the map is “conformal”. In other words, that the distortions are proportional, wherever they may occur. Thanks to Wright’s table, you can easily adjust the distance at any latitude, but even without the table, the navigator can trust the loxodrome course charted according to the wind rose network and sooner or later get to the desired destination. Wright put the key to Mercator’s map in sailors’ hands.
Further scientific progress provided the means to fine-tune this projection, and make it more accurate. As the years passed, it had begun to look ever more different than the original map of 1569. To this day, one of the modern projections being used in GPS navigation bears the name of this 16th century Flemish cartographer. It is called the UTM, which stands for the Universal Traverse Mercator.
Nothing can beat the globe as the most accurate representation of the Earth. Any attempt to convert the sphere into a flat surface inevitably distorts the image. To realize how accurate Mercator’s projection is it should be remembered how cartographers go about showing the image of the globe on a flat plane and what projections exist there. Currently, there are two possible classifications.
Firstly, the projections vary from the standpoint of the surface, the most common ones being a plane, cylinder and cone. These geometric shapes can be flattened without compression or extension.
Modern cartography is not confined to these three projection types, though. There are more sophisticated ones: circular, pseudocylindrical (for instance, Sanson’s sinusoidal projections), pseudoconic (for instance Bonne’s heart-shaped projection), and polyconic (for instance Hassler’s apple-shaped projection).
Secondly, projections are classified by the types of distortion. As it has been already stated, there is no way of completely avoiding deformations, but the distortion of some parameters can be prevented at the expense of others.
The question as to what features can be neglected depends on the tasks of the map at hand. Distortions regarding lengths, angles, areas and shapes are permissible. Distortions in length are present in all maps. The three others are its consequence. The greater the distortions of the angles, the less the distortions of areas and the other way around. According to this classification, projections belong to any of the following three types: conformal, equal area and equidistant.
In a word, Mercator’s projection is, first, cylindrical and, second, conformal. Compass directions are shown on this map as straight lines crossing the parallels and meridians invariably at the same angle, which made this projection ideal for marine navigation. Should something go wrong with the electronic instruments, the navigator will be able to bring the ship to its destination using only a compass and a map.
At the same time, Mercator’s map cannot be relied on in all respects, because the actual areas of countries and continents in his projection are distorted — scales depend on the latitude. The farther away from the equator, the greater the distortion of sizes. The undistorted size of Russia is far more modest than we usually think.
Today’s maps are often used as arguments in geopolitical debates, but as you can see this may breed risky delusions. All maps lie, to one degree or another.
Mercator has become an iconic name in the science of cartographic projection, but regrettably, all of his other achievements have been mostly neglected. Shortly after the publication of his first map of the world, Mercator, still a young man, set out to make a globe of the Earth, which he completed in 1541.
The globe not only earned Mercator recognition and fame among his fellow mapmakers, it also largely served as the driving force for his introduction to the ruler of Holy Roman Empire Charles V, who would repeatedly commission him to make astronomical instruments and instructions on using them. Unfortunately, Mercator’s proximity to the Emperor was unable to protect him from religious persecution. Several times, crackdowns on heresy in the Netherlands endangered the cartographer’s professional endeavor and even his life.
It was no earlier than 1551, ten years after he completed his celestial globe (showing starry skies) that he managed to move to Germany. When Emperor Charles V and one of the local princes concluded a treaty that guaranteed tolerance towards the Protestants, Germany became attractive to migrants from all of Europe. Duisburg, where Mercator spent his last years, was the most tolerant place to live.
Mercator’s efforts began to turn mapmaking from a handicraft into a natural science. Alongside mapping terrestrial and celestial spaces, he also made instruments crucial to the science of cartography. Such as armillary spheres and astrolabes, which were used to determine the coordinates of celestial bodies. There are only three existing astrolabes in the world that are known to be attributed to Mercator himself. One was identified in Florence just recently, in 1994. A short while later, Mercator’s monogram GMR (Gerardus Mercator Rupelmondanus) was spotted on another two astronomical instruments. One is kept in Brno, the Czech Republic, and the other, in Augsburg, Germany.
Very few may remember that Mercator coined the term atlas. He had in mind not the titan in Greek mythology, who was condemned to carry the sky on his shoulders, but a wise cosmographer from the later version of the ancient legend.
Way back in ancient times, Ptolemy had created a prototype of an atlas as a systematized collection of geographic maps. So as the Age of Exploration got underway, the idea for such an endeavor stirred the minds of Mercator’s contemporaries. The Flemish master revealed his own plan for making a world atlas back in 1569, when the well-known map was published. But Abraham Ortelius beat his friend and rival Mercator to the punch, when he published his Theatrum Orbis Terrarum (Latin for “Theater of the World”) in 1570. However, there was no stopping Mercator and he kept plugging away at his final titanic work for the rest of his life. In the end, his Atlas, or Cosmographical Meditations on the Frame for the World and its Form was published in full in 1595. It consisted of 107 maps, including fresh maps of Germany, Denmark and Russia, added by his son Rumold.
How a copy of Mercator’s Atlas surfaced in Moscow is anyone’s guess. Apparently, it might have been brought by one of its future translators. Both are known to have travelled abroad. Long before their joint work at Russia’s ministry of foreign affairs, in those days called Posolsky Prikaz, one of them, Bogdan Lykov, was taken prisoner during the Swedish-Polish war and spent 16 years in Rzeczpospolita (The Commonwealth of Poland). The other, Adam Turn, had led the Holy Roman Emperor’s diplomatic mission to Persia. He was detained in Russia for political reasons and taken prisoner for life. After 20 years of his compulsory stay in Russia, Adam agreed to serve the Russian tsar and was baptized Ivan Dorn.
Around 1637, Lykov and Dorn got down to translating the Atlas. It looks like Dorn had a better knowledge of Latin, while Lykov’s role was to help express the meaning in Russian. It would be quite fair to describe this work as a rendering, and not as a translation. Dorn and Lykov had firsthand experience, and not bookish knowledge of Russian life, so they made some amendments and corrections to the original text. At the very beginning, they dropped the erroneous statement that Russia consisted of two halves — Black and White — because nobody had ever heard here of Black Russia (this term was sometimes used in Western Europe in relation to Belarus and Lithuania). The translators also cleared up the confusion over two cities having similar names — Nizhniy Novgorod and Velikiy Novgorod. The grossly exaggerated rumors about honey were toned down. According to the original: “Honey in Russia is in abundance and there is so much of it that one may come across whole mountains and lakes of honey, so both humans and wild beasts who are careless enough to get into such pools of honey run the risk of getting drowned,” and “one peasant is rumored to have fallen into a huge beehive inside a hollow tree and got bogged down in this honey swamp chest-deep.” Some nuances of the original were misinterpreted by the translators. They failed to identify the word Borisfen as the Latin name of the Dnieper River and described Smolensk not as a city standing on the Dnieper, but as a city Tsar Boris had surrounded by a wall on one side and a moat on the other. It is quite noteworthy that their mistake was very close to the truth. A wall was built around Smolensk during the rule of Boris Godunov.
Mercator did not live to see the publication of his Atlas. He had passed away in 1594, six months before this historic moment. In the meantime, in Europe the confrontation between the Catholic South and Protestant North raged on. Fortunately, religious and political tensions were not an insurmountable obstacle to future cartographers of the Old World. Great thinkers of the following eras carried on the cause of Mercator and his contemporaries to systematically detail and prove scientifically the principles of mapmaking that the mastermind of this breakthrough projection sensed by intuition.
Anyone who views this memorial should not fear that this small clod of earth oppresses the buried Mercator as a burden: The whole Earth is no burden for a man who felt her whole weight upon his shoulders and carried it as an atlas.Epitaph on Gerardus Mercator’s tomb in Duisburg
Mercator’s projection is still used for making nautical and aeronautical charts. In a somewhat modified version, it is used for topographic maps of dry land in the United States, Canada, France, Germany and other countries. It is also the basis for Google and Yandex maps and can be found on most GPS navigation systems known to any driver. A trace of Mercator’s heritage is found even in space research: all images of the Earth taken by the Sentinel-2 and Landsat satellites are shown in his projection.
Mercator’s map turned out to be so handy and convenient that 450 years later we can still see it and enjoy its benefits in our daily routines. And sometimes, when a picture of the world unfolds before our mind’s eye, many of us see it in the image of the Mercator projection.
Images and illustrations: Nova et aucta orbis terrae descriptio ad usum navigantium emendate accomodata / Gerhard Mercator / Basel University Library, Kartenslg AA 3-5 / Public domain via Wikimedia Commons; Carta Marina Et Descriptio Septemtrionalium Terrarum Ac Mirabilium Rerum In Eis Contentarum Diligentissime Elaborata Anno Dni 1539 / Olaus Magnus / 1 Kt. in 9 Teilen auf 9 Bl. / Bayerische Staatsbibliothek München, urn:nbn:de:bvb:12-bsb00002967-7 via CC BY-NC-SA 4.0; Portolan chart of the Mediterranean Sea and the Black Sea / Hieronymus Verrazano / Bibliothèque nationale de France, Département Cartes et plans, Gallica Digital Library / Public domain via Wikimedia Commons; World map on double cordiform projection / Gerhard Mercator / From the American Geographical Society Library, University of Wisconsin-Milwaukee Libraries; Atlas sive Cosmographicae meditationes de fabrica mvndi et fabricati figvra / Gerhard Mercator, Rumold Mercator / The Lessing J. Rosenwald Collection, Rare Book and Special Collections Division, The Library of Congress, Washington, D.C. / Public domain; Terrestrial Globe / Gerard Mercator / Courtesy of Harvard Map Collection, Harvard Library; Astrolabe / Gerard Mercator / Museo Galileo, Florence — Photographic Archives.
TASS acknowledgements to Ovanes Akopian and Yelena Baldina, whose precious assistance helped this project materialize.
News agency TASS (media registration certificate № 03247 issued on April 2, 1999 by the State Committee of the Russian Federation for the Press). Some publications may contain information not meant for audiences under 16 years of age.
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