Terrestrial and Celestial Globes Vol I

Terrestrial Globes in Antiquity

The beginnings of astronomical and of geographical science.-Primitive attempts at map construction, as seen in the Babylonian plan of the world.-Anaximander probably the first scientific cartographer.-Statements of Herodotus.-The place of Hecataeus, Hipparchus, Marinus, Ptolemy.-The Romans as map makers.-The earliest beliefs in a globular earth.-Thales, the Pythagoreans, Aristotle.-Eratosthenes and his measurements of the earth.-Crates probably the first to construct a terrestrial globe.-Statements of Strabo.-Ptolemy's statements concerning globes and globe construction.-The allusions of Pliny.

THE beginnings of the science of astronomy and of the science of geography are traceable to a remote antiquity. The earliest records which have come down to us out of the cradleland of civilization contain evidence that a lively interest in celestial and terrestrial phenomena was not wanting even in the day of history's dawning. The primitive cultural folk of the Orient, dwellers in its great plateau regions, its fertile valleys, and its desert stretches were wont, as we are told, to watch the stars rise nightly in the east, sweep across the great vaulted space above, and set in the west as if controlled in their apparent movement by living spirits. To them this exhibition was one marvelous and awe-inspiring. In the somewhat strange grouping of the stars they early fancied they could see the forms of many of the objects about them, of many of their gods and heroes, and we find their successors outlining these forms in picture in their representations of the heavens on the material spheres which they constructed. Crude and simple, however, were their astronomical theories relative to the shape, the structure, and the magnitude of the great universe in which they found themselves placed.1

Then too, as stated, there was something of interest to the people of that early day in the simple problems of geography; problems suggested by the physical features of their immediate environment; problems arising as they journeyed for trade or traffic, or the love of adventure, to regions now near, now remote. Very ancient records tell us of the attempts they made, primitive indeed most of them were, to sketch in general outline small areas of the earth's surface, usually at first the homeland of the map maker, but to which they added as their knowledge expanded. The early Egyptians, for example, as we long have known, made use of rough outline drawings (Fig. 1)2 to represent certain features of special sections of their country, and recently discovered tablets in the lower Mesopotamian valley (Fig. 2) interestingly show us how far advanced in the matter of map making the inhabitants of that land were two thousand years before the Christian era.3 We are likewise assured, through references in the literature of classical antiquity, that maps were made by the early Greeks and Romans, and perhaps in great numbers as their civilization advanced, though none of their productions have survived to our day. To the Greeks indeed belongs the credit of first reducing geography and map making to a real science.4 No recent discovery by archaeologist or by historian, interesting as many of their discoveries have been, seems to warrant an alteration of this statement, long accepted as fact.

Fig. 1. Fragment Map of Egyptian Gold Mines.

Fig. 2. Tablet Representing Babylonian World-Plan.

The credit of being the first scientific cartographer has been generally assigned to the Greek Anaximander of Miletus (610-547 B. C.).5 While there is not a detailed description extant of the maps he is reputed to have made, we know that he accepted the so-called Homeric idea, that the earth has the form of a circular disc,6 and is surrounded by the Ocean Stream, an idea generally approved by the Ionic School of Philosophers.7 It is not improbable that we have an allusion to the work of Anaximander in the History of Herodotus (484-400? B. C.), wherein we are told that Aristagoras, the tyrant of Miletus, when on a mission to Cleomenes, the King of Sparta, carried with him "a copper plate on which was engraved the whole circuit of the earth, and likewise all the Seas and Rivers."8 In another passage, Herodotus takes occasion to criticise maps of this circular character. "I laugh," he says, "when I see that, though many before this have drawn maps of the Earth, yet no one has set the matter forth in an intelligent way; seeing that they draw the Ocean flowing round the Earth, which is circular as if drawn with compasses, and they make Asia equal in size to Europe. In a few words I shall declare the size of each division and of what nature it is as regards outline."9 It is, however, interesting to observe that the father of historical geography and of history nowhere records his idea of a properly constructed map, and further that the circular form, which he condemned, is one which found wide acceptance even to the close of the middle ages.

We are not definitely informed as to just the course of improvement or advancement in early scientific map making among the Greeks, yet not a few names are known to us of those who made it a matter of special endeavor, as they specifically stated, to improve the work of their predecessors. We, for example, are told that Hecataeus (550-480 B. C.),10 likewise a native of Miletus, improved the maps of Anaximander, and that scientists of his day were astonished at his results; that Dicaearchus of Massina (350-290 B. C.)11 was the first to employ a central line of orientation on a map, one passing through the Mediterranean east and west, and that he represented on his map all the lands known since the expedition of Alexander the Great into the Far East; and further, that Eratosthenes, the librarian of Alexandria (276-196 B. C.),12 was the first to attempt a representation of the curved surface of the earth on a plane in accord with geometrical rules. The scientific cartographical ideas of Eratosthenes were further developed by Hipparchus (180-125 B. C.),13 who is generally referred to as the greatest astronomer of antiquity, and by Marinus of Tyre (fl. ca. 100 A. D.),14 who introduced the idea of inscribing lines of latitude and longitude on a map, crossing the same at right angles, which lines could be made to serve the useful purpose of orientation and be of assistance in giving proper location to all known places on the earth's surface.

Map making in that early period reached its climax in the work of Claudius Ptolemy of Alexandria (ca. 87-150 A. D.).15 His ideas, however, seem not to have found general favor with his contemporaries, nor with the geographers of the middle ages. (Fig. 3.) It was not until the so-called period of great geographical discoveries and explorations in the fifteenth century that he became a real teacher within his chosen field.

Fig. 3. Ptolemy World Map.

Map making and the science of geography were continuously progressive among the Greeks. Imperial Rome witnessed little progress in either field. Among those who wrote in the Latin language, Pomponius Mela (fl. ca. 43 A. D.)16 and Pliny (ca. 23-79 A. D.)17 alone have rank of importance. In the matter of map construction the Romans held to many of the cruder methods and ideas of the Greeks, a fact which we learn from the fragmentary references in their literature, and from the itinerary or road maps (Fig. 4), of the period of the emperors, which have come down to us.18

Fig. 4. Sections of Peutinger Tables.

The idea of a globular earth was at first accepted by the geographers of antiquity with some hesitancy. That Thales (640-548 B. C.),19 one of the earliest astronomers and cosmographers, openly supported this theory, as is sometimes asserted, is hardly probable. It is rather to be assumed that according to his idea the earth has the form of a cylinder, and that it moves within a hollow sphere, an idea upheld by Anaximander, his disciple and successor, to whom reference has been made above. It was the Pythagorean philosophers who appear to have first transferred to the earth that which had already been accepted as a theory relative to the heavens, including the imaginary circles and the circular or spherical form, apparently arguing that the earth is a sphere because that is the most perfect form, that it is located in the center of the universe because that is the place of honor, and that it is at rest because rest is more dignified than motion.20 It however was Aristotle who undertook, in the manner of a philosopher, an elaborate defense of the Pythagorean doctrine of a globular earth, supporting his arguments, first, through a reference to such positive proof as may be found in gravitation or "the tendency of all particles of matter to form themselves about the middle and thus make a sphere," and secondly, through a reference to the appearance of the earth's shadow cast during an eclipse of the moon.21 A third proof, so familiar to us today, that distant objects as we approach them gradually reveal themselves above the horizon, seems not to have occurred to Aristotle, but was first employed by Strabo. "It is evident," says the latter, "that, when persons on shipboard are unable to see at a distance lights which are on a level with the eye, the cause of this is the curvature of the sea; for if those lights are raised to a higher level, they become visible, even though the distance is increased; and in like manner, if the beholder attains a greater elevation he sees what was previously hidden.... Again, when men are approaching the land from the sea, the parts nearest the shore-line come more and more into view, and objects which at first appeared low attain a greater elevation."22

After the attempt had been made to determine the circumference of the earth, as was done by Eratosthenes with more or less satisfactory results, the thought, very naturally, was suggested of making an artificial representation of the entire earth, so far as then understood, that is, of making a terrestrial globe. There is no intimation, however, in any early allusion to Eratosthenes that he was a globe maker, or that he knew anything about globe construction. We know that he thought of the earth as a sphere placed in the center of the universe, around which the celestial sphere revolves every twenty-four hours.23 Strabo, at a much later date, in referring to the geographical ideas of Eratosthenes, censured him for his unnecessarily elaborate proofs of the earth's spherical character, apparently thinking the fact one too well known to require demonstration.

Fig. 5. Globe according to Crates.

It appears to have been the grammarian Crates of Mallos, a contemporary of Hipparchus, and a member of the Stoic School of Philosophers, who made the first attempt to construct a terrestrial globe (Fig. 5), and that he exhibited the same in Pergamum, not far from the year 150 B. C.24 It seems to have been Crates' idea that the earth's surface, when represented on a sphere, should appear as divided into four island-like habitable regions. On the one hemisphere, which is formed by a meridional plane cutting the sphere, lies our own oecumene or habitable world, and that of the Antoecians in corresponding longitude and in opposite latitude; on the other hemisphere lies the oecumene of the Perioecians in our latitude and in opposite longitude, and that of the Antipodes in latitude and longitude opposite to us.25 Through the formulation and expression of such a theory the idea of the existence of an antipodal people was put forth as a speculative problem, an idea frequently discussed in the middle ages, and settled only by the actual discovery of antipodal regions and antipodal peoples in the day of great transoceanic discoveries.26 That Strabo, at a later date, had this Pergamenian example in mind when stating certain rules to be observed in the construction of globes seems probable, since he makes mention of Crates' globe. Strabo alone among ancient writers, so far as we at present know, treats of terrestrial globes, practically such as we find in use at the present day. He thought that a globe to be serviceable should be of large size, and his reasoning can readily be understood, for what at that time was really known of the earth's surface was small indeed in comparison with what was unknown. Should one not make use of a sphere of large dimensions, the habitable regions (Fig. 6), in comparison with the earth's entire surface, would occupy but small space. What Strabo states in his geography is interesting and may here well be cited. "Whoever would represent the real earth," he says, "as near as possible by artificial means, should make a sphere like that of Crates, and upon this draw the quadrilateral within which his chart of geography is to be placed. For this purpose however a large globe is necessary since the section mentioned, though but a very small portion of the entire sphere, must be capable of containing properly all the regions of the habitable earth and of presenting an accurate view of them to those who wish to consult it. Any one who is able will certainly do well to obtain such a globe. But it should have a diameter of not less than ten feet; those who can not obtain a globe of this size, or one nearly as large, had better draw their charts on a plane surface of not less than seven feet. Draw straight lines for the parallels, and others at right angles to these. We can easily imagine how the eye can transfer the figure and extent (of these lines) from a plane surface to one that is spherical. The meridians of each country on the globe have a tendency to unite in a single point at the poles; nevertheless on the surface of a plane map there would be no advantage if the right lines alone which should represent the meridians were drawn slightly to converge."27

Fig. 6. Globe according to Strabo.

It is not at all improbable that Strabo and Ptolemy made considerable advance in the practical construction of terrestrial globes, for it seems reasonable to conclude that they were in possession of such objects when writing, as they did, concerning them.

Ptolemy, we may note, expressly allowed that the size of a globe should be that which one might desire, and that it was not necessary it should be of large size. It was this great Alexandrian cosmographer who first demonstrated the scientific value of drawing on the surface of a globe or map the network of parallels and meridians, and of establishing by means of the two geographical co?rdinates the true geographical position of every known place. To the end of making globes more serviceable he suggested the use of a meridian circle, such as is today employed in globe construction, passing through both poles, within which circle the globe might be made to move freely on its axis. He, however, in this connection, did not give technical directions for the construction of terrestrial globes, but he says enough to assure us that the art of globe construction was measurably well understood in his day, and that the Greeks and the Romans considered them very useful instruments in the study of the heavens and the earth.28

The allusions of the naturalist Pliny (23-79 A. D.) to the spherical shape of the earth give us no particular intimation that he knew of the existence of terrestrial globes, but they are interesting as indicating a belief of his time in its spherical form, a belief, judging from the nature of the argument, apparently drawn from Aristotle. Referring to the shape of the earth, he observes that "everyone agrees it has the most perfect figure. We always speak of the ball of the earth, and we admit it to be a globe bounded by the poles. It has not indeed the form of an absolute sphere, from the number of lofty mountains and flat plains; but if the termination of the lines be bound by a curve, this would compose a perfect sphere. And this we learn from arguments drawn from the nature of things, although not from the same considerations which we have made use of with respect to the heavens. For in the heavens the hollow convexity everywhere bends on itself and leans upon the earth as a center, whereas the earth rises up solid and dense like something that swells up and is protruded outward. The heavens bend toward the center, while the earth goes out from the center, the continual rolling of the heavens about it forcing its immense mass into the form of a sphere."29

NOTES

1 Most of the larger general works presenting an historical survey of the science of astronomy give consideration to its beginnings, noting the interest in the subject exhibited by the early Egyptians, Assyrians, Babylonians, and by other Eastern peoples. See the introductory pages of such works as Dalambre, M. Histoire de l'astronomie ancienne. Paris, 1817; Lockyer, J. N. The Dawn of Astronomy. New York, 1894; Allan, H. A. Star Names and their Meanings; Wolf, R. Geschichte der Astronomie. München, 1877; M?dler, J. H. Geschichte der Himmelskunde von den ?ltesten bis auf die neuste Zeit. Braunschweig, 1873. 2 vols.; Narrien, J. N. An Historical Account of Origin and Progress of Astronomy. London, 1833.

2 Chabas, F. Ouvres diverses publiées par G. Maspero. Paris, 1902. Tome deuxième, Plate II, p. 208, "Carte Egyptienne de mines d'or."

3 Cuneiform Texts from Babylonian Tablets, etc., in British Museum. London, 1906. Vol. 22, Plate 48. This Babylonian plan of the world illustrates the idea concerning the world which was current in the late Babylonian period. It represents the region of Babylonia, Assyria, and the neighboring districts as a circular plain surrounded by the Persian Gulf (Ma-ra-tum). The city Babylon (Babylu) is indicated near the center, and next to it the land of Assyria (Ashshur). The position of certain other cities is indicated. The district toward the south, bordering the Persian Gulf, is represented as being full of canals and marshes. Toward the north is marked a district which is referred to as mountainous. Beyond the circle is represented the Persian Gulf, and a number of triangles pointing outward from the circular zone, each being labeled "region," indicating a vague conception concerning the same.

4 Numerous works have been published referring to the geography of the ancients. Mention may here be made of the following as being important. In each may be found extensive bibliographical references. Berger, H. Geschichte der wissenschaftlichen Erdkunde der Griechen. Leipzig, 1887-1894. This work was issued in four parts. Forbiger, A. Handbuch der alten Geographie nach den Quellen bearbeitet. Hamburg, 1877; Schmidt, M. C. P. Zur Geschichte der geographischen Litteratur bei den Griechen und R?mern. Berlin, 1887; Bunbury, E. H. History of Ancient Geography. London, 1883. 2 vols.; Tozer, H. F. A History of Ancient Geography. Cambridge, 1897. See also The History of Herodotus; The Geography of Strabo; The Natural History of Pliny; The Geography of Ptolemy.

5 Schmidt, op. cit., p. 12; Bunbury, op. cit., Vol. I, p. 122; Berger, op. cit., pt. 1, p. 8-14.

6 Iliad, XVIII, 446-447; XXI, 225-228; Odyssey, V, 282; XII, 380.

7 They indulged much in speculation concerning the physical constitution of the world.

8 Herodotus. Historia. Bk. V, chap. 49. Citation from translation by Macaulay, G. C. The History of Herodotus. London, 1890. 2 vols.

9 Herodotus, op. cit., Bk. IV, chap. 8, 36; II, 21, 23.

10 Bunbury, op. cit., Vol. I, chap. v; Schmidt, op. cit., p. 13; Berger, op. cit., pt. 1.

11 Cicero. Epistolae ad Atticum. vi. 2; Bunbury, op. cit., Vol. I, p. 617.

12 Berger, op. cit., pt. 3; Bunbury, op. cit., Vol. I, chap. xvi.

13 Berger, op. cit., pt. 3; Bunbury, op. cit., Vol. II, chap. xvii, sec. 1.

14 Bunbury, op. cit., Vol. II, chap. xxvi. Marinus is known to us only at second-hand. Ptolemy extols him in the highest terms, but he undertook to reform his maps just as Marinus had undertaken to reform the maps of his predecessors.

15 Bunbury, op. cit., Vol. II, chaps. xxviii-xxix; Mollweide, S. Die Mappierungskunst des Ptolemaus. (In: Zachs Monatliche Korrespondence zur Bef?rderung der Erd- und Himmelskunde. Weimar. Bd. 11, pp. 322 ff.); Nordenski?ld, A. E. Facsimile Atlas. Stockholm, 1889. This last-named work gives consideration to the Atlas of Ptolemy, to the numerous editions of his Geographia, to his geographical errors. The twenty-seven maps printed in the 1490 Rome edition of the Atlas are reproduced. See also the printed lists of the editions of Ptolemy's Atlas by Eames, W., Winsor, J., Philipps, P. L.

16 Bunbury, op. cit., Vol. II, chap. xxviii, sec. 2; Fink. Mela und seine Geographie. Rosenheim, 1881. Mela titled his work, "De situ orbis." Excellent tr. into English by Golding, Arthur. London, 1585. Various printed editions, first in 1471.

17 Bunbury, op. cit., Vol. II, chap. xxiv. Various editions of original; various English translations. Pliny titled his work, "Naturalis historia."

18 Miller, K. Die Weltkarte des Castorius, genannt Peutingersche Tafel. Ravensburg, 1887; Porena, F. Orbis pictus d'Agrippa. Roma, 1883; Desjardins, E. La Table de Peutinger d'après l'original conservé à Vienne. Paris, 1896.

19 Lewis, G. C. Historical survey of the Astronomy of the Ancients. London, 1862. pp. 80 ff.; Berger, op. cit., pt. 1.

20 Bunbury, op. cit., Vol. I, chap. iv, secs. 4, 5.

21 A scientific foundation for the spherical theory seems not to antedate Aristotle. See especially his work, De Coelo, Bk. II, chap. 14, and for a good translation of this work by Taylor, T., bearing title, On the Heavens, from the Greek with copious elucidations. London, 1807. Plato's statement in Phaedo merely observes that the earth, if like a ball, must be suspended without support in the interior of a hollow sphere. See also the Book of Job, chap. xxvi, v. 7, where reference is made to the earth hanging upon nothing. There is here probably the expression of an early Assyrian or Babylonian belief in a spherical earth.

22 Strabo. Geographia. Bk. I, chap. 1, §20. See translation by Jones, H. L. The Geography of Strabo. New York, 1917. 8 vols.

23 Bunbury, op. cit., Vol. I, pp. 619-620.

24 Wachsmuth, C. De Cratte Mallota. Leipzig, 1860; Berger, H. Entwickelung der Geographie der Erdkugel bei den Hellenen. (In: Grenzboten, Vol. xxxiv, pp. 408 ff.); Müllenhoff, C. (In: Deutsche alterthumskunde. Berlin, 1895. p. 248.) Diodorus Siculus attributes the discovery of the use of the globe to Atlas of Libya.

25 Berger. Geschichte, pt. 2, p. 135; Friedrich, R. Materialien zur Begriffsbestimmung des Orbis Terrarum. Leipzig, 1887.

26 A belief in the existence of antipodal peoples, very clearly was accepted by Pythagoras, Eratosthenes, Crates, Posidonius, Aristotle, Strabo, and later by Capella. Numerous others presupposed the earth to be globular in shape. See Kretschmer, K. Die physische Erdkunde im christlichen Mittelalter. Wien, 1889. pp. 54-59, wherein the author gives consideration to the doctrine of the antipodes as held in the middle ages. Berger. Geschichte, pt. 3, p. 129, notes that the idea of the earth's division into four parts or quarters persisted for centuries after Crates' day, if not among scientific geographers, at least among those who could be said to have possessed general culture. Cleomedes, Ampelius, Nonnus, and Eumenius mention the idea as one to be accepted. See in this connection the world map of Macrobius, a reproduction of which may be found in Nordenski?ld, op. cit., pl. XXXI. See also Miller, K. Die Weltkarte des Beatus, 776 nach Christus. Stuttgart, 1895. p. 28.

It was thought that Africa did not extend to the equator, or at least was not habitable to the equator. Below the equator there was thought to be water but beyond the uninhabitable and impassable torrid zone a habitable region. The map of Lambertus well represents this early theory. Pomponius Mela called the inhabitants of this southern region "Antichthoni," their country being unknown to us because of the torrid zone intervening. Pliny, and after him Solinus, says that for a long time the island of Taprobana (Ceylon) was thought to be the region occupied by the Antichthoni.

27 Strabo, op. cit., Bk. II, chap. v, §10.

28 Ptolemy. Geographia. Bk. I, chap. 22.

29 Pliny, op. cit., Bk. II, chap. 64; Bk. II, chap. 2.

* * *

Celestial Globes in Antiquity

Thales' ideas, probably not a globe maker.-Eudoxus.-The Atlante Farnese.-Archimedes.-Allusion of Lactantius.-Pappus' allusions.-Armillary spheres.-The astronomer Hipparchus.-Ptolemy.-Globes used for decorative purposes by the Romans.-Roman coins.-The Byzantine Leontius Mechanicus.

THOUGH we find but an occasional reference to terrestrial globes in the literature of classical antiquity, numerous statements appear therein which assure us that celestial globes, solid balls as well as armillary spheres, were constructed in those early centuries, for both practical and ornamental purposes. There exists, however, considerable uncertainty as to the exact character of the earliest of these globes.

The information we have concerning the Ionic School of Philosophers, of which school Thales is reputed to have been the founder, does not give us any satisfactory evidence that attempts were made by any of their number at a material representation of their astronomical or geographical theories. They were content, in the main, with mere philosophical or cosmical speculations. The statement, therefore, that Thales himself constructed a celestial globe, on which to represent his notion of the crystal sphere, is not well authenticated.30

While not assured to us by any positive statement, there appears to be good reason for believing the astronomer Eudoxus of Cnidos (409-356 B. C.) made use of a celestial globe on which to represent certain astronomical theories which he entertained.31 He traveled in Egypt in his later life, where he carried on his studies, and where he seems to have learned the construction of star catalogues. On his return to his own country he is reported to have undertaken the representation of the several constellations known to him, on a celestial sphere. The astronomical poem of Aratus (fl. 270 B. C.),32 so frequently cited and copied in following centuries, is considered to be a description of the constellations according to Eudoxus.

In the Royal Museum of Naples there may be found a large marble celestial globe, 65 cm. in diameter (Fig. 7), which the mythical Atlas bears on his shoulders, the statue itself being 1.86 m. in height, resting on one knee.33 This very interesting and artistic object was transferred to Naples museum from the Farnese Palace in Rome, hence is generally referred to as the Atlante Farnesiano. Forty-two constellations are represented on its surface (Fig. 8), and the five wanting, including Ursa Major and Ursa Minor, probably owe their absence to the obliteration which time has brought about. From the position of the several constellations, relative to the intersecting points of the ecliptic with the equator, it is thought that it must have been constructed at least three hundred years before the Christian era. It seems therefore to date from about the time of Eudoxus, being then the oldest extant globe.

Fig. 7. Atlante Farnese, ca. 200 B. C.

Fig. 8. Atlante Farnese Constellation Figures.

We learn from Cicero and from other early writers that Archimedes (ca. 287-212 B. C.), the celebrated geometrician of Syracuse, constructed a globe or contrivance for the purpose of demonstrating the movements of the heavenly bodies. Cicero's statements imply that the work of Archimedes was well known in his day, yet he thought it merited a special word of commendation from himself. "I shall propose nothing new to you," he says, "nor that which I have invented or discovered; but I remember C. Sulpicius Gallus, a very learned man, as you know, when this appearance (in the heavens) was spoken of, and he was, by chance, at the house of Marcellus, who had been consul with him, he described a globe among the spoils of that opulent and magnificent city of Syracuse, when captured, as the only thing among all the spoils which he ordered to be carried to his own house; about which globe I have often heard, on account of the fame of Archimedes, although the work itself was not very remarkable, for there was another far more beautiful and more honored by the common people, made by the same Archimedes, and placed in the Temple of Virtue by the same Marcellus. But afterward when Gallus began to explain scientifically the object of the machine, I thought there was more ingenuity in that Sicilian than human nature was capable of. For Gallus informed me that there was another ancient invention of a solid and elaborately formed globe which was made by Thales, the Milesian, to revolve. And afterward the same was, by Eudoxus of Cnidos, the disciple of Plato, adorned with the fixed stars of heaven, and with every ornament and embellishment, as described by Eudoxus, and was many years afterward celebrated by Aratus, not exactly in the scientific language of astronomy, but with the graces of poetry. This species of globe indeed, in which the sun and moon were made to revolve, and five of those stars which have been called travelers, and as it were wanderers, could not possibly be exhibited on that solid sphere. And more especially was that invention of Archimedes to be admired, for he had so contrived that one revolution of the machine served somehow to produce unequal and varied movements through their different paths. For when Gallus set the globe in motion, the moon succeeded the sun by as many turns of the brass wheel of the machine as days in the heavens, so that the globe represented in the heavens the same eclipse of the sun, when the moon arrived at a certain place or point, as the shadow of the earth did when the sun shone from the opposite region."34

Lactantius' allusion to Archimedes, at a later date, is perhaps derived from Cicero, but it is none the less interesting as indicating a belief that such a globe had existed. In his characteristic vein he refers to the mechanical device, finding therein a support for his theological arguments. "Was Archimedes of Sicily able to contrive a likeness and representation of the universe in hollow brass," he inquires, "in which he so arranged the sun and moon, that they effected, as it were every day, motions unequal and resembling the revolutions of the heavens, and that sphere, while it revolved, exhibited not only the approaches and with drawings of the sun or the increase and waning of the moon, but also the unequal course of the stars, whether fixed or wandering? Was it then impossible for God to plan and create the original, when the skill of man was able to represent them by imitation? Would the stoic, therefore, if he should have seen the figures of the stars painted and fashioned in that brass, say that they moved by their own design, and not by the genius of the artificer?"35 Günther notes that at the beginning of the seventh book of the collection of Pappus, geometrician of Alexandria, may be found a reference to those skilled in mechanical devices in which it is stated that "Mechanicians are those who understand how to construct celestial globes and to represent the heavens and the course of the stars moving in circles by means of like circular movements of water."36 It has been thought that in this passage we have a reference to a globe such as was probably constructed by Archimedes, although the reference is not to any particular example. It seems not improbable that the globe of Archimedes was made to revolve by an hydraulic contrivance, and that it resembled a planetarium or orrery.37 That the science of hydrostatics had been developed by Archimedes' time to a high degree is very certain.

Instruments for measuring angles and distances were very early employed in the field of astronomy as well as in the field of geography. Of these instruments the Egyptian gnomon appears to have been the oldest.38 In its best form it consisted of a bowl having a perpendicular rod or staff erected at the central point of the inner curved surface. This rod cast a shadow upon the inner surface of the bowl, which had been graduated, giving a reading in degrees which furnished to the observer the information desired. Time brought improvements and variations in the construction of simple instruments of this character. As early as the third century before the Christian era, adjustable rings, or armillae, for example, were employed by astronomers to aid them in the solution of their problems, which instruments later developed, as noted below, into the more elaborate and complex armillary spheres. The simplest form of such an instrument appears to have been but a single graduated circle. To this, at a very early date, a second was added, thus providing an instrument in which one of the circles was regarded as fixed in the plane of the equator, the other, intersecting this at right angles, served as a meridian circle, being movable around an axis which could be called the world axis, the axis of the celestial sphere, or the axis of the universe. The position of a celestial body in declination could be determined on the meridian circle, and its right ascension on the fixed or horizon circle.39 It seems altogether probable that Eratosthenes made use of such an instrument in his efforts to measure the obliquity of the ecliptic. He tells us that in his time one of large dimensions hung in the portico of the academy of Alexandria.40 With the addition of other circles, and of an adjustable view-tube, that more accurate and detailed measurements might be made, this device, in Hipparchus' day, came to be known as an astrolabe, and, after the addition of other rings in later years, to be known as an armillary sphere. Even in this last development it was not a true sphere on which could be represented the starry constellations, but an arrangement of circles forming a sort of imaginary sphere, the circles being intended to represent the relative position of the principal celestial circles. This instrument seems, at first, to have been suspended, when in use, but later was made to rest upon a base, the whole adjusted to revolve around an axis and within a graduated horizon circle. In the earliest examples, the earth at the center of the circles, it represented the Ptolemaic system (Fig. 9); in the later examples, having the sun at the center, it represented the Copernican system.

Fig. 9. Armillary Sphere according to Ptolemy.

It is expressly stated by Ptolemy that a celestial globe was constructed by Hipparchus, who is reputed to have been the founder of spherical trigonometry,41 and Pliny tells us that Hipparchus was the inventor of the astrolabe,42 which statement probably means that he greatly improved the simple armillae used at an earlier date as an instrument for astronomical calculations.

Ptolemy, in his 'Syntaxis,' or 'Almagest' as it was called by the Arabs, devoted a chapter to the method of constructing, and to the use of the astrolabe, which must have closely resembled the armillary sphere, describing therein, in terms not altogether easy of comprehension, its several rings and cylinders, and the method of adjusting the same for purposes of determining the latitude and the longitude of celestial bodies. He tells us also how to construct a representation of the sphere of the fixed stars by means of a solid ball, how to place thereon the several constellations, and how to use the same in the study of astronomical problems. Such a globe, he says, "should be of a dark color, that it might resemble the night and not the day." His description is detailed as to the proper method of procedure in marking the position of the celestial circles on this globe, in arranging the movable rings of "hard and well polished material," in graduating the rings and adjusting them to move about an axis which is likewise an axis of the globe proper. In marking the position of the fixed stars, we are told that the proper method is to commence at some constant and invariable point of a certain constellation, and he suggests that the best starting point is the fixed star in Canis Major, that is, the so-called dog star, or Sirius. "The position of the other fixed stars, as they follow in the list, could easily be determined," he says, "by making the globe to turn upon the poles of the zodiac, thus bringing the graduated circle to the proper point of each. The stars could be marked with yellow or with such other color as one might choose, having due regard for their brilliancy and magnitude. The outline of each of the constellations should be made as simple as possible, indicating with light strokes, differing but little in color from that of the surface of the globe, the figures which the stars in the several constellations represent, preserving in this manner the chief advantage of such representation, which should be to make the several stars very prominent without destroying, by a variety of color, the resemblance of the object to the truth. It will be easy to make and to retain a proper comparison of the stars if we represent upon the sphere the real appearance or magnitude of the several stars. While neither the equator nor the tropics can be represented on the globe, it will not be difficult to ascertain the proper position of these circles. The first could be thought of as passing through that point on the graduated meridian circle which is 90 degrees from the poles. The points on this meridian circle 23 degrees 51 minutes (sic) each side of the equator will indicate the position of the tropics, that toward the north the summer solstitial circle, that toward the south the winter solstitial circle. With the revolution of the globe from east to west, as each star passes under the graduated meridian circle, we should be able to ascertain readily its distance from the equator or from the tropics."43

That the Romans especially interested themselves in globes, either celestial or terrestrial, is not at all probable, because of their very practical inclinations. There is evidence, however, that in the time of the emperors celestial globes were constructed, especially in the studios of sculptors, but these were made largely for decorative purposes, having therefore an artistic rather than a scientific value. In the year 1900 there was found in a villa at Boscoreale, not far from Pompeii, an interesting fresco (Fig. 10), this being acquired by the Metropolitan Museum of New York in the year 1903. It has been referred to as a sundial, but was clearly intended to represent, in outline, a globe exhibiting the prominent parallels and a certain number of the meridians. It is not at all improbable that such subjects were frequently selected for wall or floor decoration.44 It appears that astrologers at times made use of globes in forecasting events.45 It may further be noted that on certain early Roman coins there may be found the representation of a globe (Figs. 11, 12), which perhaps had as its prime significance the representation of universal dominion.46

Fig. 10. Bosco Reale Roman Fresco, ca. 50 A. D.

Fig. 11. Greek and Roman Coins.

Fig. 12. Roman Gems.

Not until the day of the Byzantine Emperors do we meet with a real scholar who made a particular study of such astronomical apparatus, apparatus which he describes in a special treatise. Among historical scholars the work of Leontius Mechanicus seems not to have found the recognition which it deserves.47 He appears to have been a practical man, very active within the field concerning which he wrote, and from his remarkably detailed description we are able to learn something of the extent to which globe technique was carried in the days of the early Eastern Emperors. We at any rate learn from him that globes were constructed in his workshop, which globes, in all important respects, were like those in use at the present time, being, for example, provided with a meridian circle adjusted to move through notches in a horizon circle. The information given us by Leontius, which here follows, is in free translation or paraphrase of his treatise, the whole being condensed. He appears to have been a student of astronomy, as represented by Aratus, for he tells us that he had endeavored to construct a globe on which the constellations and the circles could be made to conform to the records of the ancient poet astronomer. He tells us further that he constructed this globe for Elpidius, an estimable man of letters, and one full of zeal for study; that at the time of its construction, though he had the leisure, he did not prepare a description of the globe, but on the insistence of his friends such description he now proposed to write. This appears to be the raison d'être for his treatise. The importance of adhering closely to the statements of Aratus he insists upon, though admitting that writer's errors, being convinced that most of the globes of which one had knowledge in his day agreed neither with him nor with Ptolemy. Leontius first directs attention to Aratus' threefold plan in describing the several constellations, in which description that author speaks first of the relation which part bears to part in each; second, of the position of each constellation relative to the celestial circles, as, for example, to the tropics, and third, its position in the heavens relative to the constellations in the zodiac. He follows this statement with a somewhat lengthy reference to the constellation Ophiuchus, or the Serpent, in explanation of the method of description. After having the surface of the globe portioned out for the representation of the several constellations and the important circles, he then proceeds, as he states, to consider the execution, by which he means representing in proper color and outline the several figures, and the mounting of the globe. Upon a properly constructed support should first be placed the horizon circle, through which a second circle should be made to pass; this second circle will serve as a meridian. These circles, he observes, will enclose the ball, all the points of the surface of which should be equally distant from the inner surface of the horizon and meridian circles, that is, there should be a perfect adjustment of the enclosing rings and the enclosed ball. The surface of the sphere should be painted a dark color, as, for example, azure. He sets forth, with considerable detail, the proper method of procedure in locating the several principal circles, each of which should be graduated. The zodiac should be divided into twelve parts, and the constellations belonging to each of the several parts should be designated by name, beginning with Cancer, following this with Leo, Virgo, and so on, one after the other. In giving the globe a position which actually conforms to the world, the pole should be set to the north, and the movement of the sky can then be imitated by turning the globe to the left. Leontius, by way of summary and definition, at the conclusion of his treatise, speaks of a sphere as a solid having a surface, from all the points of which, if straight perpendicular lines of equal length be drawn, they will reach a point within called the center. This center in the great sphere of the universe is the earth. The poles of the sphere are the extremities of the axis on which it turns. The horizon cuts the sphere into two hemispheres, the one superior and the other inferior to the earth. The sky, which is continually turning, encircles all, one half of it being above, the other below the earth, which is as far removed from the superior part of the heavens as from the inferior.48

NOTES

30 Cicero's allusion to Thales, cited p. 16, is probably a reference to a tradition.

31 Wolf, R. Geschichte der Astronomie. München, 1877, p. 193; Gassendi, P. Opera Omnia. Leipzig, 1658. Vol. V, p. 375. See statement by Cicero, cited below, p. 17.

32 Aratus' poem bore the title, "Phaenomena." See, for an excellent edition of this poem, Prince, C. L. Phenomena. A literal translation of the astronomy and meteorology of Aratus. Lewes, 1895. In his "Bibliographical remarks," the translator refers to one hundred and nineteen editions of this poem, dating from the first printed at Bonn in the year 1474. See also n. 48, below.

33 Passeri, G. B. Atlas Farnesianus Marmoreus insigne vetustatis monumentum. (In: Gori, A. F. Thesaurus gemmarum antiquarum astriferarum. Firenze, 1750. Vol. III.); Denza, P. F. Globi celesti della Specola Vaticana. (In: Publicazioni della Specola Vaticana. Torino, 1894. pp. xx-xxiii.)

34 Cicero. De Republica. Bk. I, chap. xiv. The citation is from the translation by Hardingham, G. G. The Republic. London, 1884.

35 Lactantius. Institutiones divinae. Bk. II, chap. v.

36 Pappus. Collectionum mathematicarum. Edited by Commandino. Urbino, 1588. Bk. VII. See especially the introduction.

37 Hultsch, F. Uber den Himmelsglobus des Archimedes. (In: Zeitschrift für Mathematik und Physik. Leipzig, 1878. Bd. 22. Hist. Litt. Abteilung, p. 106.); Same author. "Archimedes." (In: Real-encyklop?die der klassischen Alterthumswissenschaft.)

38 Wolf, op. cit., pp. 122-124.

39 Wolf, op. cit., pp. 160-166.

40 Wolf, op. cit., p. 130.

41 Ptolemy, C. Syntaxis. (Almagest.) Various editions. Bk. VII, chap. 1. This work was first printed in Venice, 1496; the first Greek text in Basel, 1538. See Hues, Tractatus de Globis, for an analysis of this work.

42 Pliny. Historia Naturalis.

43 Ptolemy, op. cit., Bk. V, chap. i; Bk. VII, chap. v; Bk. VIII, chap. iii. Ptolemy mentions by name forty-eight constellations, all of which he probably obtained from the earlier Greeks. These constellations, the names being still retained, are:

The Zodiac.

Aries Cancer Libra Capricornus

Taurus Leo Scorpio Aquarius

Gemini Virgo Sagittarius Pisces

The Northern Hemisphere.

Andromeda Corona Lyra Ursa Major

Aquila Cygnus Ophiuchus Ursa Minor

Auriga Delphinus Pegasus Sagitta

Bo?tes Draco Perseus

Cassiopeia Equuleus Serpens

Cepheus Hercules Triangulum

The Southern Constellations.

Ara Cetus Crater Lupus

Argo Navis Centaurus Eridanus Orion

Canis Major Corona Australis Hydra Piscis Australis

Canis Minor Corvus Lepus

44 Visconte, P. E. Nota intorno ad un' antico globo celeste scolpito in marmo porino. Roma, 1835; Gaedechens, R. Der marmorne Himmelsglobus des fürstlich Waldechschen Antikenkabinettes zu Arolsen. G?ttingen, 1862.

45 Schanz, M. Geschichte der r?mischen Litteratur bis zum Gesetzgebungswerk des Kaisers Justinian. München, 1890. See p. 75 for a reference to the astrologer Nigidius Figulus.

46 Coins on which there appears a representation of a globe were numerous. Attention may also here be called to the imperial insignia, a part of which was a globe, which the emperor was represented, in the pictures of the day, as holding in his hand. See King, C. W. Antique Gems and Rings. Vol. II, plates xxvi and xxxviii.

47 Weidler, J. F. Historia astronomiae. Vitembergae, 1741. This author is of the opinion that Leontius lived in the eighth century, p. 201; Susemihl. Geschichte der Griechischen Litteratur der alexandriner Zeit. Leipzig, 1891. See Vol. I, p. 294, for a statement of the belief that Leontius lived in the seventh century.

48 Halma, N. Les Phenoménes d'Aratus de Soles, et de Germanicus Cesar; avec les Scholies de Théon, les catasterismes d'Eratosthenes et la sphère de Leontius traduit ... par l'Abbé N. Halma. Gr. avec Fr. Paris, 1821. pp. 65-73.

* * *

Globes Constructed by the Arabs

Followers of Ptolemy.-Early armillary spheres.-Interest of the Califs in globes and astronomical instruments.-The record of the 'Fihrist.'-Ibrahim.-Caissar.-Mohammed ben Helal.-Mohammed el Ordhi.-The Paris globes.-Ridhwan Efendi.

IN passing from the period of classical antiquity to the so-called Christian middle ages, attention may first be directed to the activities of the Arabs in the field of astronomy and geography, in so far as their activities had to do with the construction of globes.49 The information which we have, concerning their astronomical studies in particular, is more detailed than is that which has come down to us respecting any other peoples who may have been interested in these centuries in the same field of study.

Doubt may be expressed at the outset that the Arabs were interested in the construction of terrestrial globes, since with the matter of descriptive geography they appear to have been very little concerned, a fact which their imperfect cartographical attempts clearly demonstrate.50 Although the theory of a globular earth was early accepted by their learned men,51 there is scarcely a trustworthy allusion in literature to Arabic terrestrial globes which can be cited. An occasional reference, however, has been made by modern writers to a globe said to have been constructed for King Roger of Sicily. Without citing his authority, Freyheer F. v. Zach states that "the oldest terrestrial globe which is known was made for King Roger II of Sicily in the twelfth century, and is especially remarkable for the value of the metal which was used in its construction, this being 400 pounds of silver. A knowledge of this globe would not have come down to our day had not Edrisi, a famous geographer of that time, given an especial description of the same, under the title Nothatol mostak (Pleasure of the Soul)."52 It is probable that the reference here is to a circular disc made by Edrisi, or an armillary sphere, but not to a terrestrial globe.53

As to Arabic celestial globes, a different situation presents itself. It is well known that the inhabitants of Arabia, long before the time of Islam, were in the habit of observing the stars, many of which, as Dorn has noted, they knew and designated by names taken from pastoral life, and several of which they worshiped as visible gods.54

Calif al-Mansur, who began his reign in 754 A. D., appears to have been the first to show a decided taste for astronomical science, and for many centuries following him this interest is strikingly pronounced among the people of his country.55 Scholars were eagerly attracted to the works of Ptolemy, which were many times translated into Arabic, and commentaries were written upon his description of the names and figures of the several constellations. The only alteration they allowed themselves to make in the names of the stars was to translate them into their own language, or to substitute for those they could not understand other names that conveyed an idea to their minds, applicable to the constellation before the eyes. Andromeda they called "The Chained Lady"; Cassiopeia they called "The Lady in the Chair"; Orion received the name "The Giant." They followed in the construction of their armillary spheres and celestial globes the description laid down in Ptolemy's 'Syntaxis,' modifying these astronomical instruments, from time to time, as their studies directed them.56

The list of califs interested in astronomy is a long one, both of those who remained in the original homeland, and of those who went to the new home in the Iberian Peninsula.57 The Mohammedan Hulagu Khan, for example, erected, about 1264, an observatory in his Mongol capital, Maragha, near Tabriz, which long remained a noted center for astronomical studies.58 This observatory, however, was but one of a number of similar institutions erected either by the Arabs or by the Persians. We are told that the construction of astronomical instruments was brought to a high degree of perfection by these peoples in the thirteenth century.59 The names of many of the Arabic astronomers who were particularly expert as globe makers are recorded, and there were many who wrote on the subject of celestial spheres, armillary spheres, and astrolabes, even before the tenth century.60 The author of the 'Fihrist,' Ibn Ab? Ja'k?b an-Nad?m, tells us that Kurra ben Kam?ta al-Harran? constructed a globe which he himself had seen.61 This, he says, was made of unbleached material from Dabik, and colored, but that the colors were much faded. Ibn Alnabdi, who was known as a clever mechanic, mentions two globes which he had examined and admired for their excellency of execution, in the public library of Kahira, in the year 1043. One of these globes, he says, was made of brass, by Ptolemy himself; the other, of silver, was constructed by Abul Hassan Alsufi, for the immediate use of the king, Adad Eddoula.62

As a visible evidence of the interest of the Arabs in astronomical science, and of their skill in the construction of astronomical instruments, we have preserved to us, besides numerous astrolabes, no less than seven globes, known to have been constructed prior to the year 1600. The oldest one extant is now in the possession of the R. Istituto di Studi Superiori of Florence, Italy.63 This fine example of the skill which was attained by the instrument makers of Valencia, Spain, at one time a flourishing center of Arabic culture, appears to date from the second half of the eleventh century. According to an inscription on the globe, we learn that it was made at Valencia by Ibrahim Ibn Said-as-Sahli, in the year 473 of the Hegira, a date equivalent to 1080 A. D. This date Professor Meucci finds confirmed by a careful study of the position of the stars represented on the globe. He notes, for example, that the star Regulus had been placed at a distance of 16 degrees 40 minutes from the sign of Leo. Ptolemy, in the year 140 A. D., gave this distance as 2 degrees 30 minutes. According to Albaregnius, this star advances about one degree every sixty-six years. Since 140 A.D. the star, therefore, would have moved 14 degrees 10 minutes, which fact would lead astronomers to place this star, about 1080, as it appears on the globe. The globe is of brass, 20 cm. in diameter, having engraved on its surface forty-seven constellations, as given by Ptolemy, omitting only the Cup, with 1042 stars, each with its respective magnitude indicated.

A second Arabic celestial globe, which dates from the year 1225, has been described in detail in a monograph by Assemani, which he issued in the year 1790.64 This remarkably interesting object belonged, at the time, to the extensive and celebrated collection of antiquities and curiosities of Cardinal Borgia, in Velletri, but may now be found in the Museo Nazionale of Naples. It is composed of two brass hemispheres, having both horizon and meridian circles, the whole resting upon four supporting feet. A Cufic inscription tells us that it was made by Caissar ben Abul Casem ben Mosafer Alabiaki Alhanefi, in the year of the Hegira 622. Caissar probably was an astronomer at the court of Cairo, and the Mohammedan date as given, translated into Christian reckoning, gives us the year 1225.

In the year 1829 Dorn published a detailed description of an Arabic globe which had been deposited in the museum of the Asiatic Society of London (Fig. 13) by Sir John Malcolm.65 It is of brass, has a diameter of 24 cm., and is furnished with a substantial mounting. The peculiar features of the figures which represent the several constellations suggest Persian workmanship. In the vicinity of the south pole is an inscription in Cufic characters, telling us that it was "Made by the most humble in the supreme god, Mohammed ben Helal, the astronomer of Monsul, in the year of the Hegira 674." This year answers to the year 1275 of the Christian era, that is, it was constructed about the same time as the Borgian globe and that belonging to the Dresden collection, briefly described below. Forty-seven constellations are represented. On the horizon circle, in their respective places, we find engraved the words, "East," "West," "South," "North."

Fig. 13. Northern Hemisphere of Globe by Mohammed ben Helal, 1275.

The Arabic globe, to be found in the Mathematical Salon of Dresden (Fig. 14), has proved to be one of much interest and scientific value to students of astronomy.66 Bode, who described it in the year 1808, refers to its remarkably fine execution and to its Cufic inscriptions as being among the finest extant specimens of early Arabic writing. The sphere is of brass, having a diameter of 14 cm., and is composed of two parts, separable on the line of the ecliptic. It has a brass horizon circle, on which is engraved at the east the word "rising," and at the west the word "setting." It is not supplied with a movable meridian circle, but within the horizon circle, from north to south, and from east to west, there are two brass half circles, of the same diameter as the horizon circle and so adjusted as to form one piece with it. Through such an arrangement it is made possible to turn the globe in any desired direction, one half of it being at all times above the horizon. In addition to the above arrangement, there are two movable half circles, attached at the zenith point by a pivot. These half circles are graduated, and are movable, making it possible to find, by means of them, the declination and right ascension of any star. The base, which must be comparatively modern, consists of a circular plate, from which rise four turned support columns, attached at their upper extremities to the two half circles of brass, on which rests the horizon circle.

Fig. 14. Globe of Mohammed ben Muwajed el Ordhi, 1279.

The date of construction cannot be far from 1279, which is determinable from the position of the stars engraved thereon, relative, for example, to the equinoctial points. The maker's name, "Mohammed ben Muwajed el Ordhi," appears near the constellation Ursa Major, and is inlaid in silver. There appear, very artistically engraved, the lines representing the principal circles, the outlines of the several constellations, with their names, some of these being inlaid with silver, some with gold. The equator and the ecliptic are represented on the surface of the sphere, each by two engraved parallel lines, and are graduated, the graduation in each instance being represented by four short and one long line, alternating thus by fives throughout the entire three hundred and sixty degrees. The equator is inlaid with gold, the other circles with silver. The names of the twelve constellations in the zodiac are alternately inlaid with gold and silver, while all star names, except as indicated, are inlaid with silver. The constellations represented number forty-eight, the human figures all being clad, turning the front and right face toward the observer.

The Bibliothèque Nationale of Paris possesses two ancient Arabic globes, one of which, neither signed nor dated, has been thought to have been constructed in the eleventh century.67 This was obtained by Jomard, in Egypt, more than sixty years ago. It has a diameter of about 19 cm., is furnished with a horizon circle, which is upheld by four semicircular arms, these, in turn, resting upon a base composed of four flat and rather inartistic supports. The engraving on the surface of the brass sphere closely resembles that on the Dresden globe. A detailed description of this globe has not been obtainable.

A second Paris Arabic globe,68 like the preceding, belongs to the Bibliothèque Nationale (Fig. 15). It has a diameter of something less than 15 cm., and was constructed by Diemat Eddin Mohammed, in the year of the Hegira 981, which in the Christian reckoning corresponds to the year 1573.

Fig. 15. Globe of Diemat Eddin Mohammed, 1573.

The Imperial Library of Petrograd possesses an Arabic globe, constructed in the year 1701.69 It is described by Dorn as a fine example of the globe maker's art, closely resembling, in its general features, the Arabic globe in the collection of the Royal Asiatic Society of London. It has a diameter of about 19 cm., rests upon an ornamental tripod base, and is adjusted to turn within a brass circle, which circle is fitted into a larger one, so marked and graduated as to represent four concentric circles. The first or inner circle, representing the horizon, is divided into thirty-six divisions of ten degrees each; on the second circle the degrees are indicated by letters; on the third circle appear the twelve signs of the zodiac and the four principal directions, east, west, north, south; the fourth circle is divided into thirty-six parts, formed by the extension of the lines which divide the first, or horizon circle, into thirty-six parts. On the last circle the names of one hundred and four cities and countries are given. Not far from the north pole is an inscription which gives us the name of the maker and the date of construction. Therein we read that it was completed in the year 1113 of the flight of the Prophet, or in the year 1701 of Christian reckoning, by Ridhwan, for Maulana Hassan Efendi, who, toward the end of the seventeenth century, was director of the astronomical observatory of Cairo, and gave substantial encouragement to makers of globes and of other instruments employed in astronomical studies. The equator, the ecliptic, and the parallels are represented, the first two by parallel circles which are crossed or joined by lines dividing them into seventy-two principal parts, each part being again subdivided into fifths. The close resemblance of this example to the earlier known Arabic globes suggests that there was little, if any, progress among those peoples in the art of globe construction since the eleventh century.

Fig. 15a. Anonymous Arabic Globe, 1635.

NOTES

49 Delambre, J. B. J. Histoire de l'Astronomie ancienne. Paris, 1817. See Vol. I, pp. 372, 516, containing references to globes, celestial and terrestrial, constructed in India and in China about the years 450 and 724 A.D.

50 Peschel, O. Geschichte der Erdkunde bis auf C. Ritter und A. V. Humboldt. Berlin, 1877. See pp. 145-160, wherein reference is made to their lack of interest in descriptive geography; Beazley. Dawn of Modern Geography. Vol. I, chap. vii.

51 Günther, S. Studien zur Geschichte der mathematischen und physikalischen Geographie. Halle, 1877. Heft 2; Ibn Ab? Ja'k?b an-Nad?m. Katab al-Fihrist (Book of Records), ed. by Gustav Flugel. Leipzig, 1871-1872. 2 vols. The greater part of this Arabic work was written about the year 987 A. D. Edrisi states it as "the opinion of philosophers, of illustrious savants, and of skilled observers in the knowledge of celestial bodies, that the earth is round as a sphere." See Edrisi, Geography, tr. de l'Arabe en fran?ais par P. Amédée Jaubert. (In: Receuel de voyages et de mémoires. Paris, 1830. 2 vols.) Vol. I, p. 1.

52 Zach, F. v. Monatliche Korrespondenz. Gotha, 1806. Vol. XIII, p. 157; Suter, H. Das Mathematiker-Verzeichniss im Fihrist. (In: Zeitschrift für Mathematik und Physik. Leipzig, 1892.) This work contains many references to distinguished oriental scholars who treated in their writings the doctrine of the sphere, the astrolabe, and the armillary sphere.

53 Wittstein, T. Historisch-astronomische Fragmente aus der arabischen Litteratur. (In: Abhandlungen zur Geschichte der Mathematik. Leipzig, 1892. Heft 6, p. 98.) The opinion is here expressed that a terrestrial globe by Edrisi never existed; Hadradauer, C. v. Die Feldzeugmeister Ritter von Hauslabische Kartensammlung. (In: Mitteilungen der K. K. Geographische Gesellschaft zu Wien. Wien, 1886. Neue Folge 19, pp. 387-388.) The opinion is expressed that Edrisi constructed a planisphere and not a globe. Amari, M. Storia dei Musulmani di Sicilia. Firenze, 1868. pp. 453 ff., 669 ff.

54 Dorn, B. Description of an Arabic celestial globe. (In: Transactions of the Royal Asiatic Society. London, 1829. Vol. II, pp. 371-392.)

55 Dorn, op. cit.

56 Dorn, op. cit.

57 See the list as given in the Fihrist, referred to in note 4. Naser ben Mohamed Abul Gioush, King of Castile, is referred to as having been much interested in astronomy, in which science he acquired such proficiency as to enable him to construct a number of very useful astronomical instruments.

58 Lelewel, J. Géographie du moyen age. Bruxelles, 1857. Vol. I, p. 116; Jourdain. Mémoire sur l'observatoire de Méragah. Paris, 1810. It is well known that under the direction of Nasr-Eddin, who was called to the charge of this observatory by Hulagu Khan, astronomical instruments were constructed.

59 Dorn, op. cit.

60 See the Fihrist, also a list as given by Dorn.

61 Dorn, op. cit.

62 Dorn, op. cit.

63 Meucci, F. Il globo celeste arabico del seculo XI esistente nel Gabinetto degli strumenti antichi di Astronomia, Mathematica nel R. Istituto di Studi Superiori. Firenze, 1878.

64 Assemani, S. Globus coelestis cufico-arabicus Veliterani Musei Borgiani. Patavii, 1790.

65 Dorn, op. cit.

66 Beigel, W. Nachricht von einer Arabischen Himmelskugel mit Kufischer Schrift, welche im kurfürstlichen Mathematischen Salon zu Dresden aufbewahrt wird. (In: Bodes Astronomisches Jahrbuch für das Jahr 1808. Berlin, 1808. pp. 97 ff.); Drechsler, A. Der arabische Himmelsglobus angefertigt 1279 zu Meragha. Dresden, 1873.

67 Sedillot, L. A. Mémoire sur les instruments astronomiques des Arabes. Paris, 1841. pp. 117 ff.; same author. Matériaux pour servir à l'histoire comparée des sciences mathématiques chez les grecs et les orientaux. Paris, 1845. Vol. I, pp. 334 ff.; Jomard, M. Monuments de la Géographie. Paris, 1854. It is very doubtful that a date so early should be given to this globe.

68 Information courteously given by M. L. Vallée.

69 Dorn, B. Drei in der kaiserlichen ?ffentlichen Bibliothek zu St. Petersburg befindliche astronomische Instrumente mit arabischen Inschriften. (In: Mémoires de l'Académie Impériale des Sciences de St. Pétersbourg. St. Pétersbourg, 1865. VIIe serie, Tome IX, No. 1.)

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