Gerardus Mercator

Gerardus Mercator (; 5 March 1512 – 2 December 1594) was a Flemish geographer, cosmographer and cartographer. He is most renowned for creating the 1569 world map based on a new projection which represented sailing courses of constant bearing (rhumb lines) as straight lines—an innovation that is still employed in nautical charts.

Mercator was a notable maker of globes and scientific instruments. In addition, he had interests in theology, philosophy, history, mathematics, and geomagnetism. He was also an accomplished engraver and calligrapher. Unlike other great scholars of the age, he travelled little and his knowledge of geography came from his library of over a thousand books and maps, from his visitors and from his vast correspondence (in six languages) with other scholars, statesmen, travellers, merchants and seamen. Mercator's early maps were in large formats suitable for wall mounting but in the second half of his life, he produced over 100 new regional maps in a smaller format suitable for binding into his Atlas of 1595. This was the first appearance of the word "atlas" in connection with maps, but Mercator did not intend the word to mean a collection of maps; it was a neologism for a treatise (Cosmologia) on the creation, history and description of the universe. He chose the word as a reference to a legendary king of Mauretania who was traditionally considered the first great geographer.

A large part of Mercator's income came from sales of terrestrial and celestial globes. For sixty years they were considered the finest in the world, and were sold in such numbers that there are many surviving examples. This was a substantial enterprise involving the manufacture of the spheres, printing the gores, building substantial stands, packing and distributing them all over Europe. He was also renowned for his scientific instruments, particularly his astrolabes and astronomical rings used to study the geometry of astronomy and astrology.

Mercator wrote on geography, philosophy, chronology and theology. All of the wall maps were engraved with copious text on the region concerned. As an example, the famous world map of 1569 is inscribed with over five thousand words in fifteen legends. The 1595 Atlas has about 120 pages of maps and illustrated title pages, but a greater number of pages are devoted to his account of the creation of the universe and descriptions of all the countries portrayed. His table of chronology ran to some 400 pages fixing the dates (from the time of creation) of earthly dynasties, major political and military events, volcanic eruptions, earthquakes and eclipses. He also wrote on the gospels and the Old Testament.

Mercator was a devout Christian born into a Catholic family at a time when Martin Luther's Protestantism was gaining ground. He never declared himself as a Lutheran but was clearly sympathetic, and he was accused of heresy by Catholic authorities; after six months in prison he was released unscathed. This period of persecution is probably the major factor in his move from Catholic Leuven (Louvain) to a more tolerant Duisburg, in the Holy Roman Empire, where he lived for the last thirty years of his life. Walter Ghim, Mercator's friend and first biographer, describes him as sober in his behaviour, yet cheerful and witty in company, and never more happy than in debate with other scholars.

Gerardus Mercator was born Geert or Gerard (De) Kremer (or Cremer) in Rupelmonde, Flanders, a small village to the southwest of Antwerp, which was in the fiefdom of Habsburg Netherlands. The seventh child of Hubert (De) Kremer and his wife Emerance, his parents came from Gangelt in the Duchy of Jülich (present-day Germany). At the time of the birth they were visiting Hubert's brother (or uncle) Gisbert De Kremer. Hubert was a poor artisan, a shoemaker by trade, but Gisbert, a priest, was a man of some importance in the community. Their stay in Rupelmonde was brief and within six months they returned to Gangelt, and there Mercator spent his earliest childhood until the age of six. In 1518, the Kremer family moved back to Rupelmonde, possibly motivated by the deteriorating conditions in Gangelt—famine, plague and lawlessness. Mercator would have attended the local school in Rupelmonde from the age of seven, when he arrived from Gangelt, and there he would have been taught the basics of reading, writing, arithmetic and Latin.

After Hubert's death in 1526, Gisbert became the 15-year-old Geert's guardian. Hoping that Geert might follow him into the priesthood, he sent him to the famous school of the Brethren of the Common Life at 's-Hertogenbosch in the Duchy of Brabant. The Brotherhood and the school were founded by the charismatic Geert Groote, who placed great emphasis on study of the Bible and, at the same time, expressed disapproval of the dogmas of the church; both of these points of view were facets of the "heresies" of Martin Luther propounded a few years earlier in 1517. Mercator followed similar precepts later in life, with problematic outcomes.

During his time at the school the headmaster was Georgius Macropedius, and under his guidance Geert studied the Bible, the trivium (Latin, logic and rhetoric) and classics such as the philosophy of Aristotle, the natural history of Pliny and the geography of Ptolemy. All teaching at the school was in Latin; he read, wrote and conversed in Latin, and gave himself a Latin name, Gerardus Mercator Rupelmundanus, Mercator being the Latin translation of Kremer, which means "merchant". The Brethren were renowned for their scriptorium, and here Mercator might have encountered the italic script which he employed in his later work. The brethren were also renowned for their thoroughness and discipline, well attested by Erasmus, who had attended the school forty years before Mercator.

From the famous school at 's-Hertogenbosch, Mercator moved to the famous University of Leuven, where his full Latin name appears in the matriculation records for 1530. He lived in one of the teaching colleges, the Castle College, and, although he was classified as a pauper, he rubbed shoulders with richer students, amongst whom were the anatomist Andreas Vesalius, the statesman Antoine Perrenot, and the theologian George Cassander, all destined to fame and all lifelong friends of Mercator.

The general first degree (for Magister) centred on the teaching of philosophy, theology and Greek under the conservative Scholasticism which gave prime place to the authority of Aristotle. Although the trivium was now augmented by the quadrivium (arithmetic, geometry, astronomy, music), coverage of the quadrivium was neglected in favour of theology and philosophy; Mercator undertook further study of the first three subjects of the quadrivium in later years. He graduated as Magister in 1532.

The normal progress for an able magister was to go on to further study in one of the four faculties at Leuven: theology, medicine, canon law and Roman law. Gisbert might have hoped that Mercator would go further in theology and train for the priesthood, but Mercator did not: like many twenty-year-old young men, he was having his first serious doubts. The problem was the contradiction between the authority of Aristotle and his own biblical study and scientific observations, particularly in relation to the creation and description of the world. Such doubt was treated as heresy at the university, and it is quite possible that he had already said enough in classroom disputations to come to the notice of the authorities; fortunately, he did not put his sentiments into print. He left Leuven for Antwerp, there to devote his time to contemplation of philosophy. The events of this period of his life are uncertain. He certainly read widely but succeeded only in uncovering more contradictions between the world of the Bible and the world of geography, a discrepancy which occupied him for the rest of his life. He certainly could not effect a reconciliation between his studies and the world of Aristotle.

During this period Mercator was in contact with the Franciscan friar Franciscus Monachus who lived in the monastery of Mechelen. He was a controversial figure who, from time to time, was in conflict with the church authorities because of his humanist outlook and his break from Aristotelian views of the world: his own views of geography were based on investigation and observation. Mercator must have been impressed by Monachus, including his map collection and the famous globe that he had prepared for Jean Carondelet, the principal advisor of Charles V. The globe was constructed by the Leuven goldsmith Gaspar van der Heyden (Gaspar a Myrica c. 1496–c. 1549) to whom Mercator became an apprentice. These encounters may well have provided the stimulus to set aside his struggle with theology and commit himself to geography. Later he said, "Since my youth, geography has been for me the primary subject of study. I liked not only the description of the Earth but the structure of the whole machinery of the world."

Towards the end of 1534, the twenty-two-year-old Mercator arrived back in Leuven and threw himself into the study of geography, mathematics and astronomy under the guidance of Gemma Frisius. At first Mercator was completely out of his depth but, with the help and friendship of Gemma (who was four years his elder) he succeeded in mastering the elements of mathematics within two years and the university granted him permission to tutor private students. Gemma had designed some of the mathematical instruments used in these studies and Mercator soon became adept in the skills of their manufacture: practical skills of working in brass, mathematical skills for calculation of scales, and engraving skills to produce the markings required.

Gemma and Gaspar Van der Heyden had completed a terrestrial globe in 1529, but by 1535 they were planning a new globe embodying the latest geographical discoveries. The gores were to be engraved on copper instead of wood, and the text was to be in an elegant italic script instead of the heavy Roman lettering of the early globes. The globe was a combined effort: Gemma researched the content, Van der Heyden engraved the geographical features and Mercator engraved the text, including the cartouche which exhibited his own name in public for the first time. The text in the cartouche attributes the production copyright to Mercator. The globe was finished in 1536 and its celestial counterpart appeared one year later. These widely admired globes were costly and their wide sales provided Mercator an income which, together with that from mathematical instruments and from teaching, allowed him to marry and establish a home. He married Barbara Schellekens in September 1536, and Arnold, the first of their six children, was born a year later.

The arrival of Mercator on the cartographic scene would have been noted by the cognoscenti who purchased Gemma's globe – the professors, rich merchants, prelates, aristocrats and courtiers of the emperor Charles V at nearby Brussels. The commissions and patronage of such wealthy individuals provided an important source of income throughout his life. His connection with this world of privilege was facilitated by his fellow student Antoine Perrenot, soon to be appointed Bishop of Arras, and Antoine's father, Nicholas Perrenot, the chancellor of Charles V.

Working alongside Gemma whilst they were producing the globes, Mercator would have witnessed the process of progress in geographical knowledge: obtaining previous maps, comparing and collating their content, studying geographical texts and seeking new information from correspondents, merchants, pilgrims, travellers and seamen. He put his newly learned talents to work in a burst of productivity. In 1537, aged 25, he established a reputation with his map of the Holy Land which he researched, engraved, printed (and partly published) himself.

A year later, in 1538, he produced his first map of the world, usually referred to as Orbis Imago. From 1539 to 1540 he made a map of Flanders and in 1541 a terrestrial globe. All four works were received with acclaim, and they sold in large numbers. The dedications of three of these works witness Mercator's access to influential patrons: the Holy Land was dedicated to Franciscus van Cranevelt who sat on the Great Council of Mechelen, the map of Flanders was dedicated to the emperor himself and the globe was dedicated to Nicholas Perrenot, the emperor's chief advisor. The dedicatee of the world map was more surprising: Johannes Drosius, a fellow student who, as an unorthodox priest, may well have been suspected of Lutheran heresy. Given that the symbolism of the Orbis Imago map also reflected a Lutheran view point, Mercator was exposing himself to criticism from the hardline theologians of Leuven .

At no time in his life did Mercator claim to be a Lutheran, but there are many hints that he had sympathies in that direction. As a child, called Geert, he was surrounded by adults who were possibly followers of Geert Groote, who placed meditation, contemplation, and biblical study over ritual and liturgy—and who also founded the school of the Brethren of the Common Life at 's-Hertogenbosch. As an adult, Mercator had family connections to Molanus, a religious reformer who later had to flee Leuven. Mercator was also a close friend and correspondent of Philip Melanchthon, one of the principal Lutheran reformers. Study of the Bible was something that was central to Mercator's life and it was the cause of the early philosophical doubts that caused him so much trouble during his student days, doubts which some of his teachers would have considered tantamount to heresy. His visits to the free-thinking Franciscans in Mechelen may have attracted the attention of the theologians at the university, amongst whom were two senior figures of the Inquisition, Jacobus Latomus and Ruard Tapper. The words of the latter on the death of heretics convey the atmosphere of that time:

It is no great matter whether those that die on this account be guilty or innocent, provided we terrify the people by these examples; which generally succeeds best, when persons eminent for learning, riches, nobility or high stations, are thus sacrificed.

It may well have been these Inquisitors who, in 1543, decided that Mercator was eminent enough to be sacrificed. His name appeared on a list of 52 Lutheran heretics which included an architect, a sculptor, a former rector of the university, a monk, three priests and many others. All were arrested except Mercator, who had left Leuven for Rupelmonde on business concerning the estate of his recently deceased uncle Gisbert. His absence made matters worse, for he was now classified as a fugitive who, by fleeing arrest, had proved his own guilt.

Mercator was apprehended in Rupelmonde and imprisoned in the castle. He was accused of suspicious correspondence with the Franciscan friars in Mechelen but no incriminating writings were uncovered in his home or at the friary in Mechelen. At the same time his well-placed friends petitioned on his behalf, but whether his friend Antoine Perrenot was helpful is unknown: Perrenot, as a bishop, would have to support the activities of the Inquisition. After seven months, Mercator was released for lack of evidence against him but others on the list suffered torture and execution: two men were burnt at the stake, another was beheaded and two women were entombed alive.

Mercator never committed any of his prison experiences to paper; all he would say was that he had suffered an "unjust persecution". For the rest of his time in Leuven, he kept his religious thoughts to himself and returned to work. His experience with the Inquisition did not affect his relationship with the court, and Nicholas Perrenot recommended him to the emperor as a maker of superb instruments. The outcome was an Imperial order for globes, compasses, astrolabe and astronomical rings. They were ready in 1545 and the emperor granted the royal seal of approval to Mercator's workshop. The instruments were soon destroyed in the course of the emperor's military ventures and Mercator had to construct a second set, now lost. He also returned to his work on a large up-to-date and highly detailed wall map of Europe which was, he had already claimed on his 1538 world map, very well advanced. It proved to be a vast task and he, perfectionist that he was, seemed unable to cut short his ever-expanding research and publish what he had; it was another ten years before the map appeared.

In 1547 Mercator was visited by the nineteen-year-old John Dee who, on completion of his undergraduate studies in Cambridge (1547), "went beyond the seas to speak and confer with some learned men". Dee and Mercator were both passionately interested in the same topics and they quickly established a close rapport which lasted throughout their lives. In 1548, Dee returned to Leuven (spelled Louvain in Dee's text) and registered as a student; for three years, he was constantly in Mercator's company. Apart from a possible short visit to Duisburg in 1562, the two men did not meet, but they corresponded frequently and by good fortune a number of their letters are preserved. Dee took maps, globes and astronomical instruments back to England and in return furnished Mercator with the latest English texts and new geographical knowledge arising from the English explorations of the world. Forty years later, they were still co-operating, Dee using Mercator's maps to convince the English court to finance Martin Frobisher's expeditions and Mercator still avidly seeking information of new territories.

Mercator's final success in Leuven was the 1551 celestial globe, the partner of his terrestrial globe of 1541. The records of the Plantin Press show that several hundred such pairs of globes were sold before the end of the century despite their high price—in 1570 they sold at 25 carolus guilders for a pair. Celestial globes were a necessary adjunct to the intellectual life of rich patrons and academics alike, for both astronomical and astrological studies, two subjects which were strongly entwined in the sixteenth century. Twenty-two pairs are still in existence.

In 1552, Mercator, aged 40, moved from Leuven to Duisburg in the Duchy of Cleves (in modern-day Germany), where he spent the rest of his life. He never made public his reasons for moving, but several factors may have been involved: not having been born in Brabant he could never be a full citizen of Leuven; Catholic intolerance of religious dissidents in the Low Countries was becoming ever more aggressive and a man once suspected of heresy would never be trusted; the Erasmian constitution and the religious tolerance of Cleves must have appeared attractive; there was to be a new university in Duisburg and teachers would be required. He was not alone; over the years to come many more fled the oppressive Catholicism of Brabant and Flanders to more-tolerant cities such as Duisburg.

The peaceful town of Duisburg, untroubled by political and religious unrest, was the perfect place for the flowering of his talent. Mercator quickly established himself as a man of standing in the town: an intellectual of note, a publisher of maps, and a maker of instruments and globes. Mercator never accepted the privileges and voting rights of a burgher for they came with military responsibilities which conflicted with his pacifist and neutral stance. Nevertheless, he was on good terms with the wealthier citizens and a close friend of Walter Ghim, the twelve-time mayor and Mercator's future biographer.

Mercator was welcomed by Duke Wilhelm who appointed him as court cosmographer. There is no precise definition of this term other than that it certainly comprehends the disciplines of geography and astronomy but at that time it would also include astrology and chronology (as a history of the world from the creation). All of these were among Mercator's accomplishments but his patron's first call on his services was a mundane survey of the disputed boundary between the Duke's territory of the County of Mark and the Duchy of Westphalia.

Around this time Mercator also received and executed a very special order for the Holy Roman Emperor, Charles V: a pair of small globes, the inner ("fist-size") Earth was made of wood and the outer celestial sphere was made of blown crystal glass engraved with diamond and inlaid with gold. He presented them to the emperor in Brussels who awarded him the title Imperatoris domesticus (a member of the Imperial household). The globes are lost but Mercator describes them in a letter to Philip Melanchthon in which he declares that the globes were rotated on the top of an astronomical clock made for Charles V by Juanelo Turriano (Janellus). The clock had eight dials which showed the positions of the moon, stars and planets. The illustration shows a similar clock made by the German craftsman Baldewein at roughly the same time.

Earlier, Mercator had also presented Charles V with an important pamphlet on the use of globes and instruments and his latest (incorrect) ideas on magnetism: Declaratio insigniorum utilitatum quae sunt in globo terrestri : coelesti, et annulo astronomico (A description of the most important applications of the terrestrial and celestial globes and the astronomical ring). The first section is prefaced by Mercator's ideas on magnetism, the central thesis being that magnetic compasses are attracted to a single pole (not a dipole) along great circles through that pole. He then shows how to calculate the position of the pole if the deviation is known at two known positions (Leuven and Corvo in the Azores): he finds that it must be at latitude 73°2' and longitude 169°34'. He also includes his calculation of the longitude difference between the pole and an arbitrary position; if his theory had been correct, he would have been the discoverer of the solution to the longitude problem. More of his comments on magnetism may be found in an earlier letter to Perrenot and on the later world map. In Hogenberg's famous portrait of Mercator, his dividers are set on the position of the magnetic pole.

Mercator was buried in the church of St. Salvatore in Duisburg, where a memorial was erected about fifty years after his death. The main text of the epitaph is a summary of his life lauding him as "the foremost mathematician of his time who crafted artistic and accurate globes showing the heaven from the inside and the Earth from the outside ... greatly respected for his wide erudition, particularly in theology, and famous on account of his piety and respectability in life." In addition, on the base of the memorial, there is an epigram:

To the reader: whoever you are, your fears that this small clod of earth lies heavily on the buried Mercator are groundless; the whole Earth is no burden for a man who had the whole weight of her lands on his shoulders and carried her as an Atlas.

Following Mercator's death, his family prepared the Atlas for publication in four months. They hoped for it to become a source of the income that was needed to support them. This work entailed supplementing the maps of 1585 and 1589 with 28 unpublished maps of Mercator covering the northern countries, creating four maps of the continents and a world map, the printing of Mercator's account of the creation and finally the addition of eulogies and Walter Ghim's biography of Mercator. The title itself provides Mercator's definition of a new meaning for the word "Atlas": Atlas Sive Cosmographicae Meditationes de Fabrica Mundi et Fabricati Figura which may be translated as "Atlas or cosmographical meditations upon the fabric of the world and the figure of the fabrick'd, or, more colloquially, as Atlas or cosmographical meditations upon the creation of the universe, and the universe as created." Over the years Mercator's definition of atlas has become simply A collection of maps in a volume.

The atlas was not an immediate success. One reason may have been that it was incomplete: Spain was omitted and there were no detailed maps outside Europe. Rumold avowed that a second volume would attend to these deficiencies, but it was not forthcoming and the whole project lost momentum; Rumold, who was 55 years old in 1595, was in decline and died in 1599. His family did produce another edition in 1602, but only the text was reset; there were no new maps. Another reason for the failure of the Atlas was the strength of the continuing sales of the Theatrum Orbis Terrarum by Abraham Ortelius. Alongside the sumptuous maps of that book Mercator's un-ornamented new maps looked very unattractive. Despite the death of Ortelius in 1598, the Theatrum flourished: in 1602 it was in its thirteenth Latin edition as well as editions in Dutch, Italian, French, German and Spanish. The Mercator atlas seemed destined for oblivion.

The family was clearly in some financial difficulty for in 1604, Mercator's library of some 1,000 books was sold at a public auction in Leiden (Netherlands). The only known copy of the sale catalogue perished in the Second World War, but fortunately a manuscript copy had been made by Van Raemdonck in 1891 and this was rediscovered in 1987. Of the titles identified, there are 193 on theology (both Catholic and Lutheran), 217 on history and geography, 202 on mathematics (in its widest sense), 32 on medicine and over 100 simply classified (by Thomas Basson) as rare books. The contents of the library provide an insight into Mercator's intellectual studies but the mathematics books are the only ones to have been subjected to scholarly analysis: they cover arithmetic, geometry, trigonometry, surveying, architecture, fortification, astronomy, astrology, time measurement, calendar calculation, scientific instruments, cartography and applications. Only one of his own copies has been found—a first edition of Copernicus's De revolutionibus orbium coelestium annotated in Mercator's hand: this is held by Glasgow University.

The globes by Gemma Frisius and Mercator are discussed in Volume 3 of the History of Cartography (Cartography in the European Renaissance). Chapter 6: "Globes in Renaissance Europe" by Elly Dekker. Chapter 44: "Commercial Cartography and Map Production in the Low Countries, 1500–ca. 1672" by Cornelis Koeman, Günter Schilder, Marco van Egmond, and Peter van der Krogt. The definitive work is "Globi neerlandici: the production of globes in the Low Countries" by Peter van der Krogt.

Wholly devised by Frisius who invited Mercator to engrave the text. The only extant example is part of the Schmidt collection held by the Globe Museum (website) of the Austrian National Library. Another example held at the Gymnasium Francisceum of Zerbst in eastern Germany was destroyed in the Second World War, but there is a full description in Stevenson.

1537 Gemma Frisius celestial globe. Image Archived 2 February 2017 at the Wayback Machine

The only known example is held by the Royal Museums Greenwich (formerly the National Maritime Museum). On this globe Mercator's name appears on equal footing with that of Frisius. The globe is also described in Stevenson.

1541/1551 Terrestrial and celestial globes

Mercator created and published many maps in his lifetime.

The Mercator 1537 Holy Land map was dedicated to Franciscus van Cranevelt. Partly based on a map by the Lutheran scholar Jacob Ziegler, Mercator's map shows the route of the Israelites from Egypt to the Promised Land and appears to be intended to help people understand stories in the Bible.

Two copies of the Mercator 1538 world map, known as Orbis Imago, remain. It is a double cordiform projection and the first map identifying North America and South America. The map was a slightly modified copy of a 1531 world map (and its text) by Oronce Fine.

The Mercator 1540 Flanders map (Flandria) was commissioned by merchants of Ghent who intended that it should be presented to an angry Charles V as a respectful replacement of a 1538 map by Pieter Van der Beke which had stressed the defiant independence of the Flemish cities. The map is remarkably accurate and it is presumed to be based on a triangulation of Flanders by Jacob van Deventer.

The Mercator 1554 map of Europe (Europae descriptio) was a cordiform projection that Mercator later cut and re-assembled for inclusion in his unique Atlas of Europe of 1570–72.

Mercator, Gerardus (1540), Literarum latinarum, quas italicas, cursorias que vocant, scribendarum ratio (How to write the Latin letters which they call italic or cursive), Antwerp, OCLC 63443530 Available online at the Library of Congress and Das Münchener Digitalisierungszentrum. It may be downloaded as a pdf from the latter. This book is the subject of a monograph which includes a translation of the text (Osley 1969).

Mercator, Gerardus (1554), Declaratio insigniorum utilitatum quae sunt in globo terrestri : coelesti, et annulo astronomico ad invictissimum romanum imperatorem Carolum Quintum. (A description of the most important applications of the terrestrial and celestial globes and the astronomical ring. For the most invincible Roman Emperor Charles V.), Duisburg. Reprinted in 1868 with a commentary by Jean van Raemdonck. (OCLC 459842538). For the Latin text and a German translation see Krücken (1996). A rough (partial) translation is on wikiquote

Mercator, Gerardus (1569), Chronologia, Hoc Est Temporvm Demonstratio Exactissima, Ab Initio Mvndi, Vsqve Ad Annvm Domini M.D.LXVIII. Ex Eclipsibvs Et Observationibvs Astronomicis omnium temporum concinnata. (A chronology, a very accurate of recorded time from the beginning of the world until AD1568. Elaborated from astronomical observations of eclipses for all times.), Duisburg: Arnoldi Birkmanni, OCLC 165787166. There are PDF downloads, at the Bayerische Bibliothek (title page) and also the HathiTrust (catalogue and title page).

Mercator, Gerardus (1592), Evangelicae historiae quadripartita monas sive harmonia quatuor Evangelistarum. (Harmonization of the Gospels.) Many other copies listed at World Cat.

Frans Hogenberg was a close friend of Mercator. His portrait features prominently at the beginning of the Atlas. The text around the portrait is

Magna Pelusiacis debetur gratia chartis// Magna tibi priscum tandem superasse laborem// Mercator, tractusque novos, terraeque, marisque// Monstrasse, et magnum quod continent omnia caelum. I. Vivian. ludeb (Great thanks are owed to the Ptolemaic charts, and great thanks to you, Mercator, for having at last surpassed that ancient labour, and for having shown new stretches of the earth and sea, and the great, all-containing heavens. By J. Vivian)

GERARDI MERCATORIS RUPELMUNDANI EFFIGIEM ANNOR. / DUORUM ET SEX – AGINTA, SUI ERGA IPSUM STV DII / CAUSA DEPINGI CURABAT FRAC. HOG. M. D. LXXIV (Gerardus Mercator of Rupelmonde at the age of 62—Frans Hogenburg made this portrait out of affection for him. 1574)

For an analysis of the Mercator portrait see Zuber 2011, pp. 524–527