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Preface

When viewed historically, geographical concepts are seen to have come from an immense variety of sources. They have sprung partly from activities that cause men to travel over the surface of the earth: war, commerce, pilgrimage, diplomacy, pleasure. They have also sprung from the accumulated learning and lore of preceding ages and to no small extent from unfettered flights of the imagination. The history of geography, therefore, leads its students into many fields, affording them a key by means of which they may gain a sounder understanding of the extensive ranges of human activity and of the evolution of important phases of intellectual life.

This book is an attempt to illustrate and trace the origins of the most characteristic geographical ideas current in Western Europe at the height of the Middle Ages. Historians of geography have tended to neglect this period partly because of the dramatic appeal of the great Age of Discovery which was immediately to follow. It should be remembered, however, that, small as the known world was during the Middle Ages and naïve as may have been men’s conceptions of it, medieval learning was none the less the central element in the scholarly background of the Age of Discovery. The Renaissance brought no sudden and complete emancipation from old modes of thought. While medieval science persisted and some of its errors may have restricted subsequent progress, on the whole the positive achievements of the fifteenth and sixteenth centuries would have been impossible had it not been for the enlightenment transferred from the centuries that went before.

C. R. Beazley in the second volume of his great work, The Dawn of Modern Geography (1901), adequately treats of the travels and explorations of the twelfth and early thirteenth centuries, but to the more theoretical aspects of geographical knowledge in this age he gives but meager space. Karl Kretschmer in a monograph, Die physische Erdkunde im christlichen Mittelalter (1889), deals systematically with the physical geography of the entire Middle Ages but necessarily slights or wholly neglects many of the more interesting writings of the century and a half to which the present book is devoted. Other, lesser studies of the geographical conceptions of this period have to do exclusively with points of detail. The present writer ventures to hope, therefore, that there is place for a book in which the geographical lore of the time of the Crusades is discussed with greater fullness and at the same time with an orientation differing in many particulars from that of any work hitherto devoted to the subject.

Except as regards a few minor points (especially in Chapter X) he makes no claim to having based his work upon hitherto unpublished manuscript sources. The main part of the study, however (that dealing with the time of the Crusades, Chapters IV-XIII), is founded essentially upon printed editions of the primary sources for the history of civilization in the period. The first three chapters, on the other hand, relating as they do to the background of medieval geography and covering an enormous field, of necessity have to a large degree been written with the aid of the secondary works of modern scholars.

The volume is an enlargement of a thesis submitted in 1922 in partial fulfillment of the requirements for the degree of Doctor of Philosophy in history at Harvard University. Some of the research was pursued in Europe in 1919–1920, during which academic year the writer held the Woodbury Lowery Fellowship from Harvard. Subsequently the American Geographical Society has generously permitted him, while acting as Librarian of the Society, to devote much time to the revision of the manuscript.

The writer owes a special debt of gratitude to Professor C. H. Haskins, largely as a result of whose advice the particular period dealt with was selected. Helpful suggestions and the occasional receipt from Professor Haskins of a photograph or transcript of a manuscript bearing upon an apposite topic have been a constant stimulus. Useful suggestions have also been made by Professor R. P. Blake of Harvard and by Monsieur Charles de La Roncière of the Bibliothèque Nationale in Paris. Dr. Charles Singer of the University of London courteously permitted the use of Plate VIII from his Scientific Views and Visions of St. Hildegard (1917) as a basis for Figure 5 of the present volume. The writer is indebted to Mr. W. L. G. Joerg, the editor, from whose editorial skill, experience, and tireless care the book has greatly profited. He also wishes to thank Mr. George W. Robinson, Secretary of the Harvard Graduate School of Arts and Sciences, Miss Genevieve R. Fallon, formerly of Radcliffe College, and Mr. Arthur A. Brooks and members of the library staff of the American Geographical Society for their painstaking aid with manuscript and proof.

New York, October 7, 1924.

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Introduction

THE TIME OF THE CRUSADES

The time of the Crusades, like all great constructive epochs in the history of civilization, was an age of contrasts. A succession of crises marked the progress of conflict between the ideals of Papacy and of Empire. The feudalism of an earlier day was giving place in Western Europe to centralized monarchy, in Italy to the growth of city states. Though faith swayed the masses of men to the undertaking of immense coöperative enterprises—cathedral building and crusades—the time, none the less, was one of questioning and doubt: faith sometimes gave place to heresy hunting. Keener intellects were not afraid to probe deep at the very foundations of established theological doctrine. A profound and widespread enthusiasm for scholarship expressed itself in many forms. The writings of older authorities were ransacked for the wisdom which they contained, and from them erudite and forbidding tomes were compiled. But wandering students and poets were abroad who hated the musty learning of the monastic cell and frankly rejoiced in the beauty of the world around them. For some time historians have been in the habit of speaking of a “twelfth-century renaissance.” This expression is not wholly apt if used in a narrow sense to imply merely a rebirth of interest in the Greek and Latin classics. If taken to mean a re-stirring of the vital forces of civilization, the twelfth and thirteenth centuries were an age of renaissance indeed.

The purpose of this book is to illustrate a limited aspect of the intellectual activity of the time of the Crusades, but an aspect that is sufficiently broad to reveal to us something of the contrasting forces of this age.

SCOPE OF THE TERM “GEOGRAPHICAL LORE”

By “geographical lore” we mean what was known, believed, and felt about the origins, present condition, and distribution of the geographical elements of the earth. This covers a wider field than most definitions of geography. It comprises theories of the creation of the earth, of its size, shape, and movements, and of its relations to the heavenly bodies; of the zones of its atmosphere and the varied physiographic features of air, water, and land; finally, it comprises theories of the regions of the earth’s surface. Because many of these theories were false they are no less deserving of attention. The errors of an age are as characteristic as the accurate knowledge which it possesses—and often more so. Moreover, in addition to formulated beliefs, whether true or false, our definition of geographical lore covers man’s spiritual and esthetic attitude toward the various geographical facts, as revealed—often unconsciously—in descriptions of regions or of landscapes.

The historian of geology or the theologian may complain that we trespass on their domains in discussing theories of the Creation in a book devoted to the history of geography. Yet this is justifiable if we hold with most modern geographers that some explanation of the immediate causes of existing terrestrial conditions is an essential part of geography. These causes, it was the opinion of medieval thinkers, were to be sought for in the processes of the Creation. No man had the vaguest conception of the countless eons that have elapsed during which air, sea, and land have been in evolution. The good Christian thought that the world was made by God in the course of the six days of Genesis and that it then assumed practically the identical geographical appearance it has preserved ever since. In the Middle Ages geology, geography, and theology were inextricably interwoven.

Then again, the geographical lore of the Middle Ages involves a wider range of subjects in space, as well as in time, than is now included in geography. If medieval man had no knowledge of the age of the earth, he also had but the feeblest understanding of the immensity of the universe. To him, earth, stellar bodies, and celestial spheres were all part of a unified system of which the earth formed the core and most important member. Cosmology, astronomy, astrology, theology all dealt with this unified, geocentric, cosmic system; the interrelations between them were immediate and intimate. We cannot avoid some discussion of the matters in which these allied sciences bore directly on geography.

ORIGINS OF THE GEOGRAPHICAL LORE OF THE TIME OF THE CRUSADES

Whence came the geographical lore of the time of the Crusades?

Some of it came from books of earlier ages, some of it from contemporary observation. A sharp distinction may be made between the geography of the scholar and churchman, drawn largely from antiquity, and the geography of the merchant, soldier, and pilgrim, who learned of the world by travel and exploration. It was exceptional when the philosopher or theologian incorporated in his book the reports of recent travels. Indeed, we are almost startled to come across a bit of “up-to-date” geography in the philosophical or theological treatises. Even the histories and chronicles of contemporary events, though perforce containing more new geography than works of deeper learning, tended to appeal to ancient authorities in explaining the course of rivers or the relation of provinces or mountain chains to each other.

Any consideration of the state of medieval geography inevitably presupposes some acquaintance with the earlier accumulation of geographical lore from which it borrowed.

This was derived for the most part from two fountainheads of original observation and thought: (1) the writings of Greek historians and philosophers and (2) the Bible. Greek geography was the main source whence Latin writers of the Roman Empire and Moslems of the eighth, ninth, and tenth centuries of our era found their inspiration and facts. The Bible, as interpreted in the exegetical works of the Church Fathers, stimulated thought on geographical problems. The scholar of our period had at his disposal many Latin writings, both classical and patristic, and a somewhat more limited number of Arabic books and translations from the Arabic.

ORGANIZATION OF THE PRESENT WORK

The aim of the first three chapters of our study is to give an estimate in broad outline of the contributions of classical, patristic, and Oriental geography to the medieval West. The purpose is to show the kind of geographical ideas which a reader of the twelfth or thirteenth century might have gathered from older works in the libraries and to reveal something of the evolution of these ideas. No attempt is made to discuss works not well known in the Occident. The writings of famous Greek geographers like Herodotus, Pausanias, Strabo, Eratosthenes, Hipparchus, and Ptolemy receive only scant attention, and their contents are noted only in so far as they became familiar to Western Christendom through Latin media. Similarly the Greek Fathers of the Church and most of the more important Moslem geographers are overlooked because they exerted almost no influence on Western thought. Nor within the period itself that forms the subject of our investigation is much space given to writers like the Moslem Edrisi or the Greek Michael Psellos, whose researches did not contribute materially to the formation of Western science.

After a fourth chapter, on the literary and cartographic sources which date from the time of the Crusades and upon which our estimate of the geographical lore of this age is based, and a fifth, on the place of geography in the medieval scheme of learning, there follows the main part of this book. The attempt is here made to illustrate from representative sources geographical lore of all kinds, whether original or borrowed, to emphasize evidences of originality where they are apparent, and to trace a few significant borrowed theories to their origins. Though the period under consideration lasted a century and a half, there was not much change during this time in the quantity of geographical information available or in the quality of geographical thinking. Hence it will be more convenient and enlightening to adopt a topical and regional arrangement for the main portion of our treatment than to try to arrange the material chronologically.

By no means all the geographical knowledge and thought of the Crusading age could be stated and discussed in a volume of even many times the size of this. It is the writer’s hope that the materials selected are sufficiently diverse to give a rounded and just, though it be necessarily far from complete, understanding of the geographical lore of a significant period in the history of science and of civilization.

PART I ORIGINS, SOURCES, AND PLACE IN THE CLASSIFICATION OF KNOWLEDGE OF THE GEOGRAPHICAL LORE OF THE TIME OF THE CRUSADES

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I. THE CONTRIBUTION OF THE ANCIENT WORLD

SOURCES

THE PYTHAGOREANS, PLATO, AND ARISTOTLE

The earliest writers who dealt with geographical matters in a more or less scientific spirit were the Greeks of Ionia and the Pythagorean philosophers of Magna Graecia. Though their theories exerted no direct influence on the formation of medieval geography, they should not be entirely overlooked. Ionic geography gave many ideas to the later Greeks; Pythagorean thought brought to bear a strong influence on the Platonic cosmology, which reached the Middle Ages through the Latin translation of Plato’s Timaeus made by Chalcidius early in the fifth century after Christ, and through the Platonists Martianus Capella and Macrobius. Until the middle of the twelfth century Plato, of all philosophers, held the strongest grip on medieval thought; after that time the influence of Aristotle became more potent in the framing of the scholastic conception of the universe. We must regard Plato and, even more, Aristotle as the indirect sources of most of the cosmological, physiographic, and meteorological knowledge which, elaborated by later writers of antiquity and by the Moslems, reached the Middle Ages at second hand. Among the many writings of Aristotle those which contain the most material of interest to the geographer are the De caelo (Περὶ οὐρανοῦ) and the Meteorology. The former, in four books, treats of the properties of the heavenly bodies, of the elements, and of the earth. Translations of the De caelo in the Middle Ages often went under the title De caelo et mundo.[1][2] The Meteorology, besides a detailed discussion of the phenomena of the atmosphere, includes many speculations on physical geography. Theories of cosmology also found expression in the Physics and De generatione et corruptione.

Footnote 1:

The notes will be found at the back of the book grouped by chapters and consecutively numbered within each chapter.

The scientific genius of the Alexandrian Greeks of the Hellenistic period showed itself in the work of men like Eratosthenes and Hipparchus. By them the mathematical and astronomical aspects of geography were developed with accuracy; but unfortunately, owing to the almost universal ignorance of Greek in the West, the products of their genius had little part in the molding of medieval theories.

ROMAN INFLUENCE ON GEOGRAPHY

The Roman conquests tended to discredit scientific investigations and to bring into favor works of a descriptive nature which would appeal to the military chief, the provincial governor, or man of the world—to the practical rather than speculative type of mind. Polybius regarded geography as an important auxiliary science to politics and history. The geographical portions of his history treat of the countries of the known world, their peoples and customs; he is not concerned with the size and shape of the earth nor with the determination of latitudes and longitudes. Strabo, writing at the time of Augustus, represents the culmination of the Polybian method; but his great and comprehensive work, though of first importance in the history of ancient geography, was not read at the time of the Crusades.

PTOLEMY

The Greek, or more purely scientific, attitude, however, did not completely succumb. Posidonius[3] in the first century before Christ reverted to the method of Eratosthenes; and with Marinus of Tyre and Claudius Ptolemy, in the reigns of Trajan and Hadrian, there came a revival of mathematical geography which almost, if not quite, equaled the high level reached by the Alexandrians[4]. Ptolemy was the author of two works, both of which were destined profoundly to modify the development of science in later ages. These were the Mathematical Composition (or Almagest, as the Arabs called it), a treatise on astronomy, knowledge of which reached the medieval West through Moslem channels; and the Geography, a work which remained virtually unknown in Europe until the fifteenth century.

LATIN WRITERS: PLINY, SOLINUS, CAPELLA, MACROBIUS

Though the most fertile investigations were made by Greeks, Latin writers naturally influenced more directly medieval thought in the West. Of those who dealt with geographic matters in the strictly classical period Pliny the Elder (23–79 A. D.) and Seneca (3 B. C.-65 A. D.) were the most influential. The Historia naturalis of Pliny, an ill-digested compilation of information of all sorts, contained books on geography that were destined to furnish the larger part of the lettered man’s geographical ideas during many centuries.[5] Pliny’s work was not merely extensively read but was used and plagiarized by other writers of possibly greater popularity. The most significant of these was Solinus,[6] a compiler of fables in the third century after Christ, whose Collectanea rerum memorabilium consists almost entirely of borrowings from Pliny or from a book from which Pliny drew.[7] The geographical information in Isidore’s Etymologiae is largely made up of quotations and paraphrases from Solinus. Seneca’s Quaestiones naturales[8] was also widely read and formed the source of the bulk of the meteorological lore of the Middle Ages.

Two Latin writers of the late Empire also contributed materially to the evolution of geographical knowledge, Martianus Capella (fourth or fifth century) and Macrobius (fifth century). Capella’s encyclopedic De nuptiis Philologiae et Mercurii is an elaborate commentary on and exposition of the seven arts; the book dealing with geometry gives the author an opportunity of presenting a résumé of geography, more particularly in its mathematical aspects.[9] That Martianus Capella’s treatise enjoyed an immense popularity in the medieval period is indicated by the quantity of manuscripts extant and by the frequency with which we find it listed in the medieval library catalogues[10] that have been preserved. The general sketch of the distribution of land and water on the surface of the globe contained in Macrobius’ commentary on the Somnium Scipionis[11] of Cicero was often quoted at later periods and formed the basis for some of the extremely crude maps of the world used in the twelfth, thirteenth, and fourteenth centuries.

In the remainder of the present chapter a very general review will be given of the more important geographic ideas borrowed by the Western world in these centuries from Aristotle, Pliny, Solinus, Seneca, Martianus Capella, Macrobius, and some others, and an attempt will be made to indicate the relationship between the growth of these ideas and the broader evolution of ancient geography as a whole.

THE HISTORY OF THE UNIVERSE

ANCIENT COSMOGONY

Though it is not now regarded as lying strictly within the field of geography, the history of the evolution of theories about the origin of the earth is so closely allied to the history of geography that the two cannot well be dissociated. A marked antagonism inevitably arose between the usual Greek view, which regarded matter as eternal, and the Christian view, which was based on the first chapter of Genesis and conceived of the universe as created at a definite point in time or concurrently with time. The men of the Middle Ages tended to adhere strictly to the Christian opinion, for to have done otherwise would have been heretical. Nevertheless, the ancient theory was well known to Christians and exerted in its various forms no small influence on the development of certain phases of Christian thought.

CELESTIAL INFLUENCES

It was a deeply rooted belief of many classical thinkers that the events and conditions on this world and on all the regions below the sphere of the moon’s orbit are regulated by the heavenly bodies. Aristotle and his followers taught that the heavenly bodies themselves are made of an imperishable and incorruptible, almost divine, fifth element, ether, which distinguishes them from the four corruptible elements (fire, air, water, and earth) that constitute the immediate world of our senses.[12] By virtue of this semi-divine quality, it was argued, the sun, planets, and stars exert an all-powerful control over the earth around which they revolve—an absolutely determining control over all events both great and small.[13] From this fatalistic belief sprang the science of astrology, a science which throughout antiquity was held in equal esteem with astronomy.

The study of the movements of the celestial bodies revealed the fact that at some time in the distant future, sun, planets, and stars will bear exactly the same relative position one to another that they do at the present moment. Consequently, it was inferred that the influence exerted by them on the sublunar regions will at that time be exactly the same as it now is, and all the phenomena now apparent on the earth’s surface will be exactly repeated. They will be repeated not only once but an infinite number of times at periodic intervals in the future; similarly they have been repeated throughout infinite cycles in the past.[14]

COSMIC CYCLES: THE GREAT YEARS

This idea of cosmic cycles, or Great Years, appears to have originated in the Orient, possibly with the Chaldeans.[15] It was firmly established among the Ionian Greeks[16] and Pythagoreans,[17] from whom Plato adopted it. Many and various opinions prevailed about the violence and character of the changes produced by the celestial cycles. The Chaldeans had thought that whenever all the planets come into conjunction on one straight line in the sign of the zodiac Cancer, the entire universe is destroyed by fire but destroyed only to be born again; similarly the world is destroyed by water when the same phenomenon occurs in Capricorn.[18] The theory of a complete and universal birth and rebirth (palingenesis) was held by some of the Greek philosophers.[19] Plato and Aristotle, however, seem to have restricted the destructive effects of the celestial influence to the sublunar sphere and maintained that the realms above the moon were eternal.[20] On the whole, belief in periodically recurrent destructions of the earth by water was more widespread and was given greater definition than belief in corresponding destructions by fire.[21] The main reason for this is probably to be looked for in the dissemination among nearly all peoples of legends of a great flood, but it also in no small measure may be attributed to rudimentary geological observations (notably of the presence of shells on high ground) which showed that portions of the earth’s surface had at one time lain beneath the waters.[22]

GEOGRAPHIC APPLICATION OF THE THEORY OF THE GREAT YEARS

The theory of the Great Years was invoked to explain changes in geographic and climatic conditions on the earth’s surface.[23] When the various planets and stars bear a certain relation to one another, a period of dryness and heat, or a Great Summer, is experienced; conversely, when other stellar relationships prevail, there is a period of cold and wetness, or a Great Winter. Even land and sea gradually change places under stellar control. Certain parts of the land, Aristotle observed, had once been covered by the sea, and what is now sea had once been land: like plants and animals, land and sea grow to maturity and old age. If the causes adduced for these changes were not so utterly different from those that are now accepted, we might almost be tempted to think that Aristotle had some conception of climatic cycles and cycles of erosion.

After Plato and Aristotle, as before them, the doctrine of the Great Years, though by no means universal, was very popular in antiquity.[24] The Stoics adopted it in its more extreme form involving successive burnings and liquefactions of the universe.[25] It entered into Neoplatonism and was ultimately taken over by the Jews. It seems to have penetrated to India, where the Greek elaboration of the theory gave precision to ideas that were probably already in existence there. The Indian belief in the recurrent reincarnations of Brahma was brought into connection with Hellenic calculations of the duration of the Great Years.[26] From the Hindus and from the Greeks the conception was transferred to the Arabs and by them to the knowledge of the Latin West.

DURATION OF THE GREAT YEARS

Numerous endeavors were made in antiquity to calculate the length of a Great Year.[27] The figure that was adopted by the Arabs and passed on to the Christian world originated in Hipparchus’ discovery of the precession of the equinoxes, or apparent gradual revolution of the fixed stars around the pole of the ecliptic.[28] Ptolemy calculated that the period of this revolution was 36,000 years,[29] a figure which became known to the Hindus and Arabs and ultimately to medieval Christendom.[30] The actual figure is approximately 25,800 years.

SHAPE, MOVEMENTS, AND SIZE OF THE EARTH

SPHERICITY OF THE EARTH

Nearly all scholars of antiquity after the fifth century before Christ thought that the earth was a globe.[31] The earlier opinion of a disk-shaped earth resting upon the waters, which appears to have been held by Anaximander (although some students have thought that he, too, believed in a spherical earth [32]), was discarded by the Pythagoreans and Plato, and after their time no serious thinkers questioned the theory of sphericity. The Pythagoreans based their opinion on speculative and philosophical grounds rather than on physical and experimental proofs; they thought that since the sphere is the most perfect mathematical form, the earth must therefore be a sphere. The whole tendency of Aristotle’s thought, less speculative and less hypothetical than Plato’s,[33] led him to look for proofs of sphericity,[34] and these he enunciated with great emphasis. Cleomedes,[35] Pliny,[36] Ptolemy,[37] Martianus Capella,[38] and other ancient writers likewise adduced more or less convincing proofs, which were well known and often cited in the medieval period.

IMMOBILITY OF THE EARTH

Though the learned men of the ancient world were almost universally agreed that the earth is a globe, they were not unanimous in the belief that it stands immovable in the center of the universe; yet the various theories which diverged from this orthodox view had no place in the development of medieval cosmology until long after our period.[39] Certain among the Pythagoreans maintained that there is a fire in the heart of the earth.[40] Plato said that the center of the earth, which stands immobile[41] in the center of the universe, is the seat, not of a fire, but of the World Soul.[42] Through its own internal movement the World Soul causes the movement of the universe as a whole. Belief in the World Soul of Plato was extraordinarily tenacious, and it emerges in the writings of more than one Neoplatonist of the Middle Ages. Aristotle, however, though he likewise held fast to the doctrine of the immobility of the earth in the center of the universe, differed both from the Pythagoreans and from Plato in refusing to believe that the center of the universe could be the seat of an incorruptible being of the same substance as the celestial bodies, be it fire or World Soul. Aristotle,[43] Pliny,[44] and Ptolemy[45] also brought forward proofs of varying validity in favor of the immobility of the earth.

CIRCUMFERENCE OF THE EARTH

Several figures were given by ancient authors for the circumference of the earth. Aristotle stated it to be 400,000 stades;[46] Eratosthenes determined it to be 252,000 stades according to the testimony of many writers, including Pliny,[47] Vitruvius,[48] Martianus Capella,[49] and Macrobius,[50] although Cleomedes, who gives the most circumstantial account of Eratosthenes’ measurement, had said that the latter’s figure was 250,000.[51] It is probable that Eratosthenes himself arbitrarily added 2000 stades to his result in order to obtain a figure more easily divisible.[52] Cleomedes quotes Posidonius as giving 240,000 stades,[53] and Strabo says that the latter gave 180,000 stades.[54] The last number was that adopted by Marinus of Tyre and by Ptolemy.

Though we have several distinct figures cited by ancient writers, these assuredly do not indicate that as many distinct processes of measurement were carried out. The circumference given by Aristotle was a mere estimate; Eratosthenes’ result was the only one based on accurate measurements and calculations;[55] the two figures given by Posidonius may well have been derived from Eratosthenes, the larger arising from a mistaken interpretation or intentional alteration of the latter’s figure, and the smaller from the use of a longer stade.[56]

At all events, so far as we know, only one method was employed by the Greeks for determining the size of the earth. This consisted of finding on the same day of the year the meridian altitudes of the sun at two places supposed to be on the same meridian of longitude, the distance between which was known through itineraries. The angle between the two meridian altitudes was then assumed to bear the same relation to the circumference of the heavens as the distance between the two points of observation bore to the circumference of the earth. Cleomedes[57] and Martianus Capella[58] described how Eratosthenes carried out such observations in Egypt.

The figure determined by Eratosthenes is surprisingly accurate. Whether the stade used by him was 157.50[59] or 168[60] meters, as different modern scholars contend, the circumference according to his estimate would be 39,375 or 42,336 kilometers. In either case the error is seen to be very slight, the true circumference of the earth being about 40,000 kilometers.

THE DISTRIBUTION OF HABITABLE REGIONS; ZONES; THE DISTRIBUTION OF LAND AND WATER

We see, then, that the writers of antiquity whose opinions were destined to mold the thought of the medieval period believed that the earth is a sphere, immovably fixed in the center of the universe. We must now examine their theories regarding the distribution of phenomena on the surface of the globe and the interaction of these phenomena. Of prime importance were their views concerning the distribution of habitable areas of land, but these were so closely bound up with the theory of climatic zones that it is absolutely necessary to understand what this theory was before going further, even though the subject of zones might more properly be included in the study of the atmosphere.

ZONES

Parmenides may have been the first to conceive of zones upon the earth’s surface corresponding to the zones into which the astronomers had divided the heavens. Eratosthenes is said to have been the first to place the theory of terrestrial zones upon a firmly scientific footing, “by determining exactly upon the sphere the position of the fixed circles which mark the limits of each zone” (Thalamas).[61] Ancient geographers set the number of terrestrial zones at five, though they differed as to the character of the climates within them. The general opinion—one which was shared by Aristotle—was that the polar caps and the equatorial regions were incapable of sustaining life, the first on account of cold, the second on account of heat. Despite the fact that the notion of the existence of a fiery belt between the tropics was challenged by Polybius and Posidonius, who had heard reports from expeditions in these regions, this notion persisted in the writings of Martianus Capella, Macrobius, and many others and exerted an extremely restrictive effect on the subsequent development of geographical knowledge and enterprise.

The majority of the ancient writers whose works were read in Christendom before 1300 also thought that the oikoumene, or portion of the earth inhabited by men of our kind, is completely surrounded by an ocean. This is a belief common to many early peoples.[62] In the Greek world we can trace it back to the Homeric and Hesiodic Ocean Stream and to the conceptions of early Ionian philosophers, who had gone so far as to maintain that the earth had been created out of water,[63] or at least that it was originally submerged beneath the ocean and had been brought forth through the evaporation of the water by sun and stars.[64] The theory of an encircling ocean was certainly held by Aristotle, Pliny,[65] Seneca, Macrobius, and Martianus Capella.

CRATES’ THEORY OF FOUR LAND MASSES

The two last-named writers set forth an elaboration of an opinion first held by the Pythagoreans and worked out in detail by Crates of Mallos in the second century before Christ, which gained great ascendancy over the minds of map makers and writers of the Middle Ages. They explained that the oikoumene is one of four similar inhabited bodies of land on the surface of the globe. These bodies of land are separated from one another by two oceans which encircle the earth, one running east and west in the fiery equatorial regions, and one running north and south at right angles to the equatorial ocean. This idea, which we shall call the “Cratesian” theory after its foremost expositor, did not pass unchallenged either in antiquity or in the Christian period. Involving as it did the doctrine of the antipodes—people dwelling in quarters absolutely inaccessible to men of our race, eternally cut off from our oikoumene by the fires of the equator and the terrors of the meridional ocean—the Cratesian theory provoked the indignation of the Fathers of the Church as containing the seeds of heresy.[66]

EXTENT OF THE “OIKOUMENE”

Aristotle, although he had derived from the Pythagoreans the theory of an uninhabitable torrid belt,[67] believed in a greater southward extension of our oikoumene than would be possible in accordance with the Cratesian theory. He harbored no idea of the existence of another oikoumene in the same latitude as ours. He says very clearly in the De caelo[68] that there is no great distance between India and Spain and hinted at the same opinion in the Meteorology.[69] Seneca[70] held similar views.

The opposite theory—which has been called the continental as opposed to the oceanic hypothesis[71]—that Africa and Asia extended unknown distances south and east and that the Atlantic and Indian Oceans, like the Caspian Sea, were enclosed basins—also had its adherents, among them Herodotus, Hipparchus, and, most significant of all, Ptolemy. But Ptolemy’s Geography, though its content was reflected in Arabic notions of the earth’s surface, had almost no readers in the Christian West until the fifteenth century, and the works of Herodotus and Hipparchus were unknown.

PHYSICAL GEOGRAPHY

ARISTOTLE, SENECA, AND PLINY

Among the writers of antiquity who dealt with physical geography only three can be said to have influenced twelfth- and early thirteenth-century thought to any marked degree. These were, first and foremost, Aristotle, the substance of whose De caelo and Meteorology had reached the West before the year 1187 through the borrowings and plagiarisms of later scholars and after that time could be read in translations from the Greek and Arabic. In the second place, Seneca’s Quaestiones naturales was popular before the direct influence of the De caelo and Meteorology began to be felt. In the third place, as we have seen, the Elder Pliny’s Historia naturalis was not only widely read in the original, but also much that it contained was familiar through the intermediary channels of Solinus, Isidore, Martianus Capella, and others. Aristotle, however, was the fundamental authority, for a large portion of the material in the books of the two Latin authors came from his treatises.

THE FOUR ELEMENTS

Most ancient authorities believed that the universe is composed of four elements, fire, air, water, and earth, arranged in concentric spheres. Theoretically, according to this view, the sphere of water should entirely enclose the earth. Practical observation shows that it covers the lower levels of the earth’s surface only. How to reconcile the theoretical conception with observed facts was a problem which, as we shall see, greatly puzzled geographers and physicists during the later Middle Ages.[72]

According to Aristotle the four elements, under the control of the heavenly bodies and through their interaction upon each other, produce all the physical phenomena of the atmosphere, sea, and earth.[73] Working from this axiom, he, and all the ancient writers who dealt with the subject, attempted to explain winds, tides, earthquakes, and other occurrences of nature; but there was little agreement among them as to the manner in which these interactions were manifested. Though there were many theories, the actual matters under discussion were not very numerous. Only the most striking and unusual happenings—such as tides, earthquakes, and floods—attracted attention, and we find almost no trace of a minute and careful observation or even of a superficial understanding of those imperceptibly slow natural forces which modern geology recognizes as having fashioned mountains, rivers, and seas.

A logical division of the subject matter of physical geography is into three studies: that of the atmosphere, that of the waters, and that of the earth. In each of these there is room for a great deal of hairsplitting about what belongs to geography and what to geology, geophysics, or meteorology. Physical geography merges into the other natural sciences as human geography merges into history, politics, economics, or ethnology. Even at the present day, when the often futile attempt is being made to delimit the domains of the various sciences ever more definitely, it is impossible to distinguish where one begins and another ends, and it would be foolish to set up hard and fast definitions in dealing with the lore of the ancient and medieval worlds, when natural science was as yet inchoate.

METEOROLOGY

The ancients were more interested in meteorology[74] than they were in oceanography and physiography (if such terms can be used for their naïve attempts at explaining the features of ocean and land), perhaps because the phenomena of the air make a deeper impression on men than the phenomena of the sea and earth—tides, earthquakes, and volcanoes excepted. Thunder and lightning, comets, rainbows, balls of fire were looked upon as portents, and complex theories were created to explain them and what they were supposed to foretell. But all this type of meteorological lore, however interesting in itself, is, strictly speaking, not geography. On the other hand, there are certain distinctly geographical aspects of the study of the atmosphere as pursued by the Greeks and Romans that deserve our attention.

The men of antiquity conceived of the interaction of atmosphere and earth in two ways: effects produced by the land upon the atmosphere, and effects produced by the winds upon the land. In connection with the first, Seneca makes a remark which, when taken from its context, would not be out of place in a modern manual of meteorology. He conceived the lower portion of the atmosphere to be extremely variable and inconstant as a result of the proximity of the earth. “The earth is a more important cause than all others ... for the air’s changefulness and inconstancy. The varying positions of the land, facing here this way and there another way, are of great moment in determining the temperature of the air.”[75] Nothing is truer than this, but the reasons that Seneca gives for the influence of the atmosphere upon the land are not satisfactory, being based to a large extent on the supposition that winds are produced by vapors. Indeed, by the theory of vapors and exhalations many ancient and medieval thinkers attempted to explain nearly all the phenomena of the atmosphere and heavens as well. Aristotle had pointed out that a dry and smokelike exhalation is caused by the sun to rise from the earth’s surface through the air and even to penetrate the zone of fire.[76] While near the earth this exhalation takes the form of wind; when ignited at higher levels it becomes comets and shooting stars. Besides this, Aristotle maintained that a damp and watery vapor is also drawn into the atmosphere by the sun’s heat and when cooled turns into cloud or falls in the form of rain and snow.[77] These ideas of Aristotle became known to the Western world of the Middle Ages with translations of the De caelo and Meteorology and found their expression in the thirteenth-century writings of Albertus Magnus.[78] Seneca, on the other hand, explained that the winds were air in motion and that they might be produced by many and various causes.[79]

WINDS

All three of the writers whom we are specially considering,[80] Aristotle, Seneca, and Pliny, had observed that there is a variety of local winds—valley, river, sea, and marsh breezes—taking their origin from the exhalations and vapors arising from these natural features. But even though their explanations of the causes for these winds are now regarded as archaic, the observations they made of their occurrence were not inaccurate.

As to the effects of the winds on the earth, we encounter a theory that sounds most extraordinary in the light of modern science but which corresponds logically to the Aristotelian hypothesis of the elements and to the general ideas current in classical times regarding the structure of the earth. This theory, that the winds are the cause of earthquakes, can better be understood after we have examined the ancient opinions about the physical geography of the water and of the earth.

Another persistent belief, held alike by poets, physicists, and geographers, originated in the Homeric mythology of the calm heights of Olympus, dwelling place of the gods. This was to the effect that the winds are limited to the lower part of the atmosphere,[81] a zone some ten or fifteen stades in thickness.[82] The highest mountains were thought to reach above into a realm of perpetual tranquillity where clouds and dew and frost were unknown and where the ashes of sacrifice would remain undisturbed for a year’s time.[83] This idea was transferred to the Middle Ages through the writings of Pomponius Mela, Solinus, and others.

CLIMATOLOGY

As to the climates, it has already been shown that many writers of antiquity divided the earth’s surface into zones: fiery, temperate, and frozen. Aristotle, Seneca, and Pliny do not seem to have had that more exact understanding of the distribution of climates which recognizes that two countries in the same latitude may, nevertheless, have different climatic conditions and products.[84] To them, all places on the same parallel were virtually the same from the climatic point of view. In this connection it must be pointed out that the parallel strips, or climata, into which Eratosthenes, Hipparchus, Ptolemy, Pliny, and Martianus Capella divided the oikoumene were not climatic divisions in our modern sense—implying the prevalence of well-defined conditions of temperature and weather—but, rather, artificial astronomical divisions the boundaries of which were determined by arbitrary means.[85] Nevertheless, true climatic differences were well understood; Seneca describes vividly in more than one place in the Quaestiones naturales the intense heat and dryness of southern regions[86] and the cold of the far North; Seneca and Pliny had acquired more detailed knowledge than Aristotle of the northern ice and snows.[87] Pliny made some interesting, if unsound, observations connecting the dark complexions of the Ethiopians with the scorching effects of the sun and foreshadowed a modern theory by asserting that the inhabitants of northern Europe are blonde (and savage) because of the coldness and inclemency of the climate in which they dwell.[88] A brief but striking passage from the Octavius of Marcus Minutius Felix explains as follows the warming effect of the western ocean upon the climate of Britain: “God is mindful of our welfare not only universally but locally. Britain is deficient in sunshine, but this deficiency is made good by the warmth of the sea that flows around it.”[89]

The Greeks and Romans certainly had no satisfactory understanding of the general circulation of the atmosphere. Only with the maritime voyages since the fifteenth century have we come to know the distribution of belts of prevailing winds and calms. Aristotle said that the etesian, or north, winds blow from the cold countries full of water and snow under the Great Bear; and that the south wind originates at, but not south of, the Tropic of Cancer;[90] this is the nearest he came to giving a theory of atmospheric circulation. Megasthenes had heard of the monsoons of the Indian Ocean; Pliny described the use made of them by sailors in going out to India,[91] but he made no attempt to explain the general areas of westerlies or trades. On the other hand, Aristotle,[92] Seneca,[93] and Pliny[94] all recognized and discussed at considerable length the influences of wind on weather; for example, the fact that the etesians, though they bring clear skies to Italy, deluge Ethiopia and India with rain—a conception which contains a shadow of truth.[95] Auster, the south wind, was supposed to bring rain to Italy.

THE WATER ELEMENT

Since water was one of the four—or, according to Aristotle, five—elements that were supposed to make up the universe, the ancient authorities looked upon the ocean as necessarily as old as the earth itself. Seneca thought that the Nile and the Ister (Danube) are of equal age with the primordial ocean, because of remarkable characteristics which differentiate them from all other streams.[96]

THE SEA: ITS SALINITY, DEPTH, CURRENTS, AND TIDES

We must note what features of the sea interested the Greeks and Romans. These were primarily its saltness, its depth, its currents, and its tides.

The problem of why the sea is salt gave rise to a good deal of theorizing. That the evaporation of the lighter fresh water leaves behind the heavy salt water was well understood, but in the further solution of the problem opinions diverged widely. Aristotle thought that the salt was the result of combustion;[97] that it was an ashlike substance first carried into the air by the exhalations from the earth and then deposited in the sea by rainfall—particularly by the autumn rains that accompany the south winds blowing from hot, dry districts where the process of combustion is most active. Pliny believed that the salt came partly from dry vapors intermingled with the sea waters and partly from the nature of the earth, which tends to impregnate the sea with salt.[98]

Aristotle said[99] that the Pontus (Black Sea) was deeper than the Maeotis (Sea of Azov), the Aegean deeper than the Pontus—except in one place—the Sicilian Sea deeper than the Aegean, and the Sardinian and Tyrrhenian the deepest of all seas. Pliny quotes[100] a certain Fabianus to the effect that the greatest known depth of the sea is fifteen stades, or about 1200 fathoms—not an excessive figure, for parts of the Mediterranean are in fact even deeper. Pliny,[101] following Aristotle,[102] believed that the “Deeps of the Euxine,” opposite the shores of the people of the Coraxi, were unfathomable.[103] Aristotle had a very false idea that the Atlantic is made up of shallows and mud banks and that it is calm, an idea shared by the Mohammedans and one that may have contributed to the horror of the Western Ocean which lingered in the minds of Mediterranean peoples throughout antiquity and until the close of the Middle Ages.[104]

The ancient geographers certainly had no clearer understanding of the general circulation of the ocean than of the atmosphere, and for the very same reason: they had not traveled sufficiently. Aristotle thought that there is a flow of water southward from the higher northern part of the earth,[105] and Macrobius explained a series of currents in the oceanic belts which he imagined surrounded the earth.[106] Certain currents of the Mediterranean attracted attention: the constant flow from the Euxine into the Aegean and the fluctuating currents of the Strait of Messina and the Euripus (between Euboea and the mainland). A tradition arose at later times that the death of Aristotle was caused by his disgust at being unable to explain to his satisfaction the currents of the Euripus.[107]

Only with the travels of Pytheas of Marseilles along the North Atlantic coasts, the expedition of Alexander, and Nearchus’ voyage and exploration of the mouths of the Indus and coasts of Beluchistan and Mekran did the Greeks gain any adequate knowledge of tidal phenomena; for the tides of the Mediterranean, except in a few places, are so low as to be almost negligible.[108] Eratosthenes thought that the currents through narrows in the Mediterranean are caused by variations in the relative levels of the sea at either end of the channels and that these variations are a response of the sea to fluctuations of the tides in the ocean beyond the Pillars of Hercules.[109] As early as the third century before the Christian era the Greeks had understood the relation of the moon’s phases to the ebb and flood, but certainly not much earlier, for Aristotle appears to have been ignorant of it.[110] Posidonius was the first to give a full account of the manner in which the moon and sun regulate the tides.[111] He had accurate knowledge of the diurnal, the monthly, and perhaps the annual tidal periods,[112] a knowledge which formed a bulwark of the structure of his astrology. Pliny also believed that the tides were caused by lunar influence and described the three periods with even greater accuracy than Posidonius.[113] He recognized that the tides must correspond to a lunisolar cycle of one hundred lunations, or eight years, an astronomical cycle that had long been familiar to the Greeks.[114] He included in his account an astute observation that the tides, like everything else on the earth’s surface depending on celestial controls, tend to drag behind the time when these controls are exerted.[115] Seneca does not try to explain the tides; he mentions them only incidentally in connection with a graphic description of the terrible deluge that will overwhelm the earth at the end of the Great Winter. Though in some respects like the spring tides at the equinoxes, when the sun and moon are in conjunction, this flood will be bound by no law of nature and will have no curb to its fury.[116] Macrobius’ explanation of the tides,[117] which was copied by many later writers, though ingenious, was not founded on actual knowledge or observation. He said that the ebb and flood are caused by the impact of the opposing currents of the two ocean belts which encircle the earth, and, with Eratosthenes, he thought that the tide of the Mediterranean is a repercussion of the ocean tides. Indeed, after the time of Pliny there was no addition to the scientific understanding of tidal phenomena until the eighth century.

SUBTERRANEAN CHANNELS

Evaporation was given by Aristotle as a reason why the sea does not overflow its bed on account of the constant inflow from the rivers.[118] Another explanation of this puzzling circumstance was found by Pliny[119] in a curious theory that prevailed throughout antiquity and the Middle Ages to the effect that the land is seamed with veins, cavities, and tunnels.[120] Into some of these the air enters; others are the passages for rivers which sink into the ground; through still others the water of the sea finds its way to wells, springs, and fountains, where, made fresh by its passage through the earth, it bursts forth to form rivers which return it to the sea. A continuous circulation of the waters of the earth is thus maintained through passages corresponding to the veins, arteries, and canals of the human body.[121]

The origin of the latter theory is undoubtedly to be sought for partly in the nature of the ground in Greece and the Aegean region and partly in the age-old belief that the interior of the earth is the abode of the dead.

The soluble character of the limestone rocks throughout parts of the Balkan Peninsula has led to the production of what is now known as karst topography, so called from the Karst, a plateau between Trieste and Fiume, where it has attained its most typical development. In such regions many streams disappear into hollows of the ground; caverns and underground galleries are extremely common; and the traveler occasionally comes across a full-grown river bursting out of the depths of the earth. The old and persistent story that the river Alpheus of the Peloponnesus passes beneath the Ionian Sea only to gush forth in the well of Arethusa in Syracuse was destined to have a medieval counterpart in the explanation of the subterranean courses of the rivers of Paradise.

RIVERS OF THE UNDERWORLD

Among the most famous and sinister of the subterranean streams of antiquity were the dark waters of Cocytus, Acheron, Pyriphlegethon, and Styx.[122] These were the streams of the nether world, the world of the dead. Belief in the subterranean position of the after-world, the Hades of the Greeks, the Inferi of the Italian folk, was widespread and lasting among early Mediterranean peoples. Hellenic mythology placed not only Tartarus, the abyss of torment, but also the Elysian Fields in the depths. Plato taught that within the bowels of the earth are immense caverns, some filled with fire, some with water, others the abode of the shades. To be sure, rationalistic arguments against such doctrines were raised by the incredulous. Aristotle had believed that of all four elements the earth is the most dense and solid and that its position is at the center of the universe. Although the earth might be seamed with small water channels, it would be a reversal of the physical laws of the universe to suppose that within it there could exist caverns large enough to “hold Tartarus, the Elysian Fields, and the infinite multitude of the dead” (Cumont).[123] Hence some would identify the Elysian Fields with the Islands of the Blessed, placing them in the antipodes, and would relegate Tartarus to the lowest hollow of the celestial sphere.[124] But even this explanation could not be reconciled with the more mature cosmography of the Alexandrian age. The Epicureans resorted to out-and-out disbelief in a future life and future dwelling place of the spirit.[125] Others looked for the shades in the atmosphere below the moon’s orbit or else treated the whole problem in a lofty vein of allegory. Rationalistic questioning of the subterranean position of the next world, however, did not shake faith in this doctrine as it persisted among the ignorant, and the doctrine was given new life, if in somewhat different forms, by the Neoplatonic movement and the influx of Oriental cults during the waning years of the Western Empire.[126] The Neoplatonists reverted to Plato’s theory that the interior of the earth may well include hollows large enough to contain the future abode of men’s souls. The religion of Mithras tended to spread throughout the Occident the dualistic cosmology of an eternal conflict between the powers of light and goodness on high and the powers of darkness and evil below. In the words of Franz Cumont, whose truly fascinating study of this subject we are here following: Oriental dualism cut “the abode of the souls into two halves, of which it placed one in the luminous sky and the other in subterranean darkness. This was also the conception which, after some hesitation, became generally accepted by the Church and which for long centuries was to remain the common faith of Christendom.”[127] In the period with which it is our special problem to deal, then, we shall find that Hell is almost invariably placed in the heart of the earth.[128]

ORIGIN OF RIVERS

To return from this digression to the vexed question of the origin of super-terrestrial rivers, we find that the circulation of water from the sea either by underground passages or by rain was not regarded by the majority of ancient thinkers as sufficient to account for the huge volumes of water that rivers constantly pour into the sea. Plato had thought that there were enormous reservoirs in the interior of the earth which served to keep the rivers supplied,[129] but Aristotle rejected this hypothesis.[130] A reservoir as large as the entire earth, he said, would be necessary for the purpose. His explanation was worked out of the theory that one element actually may be transformed into another. In a relatively unscientific age what is more natural than to believe, when one sees soluble substances passing into solution in water, that they actually become water? Or when one sees the condensation of invisible vapor into clouds and of clouds into rain, that the air is actually turning to water? Aristotle, followed by Seneca,[131] argued that the air which penetrates into the internal cavities and recesses of the earth is chilled and liquefied by the cold encountered there, just as air seems to be condensed by cold in the outer atmosphere. Aristotle cited as a proof of this the supposed fact that most great rivers have their sources in mountains.[132] Mountains were to be looked upon as enormous elevated sponges exuding water on all sides. Aristotle concluded likewise that the northern part of the earth must be high and mountainous,[133] because many great rivers originate there. But, if the air is transmutable into water, why, then, was it not perfectly logical to suppose that the earth could also undergo a similar change? This as a theory to explain the origin of some of the water of rivers was clearly expressed by Seneca and, among the early Church Fathers, by Gregory of Nyssa.[134] The faulty character of Seneca’s scientific thought is seen in his failure to account satisfactorily for the logical demands of his theory, i. e. for the replacement of the land lost by its liquefaction.

THE NILE FLOOD

One of the natural phenomena most puzzling to the Greeks and Romans was the inundation of the Nile.[135] Herodotus in his famous book on Egypt had given a lengthy account of the Nile and what it meant to Egypt. He had called Egypt the “gift of the Nile,” for he understood the alluvial character of the country. His theory as to the cause of the flood—he held that the normal height of the river was its flood height but that the etesian winds, by driving the sun southward out of its course in winter, caused the sun to dry up the headwaters of the stream—was less successful than his description of the features of the flood itself. Seneca also gives a long and extremely picturesque description of the inundation[136] and sets forth various older explanations of its origin, all of which he tries to refute without presenting an opinion of his own. He tells how, starting in the upper reaches of the river, the flood travels downstream and arrives in Egypt about midsummer; how it adds to the fertility of the country by its deposits of silt; and how—here Seneca repeats the crisp phrase of Herodotus—Egypt is the creation of its stream. Among the various theories which he comments upon and refutes it is rather significant to find one which had been propounded by Anaxagoras and which is now recognized, in part at least, as the right explanation: that the high water is caused by the melting of the snows on the Ethiopian mountains. Seneca said that there were twenty proofs available to refute this hypothesis.[137] Another view which Seneca rejected was that the flood was caused by the etesian winds backing up the water, a theory fated to reappear in many medieval books, among them the Expositio in hexaemeron of Peter Abelard.[138] Pliny discussed the Nile and its peculiarities.[139] Like Herodotus, he believed that it rises in the western part of Africa and reaches the Sudan and Upper Egypt only after a series of long subterranean journeys. He described the flood, giving statistics of the various heights of the water on the nilometer and explaining which heights meant plenty and which meant famine. He shows a lack of critical sense in his remarks on the causes of the high water; for he held that two theories are equally worthy of credence, the theory of the etesian wind, which we have just examined, and the true explanation that the floods are due to summer rains in Ethiopia.

THE LANDS

To turn now from water to land. We have already discussed Aristotle’s idea of the gradual transposition of continents and oceans under the control of the celestial bodies. Pliny describes a large number of local changes of land and sea:[140] the building of new land by alluvial deposits, the sudden appearance of land and islands out of the depths of the waters, the separation of islands from the mainland, the tying of islands to the shore, the total disappearance of entire countries beneath the sea—Plato’s Atlantis is given as an example[141]—the collapse of mountains; but in all this, though he tells where such prodigies took place, he rarely tries to explain how and why they happened.

EARTHQUAKES AND VOLCANOES

The explanation of the causes of earthquakes and volcanoes, however, was attempted by Plato, Aristotle, Pliny, Seneca, and many other writers of antiquity with no small measure of ingenuity. We have seen that ancient philosophers almost universally were of the opinion that the earth is honeycombed with cavities and subterranean passages. Plato said that some of these cavities were filled with water and air but that others contained mighty swamps and streams of fire, including the immense fiery river Pyriphlegethon. The volcanoes of the earth’s surface were outpourings from these internal streams, and their minglings with the atmosphere and strivings to burst forth were the cause of earthquakes.[142] Aristotle, on the other hand, denied the possibility of subterranean fires. According to his scheme of physics the place for fire in the universe was above the sphere of air. He maintained that the dry and smokelike exhalation which causes the winds of the atmosphere not only penetrates into the cavities of the earth from the outside but is generated within the earth’s interior[143] and that when this exhalation tries to escape and is opposed by any obstacle—for example, by the sea—there is a tremendous upheaval and the land is shaken. Seneca[144] and Pliny[145] ascribed the cause of earthquakes to the winds. Pliny believed that after a great storm, in which wind is driven down and compressed in the interior of the earth, it frequently strives to come forth and in so doing shakes the earth’s surface far and wide. Occasionally, if the pressure is too tremendous to be withstood by the crust of the earth, the winds burst through, accompanied by a violent tempest and a rain of sparks and cinders. Aristotle describes such a volcanic eruption in the Eolian (Lipari) Isles.[146] While this was the explanation of violent eruptions, the quiescent volcanic activity of mountains like Etna was usually attributed to a different cause. Pliny[147] speaks of Etna, Chimaera in Lycia, and various other volcanoes as burning, and it would seem that he connected them with such phenomena as burning naphtha wells and pits of bitumen and sulphur.

HEIGHT OF MOUNTAINS

A word must be said about classical estimates of the height of mountains.[148] Aristotle suggested that these altitudes might be determined by observing the duration of sunlight on the peaks. He would have us believe that the Caucasus range is illumined by the sun for a third of the night after sunset and for a corresponding time before sunrise. If this were true, these mountains would be from 60 to 180 miles high![149] Less fantastic were the estimates of Dicaearchus and Eratosthenes. The former, Pliny tells us, measured Pelion and found it to be 1250 paces (10 stades) in height.[150] If we are right in our understanding of the length of the pace here employed, this represents 5167 feet[151]—certainly not far short of the actual altitude (5308 feet). We do not know the method used by Dicaearchus in this survey, but his calculation was probably determined from simple triangulation with the aid of a diopter, an instrument for measuring angles.[152] Triangulation as a means of finding the height of trees and buildings was well understood. Eratosthenes probably did not carry out a triangulation of his own but adopted the results obtained by Dicaearchus, asserting that the highest mountains in the world do not exceed 10 stades in elevation. He demonstrated by an ingenious and graphic mathematical proof that the volume of mountains is so utterly insignificant in comparison with the volume of the earth as a whole that the earth can be regarded as essentially a sphere,[153] a conception which became well established in the astronomical thought of antiquity and one which reappeared in the Middle Ages.[154] When the Greeks learned something of the Alps, they were able to correct Eratosthenes’ underestimate of the maximum height of mountains. Posidonius argued that 15 instead of 10 stades should be taken as the correct figure and that the maximum depth of the sea was no greater than 15 stades.[155]

MATHEMATICAL GEOGRAPHY AND CARTOGRAPHY

Mathematical geography deals in part with the accurate determination of the location of places and with the accurate representation of the earth’s surface on maps.

MATHEMATICAL GEOGRAPHY LARGELY BASED ON ITINERARIES

The method almost universally employed by ancient geographers for determining locations was the compilation of itineraries; the position of a place was found, not by accurate surveys, but by reference to other places at so many stades or so many days’ journey in such and such a direction. Whatever maps the Romans may have had (for example the great representation of the Empire set up by Agrippa in the Porticus Octaviae in Rome) were probably compiled entirely from route traverses. The greater part of the information which even the most accurate and scientific of the Greek geographers, Eratosthenes, Marinus of Tyre, and Ptolemy, possessed, was drawn from such itineraries and from estimates of sea voyages. The figures for the latitude and the longitude of the large number of places given in Ptolemy’s Geography are for the most part not the result of astronomical observations, and the tables cannot be regarded as analogous to modern tables of latitudes and longitudes but must be considered rather as guides for the construction of maps.[156]

Other methods besides these simple reckonings of locations were well known, none the less.

ASTRONOMICAL DETERMINATION OF LATITUDE

The determination of latitude has always been a comparatively easy astronomical problem. No complicated instruments are needed to measure either the vertical elevation of the sun on the meridian or of the north celestial pole, and from both of these the latitude of the observer can be calculated with extreme accuracy. The instrument commonly used by the Greeks for measuring the angle of the sun[157] consisted of an hemispherical bowl (scaphe) with a vertical rod (gnomon) for a radius. The shadow of the rod on the concave interior of the bowl gives the elevation of the sun (with an error of 16′[158]) and thereby the latitude. Eratosthenes, Hipparchus, and Ptolemy were all familiar with the latitudes of several places that had thus been determined.

ASTRONOMICAL DETERMINATION OF LONGITUDE

To find longitude by astronomical means is a more difficult matter for people who have neither chronometers nor telegraphs. Eratosthenes, Hipparchus, Pliny, and Ptolemy all understood that it may be found by observing the time of eclipses in different localities.[159] Hipparchus believed that an extensive series of observations should be carried out in order to ascertain, by mathematical and astronomical means alone, latitudes and longitudes of a large number of places.[160] To facilitate such a survey he prepared tables of lunar eclipses and tables to aid in the determination of latitudes, but the practical difficulties of the undertaking were too great and the work was never completed. In fact, throughout antiquity the total number of places whose position had thus been accurately determined probably does not exceed half a dozen, if it is as many.

Pliny gives[161] an account of two different occasions when observations were made of the same eclipse at two different places. He says that at the time of the battle of Arbela the moon was eclipsed at the second hour of the night, when at the same hour it was rising in Sicily. He also speaks of an eclipse of the sun that was seen in Campania between the seventh and eighth hours and in Armenia between the eleventh and twelfth, indicating a difference in longitude of four hours, or 60°. The actual distance is no more than half of this. Ptolemy also cites[162] the eclipse of 331 B. C. as giving the distance between Carthage and Arbela. We shall see later that much greater accuracy was attained by the Arabs in their calculations of longitude and that some of their figures were passed on to the Western world in astronomical tables during the twelfth and thirteenth centuries.

CARTOGRAPHY

Little need be said of the cartography of antiquity,[163] for although medieval maps undoubtedly owe much to classical predecessors, none of the classical maps which were destined directly to influence the cartography of the Middle Ages have come down to us. Indeed we have good copies of only two. These are the maps of Ptolemy and the so-called Tabula Peutingeriana,[164] or Peutinger Table. Ptolemy’s maps exerted no influence whatever on the cartography of the age of the Crusades.[165]

The Tabula Peutingeriana is preserved in a manuscript of the twelfth century or earlier and probably was originally copied from a large chart showing the main routes and provinces of the Roman Empire. It is an extremely long and narrow affair in which the geography is woefully distorted. Though in itself hardly representative of the best in the Roman cartographer’s art, the original may have been compiled from a contemporary Roman map of the world and adapted through its long and narrow form to the especial purpose of illustrating itineraries. We know that maps of the world were officially drawn in imperial Rome and posted up for the benefit of the public: the one constructed by the order of Agrippa and Augustus in the Porticus Octaviae was the most famous;[166] and others are mentioned in literary sources.[167] Certain medieval maps of the world are possibly related to some of these Roman charts,[168] but unfortunately in the absence of the Roman maps themselves the exact relationships cannot satisfactorily be worked out.

Although the ancient astronomers knew a variety of projections for representing the heavens—stereographic, orthographic, and others[169]—these were not applied to maps of the earth until long after our period. Ptolemy describes several projections, among them the conic, which he may have used; but there is no question of any mathematical projections in the twelfth and thirteenth centuries, and none of the cartographers of that period took account of the fact that they were endeavoring to show a globe on a flat surface.

THE EXPANSION OF REGIONAL KNOWLEDGE

We have seen what the geographers of antiquity thought about the general distribution of land and water and about the physical processes of the earth’s surface. We now must study a subject which is less concerned with what they thought than with what they actually knew—however vague and inexact this knowledge was. Though the heritage of knowledge which antiquity left to the Middle Ages of the countries and regions of the oikoumene was vast, much had been lost and much garbled in the process of transmission. Hence it would be beside the point to discuss the details of topographic information contained in the works of Strabo, Pliny, and Ptolemy; our aim is merely to indicate in a broad way the limits of the regional knowledge of the ancient world. This can best be done by sketching the various stages in which the horizon of geography was expanded until it reached the Shetlands and Scandinavia in the north, China in the east, and, perhaps, the Central African mountains in the south.

EXPANSION OF GREEK REGIONAL KNOWLEDGE

Homer’s geographical horizon was limited by the Mediterranean—one might almost say Aegean—shores; Italy, Sicily, and everything to the west was a realm of fable, and his acquaintance with the Black Sea coasts was little better. The colonizing movement of the eighth to the sixth centuries before Christ brought Greek settlers to these coasts; and through them there was gained some acquaintance with the country behind them, which found expression in the writings of Hecataeus at the close of the sixth century. With this writer ancient geography begins to assume its familiar classical form. He shows some slight knowledge of Central Asia beyond the Caspian Sea and is even aware of the existence of India—or at least of the northwestern portions of that peninsula. The great struggle with Persia brought the Greeks into much closer relations with Asia, and a corresponding increase in geographical knowledge ensued. This was summed up by Herodotus. Much of his geography is fabulous and legendary, but much of it is of surprising detail and accuracy. The voyage of Scylax of Caryanda from the Indus to the Persian Gulf had brought the Indian Ocean within Greek ken. Herodotus also describes the rivers of Scythia and of Central Asia and displays detailed familiarity with Egypt and northeastern Africa; he knew less of the West, although at about this same time the voyages of the Carthaginian Hanno in the Atlantic Ocean extended the horizon at least as far as the Canaries, which were destined to remain on the limits of the known world in that direction for many centuries to come. Shortly after Herodotus, Ctesias, who had lived seventeen years at the Persian court, wrote his Persica and Indica, in which we find collected together many of the fabulous and marvelous tales of Oriental animals and monsters which were later to figure so strikingly in the Historia naturalis of Pliny, in the medieval encyclopedias, and in the Physiologus, a collection of animal lore widely read in the Middle Ages. Further detail regarding the local features of Mesopotamia and Armenia was learned from the expedition of Cyrus and preserved for the future in Xenophon’s Anabasis. But the events which did most to expand the regional knowledge of the ancients were those connected with Alexander’s conquests and with the reigns of his successors. Alexander’s march in itself opened to Greek eyes wide territories that had been unknown before; it brought Greek armies and, after them, Greek merchants into the innermost heart of Asia; it established direct connections with India; rumors reached the companions of Alexander of an enormous island of Taprobane in the Southern Ocean, an island which we now recognize to be Ceylon. With the voyage of Nearchus came a better understanding of the Indian seas; and subsequently under Seleucus I (Nicator), Megasthenes, who was sent as ambassador to the court of an Indian potentate on the Ganges, gave a detailed description of the tribes and products of Hindustan, more extensive notes on Taprobane, and—unfortunately—a repetition of the fabulous legends of Ctesias. Patroclus, in command of the easternmost provinces of the kingdom of Antiochus I, provided some valuable statistical and geographical facts about the peoples of the Caspian region, although he was quoted as an authority for the belief that the Caspian communicates with the outer ocean and that it is an easy matter to sail thence to India.

GEOGRAPHY AT ALEXANDRIA

In addition to the reports of travelers and eyewitnesses, the establishment of Greek control over Egypt and the greater part of southwestern Asia led to a scientific awakening that centered in Alexandria. One of the greatest triumphs of Hellenistic science was the geographical and astronomical school that flourished at Alexandria under the Ptolemies. Eratosthenes and Hipparchus were undoubtedly the most famous representatives of this school, and in them we see the culmination of Greek scientific geography; for their work, all things considered, surpassed that of Claudius Ptolemy, and the work of no other man approached it. Though Eratosthenes’ researches were significant mainly in the field of mathematical geography, he made use of much of the regional knowledge which was available in the library at Alexandria and which he could gain from enterprising Greek traders, administrators, and soldiers who had actually visited the countries with which he deals in his treatises.

One striking result of this broadening of regional knowledge was the lesson it taught in regard to the countries south of the Tropic of Cancer. The progress of exploration in Upper Egypt and in India showed that these countries were not only habitable but thickly settled. Adherents of what we have called the Cratesian theory were obliged to acknowledge that the tropic could not be taken as the beginning of the burning zone. Eratosthenes pushed the limit of the oikoumene as far south as latitude 11½° N.[170]

HELLENISTIC REGIONAL KNOWLEDGE

While Greek military enterprise had been opening up the Orient and exploratory enterprise penetrating the tropics, an important advance was made in the direction of the northwestern seas and the British Isles. The voyage of Pytheas of Marseilles, about 330 B. C., had brought within the scope of ancient knowledge Britain, Scandinavia, Thule, and the frozen ocean beyond. Thus, in the Hellenistic period the frontiers of knowledge included the Orkneys, Shetlands, Faroes—or whatever of the northern isles was meant by Thule—the Canaries, tropical Africa, and Ceylon. No further notable extension of these borders seems to have been made until the first century after Christ, except that vague rumors of a people called “Seres” and of the use of silk had crept into the Roman world in Virgil’s time. This may have indicated acquaintance with China, although Horace took the Seres to be a tribe of Central Asia.[171] The Scythian invasions which overwhelmed the Greek kingdom of Bactria and the conquest by the newly risen power of Parthia of the provinces of the Seleucids east of the Euphrates tended to cut all communication with the interior and farther parts of the Asiatic continent; but the Mithridatic wars, as described by Theophanes, familiarized the public with the local geography of Armenia, Pontus, and the Caucasus. Similarly Caesar’s campaigns in Gaul, Germany, and Britain opened Western Europe to the Roman world.

REGIONAL KNOWLEDGE OF MELA AND PLINY

The most complete and accurate summing up of the regional geography of the ancients was the Geography of Strabo, written in Greek probably shortly before 17 A. D. But, as we have seen, this work was unknown to our period of the Middle Ages, when men had to rely on Latin writers like Pomponius Mela and Pliny, whose writings were of distinctly inferior quality and included a great deal of fabulous and worthless material. Devoid of that critical judgment which characterized Eratosthenes and Strabo, Mela and Pliny were content to bring together huge quantities of miscellaneous information, much of which was derived from antiquated Greek sources. Mela, for example, closely follows Herodotus’ description of the marvels of Asia, and Pliny retails many of the fanciful legends of Ctesias and Megasthenes. Pliny’s contributions to geography were somewhat more satisfactory than those of Mela; for he added some details about Asia that had not been mentioned before, especially in his description of Serica and of India and in his account of the monsoons. On the other hand Mela was the first writer to mention the Baltic Sea, or “Sinus Codanus,” which he described as a great gulf full of islands.

THE “PERIPLUS OF THE ERYTHRAEAN SEA”

Nearly contemporaneously with Pliny there came an advance in the knowledge of the Indian Ocean in the anonymous Greek Periplus of the Erythraean Sea, a manual for sailors and merchants. This is of interest because it gave indications of the existence of coasts and islands beyond India, the islands of Chryse, the land of the Seres, and, at the end of the earth to the east, a region of “Thin”—the first mention of the word “China” in the West unless we take into account the “Sinim” of Isaiah xlix, 12, which may or may not have referred to the great nation of the Far East.

At about the same time, as we have already seen, the upper reaches of the Nile, possibly as far as the great marshes of the White Nile in about latitude 9° N., were explored by the expedition described by Seneca and Pliny which Nero sent out to solve the age-long mystery’ of the sources of the river of Egypt.[172] Pliny accordingly placed the southern border of the oikoumene some 7½° south of the position to which Eratosthenes had assigned it, or at about latitude 4° N.[173]

LIMITS OF ANCIENT REGIONAL KNOWLEDGE ON THE SOUTH AND EAST

Before the days of Marinus of Tyre and Ptolemy the limits of geographical knowledge were again much extended both southward and eastward. The Ptolemaic map depicts a wealth of detail in the interior of Africa, although we are unable to say with assurance what most of this detail represents in reality.[174] Ptolemy certainly had some knowledge of the great lakes and mountains of east-central Africa. The snow-covered mountains which he placed at the sources of the Nile may be associated with reports derived from the east coast of Africa, of Kenya, Kilimanjaro, or possibly the Ruwenzori range.[175] Farther to the west he describes a river, the Nigir, flowing from a region south of the country of the Garamantes (probably modern Fezzan) to the westward into a lake near the Atlantic. It seems altogether likely that by this river he meant the Niger. Ptolemy mentions two expeditions that had been made at an unknown period to the south from the land of the Garamantes, one under Septimius Flaccus, who arrived at the country of the Ethiopians after three months’ journey, and the other under Julius Maternus and the king of the Garamantes, a four months’ journey to a country called Agisymba, abounding in rhinoceroses. Ptolemy’s regional knowledge certainly extended as far south as the equator, and he was well aware of the fact that the equatorial zone is inhabited.

In the east, also, the Ptolemaic map reveals an advance in knowledge over its predecessors. Chryse appears as a peninsula, and other islands and coasts are shown that certainly indicate familiarity with the Malay Peninsula and China, possibly also with Borneo and Java. We shall find, however, that these valuable extensions of knowledge eastward and southward were universally lost sight of in the West in the Middle Ages and that cosmographers were united in placing India or Paradise as the farthest end of the world in the one direction and either the shores of the Ethiopian Ocean immediately beyond the Garamantes or the edge of the uninhabitable zone at the tropic or not far beyond it, as the extreme limit in the other.[176]

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II. THE CONTRIBUTION OF WESTERN CHRISTENDOM BEFORE 1100 A. D

INTRODUCTION

The geographical lore of antiquity was carried over to the Western Europe of the Crusading age by the Christians of the first eleven centuries of our era and by the Moslems. In this chapter we shall study the manner in which it was transmitted, transformed, and augmented by Christian agencies.

SCRIPTURAL INFLUENCE ON EARLY MEDIEVAL GEOGRAPHY

Our primary problem is to examine the effects of Christianity on geographical knowledge and belief, effects which sprang in large measure from men’s varying attitudes toward the Bible. Some believed that Scripture contains the absolute and only truth, but others were willing to grant a partial authority to pagan teachings. The evolution of science was profoundly modified by the conflicts between these divergent tendencies of thought and by the efforts made to reconcile one with the other. The general result spelled disaster to clear thinking in geography. Moreover, many of the facts which the scholars of antiquity had gathered together were wholly lost sight of in the confusion that accompanied the disintegration of Roman civilization. The horizon of the known world was narrowed from the wide bounds it had reached in the time of Ptolemy.[177] New information acquired by exploration and travel was ignored; and a host of legends, fancies, and false theories took the place of the reasonably accurate body of information which the Greeks and Romans had possessed.

IGNORANCE OF THE BEST WORK OF ANTIQUITY

During these long years Constantinople was the only great metropolis of Christendom, the only center where the arts and sciences of civilization were cultivated without interruption. We might expect, therefore, that the Byzantine influence upon Western geography would be as marked as it was upon Western art and architecture. But this was not the case. However much the scholars of Constantinople may have been interested in the historians of antiquity, they neglected the geographers; and the scientific geography of the Greek Empire was at best a work of lifeless compilation and commentary. Furthermore, knowledge of Greek was at no time widespread in the West until the Renaissance, and the great majority of Western scholars were profoundly ignorant of Byzantine literature.[178] For their geography the men of the Occident turned rather to the Bible and to the mediocre and worse than mediocre works of an age of intellectual degeneracy. Solinus, Martianus Capella, Macrobius, Aethicus of Istria, and Orosius became authorities from which later writers derived their facts.

SCIENTIFIC STAGNATION DURING THE EARLY MIDDLE AGES

The earlier Fathers of the Church, whatever may have been their merits as theologians and dialecticians, were not distinguished by an ability to understand the truths of natural science or to combat error in that field. With the establishment of the barbarian kingdoms between the sixth and eighth centuries came an epoch of mental stagnation in nearly all realms of science and scholarship. Learning in general and geography in particular suffered almost universal eclipse. Yet dark and ignorant as the times may have been, the torch of civilization was kept burning, if feebly, by a few Irish and English monks[179] and by contacts with the Levant that were maintained through Greek, Asiatic, and Egyptian traders in the principal cities of Europe.[180] If not much authentic geographical information was contributed to Western society by these agents of enlightenment, they served to disseminate certain geographical legends and traditions destined to seize a strong hold on the Western imagination.

In the days of Charlemagne came the new awakening sometimes known as the “Carolingian Renaissance;” and, although tenth-century Europe relapsed temporarily into a torpor, a current of theological interest and, with it, interest in the natural sciences had by then once more set in—a current which was to reach full flood at the time of the Crusades.

SOURCES

What works widely read during these centuries served as sources of geographical information for the scholar of the era of the Crusades?

THE BIBLE

First and foremost we must place the Bible. Certainly in the pagan world no one book had ever held the paramount position in the minds of thoughtful men that Scripture held during the Middle Ages. As we saw in the Introduction, the two great fountainheads of medieval geography were the works of Greek philosophers and historians and the Bible. The geographic material in Scripture is neither very extensive nor very explicit in comparison with the contributions of such writers as Strabo and Ptolemy to the geographic education of mankind, and yet so tremendous was its authority that it tended at one time completely to supersede classical teachings. Slight and confusing as may have been its geographical references, the man of the Middle Ages attached to all of them paramount importance. Simply compare a map of the world reconstructed from Ptolemy’s data[181] with one of the crude Beatus sketches reflecting Biblical beliefs,[182] and some of the changes which the reading of Scripture had wrought become strikingly apparent.

Genesis was the most important book of the Bible from the geographical point of view. Here we find, in the history of the Creation, texts which were the starting point of many speculations about the origin of the world and the elucidation of which was attempted in many a long commentary on the Works of the Six Days.[183] Furthermore, in Genesis we find the description of Paradise and its four rivers, which figured largely on most medieval maps, and the account of the division of the earth among the descendants of Noah, which lay at the bottom of the crude ethnography of the Middle Ages. By some writers the description of the tabernacle of the Lord and its furnishings[184] was regarded as an allegorical account of the heavens and earth. Gog and Magog, described in Genesis, Ezekiel, and Revelation, were prominent among the supposed medieval tribes of Asia.[185] And in the apocryphal Acts of the Apostles, which, though technically not a part of Scripture, were often given the authority of Scriptural truth, we find accounts of the preaching of the Gospel in far lands, India, Ethiopia, Babylonia.[186]

WRITINGS OF THE CHURCH FATHERS

These and many other incidental references gave rise to those relatively restricted portions of the vast mass of patristic literature which deal with geography, but which nevertheless inevitably marked out the channels that certain elements of geographic thought and tradition were destined to follow until the beginnings of the Renaissance. How these passages were interpreted was, then, of great importance.[187]

INTERPRETATION OF THE BIBLE

According to the Church Fathers there were four methods of interpretation; but for our purposes we need consider only two of these, the literal and the allegorical.[188] Both led to pitfalls: the literal interpretation tended to narrow the thought and make it correspond to the exact words of a text; the allegorical, unjustifiably to expand the meaning of simple statements.[189] To these dangers were added the difficulties and contradictions due to the manifold authorship of Scripture and to the misunderstanding of passages woefully faulty from the textual point of view.

Yet the writers of the early Christian age were in most cases unaware of these pitfalls and did not even know when they had fallen into them. Faith in the truth of the Holy Word was usually sufficient to render men supremely oblivious to conflicting and inconsistent assertions that would otherwise have been revolting to reason. Tertullian said: “When we believe, we desire nothing besides belief. For we believe this in the beginning: that there is nought which we need to believe beyond it.”[190]

CLASSICAL INFLUENCES

This faith in the truth of the written Word persisted throughout the Middle Ages and down to our own day. During the earliest Christian centuries the Bible was sometimes regarded as the only source of truth, and the teachings of pagan writers were often looked upon with abhorrence. Lactantius Firmianus (early fourth century), with an inconsistency characteristic of many of the Church Fathers, made use in his Institutiones divinae of the classical authors themselves to prove the supposed fallacies and evils of pagan science.[191] About the fourth century men began to try to amplify and expound the fundamental Biblical truths by appeal to the legacy of classical learning. To effect a reconciliation and combination of Christian teachings with the classics—especially the works of Plato and his followers—became one of the main preoccupations of theologians. Platonic and Neoplatonic influences made themselves felt in the thought of churchmen and scholars, and among the most popular works of the entire period was Chalcidius’ translation of the Timaeus of Plato. Neoplatonism was interwoven into the theological system of Augustine.[192] In the ninth century it appears in the writings of the great Irish scholar, John Scot Erigena.[193] In the tenth and eleventh centuries the Platonic commentary by Macrobius on Cicero’s Somnium Scipionis enjoyed an immense vogue;[194] it was read by the mathematician and astronomer Pope Sylvester II (Gerbert) at the end of the tenth century and on the threshold of our period aroused the protests of the more old-fashioned churchmen like Manegold, who objected to the seeds of heresy which it contained.[195]

ENCYCLOPEDIC COMPILATIONS

For more strictly geographical, rather than “cosmogonic” or cosmological material, we must turn to the encyclopedias rather than to the thoughtful and speculative theological books of such men as Augustine. Like the mighty volumes of Aristotle or the Natural History of Pliny these encyclopedias were attempts to encompass and to put in convenient form the entire range of human knowledge. The most significant was the Etymologiae sive originum libri XX of Isidore of Seville (died 636 A. D.). This large compilation of miscellaneous information served as a model of style and composition as well as a mine out of which later writers dug their “facts.” For the geographical portions of the Etymologiae, Isidore used the Bible and classical authorities alike; he derived much from Orosius and Solinus; and, though it is doubtful whether he was acquainted with Pliny at first hand,[196] he incorporated in his book not a little Plinian material taken from Solinus. Isidore’s method was followed, and much of his work copied, by the Irish and English monastic encyclopedists of the eighth and ninth centuries. We find a great deal from Isidore in the Venerable Bede’s (died 735 A. D.) De natura rerum, in Raban Maur’s (776–856 A. D.) De universo, in Dicuil’s De mensura orbis terrae (825 A. D.),as well as in the De imagine mundi of our period. John Scot Erigena, the great Platonist of the eighth century, stands out among his contemporaries as one of the most original and critical scholars of the Middle Ages. The range of his interests was very broad, and it seems probable that he understood Greek. In his De divisione naturae, beside the Latin sources which Isidore, Bede, and other encyclopedists had copied, he made use of the De nuptiis Philologiae et Mercurii of Martianus Capella and also of various Greek works, including the Geography of Ptolemy.[197] Martianus Capella was held in high favor during this epoch, and his works were commented upon by such men as Remy (Remigius) of Auxerre, the master of Gerbert, and by Adam of Bremen.[198]

MISCELLANEOUS GEOGRAPHICAL WRITINGS

Closely akin to the geography of the encyclopedias, and not infrequently borrowed from by the encyclopedists, are a number of miscellaneous writings, which, though intrinsically of slight value, nevertheless profoundly affected the development of geographical ideas. The most important of these was the brief description of the countries of the world forming the second chapter of the first book of Orosius’ Historiae adversus paganos (fifth century). Enjoying great popularity, as is testified by the existence of over two hundred manuscripts, this was much plagiarized by later scholars: parts of it became incorporated into Isidore’s Etymologiae; it was translated into Anglo-Saxon by King Alfred the Great;[199] and during our period it was extensively quoted and copied by nearly all who attempted to write on geographical subjects. Another of this miscellaneous group is a seventh-century cosmography in barbarous Latin, a pretended translation of a fictitious work originally written in Greek by Aethicus of Istria.[200] We find set forth here for the first time many of those marvels of Scythia and the northern regions employed by later writers to add interest to their pages. Priscian’s sixth-century translation of the geographical poem[201] of Dionysius Periegetes was also extensively quoted. In the middle of the seventh century an anonymous cleric of Ravenna wrote a description of the world in five books. Though entirely the result of compilation, this cosmography is in many respects the most elaborate and interesting geographical book dating from the early medieval West. The sources quoted and utilized are extremely varied, including the Bible, “Jordanis” (Jornandes), Ptolemy, Orosius, Isidore, and possibly the Tabula Peutingeriana, in addition to a number of Greek, Roman, and Gothic writings otherwise unknown.[202] The main importance of the work of the Ravenna geographer in relation to the geography of the Crusading age lies in the fact that a large portion of it was included in a compilation made by a certain Guido in 1119.[203]

LEGENDS

During the twelfth and thirteenth centuries many legends were current in the West, some of which contained geographical elements. Though we shall have occasion to discuss this subject in greater detail later on, the fact should be brought out here that the origin of most of these legends may be traced far back into the centuries before the beginning of the Crusading age.

Perhaps the most significant was the cycle of stories of the exploits and adventures of Alexander the Great which originated in a Greek history purporting to be the work of Callisthenes, a companion of the Macedonian conqueror, and is hence known as the Pseudo-Callisthenes. Written in Alexandria about the beginning of the third century after Christ, this work subsequently became widely dispersed through the East, where translations were made into Syriac, Arabic, Ethiopic, and other Oriental tongues. Put into Latin by Julius Valerius about the middle of the fourth century, again translated in the tenth century,[204] given further Latin vernacular renderings with many additions at later dates, the Romance of Alexander had come, by the time of the Crusades, to form the nucleus of a mass of stories and fables whose scenes were laid in distant Asiatic countries. With it had been associated those mysterious tales and prophecies of Gog and Magog whose origins were ultimately connected with the Biblical revelations of the end of the world.[205] Alexander the Great and Gog and Magog appear in the Pseudo-Methodius, a book of prophecy which foretold the dread events of the Last Day. Rendered into Latin at an early period from a Greco-Syrian original, the Pseudo-Methodius made a deep impression on the medieval mind, especially at the time of the Mongol invasions in the early thirteenth century.

Writers of our period like Gervase of Tilbury and Giraldus Cambrensis also drew on the legends found in Geoffrey of Monmouth’s mythological history of Britain, many of which had entered into the composition of the Romance of King Arthur. Some of the latter were of slight geographical interest.

Finally, the mythology and folklore of Ireland, with infusions from classical and even Arabic literature, gave rise to the story of the wanderings of St. Brandan[206] among mysterious islands in the Western Ocean, an account of which we have in a manuscript dating back perhaps to as early a period as the ninth century.[207]

BOOKS OF TRAVEL AND DESCRIPTION

The most important books describing actual travels and explorations written between the conversion of Constantine and the Crusades were for the most part in languages unknown to the men of the West—Greek and Arabic. Zemarchus’ account of the tribes and trade of Central Asia[208] and the Meadows of Gold of Al-Masʿūdī, wherein were described things personally seen by the travelers between Spain and Burma and south as far as Madagascar, were treasures of geographical lore unknown to Occidental readers of this age.

In Adam of Bremen’s Gesta Hammenburgensis ecclesiae pontificum, written in the latter half of the eleventh century, we find a description of the countries of the North. This was based on knowledge acquired from the voyagings of the Northmen between the eighth and eleventh centuries and, together with the Sagas, will be discussed in a later chapter.

From the varied narratives of Christian pilgrims the Western student might have gleaned some arid details about routes eastward and about the topography of the Holy Land.

THE HISTORY OF THE UNIVERSE

We saw in the first chapter that Plato, Aristotle, Seneca, and most of the other Greek philosophers had believed that the universe is eternal, though subject to ever-recurring destructions by fire or water, followed by “rebirths” (palingeneses).[209] Aristotle had attributed to the stars control over all occurrences in the sphere below the moon; not only over physical and material happenings, but over the mind and will. He had believed that this was by virtue of the fact that the celestial bodies are formed of a divine substance different from the four corruptible elements which constitute the sublunar world. On this theory of the stars had been built the “science” of astrology.

CHRISTIANITY OPPOSED TO BELIEF IN AN ETERNAL UNIVERSE

What could be more antagonistic to such ideas than the teachings of the Bible? The antagonism, however, was not felt by all the Fathers of the Church. The fascination of Platonism led many to seek for analogies between Greek and Biblical cosmology. Clement of Alexandria, for instance, thought that the destruction of the world by fire prophesied in Deuteronomy (xxxii, 22) was one of those general burnings which would occur when the stars find themselves in conjunction in Cancer.[210] Indeed, it was a common belief, and one shared by Augustine, that the Greeks themselves had actually derived the best of their theological concepts from the Bible.[211] But the glaring contradictions between Scriptural and classical cosmology could not be overlooked even by the Augustinians, and classical theories of the periodicity of the universe in general were vigorously combated. Christian monotheism could never be reconciled with a fatalistic doctrine that attributed to the stars in their control over the destinies of the world a quality that approached the divine; and through Christian teachings the astrology built on this doctrine was discredited and the stars stripped of their divinity.[212] This alone was enough to strike a deathblow at the idea of the unvarying periodicity of the universe under celestial controls; but other arguments equally potent were leveled against it. Augustine refused to believe that Christ had been incarnated an infinite number of times in the past or was destined to suffer the Passion an infinite number of times in the future.[213] Origen declared that another Adam, another Moses, another Judas were unthinkable and asked how the belief in the stellar control of man’s actions and volition could be reconciled with the Christian doctrine of the freedom of the will.[214]

Perhaps the most fatal argument lay in the express contradiction, by the Old Testament account of the Creation, of the Hellenic idea of an eternally recurrent universe.[215] Neoplatonist and Peripatetic alike had denied that there ever had been a first day or a first Great Year.[216] Yet the words of Scripture are very definite and very explicit: “In the beginning God created heaven and earth.” Neither Christian nor Jew could question the meaning of these words nor think otherwise than that all things were created at a certain fixed and calculable point in time or else, following Augustine, that the universe and time were created simultaneously.

In spite of these fatal objections, neither the Great Year theory nor astrology perished completely in the Middle Ages. Lingering on underground, they gave an heretical and pagan tinge to the thought of many a philosopher and theologian during our twelfth and thirteenth centuries and thereafter.[217]

THE CREATION

Even the Scriptural history of the Creation did not wholly satisfy the inquiring curiosity of theologians or philosophers. One of the primary problems dealt with by scholars was the problem of the first chapters of Genesis. This inquiry led into the domain of metaphysics and theology: through it men hoped to arrive at an understanding of the nature of God and of his relation to the universe, to time, and to man. It also led to innumerable speculations about the actual manner in which the will of God operated in fashioning the world and to discussions of this question from very diverse points of view—literal, allegorical, transcendental. Indeed, there were even a few writers, notably the Venerable Bede, who went so far as to try to reconcile a physical conception of the processes of creation with the account given in the Bible[218] and who thus prepared the way for more rationalistic studies of the Works of the Six Days in the centuries which were to follow.

SHAPE AND SIZE OF THE EARTH

EARLY CHRISTIAN BELIEF IN A FLAT EARTH

Prevalent among most peoples in an early stage of their intellectual development is the natural and obvious theory that the earth is a flat disk covered by a dome-shaped heaven. This view was held by the Assyrians, Chaldeans, Egyptians,[219] and, as we saw in the first chapter, by the early Greeks; it was long believed by the Jews[220] and is found in the Koran;[221] it was undoubtedly reflected in the words of Scripture, although what is said there on the subject is by no means definite and occurs in connections wholly incidental to other subjects. We read in Isaiah (xl, 22):[222] “It is he that sitteth upon the circle of the earth, and the inhabitants thereof are as grasshoppers; that stretcheth out the heavens as a curtain and spreadeth them out as a tent to dwell in.”

This can hardly be called an exhaustive dissertation on the shape of the universe, yet on it and on other scraps even less detailed were erected the medieval arguments in favor of the flatness of the earth, a firm belief in which was probably held by the majority of the earlier Church Fathers, especially those of the East.[223] Not only were the ancient proofs of sphericity overlooked; but such ideas were regarded as heretical, and elaborate new systems were raised on the weak foundations of littleunderstood Scriptural texts. The most remarkable theories of the universe, however, were devised by the Greek fathers Patricius, Cosmas Indicopleustes, and Severian of Gabala.[224] They remained unknown to the men of the Western world and consequently do not concern us. The Latin father Lactantius contented himself with endeavoring to prove by pseudo-scientific means that the earth is not a sphere; a spherical heaven, he argued, does not necessitate a spherical earth; and the idea of the possibility of antipodes was to him thoroughly absurd.[225]

EARLY CHRISTIAN BELIEF IN A SPHERICAL EARTH

On the other hand, the theory that the earth is a globe never, perhaps, suffered complete eclipse.[226] Augustine was non-committal in this regard, evidently troubled and puzzled by contradictory statements in the Bible and in the writings of classical astronomers.[227] Isidore quotes writers of antiquity who favored a spherical earth, though if we interpret correctly texts in the De natura rerum[228] and Etymologiae[229] we are impelled to think that he himself conceived of a flat earth surrounded by a spherical heaven. The Venerable Bede, on the contrary, did not mince matters; he stoutly maintained that the earth is a sphere and cited as proof the fact that stars visible in one latitude are invisible in another.[230] After the so-called Carolingian Renaissance the world of thinkers seems gradually to have outgrown the primitive notion of a flat earth. To the De nuptiis Philologiae et Mercurii of the Neoplatonist Martianus Capella may be ascribed much of the credit for keeping alive the doctrine of sphericity during these centuries. This immensely popular work, with its condensed argument in favor of a globe-shaped earth, doubtless contributed to the formation of the opinions of men like John Scot Erigena, Gerbert, Hermann of Reichenau, and Adam of Bremen, adherents to the only theory compatible with any observation better than the most superficial and any reasoning better than the most trivial.[231]

SIZE OF THE EARTH

With the reëstablishment of the belief in a spherical earth we find men again making conjectures about its size, though there is no evidence that attempts were made in Christendom (as in the Moslem world) actually to measure the circumference. In the ninth century John Scot Erigena gave, from Martianus Capella, a full explanation of the famous Eratosthenic measurements.[232] An unknown author of the ninth or tenth century of a work on geometry often attributed to Gerbert also explained, from Capella, Eratosthenes’ method of measuring a degree;[233] and the eleventh-century mathematician Hermann of Reichenau[234] had learned (possibly from Macrobius) how the length of a degree could be ascertained from observations of the pole star. His result, 700 stades, was the same as that of Eratosthenes, a fact which alone indicates that he did not himself undertake any measurement. Thus we see that as a result of the Platonic movement between the ninth and eleventh centuries knowledge of one of the most magnificent achievements of classical geographical investigation had been revived.

ZONES AND THE ANTIPODES

ZONES

Most Greek thinkers had agreed in dividing the earth’s surface into five zones, though they differed as to whether or not the equatorial zone was habitable. By Ptolemy’s time the discovery of countries in the heart of the tropical regions and possibly beyond had exploded the old idea of an equatorial ocean and fiery belt around the middle of the globe. Unfortunately the broader regional knowledge which had been at Ptolemy’s disposal was lost in the Middle Ages, and older views reappeared. The maps of the period show us the encircling ocean in which Homer had believed, and nearly all writers of the patristic age thought that Africa has a very limited extension toward the south.[235] Beyond Africa, they said, lies an equatorial ocean and an equatorial zone uninhabitable on account of heat.

THE ANTIPODES

Whether or not there were other regions of the world on the other side of this equatorial zone or beyond the waters of the western ocean, and whether or not such regions were inhabited, were questions which piqued the curiosity of the Church Fathers. The possibility of antipodal regions—perhaps continents—must, in the logic of things, have been admitted by those who were ready to believe that the earth is a sphere; and even those who were not believers in the sphericity of the earth were prone to discuss the possibility of a fourth, or austral, continent, usually called by analogy the region of the antipodes, lying immediately south of the equatorial zone.[236] Bede adopted Crates’ theory of two oceans encircling the earth, east and west, and north and south, dividing its surface into four temperate habitable areas; and after the interest in Macrobius had become widespread in the ninth century this theory undoubtedly must have been generally familiar if not generally accepted.

Whether or not the antipodes were actually inhabited was another matter. Lactantius, who thought that the world is flat, was a determined opponent of the possibility of inhabited antipodes for physical reasons. His arguments were obvious but seem puerile to us: “Is there any one so stupid,” he asked, “as to believe that there are men whose feet are higher than their heads?”[237] It puzzled him to explain how trees could grow upside down or rain fall upward. More serious were the religious objections to the possibility of inhabited regions in other parts of the earth, for this was as antagonistic to the words of the Bible as the Great Year theory and antagonistic in much the same way. The theory of the antipodes, as generally presented in association with the theory of a fiery equatorial zone, presupposed the existence of other races of men absolutely cut off from our race. How, then, inquired Augustine,[238] could such races be descended from Adam, who, the Bible tells us, was the forefather of all men? How could Christ have died for antipodeans? How could the Gospel have been preached in “the four corners of the earth” if half the earth is cut off from our quarter by tropical fires? How could the text of Romans x, 18, be true which says: “Yes, verily, their sound went forth over all the earth, and their words unto the ends of the whole world”? Isidore[239] and Bede[240] categorically denied the possibility of inhabitants of antipodal regions. Their authority, together with the strength of their arguments and the arguments of Augustine, were sufficient to arouse suspicions of the man who ventured to believe in this doctrine. Such a man must certainly be a heretic. A tenth-century interpreter of Boëthius wrote: “God forbid that anybody think we accept the stories of antipodes, which are in every way contradictory to Christian faith.”[241] In the middle of the eighth century the question reached a head in a controversy between St. Boniface and a certain Virgil, bishop of Salzburg.[242] The latter, who doubtless thought that there were antipodal regions if not antipodeans, was accused by Pope Zachary, to whom St. Boniface had complained, of holding “perverse and iniquitous doctrines regarding another world.” Unfortunately we do not possess Virgil’s own account of the incident and are unable to tell exactly what these doctrines were.[243] At all events, belief in antipodes contained the seeds of bitter religious quarrels and was one of the charges brought against Cecco d’Ascoli, who, after our period, was burnt to death for holding this and other damning convictions.[244]

PHYSICAL GEOGRAPHY

In the field of physical geography slight was the contribution of the early medieval writers.

METEOROLOGY

Classical ideas about the atmosphere were repeated and garbled,[245] little progress was made in the development of earlier theories, and little new was added but superstition. Isidore, followed closely by Bede and Raban Maur, was the primary authority in matters of meteorology.[246] The ancient view persisted, that the polar regions were uninhabitable on account of cold and the equatorial zone on account of heat. The sort of popular meteorology that prevailed is illustrated in an early ninth-century treatise written by Agobard, archbishop of Lyons, and entitled Against the Absurd Opinion of the Vulgar Touching Hail and Thunder.[247] This was an attack on charlatans who claimed that they could control the weather, produce storms and hail at will, and who asserted that there is a region, called Magonia, “whence ships come in the clouds” (Poole’s translation).[248] Natural enough as it is for the uneducated in any age to believe such things,[249] the significant fact here is that Agobard did not attempt to invoke scientific arguments to confute the claims of the impostors. Poole says: “He disdained to allege scientific reasons to overthrow what was in its nature unreasonable. He could only fall back on ... broad religious principles. He argued that God’s relation to nature is immediate and least of all conditioned by the artifices of men.”[250]

THE WATERS ABOVE THE FIRMAMENT

One distinctly new idea, however, was introduced by the Bible into the circle of what we may, with a slight stretch of the imagination, consider the medieval physical geography of the water element. This new conception tended to revolutionize theories based on classical physics and to cause much confusion and doubt in the minds of the Fathers of the Church. The orthodox classical physicists had held that the elements normally form four concentric spheres surrounding the center of the universe, in order, from the heaviest to the lightest, earth, water, air, fire. Genesis (i, 6–7) states that “God said: Let there be a firmament made amidst the waters; and let it divide the waters from the waters. And God made a firmament, and divided the waters that were under the firmament from those that were above the firmament.” Though belief in waters above the firmament is found in the cosmologies of the ancient Egyptians and Persians and is there closely associated with belief in a disk-shaped earth covered by a dome-shaped heaven, water in such a position was very far removed from its proper place in the scheme of nature of Aristotle and his followers. The Church Fathers, nevertheless, were unwilling to doubt the actual existence of these waters, and in general they accepted the text literally.[251] Gregory of Nyssa even went to the extent of imagining mountains on the back side of the firmament and that the waters were contained in the hollows and valleys between them.[252] Others thought the waters were in the form of clouds or fine drops. Jerome, Josephus, Ambrose, and Bede all held that the waters were crystal.[253] Augustine was non-committal, though he gathered together the statements of many who had expressed concrete views on the subject.[254] Ambrose argued from analogy that if the earth can hang in the center of the universe without support so also can the waters hang unsupported above the firmament.[255]

The purpose which the waters were to serve was also a thorny problem. Ambrose said they were intended to cool the axis of the universe, overheated by its perpetual rotation;[256] others thought that they were meant to screen the earth from the fiery heat generated by stars and sun;[257] others that they were stored up as a reservoir to supply hydraulic resources at the time of the Great Flood.[258]

THE CONGREGATION OF THE WATERS

According to the description of the Creation in the book of Genesis “God also said: Let the waters that are under the heaven be gathered together into one place; and let the dry land appear. And it was so done.” The difficulty in explaining this text was to account for what became of these waters. Great as are the seas, they were not considered large enough to absorb all the primordial waters, and consequently arguments were elaborated in favor of the existence of vast reservoirs within the earth. Bede, for example, was of the opinion that the waters under the firmament at first took the form of clouds and that when they became condensed and fell as rain the water was sequestered in caverns of the earth’s interior.[259]

Of even greater significance was the assertion that God had gathered the waters below the firmament into “one” place. This could mean nothing else than that all the waters of the earth, whether in subterranean reservoirs, oceans, lakes, rivers, or in the atmosphere, must be connected and must constitute a unit. Probably with this idea in mind Isidore wrote: “The abyss is the deep water which cannot be penetrated, whether caverns of unknown waters from which springs and rivers flow, or the waters which pass secretly beneath, whence it is called abyss. For all waters or torrents return by secret channels to the abyss which is their source” (Brehaut’s translation).[260] Certainly most medieval theorizing about the origin of springs and rivers[261] was dependent on the doctrine of a “congregation of waters.” In further elaboration of this doctrine it was often said that the water of the sea found its way by underground channels to the Garden of Eden and returned again to the sea, flowing first through a subterranean passage and thence through the four rivers of Paradise. Augustine maintained that the words of Genesis (ii, 6), “But a spring rose out of the earth, watering all the surface of the earth,” mean that all the waters of the earth come from a single source.[262] Rainfall as a source of springs and well water, however, was also recognized,[263] and Gregory of Nyssa accepted and elaborated the classical theory of the transmutation of earth into water.[264]

THE NILE FLOOD

The strange phenomenon of the flood of the Nile brought forth no new theories during the Middle Ages, and Isidore, whose words were most often copied, reverted to the explanation of Thales that the flood was caused by the building of sand bars at the mouth of the river during the summer when the etesian winds blow.[265]

THE EARTH UPON THE WATERS

Another Biblical phrase that provoked discussion of the problems of hydrography was in the one hundred and thirty-fifth Psalm (Vulgate): “Praise ye the Lord of lords, ... Who established the earth above the waters” (qui firmavit terram super aquas). Many writers took this literally and thought of the earth as actually floating upon water, held up by the arbitrary force of God’s will. A few, despite the explicit words of Scripture, were inclined to doubt; they either explained the phrase by urging that the word “above” (super) should be taken to mean “beside” or argued that all that was meant here was that the land rises to a higher level than the sea.[266] The difficulty was also avoided, as was frequently the case with puzzling Scriptural passages, by saying that the passage was allegorical and should not be taken literally.

THE SEA

There is not much to record about the development of knowledge or theory concerning the physical geography of the sea. The ancients themselves had known little enough about the sea to pass on to an age when maritime ventures were almost unknown—to learned men at least—and certainly we cannot find a great deal of marine lore in the Bible. Occasional glimmerings of intelligence, however, break the darkness of the times in this respect. Dicuil, for instance, in his De mensura orbis terrae, questions Fabianus’ statement that the sea is at most fifteen stades deep. “Has Fabianus measured its depth?” he asks; “if not, how can we believe what he says?”[267] Bede understood the difference in density between fresh and salt water; and in accord with Isidore and others he explained why the seas do not overflow their banks by pointing out that water is constantly being removed into the air and into the land.[268]

Though the Church Fathers stood out valiantly against those teachings of astrology which tended to exaggerate the powers of the heavenly bodies, they were none the less ready to admit that the moon may exert a physical attraction on the ocean and in that way may produce the tides. Basil even explained that there is a corresponding lunar control over the atmosphere.[269] Augustine and Ambrose believed that the moon causes tides;[270] and a certain Augustine, writing in the seventh century, described the spring and neap tides and tried to show how they follow not only the moon’s phases but also the equinoxes and solstices. He made a serious mistake by placing spring tides at the time of the solstices.[271] Bede corrected this in his De natura rerum, apparently from personal observation—a rare thing at this time—and noted a number of tidal peculiarities which had not been commented on before.[272]

Not all writers attributed the action of the tides to the moon. Most significant among the opponents of the lunar theory was Paul the Deacon (720–780 A. D.). In his Historia gentis Langobardorum he described[273] the maelstrom on the coast of Norway. He asserted that this gigantic whirlpool and another one, which he placed off the coast of Ireland, made the tides by sucking in and spewing out vast quantities of water twice a day. With the fashion of reading Macrobius a theory became popular that the flood and ebb result from the impact of opposing ocean currents; and in the twelfth century, as we shall see later,[274] William of Conches and Giraldus Cambrensis made curious combinations of the theories of Paul the Deacon with those of Macrobius.

THE LANDS

There was no science of geomorphology in the Middle Ages. The medieval mind interested itself for the most part only in those natural phenomena that force themselves upon the attention or seem out of the ordinary. Commonplace and static elements of the earth’s surface such as hills, valleys, and plains were taken more or less for granted by those who sought to explain the secrets of Nature. In the geographical writings of the period, on the other hand, not a little space was devoted to volcanoes and earthquakes. Their violent and spectacular qualities have made these the object of interest throughout all time. And yet in the early Middle Ages there seems to have been no originality in observing them or in speculating about their causes. Men were content uncritically to accept what classical writers had said.[275] Isidore, for example, following Aristotle and Pliny, wrote that volcanoes were burning mountains rather than vents for deep-seated terrestrial fires and that the whole of Sicily was filled with seams of sulphur and bitumen, readily kindled by the winds into flame. The eruption of Etna, more especially, was caused by winds driven down into the interior of the earth by the waves of the Strait of Messina.[276] This theory of vulcanism was reiterated by Bede, Dicuil, and the multitude who copied from Isidore’s work. Other writers explained volcanoes as the outlets of profound subterranean fires,[277] a view fostered by Plato and one that gained authority in the minds of many of the Church Fathers as well as of laymen through the widespread belief, derived from classical mythology[278] as well as from the Bible, that the heart of the earth is the seat of Hell.[279]

THE MEDIEVAL ATTITUDE TOWARDS LANDSCAPE AND SCENERY BEFORE 1100 A. D.

Man has been accustomed to look upon the geographical elements of the earth’s surface from widely different points of view. So far we have been concerned with the record of his scientific or pseudo-scientific investigations of these elements. Let us now turn for a moment to his emotional attitude toward them. The impression made upon the heart and imagination by the aspects of countryside, mountain, and sea has constantly changed with changing religious and philosophical beliefs and with shifting social régimes. We may estimate the character of these changes in a multitude of descriptions of landscape and scenery scattered throughout the whole realm of literature.

ESTHETIC APPRECIATION OF NATURE IN ANTIQUITY

It is probably safe to assert that there prevailed in antiquity a genuinely esthetic appreciation of nature. If the Greeks seldom made conscious efforts to paint word pictures of the form and colors of their land, their poetry and drama none the less show in many a turn of phrase that they were alive to its beauty. The Romans rejoiced in the tranquil serenity of mild and cultivated landscapes as an escape from the welter of city life.[280] Perhaps the Roman attitude toward nature was tinged with pessimism, with regret that beauty is transient, that man’s span of life is short, and that all too soon we must cease to find solace in the loveliness of the world.[281] With the crystallization of Latin literary forms there appeared a stereotyped conception of the ideal landscape in which the essential elements were always the same: a rich meadow shaded by laurels, myrtles, and elms and watered by a murmuring stream, clear and cool; a placid spot where eternal spring prevails and where rain and storm, frost and heat are alike unknown.[282] This formula was used by the Latin poets in describing the blessed Isles of the Hesperides and the Elysian Fields; ultimately it was employed by the Christians in picturing the terrestrial Paradise.[283]

EARLY CHRISTIAN ATTITUDE TOWARDS NATURE

A new and different spirit pervaded the early Christian’s attitude towards nature. His thoughts were turned to the world to come and to the glory of the Kingdom of God.

The more austere and ascetic of the Church Fathers believed that, as it is sinful to take pleasure in things of this world, so also sin must lurk in the breast of him who derives personal and esthetic satisfaction from scenes of natural beauty. This is one of the reasons why hermits retired to deserts and rugged mountains, where they might no longer be tempted either by things of the flesh or by the charm of green and level meadows or of rolling, cultivated hillsides. Among some of the hermits there arose an actual love for the grandeur of the very wildernesses to which they betook themselves. Jerome regarded the desert as a place of beauty: in deep valleys, rough mountains, and steep rocks he saw not only negative excellence, in so far as these were free from the pollutions of “civilization,” but also a congenial background for his work and thought.[284] The eremitic movement was primarily characteristic of the Eastern branch of Christendom, but it extended to the West, where its influence was powerful during the early centuries of our era.[285] Nevertheless an ascetic disdain for the haunts of man and glorification of the wilderness was, at best, alien to Western modes of thought. The normal habit of the Occidental Christian was, rather, to take joy in the immensity of earth and heaven and in the marvelous detail of the created world because these stand as manifestations of the unity and glory of the Deity, symbols of the omnipotence of God.

REVIVAL OF ESTHETIC FEELING IN THE MIDDLE AGES

On the other hand, pleasure in a landscape by reason of the merely personal satisfaction it affords the beholder was exceptional before the time of the Renaissance. But, though exceptional, an esthetic as distinguished from a religious or transcendental love of nature was by no means wholly lacking. Certainly from the eleventh century onward we find many poems and letters that testify to the existence of a truly pagan enjoyment of scenery. Whether this can be said of the earlier periods is more doubtful. Ganzenmüller, whose important study of the feeling for nature in the Middle Ages we are following in this connection, maintains that the term “Carolingian Renaissance” is more or less of a misnomer because under Charlemagne the classical spirit was lacking, even though classical forms of expression were revived; that the classical influence on descriptions of landscape was but rarely felt; and that we find at that time nothing of the subjective and pessimistic attitude of the Roman poets. In short Ganzenmüller concludes that the feeling for nature was altogether Christian.[286]

However this may be, there is no question that throughout a century or more before the age of the Crusades individuals not only among the laity but even in the monasteries were openly writing poems of earthly love and openly lauding the beauty of natural scenery in more or less the vein of the Romans.[287] This was but one aspect of the worldly tendency in Church and society which brought about the Cluniac and later movements of reform.

MATHEMATICAL GEOGRAPHY AND CARTOGRAPHY

MATHEMATICAL GEOGRAPHY

We may pass over the mathematical geography of the Christian period before 1100; no discoveries were made, nor were there any attempts to apply the results of older discoveries. Gerbert, indeed, in his Liber de astrolabio, gives a few details of the division of the earth’s surface into seven climates, details which he had probably derived entirely from Latin authors like Pliny and Martianus Capella.[288] Though Gerbert owed much to Arabic writers, he did not draw from them the semi-geographical portions of his writings. Certainly in the strict application of mathematical geography to the determination of positions—latitudes and longitudes—nothing was done in the West. Ptolemy was forgotten, and the labors of the Arabs in this field were as yet unknown.

MAPS

Though very few maps dating from these centuries are actually in existence, maps were then made in no inconsiderable numbers.[289] Three circumstances convince us of the truth of this statement. In the first place, we find frequent references to lost maps in contemporary literature. Then again, many of the cosmographies and encyclopedic works, such as those of Orosius, Isidore, and the Ravenna geographer, show undeniable indications that they were either compiled from maps or else were accompanied by maps as illustrations. And, finally, most of the examples of twelfth- and early thirteenth-century cartography can only have been derived from older models, some of which in the final analysis may well have been inspired by the cartography of the period of the Roman Empire.[290]

With a few exceptions[291] the existing specimens of the cartography of Western Europe dating from before 1100 may be classified as regards form in four more or less well-defined groups, representatives of each of which are also found from the Crusading age and even later. The character of the maps was largely determined by the purposes intended to be served.[292]

Macrobian Maps

The first group consists of outline diagrams illustrating Macrobius’ division of the earth’s surface into zones and is to be found in manuscripts from as early as the ninth century. This group cannot properly be said to include true maps.[293]

T-O Maps

The second group is made up of simple representations of the three continents, often called T-O maps (Figs. 1a-1b). On these the known world is shown as a circle within which a T is drawn dividing it into three parts. East is at the top. The upper compartment, that above the crossbar of the T, represents Asia; the two lower compartments, Europe and Africa. The surface is usually unadorned with vignettes or conventional symbols of any sort, and the legends are reduced to a minimum. It seems likely that Augustine had before him such a diagram when he wrote a passage in De civitate dei which describes to perfection the division of the known world as the T-O maps show it, and it may well be that the map which Orosius must have used when he wrote the geographical chapter of his history was a modified example of the same type. An extremely large number of T-O maps are to be found in codices dating from the eighth century onward, illustrating the writings of Isidore, Bede, Raban Maur, and others.[294]

Sallust Maps

Closely akin to the T-O maps, but somewhat more elaborate, are the sketches of the third group (Fig. 1c). These accompany manuscripts of Sallust’s works and may have been drawn to illustrate a passage in Sallust’s De bello Jugurthino describing briefly the countries of the known world. The T-O form is carefully followed, but legends and pictures add a touch of life. The oldest example (tenth century) is strictly classical and fails to show Jerusalem, a stock feature in most medieval maps. Later specimens reveal the influence of the Christian tradition, and upon them Jerusalem figures as an immense church or castle.[295]

Beatus Maps

The fourth group is by far the most interesting. In the latter part of the eighth century a priest, Beatus, of the Benedictine abbey of Valcavado in northern Spain wrote a commentary on the Apocalypse, destined to become very popular in later times. To demonstrate graphically the division of the world among the twelve apostles, which is spoken of in a passage included in this commentary, either Beatus or one of his contemporaries drew a map. Though the original of this is not now extant, no less than ten subsequent maps for which it served as a model are preserved in manuscripts of the tenth century and later. The researches of Miller[296] have shown that three of these ten were probably derived from a fairly full and faithful copy of the original, but that the others represent merely a generalized outline. The best example, the so-called St. Sever map, dating from about 1050 and now in the Bibliothèque Nationale at Paris, displays an immense wealth of detail, legends, vignettes, and pictures of all sorts (Fig. 2).

REGIONAL GEOGRAPHY

LIMITED GEOGRAPHICAL HORIZON IN THE EARLY MIDDLE AGES

In the first chapter, under the heading “The Expansion of Regional Knowledge,” was discussed the expansion of actual knowledge of the earth’s surface, and a careful distinction was made between that section dealing with actual knowledge and the preceding sections of the chapter which had been concerned with theories. We cannot make this distinction in speaking of the regional geographical ideas of the early Christian centuries, for fact and fancy were irrevocably blended. In the Greek and Roman age knowledge of the earth’s surface was widened by exploration, trade, wars, and conquests; but in the early Middle Ages the limits of the accurately known world contracted, and the ocean, Asia, Africa, even Western Europe itself, became domains of legend and fable.

This does not mean that exploration, trade, and conquest did not progress. Commerce in silk flourished in the sixth century between Byzantium and the nations of Central Asia, and much knowledge of those distant countries was thereby acquired in the Greek world.[297] Between the eighth and the beginning of the twelfth centuries the Northmen had penetrated in their open ships to the innermost recesses of the White Sea[298] and westward as far as Iceland, Greenland, and the shores of America. Throughout the Middle Ages there was an intermittent flow of pilgrims to and from the Holy Land. At a very early date the Italian cities began to lay the foundations of their great Levantine trade. Why, then, was geographic knowledge not enriched by all this activity? There were many reasons. The spirit of the age turned the scholar’s mind almost exclusively to religious and theological matters. He felt no particular interest in voyages unless they had some religious significance. He cared nothing about the exploits of piratical Norse rovers in subarctic seas or about things that Byzantine traders and diplomats might have seen in the heart of Asia. Even if he could have read the languages in which the stories of these discoveries were written, he probably would not have troubled to investigate them. The pilgrim, forcing his way through hardships and privations to the Holy Land, was certainly stirred by no interest in the geography of the lands and seas through which he passed beyond that of finding the best and quickest practicable route. Once arrived in Palestine, he may have felt some slight enthusiasm about studying out the topography of the sacred places. On the whole, however, pilgrim narratives added as little to Western geographical knowledge of the East as American soldiers’ letters during the World War added to our geographical knowledge of France.

MEDIEVAL CONCEPTION OF THE KNOWN WORLD

The usual medieval conception of the known world was of a circular or oval area, divided into three continents. Asia occupied the eastern portion and was cut off from Europe by the Tanaïs (Don) and from Africa by the Nile. The Mediterranean, piercing the center of the western section, separated Europe from Africa. The relative size of the continents was variously represented; Asia was usually thought to be much larger than either Europe or Africa. The two latter were believed to be of about the same size.

PARADISE

One of the principal Biblical contributions to medieval geography was Paradise with its four rivers.[299] In the maps of the period, the garden is drawn at the easternmost limits of the world in accordance with the words of Genesis (ii, 8), “And the Lord God planted a garden eastward in Eden.”[300] Martianus Capella, however, by following a Greek tradition which placed the Hyperboreans in a favored and delightful country of the far north, caused certain of the Church Fathers to look northward for Paradise.[301] Modeling their account of Paradise on the Biblical description and on the ideal landscape of the Roman poets,[302] the men of the Middle Ages conceived of the garden as a deliciously cool and shady meadow, made beautiful with flowers of many sorts, watered by murmuring streams, and redolent with sweet odors.[303] Many theories were elaborated concerning the surroundings of the forbidden garden.[304] In order that men be kept out, an impassable barrier must have encircled it. Some believed that this was an immense wall; others, a ring of flames; others, mountains and deserts. Some placed Paradise on an island in the ocean; Cosmas removed it beyond the ocean to the shores of unknown lands in the east; Augustine, Origen, and Philo regarded it as allegorical and not real at all.

RIVERS OF PARADISE

“And a river went out of Eden to water the garden; and from thence it was parted, and became into four heads” (Gen. ii, 10).[305] These four heads were the sources of the four rivers of Paradise: the Pison, later thought to be either the Indus, the Ganges,[306] or, sometimes, the Danube; the Gihon, or Nile; the Hiddekel, or Tigris; and, finally, the Euphrates. It was a little difficult for some persons at first sight to understand how all these rivers, whose upper reaches were known in reality to be very far apart, could actually spring from one source.[307] Many cosmographers were even tempted to place Paradise in Armenia, near the known sources of the Euphrates and Tigris. In general an appeal to the simple theory of the existence of subterranean watercourses sufficed to solve the problem and to explain the otherwise absurd belief that the Nile had its headwaters in the far east beyond the Red Sea.

ASIA

Gog and Magog

Asia was frequently made the scene of Paradise and of the creation of man. Here, too, medieval tradition placed Gog and Magog,[308] whose advent at the Last Day should bring destruction to the world. There are three different Biblical accounts of Gog and Magog. On the basis of Genesis (x, 2), which makes Magog a son of Japhet, a Jewish tradition conceived of this shadowy and fearful personage as the progenitor of the Scythian tribes. In the book of Ezekiel (xxxviii, xxxix) we read the prophecy of the ravages and destructions of “Gog, the land of Magog, the chief prince of Meshech and Tubal,” who should issue with his terrible hordes from the north and bring death and devastation to the lands of Israel. Finally, in Revelation (xx, 7) we are warned that “when the thousand years shall be finished, Satan shall be loosed out of his prison, and shall go forth and seduce the nations which are over the four quarters of the earth, Gog and Magog, and shall gather them together to battle, whose number is as the sand of the sea.” Here “Gog and Magog” are not the names either of men or of a country, but rather of savage tribes. Most medieval writers, following the Jewish tradition, thought of these tribes as Scythian barbarians of the north—so Josephus, Jerome, and Isidore, though Eusebius believed that they were Kelts, and Jerome referred to a certain history which identified them with the Goths; one chronicle even made the Aquitanians their descendants.[309]

The apocalyptic story of Gog and Magog spread widely in the Orient as well as through the Christian world. In the East, curiously enough, it was made a part of the Romance of Alexander. We read in the Koran[310] that the “two-horned Alexander” built a great wall of bronze and pitch and brimstone, behind which he enclosed the wild peoples of Yajūj and Mājūj (Gog and Magog) until they should break forth on the day of the Last Judgment. This story was probably told for the first time in connection with Alexander the Great by Procopius in his De bello Persico.[311] It formed one of the most important parts of the immensely popular work, the Pseudo-Methodius, which foretold with considerable detail the events of the Last Day.[312] It entered into later versions of the Romance of Alexander itself, although it formed no part of the versions of the Pseudo-Callisthenes or of the translation of Julius Valerius.[313]

Romance of Alexander the Great

The Romance of Alexander, one of the most widely known of the various cycles of medieval legend, deserves some comment here because the scene of most of Alexander’s exploits was laid in Asia. The Romance contains some fantastic geographical details concerning the East in general and India in particular. The classical stories of the monsters and marvels of these mysterious lands are here preserved in attractive form. We meet with Amazons and mermaids, griffons, and men who live on the smell of spices. We have a text of correspondence between Alexander and the Brahmin king, Dindimus, in which the latter explains to the Macedonian conqueror his religion and the simple habits of the Brahmins.[314]

St. Thomas in India

India was also supposed in the Middle Ages to have been visited by St. Thomas, the Apostle,[315] who was said to have built therein a great castle for King Gundophorus. Though little geography is to be gleaned from the apocryphal legends of St. Thomas and St. Bartholomew in India and of St. Matthew in Ethiopia, they served to carry the reader’s mind to distant corners of the earth and are of passing interest to us because certain elements of the story of St. Thomas became part of the fabric of the great twelfth-century legend of Prester John. If we are to believe the Anglo-Saxon Chronicle,[316] an Englishman visited India in the ninth century, for we are told that King Alfred sent a certain Sighelm to the shrines of Saints Thomas and Bartholomew in A. D. 883.

AFRICA

Africa was utterly neglected. Unlike Asia, it did not become the habitat of legend and fable. Supposedly of small extent and made up mostly of desert, it failed to arouse much interest until long after our period. The universal testimony of cosmographer and cartographer during the entire age under consideration was to the effect that the African continent stops well to the north of the equator at the borders of the sea.

EUROPE

Europe was of course less a land of romance than Asia, but geographical ideas concerning it were crude enough, as a glance at any contemporary map or at the brief and dry catalogue of facts given in the encyclopedic works will show. Isidore, Orosius, and Bede added little to what classical writers had already said. Local mythology tended to creep into the geographical conceptions of the best-known countries and to blur what had been in classical times fairly distinct and clean-cut conceptions.

EXPLORATIONS TO THE NORTH

In one quarter, however, to the north, the horizon of geographical knowledge was immensely widened. The inner shores of the Baltic, of which the Romans and early Christians had known next to nothing, became from the eighth century familiar ground to the Northmen. Furthermore, the widespread rovings of these adventurous seamen carried them not only westward and southward to harry Britain, France, and Spain and to penetrate into the Mediterranean but also northward along the long stretch of Norwegian coast. Alfred the Great appended to his translation of Orosius an account of the journey in 890 of Othere of Halogaland around the North Cape and into the White Sea even as far as the shores of Biarma Land (near modern Archangel; the word “Biarma” is said to be related to the Russian “Perm”). In later years Norse expeditions visited the remote coasts of Finnmark and Biarma, seeking trade and carrying war and destruction.[317]

THE ATLANTIC

The maritime wanderings of the early Irish and their successors, the Northmen, gave rise to a circle of legends regarding fabulous islands in the Atlantic and fabulous voyages among them. The poetic imagination of both Kelt and Viking contributed marvelously to the growth of these tales. Great and often misguided ingenuity has been shown in modern times in attempts to find the seeds of truth from which these stories may or may not have sprung.[318] The most famous legend and the one destined to exert the strongest influence on the imagination of the future told of St. Brandan’s journeyings among enchanted isles and fantastic seas to the west and northwest of Ireland. Actual discovery in these quarters is recorded in the pages of the ninth-century Dicuil, who narrates the finding of Thule by Irish priests some thirty years before his time (825 A. D.) and describes the cold of those regions and the long twilights at the time of the summer solstice, when one day merges into the next.[319] The Northmen reached Iceland in 860 and settled there a few years later; Greenland was discovered by them in 877, though it was not colonized until the close of the following century.

AMERICA REACHED BY THE NORSEMEN

Icelandic rovers also reached America in the latter years of the tenth century.[320] The Landnámabók, compiled from an original version written about 1200, tells how, about the year 983, Ari Marsson “was driven out of his course at sea to White-men’s-land (Hvitramanna-land), which is called by some persons Ireland the Great (Irland-it-mikla); it lies westward in the sea near Wineland the Good; it is said to be a sail of six doegr west of Ireland” (Reeves’s translation).[321] Though we may not be certain whether this brief passage is rightly to be interpreted as referring to America, it is undeniable that soon after Ari Marsson’s discovery the northeastern shores of our continent were visited by Biarni, the son of Heriulf, and by Leif, the son of Eric the Red, and that the latter were followed by Thorfinn Karlsefni and others.[322] Sailing southwestward, these adventurers came to the shores of a barren country of flat stones which they called Helluland; thence they coasted southward past the forested Markland and past long beaches and sand reefs, until they reached Wineland, with grapevines, a mild climate, and savage inhabitants (or Skraellings). From some of the latter, captured by Karlsefni in Markland, the Icelanders learned that “kings governed the Skraellings” and that “there was a land on the other side over against their country which was inhabited by people who wore white garments and yelled loudly and carried poles before them to which rags were attached” (Reeves’s translation). This land they identified with White-men’s-land, or Ireland the Great.

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III. THE CONTRIBUTION OF THE MOSLEMS

There is no necessity here of giving a general review of the very broad field of Arabic geography. The works of the foremost Mohammedan geographers, Al-Masʿūdī, Ibn Ḥauqal, Al-Iṣṭakhrī, were unknown in Europe during the Middle Ages, and formal Arabic geography certainly contributed next to nothing to the knowledge of the earth possessed by the Occidentals of the Crusading age.

SOURCES

Other branches of Arabic science, however, profoundly influenced the development of European thought at this time. As transmitters of classical learning to the West, the Saracens reintroduced fragments of the geographical lore of the Greeks. The two classical authors in whom they had taken the deepest interest were Aristotle and Ptolemy. Their most important contribution to Western geographical knowledge was to make known to the West geographical speculations in the works of these men and in the various treatises which the Moslem writers themselves had composed under Peripatetic and Ptolemaic influences.

INFLUENCE OF ARISTOTLE

Aristotle held a position of preëminent authority among the Moslems in all matters scientific. Arabic scholars had received his writings both through Syriac translations and direct from Greek texts. Vast commentaries on his works were made by Avicenna (Ibn Sīnā, 980–1037 A. D.) in the Eastern Caliphate and by Averroës (Ibn Rushd, 1126–1198 A. D.) in Spain. Aristotelian astronomy, as distinguished from Ptolemaic, was reproduced with modifications in the work On the Sphere of Al-Biṭrūjī of Cordova, known to the Christians as Alpetragius.[323] By the end of the twelfth century, owing to the rising interest in Aristotelianism in Europe (the “flood of Aristotelianism,” as Duhem calls it), translations had been done from the Arabic into Latin of a large number of Aristotelian works on astronomy, physics, meteorology, and many other subjects.[324] It was in these works that most of Aristotle’s thought and observation in geography had found expression. Aristotelian physical geography, transmitted through these channels, was destined to dominate the geographical speculations of many Christian writers of the thirteenth century.

INFLUENCE OF PTOLEMY’S “ALMAGEST”

The Moslems of the Eastern Caliphate also had become familiar with Ptolemy’s Almagest and Geography through Syriac translations and through versions of the original Greek text.[325] A manuscript of the Kitāb al-Majisṭī, or Almagest, was translated into Arabic in the days of Hārūn ar-Rashīd by that caliph’s vizier, Yaḥyā, and other translations appeared during the middle part of the ninth century. Study of the Almagest stimulated Arabic scholars and incited them to write such original treatises of their own as Al-Farghānī’s (Alfraganus’) On the Elements of Astronomy, Al-Battānī’s On the Movements of the Stars, or Astronomy,[326] and Ibn Yūnūs’ Ḥakīmī Tables.

INFLUENCE OF PTOLEMY’S “GEOGRAPHY”

Furthermore, Ptolemy’s Geography was certainly known to the Moslems in Syriac translations and probably also in copies of the original Greek text.[327] With the Geography as a model a number of Arabic treatises, usually entitled Kitāb ṣūrat al-arḍ, or Book of the Description of the Earth, were composed at an early period of Islam and served as bases on which later geographical writers built more complex systems. One of the most significant was the Kitāb ṣūrat al-arḍ of Al-Khwārizmī, composed about the time of Al-Maʾmūn (813–833 A. D.), the full text of which was discovered forty-four years ago by Spitta.[328] From another book of the same sort and title Al-Battānī derived the geographical details included in his Astronomy.[329] The latter was translated into Latin during the twelfth century; and Al-Khwārizmī’s work was known in Europe at second hand.[330]

AZ-ZARQALĪ AND THE “TOLEDO TABLES”

Ptolemy was studied in the western as well as in the eastern centers of Islam. Toledo, notwithstanding its conquest by the kings of Castile in 1085, long remained a scientific center, where the Arabic spirit of investigation lingered on among Jew, Christian, and Moor. It was largely through Spanish channels that the Latin West found its Oriental inspiration in astronomy and astrology.[331] About 1080 Az-Zarqalī, of Toledo,[332] who had devised a new type of astrolabe, wrote various works on astronomical subjects, including a commentary on a series of astronomical tables that had been constructed by a group of Jewish and Moslem scholars before his time.[333] These so-called Toledo Tables, with Az-Zarqalī’s Canons explaining them, contained some incidental geographical information derived in part from Ptolemy’s Geography and from Al-Khwārizmī.[334] They were rendered into Latin in the twelfth century by the famous Gerard of Cremona, who probably found in Spain most of the manuscripts from which he made his many Latin translations.[335]

GEOGRAPHY IN SICILY

Ptolemy’s Geography was also studied in Sicily under the Moslem emirs and their successors, the Norman kings. From the eleventh century date several Arabic descriptions of Sicily now known only in fragments but bearing eloquent witness to a true enthusiasm for geography prevalent among the Moslem aristocracy of the island.[336] The Normans, who became masters of Sicily between 1060 and 1071, preserved much that was best of Arabic traditions and culture, and Moslem scholars played a brilliant part in the intellectual life of the court. Roger II himself was a devotee of geography, occupying much of his spare time in collecting Arabic geographical treatises and in questioning travelers about distant parts of the earth. “He gave himself up to this work tirelessly for fifteen years, never ceasing to examine personally into all geographical questions, to search for their solution and to verify facts, in order that he might obtain in complete form all the information that he desired” (from Jaubert’s translation of Edrisi).[337]

EDRISI

At Roger’s instigation and with his aid Al-Idrīsī, or Edrisi (as the name is more usually written), who had come to the Sicilian court from Spain, undertook a great series of geographical labors. Little is known of the life of Edrisi besides a few details to be gleaned from later biographers[338] and what he himself tells us in the preface to his Geography, as it is usually known, or, to cite its Arabic title, The Recreation for Him Who Wishes to Travel Through the Countries, which was completed in 1154 or later.[339] We know that he constructed for Roger a celestial sphere and a disk-shaped map of the world, both of silver. Furthermore, we are told that Roger provided him with special facilities for the construction of maps and for the compilation of his great treatise. It appears that the king and Edrisi together selected “certain intelligent men, who were despatched on travels and were accompanied by draftsmen. Just as soon as these men returned Edrisi inserted in his treatise the information which was thus communicated to him.” On the basis of observations made in the field, data derived from Ptolemy and earlier Arabic geographers were correlated and brought up to date. The book and the maps which were drawn to elucidate the book are for this reason unquestionably among the most interesting monuments of Arabic geography; furthermore, the book is the most voluminous and detailed geographical work written in twelfth-century Europe. After a very brief description of the earth as a globe, the hemispheres, climates, seas, and gulfs, Edrisi launches into a long and minute account of the regions of the earth’s surface. He takes up the seven climates in order, dividing each climate into ten sections, an arrangement that is artificial to excess. None the less, Edrisi’s works are of exceptional quality when considered in comparison with other geographical writings of their period, partly by reason of their richness of detail but mainly because of the scientific method used, the coöperative employment of many observers, and the critical correlation of their observations—a procedure which was indeed unlike that adopted by Latin scholars of the time.

INFLUENCE OF SICILO-MOSLEM GEOGRAPHY

The question of the full extent to which the fruits of this Sicilian geographical school became known in the Latin Europe of the late twelfth and early thirteenth centuries is a matter that awaits further investigation.

Certainly the influence of Edrisi’s Geography could not have been great in the world of letters or else traces of it would more easily be detected in Western literature. Unlike a multitude of Arabic writings of far less intrinsic value, the Rogerian Description (as the Geography of Edrisi is often called) found no Gerard of Cremona to put it into Latin, and the authoritative geographical knowledge of the Western world was destined to develop unenriched by the treasures which Roger and Edrisi together had amassed.

On the other hand, there is no question but that the Sicilo-Norman enthusiasm for geography exerted an indirect influence on the evolution of geographical knowledge, an influence that was to make itself felt more especially after the close of our period. This enthusiasm for geography was the product of a mingling of Arabic scientific and scholarly traditions with Norman maritime enterprise in an island which occupied a central position in relation to the world of its day. It was an enthusiasm that arose partly from pure love of knowledge but also in very large degree from the practical necessities of a sea-faring people, and it was early applied to the solution of the problems of navigation. In the words of De La Roncière, “The use of coast charts was destined to become general in Sicily; a rational method of navigation to be substituted for the routine of pilotage, and thus the way was prepared for the progressive conquest of the world.”[340] As De La Roncière goes on to point out, the Genoese learned the arts of navigation from the Sicilians in the early thirteenth century and transmitted them subsequently to the Spaniards, Portuguese, French, and English; and a new science of the sea was developed upon the foundations originally laid by Sicilian Moslems and Normans.[341]

ORIENTAL IDEAS TRANSMITTED TO THE WEST

Besides the classical heritage, the Moslems also transmitted some peculiarly Oriental ideas to the West. Al-Khwārizmī was the author of a treatise with astronomical tables, the translation of which by Adelard of Bath usually goes under the name of Khorazmian Tables.[342] The original work was a redaction of a book drawn ultimately from Hindu sources and known as the Little Sindhind.[343] Thus it was from Hindu sources, as is shown by this work, that the Mohammedans got their idea of the world center of Arin. Hindu religion, furthermore, contributed something toward the molding of Greek and Moslem doctrines of the periodicity of the universe and of the Great Year—doctrines which became widely known in the West through Hermann the Dalmatian’s Latin translation of the Persian Abū Maʿshar’s book, The Great Book of the Introduction, entitled in the Latin, Liber introductorius in astrologiam.[344] Hindu influences were also felt in an anonymous but widely read Arabic treatise falsely attributed to Aristotle in the Middle Ages and called Liber de proprietatibus elementorum.[345]

ASTRONOMICAL GEOGRAPHY; THEORIES OF THE TIDES

Turning now from the sources to the material substance of the contribution of the Moslems, we find that, except in so far as it brought a knowledge of Aristotle to Europe, it added little to Western notions either of physical or of regional geography. Though the Moslems entirely failed to share with the Western World their wide practical acquaintance with lands and seas, the Arabic writers did nevertheless introduce some new ideas in the fields of astronomical—or, better, astrological—geography and in the closely allied study of tidal phenomena.

THE GREAT YEARS

The theory of the Great Years was very popular among the Orientals, possibly because it appealed to their fatalistic spirit. Arabic astronomers adopted Ptolemy’s calculation of the length of the Great Year at 36,000 terrestrial years[346] and seem to have believed that after every complete revolution of the sphere of the fixed stars, the planets, as well as the fixed stars, will find themselves in the same relative positions that they held at the beginning of the revolution.[347] The Arabic work on this subject most read in the Latin West was Hermann the Dalmatian’s translation of Abū Maʿshar’s book, in which it was explained that astral influences—especially the perpetual circulation of the fixed stars—are the cause of everything which is born and dies and of everything which occurs between birth and death on this earth.

COSMIC CYCLES AND GEOGRAPHICAL CHANGES

In much the same way that the Chaldeans, Hindus, and Greeks had done, the Moslems worked out a theory of the supposed influence of these cosmic cycles on geography.[348] The most striking elaboration of the theory was made by the “Brothers of Piety and Sincerity,” who formed a philosophical school in the tenth century after Christ. In the great encyclopedic work[349] produced by this school (which, incidentally, contains many other interesting speculations on the subject of physical geography) gradual alterations in the relative position of land and sea are ascribed to almost imperceptible changes in the longitude of the fixed stars resulting from the precession of the equinoxes. Not only do lands and seas change places, but various types of terrain; in the course of time “cultivated land becomes desert, desert becomes cultivated land, steppes become seas, and seas become steppes or mountains.”[350]

Whereas this curious theory was accepted by the Aristotelian Al-Biṭrūjī, the author of the pseudo-Aristotelian Liber de proprietatibus elementorum vigorously opposed to it the following argument.[351] If the fixed stars revolve around the earth in 36,000 years, the land ought to revolve around the 34,000 miles which he believed make the circumference of the earth in the same time, or, as we may infer, at a rate of slightly less than a mile per year. We should therefore expect to find certain cities much nearer the coast and other cities farther from the coast than they used to be. The anonymous author says that if the theory were valid one ought to be able to observe great changes in the position of such places as Arin, Ceylon, Byzantium, and Rome in relation to the sea. But since, as a matter of fact, no such changes are apparent, the whole theory of the transposition of land and sea falls to the ground.

Obvious as it may seem to us, this reasoning is remarkable at a time when actual observation as a foundation for, or check on, theorizing was rare indeed; and hence it is gratifying to note that the Liber de proprietatibus elementorum with its argument against the Great Year, rather than the encyclopedia of the “Brothers of Piety and Sincerity” with its argument for it, was the work on this subject that was read by Occidental scholars.

THEORIES OF THE TIDES

The Moslems did not add much to the classical theories of the tides which they transmitted to Christendom. Their fundamental work concerning tides was that treatise of Abū Maʿshar which we have already mentioned, a work from which, as Duhem says, all the Middle Ages learned the laws of the ebb and flood.[352] Here, in the chapters on the moon,[353] a full description is given of the various characteristics of the tides together with copious speculations regarding their causes. The actual observations of fact were exact and careful. Abū Maʿshar explains with not a little accuracy the relation of the tides to the moon’s rising and setting, to her phases, and to the position of the sun; he understood that winds might cause exceptionally high water; he recognized the influences of local topographic features, that some seas display different tidal phenomena from others and that the flood waters may be retained by reefs, or valleys, or deep bays. On the other hand, Abū Maʿshar’s treatment of the causes of the tides was less successful. Though he believed firmly that the moon produces the ebb and flood, he failed to account for the presence of the high tide at the time of the moon’s opposition. His explanation of the moon’s attraction of the waters was in keeping with astrological methods of reasoning. Our satellite was supposed by astrologers to be of peculiarly aqueous nature and for that reason exceptionally capable of governing the movements of the liquid element of the earth.

Other theories of the tides entered the West from Arabic sources. Al-Biṭrūjī’s On the Sphere ascribed their origin not to the moon but to the general circulation of the heavens.[354] Averroës, in a commentary on the Meteorology of Aristotle, devoted a confused chapter[355] to an attempt at showing that ebb and flood are the results partly of currents produced by differences in level between the ocean and certain seas and partly of the moon’s attraction of the waters. The possibility of differences in level between seas and ocean had probably become known to the Spanish scholar through some garbled rendering of Eratosthenes’ observations on the currents and levels of the Mediterranean.[356]

MEASUREMENT OF A TERRESTRIAL DEGREE

That the Saracens also were interested in the more strictly mathematical aspects of astronomical geography is emphatically proved by the fact that they undertook actually to measure the length of a terrestrial degree[357] and thereby to determine the circumference of the earth. Some knowledge of this great work came to the Western world in our period through translations of the Astronomy of Al-Farghānī.[358]

GEOGRAPHICAL POSITIONS

The Arabic investigations, however, which most profoundly interested the men of the West were those concerned with the determination of the location of places on the earth’s surface rather than those whose aim was to find the size of the globe. Stimulated by their interest in Ptolemy, the Moslems felt a special need for the accurate knowledge of positions, for upon such knowledge depended the construction of mosques, which, according to religious law, must face in the direction of Mecca. Astrology also necessitated this type of investigation. In order to cast a horoscope one must know what stars are overhead at a particular moment; and, to ascertain this, one must know latitude and longitude. In the Arabic astronomic works there occur rules for determining positions and tables of the latitudes and longitudes of places throughout the world.[359]

One of the most practical results of Arabic investigations in this field was a reduction of Ptolemy’s exaggerated estimate of the length of the Mediterranean Sea. The Greek geographer gave the length as 62° or about half again too long. Al-Khwārizmī cut this figure down to about 52°, and, if we are right in our interpretation of the available data, Az-Zarqalī still further reduced it to approximately the correct figure, 42°. As we shall see in a later chapter, the results of these corrections became known in the medieval West.[360]

The Moslems, as a general rule, measured longitudes from the prime meridian which Ptolemy had used, that of the Fortunate Islands (now the Canaries), situated in the Western Ocean at the westernmost limit of the habitable earth; but individual writers came to make use of another meridian farther west, a meridian destined to become known to the Christian world as that of the True West as distinguished from the supposed border of the habitable West.[361] Abū Maʿshar, on the other hand, referred his prime meridian to a fabulous castle of Kang-Diz, far to the east in the China Sea.[362]

ARIN

The western prime meridian was commonly supposed to be 90° from a mythical city called Arin (or Arim) situated on the equator, halfway between the farthest east and the farthest west. This city was said to have neither latitude nor longitude, and its meridian came arbitrarily to be placed at 10° east of that of Baghdad. The idea of Arin probably originated among the Hindus,[363] who believed that the city of Langka in Ceylon (or perhaps Sumatra)—the abode of devils—lies on the equator. They traced their prime meridian from Langka through Odjein, a place in India, to Mount Meru at the north pole—the abode of angels. Odjein was transliterated into Arabic as “Arin” or “Arim” and was shifted by the Moslems to the equator. It was made known to the Christian world through such works as Adelard of Bath’s translation of the Khorazmian Tables (which, as we have already seen, was an Arabic redaction of a Hindu work) and Plato of Tivoli’s translation of Al-Battānī’s Astronomy. In the latter, Arin was represented as a cupola or tower; and on Christian maps and diagrams of the Middle Ages it was not infrequently so depicted.

ARABIC EXPLORATION AND TRAVEL

This sums up briefly a few of the more significant original ideas that the Moslems added to twelfth-century geographical knowledge in the West. By way of contrast, it is not out of place briefly to recall what they had actually accomplished in the field of geographical investigation.[364] Moslem trade between the seventh and ninth centuries reached China by sea and by land; southward it tapped the more distant coasts of Africa, including Zanzibar; northward it penetrated Russia;[365] westward Mohammedan navigators saw the unknown and dreaded waters of the Atlantic. Al-Masʿūdī speaks of the presence of Moslem traders in the heart of Europe, in a country to which he gave the name Ad-Dir (probably Bohemia).[366] Arabic literature abounds with descriptions of the lands within these wide borders; of their products and kingdoms and marvels, true and fanciful. But all this was destined to remain a sealed book to the man of the Latin Occident,[367] who as a rule felt little genuine interest in the world beyond his immediate ken. He looked to Arabic books for practical aid in making calendars and star tables and horoscopes; he looked to Arabic translations and commentaries on Aristotle for help toward a better understanding of the dark and hidden meaning in the words of Scripture. The geographical knowledge which he acquired from the Moslems during our period was merely incidental to other interests, a sort of flotsam borne in on the great wave of astrologic and Aristotelian lore sweeping into Europe at this time.

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