Popular Science Monthly/Volume 29/July 1886/Sketch of Gerard Mercator

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GERARD MERCATOR, the distinguished geographer and author of the system of map-drawing which bears his name, was born at Rupelmonde, Flanders, March 5, 1512, and died at Duisburg, December 2, 1594. The name by which he is known, Mercator, is a translation into Latin of his real name, which is given by one authority as Kaufmann, by others as Krämer, or De Cremer, all meaning merchant or trader. He was first sent to school at Bois-le-Duc, under Macropedius, but afterward went to Louvain, where he applied him-self to the study of philosophy and mathematics so earnestly that he was prone to let his days pass without eating and his nights without sleeping, and had to be reminded that those duties should be attended to. Of the nature and influence of his studies at Louvain an interesting incident is related by his biographer, Van Raemdonck ("Gérard Mercator, sa Vie et ses Œuvres"), which also illustrates a striking trait of his character. The Bible to him was a book of authority, and he had conceived a high respect and formed a fixed attachment for its text. He had also been taught the physics of Aristotle, which then prevailed in all the schools. His studies in the book of Genesis soon showed him that there were many discrepancies between the cosmogony of Moses and the teachings of Aristotle and other accepted philosophers; thus a dilemma was presented to him. He would not give up his Bible; must he give up Aristotle? To relieve himself from his embarrassment, he took a course, says Van Raemdonck, "that was as Christian as it was logical. Believing in the inspiration of the Bible, and convinced of man's fallibility, he ventured to doubt the orthodoxy of the philosophers, resolved to revise all his accepted opinions, and, with his reason as his only guide, undertook to penetrate for himself the mysteries of Nature." He went to work to construct a new cosmogony. In order to escape critical annoyance, he left Louvain and retired to Antwerp, where he hired rooms and gave himself up to his investigations on this subject. There he framed a cosmogony which agreed at once with his reason and with the Bible. When he returned to Louvain, the doctors of the university, shocked at his boldness in questioning what was almost universally received, were ready to attack his new doctrines, anticipating their immediate publication. But he kept his own counsel, and held his cosmogony in his portfolio till such time as he should judge best to make it known. Being obliged to make his living by manual labor, Mercator selected the making of mathematical instruments, with the designing, engraving, and illumination of maps, as his business. He thus entered upon a career which he never left, and which was destined to bring him fortune and glory. In order better to qualify himself for doing this work, he began a thorough course of mathematics. He studied with Gemma le Frison, who was in the habit of giving lessons at his house to a number of high-born pupils, and practiced engraving with him. He made rapid progress, and was able in a short time, having been licensed by the university, himself to give lessons in geography and astronomy; and he made with a precision which was remarkable at that time the instruments which his pupils had to use. In 1541 he presented to Cardinal de Granville a very handsomely executed terrestrial globe, with which his Grace was so well pleased that he introduced the author of it to the Emperor Charles V. He afterward entered the service of that prince, but it is not exactly known in what particular capacity. He is styled in his epitaph imperatoris domesticus, but that merely signified that he was attached to the imperial household. He made for his Majesty two other globes, a celestial one of glass, and a terrestrial globe of wood, which were greatly admired as superior to any specimens that had been before produced. They were unfortunately destroyed in the wars by which the Low Countries were afterward overrun. In 1559 he removed to Duisburg, where the Duke of Juliers and Cleves was contemplating the establishment of a university, and had assigned an honorable position in it to Mercator. The duke conferred upon him the appointment and title of his cosmographer. He published at that place a large number of maps, but delayed the publication of his atlas for a considerable time, out of regard to his friend Ortelius, who had also prepared a set of maps, and through Mercator's accommodating spirit was given an opportunity to work off his stock without the embarrassment of competition. It is to Mercator and Ortelius that the world owes the enfranchisement of geography from the errors ingrafted upon it by Ptolemy; and the maps of these two fellow-workers were the most exact known till those of Guillaume de l'Isle and D'Anville were published.

Geography was in his time a mixture of facts and fancies, much of what was taught in it having no better authority than old-time traditions and the fabulous stories of travelers who addressed themselves more to exciting wonder than to telling the truth. Maps were in a worse condition than the descriptive accounts, and gave the most erroneous possible views of the relative situation of the various parts of the earth. It was Mercator's work, to adapt an expression of Malte-Brun's, to demonstrate the extreme imperfection of the systems of the ancients and provoke their abolition. Modern geography, this distinguished authority on the subject adds, dates from his time. He seems to have had a strong natural taste for the study of this science, to which he himself testified when he said, in the preface to his "Chronology": "I consecrate myself wholly to that study, so beautiful, so useful, and at the same time so difficult. Nothing in the world is so pleasant to me. In fact, compared with it, other occupations, no matter how necessary they may be, are irksome to me." In his opinion, a knowledge of geography was indispensable to successful government and lucrative commerce. "Without maps, giving visible representations of the whole of an empire and its different countries," he said, "merchants would not be able to reach the richest and most important lands, to trade there, and bring all the earth into fraternity with Europe; and, without them, princes could only with difficulty and by means of intermediaries, often of doubtful fidelity, arrive at safe and stable decisions respecting the government of their dominions." Thus, availing himself of the instructions he had received from Gemma le Frison, and having served no other apprenticeship in the art, he began, about 1537, to design on paper, and then to engrave on copper, and illuminate the chorography of various countries. "The skillful instrument-maker became also in a short time an accomplished map-engraver; and no maps of his time were comparable in workmanship with his."

Mercator's principal title to fame rests upon his invention of the method of drawing maps, which is known as Mercator's Projection. Under this system the map represents the earth as an unrolled cylinder, and the poles are remanded to infinity. The parallels of latitude and the meridians are drawn as straight lines, crossing one another at right angles. This method gives a tolerably fair representation, and accurate enough for practical purposes in the neighborhood of the equator and for about thirty degrees on either side of it; but, in approaching the poles, the proportions of the parts are distorted. The length of the degrees of longitude and of the parallels is exaggerated—vastly in the immediate neighborhood of the pole—for to preserve the parallelism of the meridians and their perpendicularity to the parallels of latitude, the degrees must be drawn of equal length in all parts of the map. The plan has, however, the great practical advantage for sailors of causing the curve drawn on the sphere crossing all the meridians at the same angle—the loxodromatic curve, which a vessel would describe in sailing around the earth without changing its course—to be projected into a straight line. It thus furnishes a way in which the bearing of a vessel sailing directly between two distant ports can be clearly discerned on the map. While Mercator was successful in executing the designs of his maps on this method, he was not able to explain its theory, or at least did not explain it. The explanation was given by Edward Wright, in 1599, in his "Correction of Errors in Navigation," and from this circumstance the method was long known to the English as Wright's Projection.

Mercator expressed a full appreciation of the importance of astronomy as connected with geography. That science was then cultivated largely in connection with astrology and was invoked in the solution of the most trivial questions. For this he had a profound contempt, while he believed in the significance of celestial phenomena and extolled the study of them. "The purposes for which the luminaries of the sky are created," he said, "are much higher than to assist in the predictions of the astrologers. Those lights exist to reveal to man the omnipotence, the majesty, and the divinity of his Creator, and not to be at the service of the vanity of the astrologers. They exist to mark the revolutions of the centuries; it is for this that they become obscured and are dissolved to announce the end of ages and proclaim judgment upon the world. It was thus that in the time of the passion of Christ, when the law was to be changed, Dionysius the Areopagite was permitted to see an eclipse. It was thus that Joshua perceived the astounding action of the hand of God in the spectacle of the sun. These bodies exist to mark the limits of days and years; and the stars, which glow by night in the firmament, shine upon the earth, and point out by their position the annual course of the sun." Mercator had collated the results of his studies on this subject, and had announced for publication a work embodying them, when death prevented his carrying out his intention.

Among the larger works mentioned by various authors as having been executed by Mercator, are the maps of Palestine, Flanders, Europe, Great Britain, Lorraine, the terrestrial and celestial globes already mentioned, and a great planisphere. These were all larger than the maps of the atlas. None of them, except the planisphere, are now known to be in existence. A few loose sheets from the plates of the atlas, preserved in collections at Brussels, London, the Hague, and St. Petersburg, constitute the chief part of the works of this class known to be by him that are now extant. For his chorography of Palestine—"Amplissima Terræ Sanctæ Descriptio" ("Most Ample Description of the Holy Land"), Mercator had to depend upon the best authorities he could command—"the testimony of an unknown traveler"—and they have not been identified. He is credited, however, with having made good use of the critical faculty in the composition of the work. It had the honor of having been sought for by the learned André Masius for the illustration of his commentary on the book of Joshua, who, in a letter to Georges Cassander, spoke of it in the most complimentary terms. The map of Flanders was produced after the spending of three years in personal surveys of the country, and appeared in 1540. It exists now only in reduced copies in the "Theatrum" of Ortelius and in Mercator's atlas; but the historian Jacques Marchantius, who had seen it, says that it surpassed all the maps of all other geographers. The map of Lorraine was also made after personal surveys, in the prosecution of which the author appears to have been exposed to some danger. When the map of Europe appeared in 1554, with Ptolemy's errors corrected and the continent shown in something like its real extent and proportions, the learned of all countries, according to Ghymmius, pronounced such extravagant eulogies upon it that one might have thought that no such perfect work had ever before seen the light. A single copy of his great "Mappa Monde" exists in the Bibliothèque Impériale of Paris. It is two metres by one metre thirty-two centimetres, or about six feet and a half by four feet, in dimensions, and shows the world from 80° north to 66° 30′ south. It includes three continents or land-masses—the Old World, America, and a southern continent, which Mercator conceived to be necessary to the balancing of the globe, but which had not yet been found, and which is only imperfectly represented by Australia and the larger islands and the south polar lands. The regions around the pole could not be given, on account of the exaggeration of the degrees on the plane projection, so a special supplementary map was provided for them. As not much was known about these regions, not much could be shown, and the little that could be, with no great accuracy. Behring Strait had not yet assumed definite form in the minds of geographers, but Mercator, thinking there ought to be some such body in that region, marked one on the map. In the main map also, some curious features were marked in the islands of the ocean, on the word of travelers, that have not yet been verified.

The "Atlas" was published in 1595, although several of the maps had already been published separately, that of France in 1585, and the map of Europe in 1572. Larger and smaller forms of the work were published in Latin, French, German, Flemish, and Turkish, in at least fifty editions. The more important editions were published by Hondius, at Amsterdam. That of 1623 had one hundred and fifty-six maps, and the edition of 1630 was prefaced by a biography of Mercator, by Gautier Ghymm (Ghymmius). This work included accounts of the political and the physical geography of the countries described.

To the uniform edition of his maps, Mercator prefixed an essay, "De creatione ac fabrica mundi" ("Concerning the Creation and Structure of the World"), the theological doctrines of which excited some question. But Van Raemdonck, his admiring biographer, says of it: "We have hardly been able to disengage ourself from the reading of it, so much does it attach, lead on, and transport us. In turning over those noble and pious pages, we might have thought we were reading a sacred canticle, a real hymn to the Lord. Invocation of divinity, holiness of purpose, grandeur of conceptions and ideas, sublime style, and enthusiasm—all are there and help to make us believe, with Dr. Solenander, that Mercator speaks in this book as an inspired prophet, as one who has been initiated by God himself into the mystery of the origin of the world."

In preparing his maps, Mercator had to give attention to the study of the best methods of lettering. The results of these studies were published for the information of the public, in an essay on italic and cursive letters—"Ratio scribendarum literarum latinarum quas italicas cursoriasque vocant"—which was a treatise on calligraphy and much more; for it embodied the fruit of much thought and careful investigation on a subject which was of great importance, to him at least.

The services of Mercator were in frequent demand for the preparation of maps of private estates, and from this occupation he was able to meet the current expenses of his living and his family, and derived a considerable income.

Mercator's most important work, after his maps and atlases, was his chronology: "Chronologia a Mundi exordio ex eclipsibus et observationibus ac bibliis sacris" ("Chronology from the Beginning of the World; from Eclipses and Observations, and Holy Books"); Cologne, 1568; Basle, 1577. It was an elaborate work, the result of four years of labor, and gave 3965 years from the creation to the birth of Christ. Scaliger expressed a high opinion of it, and Lenglet Dufresnoy spoke of it as clear but dry; but it was pronounced by one of the best judges of the time, Onupbre Panvini, of Verona, author of several historical and chronological books, preferable to all existing chronologies. In the preface to this work he sketched a plan of a universal cosmography. Repeating this plan in 1585, he described it as intended to include, first, the form of the world and the general distribution of its parts; second, the order and motions of the heavenly bodies; third, their nature and radiation, and the concurrence of their influences, from which may be derived a veritable astrology; fourth, the elements; fifth, descriptions of kingdoms and of the whole earth; sixth, the genalogies of princes from the beginning of the world, with the emigrations of the peoples, their abodes, their first inventions, and antiquities. This order was not, however, observed in actual publication.

Piety was a predominant feature in all of Mercator's life. To extol the works of God, he said, "to exhibit the infinite divine wisdom and inexhaustible goodness by showing how all things in their composition concur to glorify him and reveal his incomprehensible providence—such is the end toward which I shall direct all my efforts, all my readings, and all my meditations."

This feeling it was, probably, that impelled him, in the latter part of his life, to give attention to theological questions, and which prompted the composition of his "Harmony of the Gospels" ("Harmbnia Evangelistarum" ), which was published at Duisburg in 1592.

He seems to have had opinions of his own on theological subjects, even earlier in his life—and that was against the order of society. He was arrested in 1544, while residing at Louvain, by order of some one having authority in the prosecution of heretics, and imprisoned, on a charge of being infected with the Lutheran doctrines. Twenty-eight other citizens were taken under the same order, but Mercator, being at Rupelmonde to look after the estate that had been left him by his great-uncle, escaped till he was found. His absence from home was construed into a confession of guilt by flight. His parish priest immediately addressed a letter to the authorities, testifying that "Gérard Mercator enjoys a good reputation, lives a religious and honorable life at Louvain, and is in no way infected with heresy"; and that he was always to be found at home, except when absent on legitimate business. The conservator of the university demanded that he be tried, if he was to be tried, before the court of that institution, within whose jurisdiction he resided; and the rector of the university interceded in his behalf. But all these protests were without immediate effect. He was kept in custody for four months, and then discharged, in the absence of evidence against him—and, perhaps, by the force of the evidence for him.

Two works of Mercator's remain to be mentioned. They are his edition of Ptolemy's "Geography" ("Tabulæ Geographicæ ad mentem Ptolemæi restitutæ et emendatæ"), with twenty-seven maps; and his "De usu annuli astronomic" ("Concerning the Use of the Astronomical Ring"), an explanation of the horizon, meridian, and other rings of his globes.

Mercator is described as having been small, but well shaped. He regarded material life as a necessity and not as an enjoyment, and was strictly sober in his repasts. But the gravity of his labors did not exclude gayety; and, in whatever festivities, official or private, he participated, he contributed to the general good cheer with his sprightly humor, and yielded to the tastes of the others such conformity as was consistent with his health and the precepts of religion. He was vivacious and adroit in discussion, easy and agreeable in conversation, and knew no greater pleasure than to talk familiarly in the society of the learned concerning subjects of knowledge. Observing moderation in good fortune, resigned and patient in adversity, he constantly preserved the calm that was necessary and favorable to his studies. And he was distinguished for his devotion to the interests of his country.