Men, however, such as Basil, Gregory of Nyssa, and Philoponos inclined strongly toward the Aristotelian doctrine of a spherical earth.74 Isidore of Seville appears to have been a supporter of the spherical doctrine,75 as was also the Venerable Bede, who, in his ‘De natura rerum,’ upholds the doctrine of a spherical earth on practically the same grounds as those advanced by Aristotle.76
Fig. 16. The Universe according to Cosmas Indicopleustes, Sixth Century.
Fig. 17. Cosmas’ Illustration Confuting the Existence of Antipodal Peoples.
In illustration of the doctrine of a circular earth, terrestrial globes certainly could not have been thought of as having any practical value. With a rejection of the spherical theory of the ancients very naturally went the rejection of their globes.
The circular or Homeric theory, as noted above, had its supporters, even to the close of the middle ages, but the inclination is more or less marked, even as early as the seventh century, to accept again the doctrine of a spherical earth. It seems to have come into prominence again with the growing belief in the importance of the place of the earth in the universe. After the eighth century this theory may be said to have had a very general acceptance by those who, Faust-like, felt a desire for a larger freedom from theological restraint than the church encouraged. (Figs. 18, 19.)
Fig. 18. Hereford World Map, ca. 1283.
Fig. 19. The Earth Pictured as a Sphere by Nicolas d’Oresme, 1377.
Attention has been called to the attitude of the writings of the Anglo-Saxon Church Father, the Venerable Bede. Although we have no unquestionable proof that Bede, or Alcuin,77 who was greatly influenced by him, insisted on the use of globes in geographical instruction, there is good reason for thinking these scholars would have inclined to encourage their use. The monastic schools, which, in the methods of instruction, rested upon the plan wrought out by Alcuin for the Palace School of Charles the Great, considered globes to be apparatus of great educational value. Professor Günther is inclined to think it probable that celestial globes were used throughout the early centuries of this mediaeval period in the better schools, though no positive statement to that effect can be cited.78
We know that an exact knowledge of the movements of the sun, of the moon, and of the constellations was considered to be of first importance for the priesthood in the middle ages, since it was through a knowledge of their movements that the times for the observance of the rigid church rules were fixed.79 The acquisition of such knowledge could best be secured through the use of the celestial globe.80 We learn from Notker Labeo (950–1022), one of the most distinguished teachers of the monastic school of St. Gallen, that he made use of such globes for astro-geographical instruction, which, in their important features, were like our modern celestial globes, for he tells us “they were supplied with all necessary parts.” It seems evident that those of which he made use could be adjusted to every desired altitude of the pole.81
One of the most distinguished scholars of the tenth century was Bishop Gerbert (ca. 940–1003), later Pope Sylvester II, of whose learning we possess reliable evidence.82 His astronomical knowledge so astonished his contemporaries that he was thought to be a necromancer and was accused of being in league with the evil one.83 He was a diligent student of the literature of antiquity, which had survived to his day, especially surpassing all others, it is reported, in his acquaintance with the learning of pagan Rome. In the instruction which he gave in astronomical science he made use of various instruments, to the end that his pupils might the better understand the subject, among which instruments were celestial globes and armillary spheres. These were a source of much wonderment to his contemporaries. It is said that one of these instruments was so skilfully constructed that even the untrained by its use, having one constellation pointed out, would be able to locate all others “with the aid of a globe and without the aid of a teacher.”84 In a letter to the monastic teacher Constantius, with whom Gerbert stood in the friendliest relations for many years at Rheims, he refers to the construction of a celestial globe, and in a more detailed manner he makes mention of this when writing to Remigius of Trier. In four of his letters to this last named prelate, Gerbert touches upon his purpose to construct a globe, but on account of the added duties which were his, occasioned by the death of Archbishop Adalbero, he seems not to have been able to complete his work. He expresses himself, in the third one of these letters, as hopeful that a favorable time might yet come for him to take up the plan, but the increasing opposition of his enemies left him no leisure for scientific labors of this character, and it does not appear that he turned his attention again to globe making.85
The thirteenth century furnishes us with the names of two distinguished princes who were especially active in advancing scientific studies of their times. One of these was the Hohenstaufen Frederick II, concerning whom we are informed that he directed a learned Arabian, who sojourned at his court, to construct for him a celestial globe of gold on which the stars were to be represented by pearls.86 We are further told that as an outcome of his friendly relations with the rulers of the East, the Sultan of Egypt sent to him an astronomical tent of wonderful construction. In this the sun and the moon were represented and by means of a skilfully constructed mechanism they were made to rise and set, marking out the hours of day and night.87
As a ruler of like intellectual and scientific interests, the Castilian, Alfonso X, who lived in the thirteenth century, known as “The Wise” and as “The Astronomer,” deserves to be especially mentioned. By his order an elaborate astronomical work was prepared, which holds a place of first importance among mediaeval productions of its character. In this work the construction of globes is discussed in a very detailed manner, mention being made of every feature regarded as belonging to a properly constructed celestial sphere. So significant are certain chapters of this work for the history of globes and of globe making that a free translation is here given of that part relating to materials of which globes may be constructed.88 “A sphere may be made of many materials,” says the author, “as of gold, or silver, or copper, or brass, or iron, or lead, or tin, or of a combination of these metals; or they may be made of stone, or clay, or wood. They may also be made of leather, of cloth, of parchment in many layers, and of many other materials which men employ when they wish to give