Among countries represented on a larger scale on maps, Pal estine not unnaturally occupies a prominent place in this age of pilgrimages and crusades (1095-1291). Maps of Palestine accom pany St. Jerome's translation of the Onomasticon of St. Eusebius (388). The same subject is illustrated by a picture-map in mosaic, portions of which were discovered in 1884 on the floor of the church of Medeba to the east of the Jordan. This is the oldest original of a map in existence, for it dates back to the 6th century and shows the country before the Mohammedan conquest.
There also exist a few special maps of European countries. Of Great Britain we may mention the one of the 12th century, another by Matthew of Paris, the famous historiographer of the monastery of St. Albans (fig. 6) (1236-1259) ; and the map at the Bodleian Library at Oxford, dated about A.D. 1300. This is a genuine piece of map-making and may perhaps have been used by officials of the king's court.
Celestial globes were known in the time of Bede ; they formed part of the educational apparatus of the monastic schools. Ger bert of Aurillac is known to have made such globes (929). Their manufacture is described by Al phonso the Wise (1252), as also in De sphaera solida of G. Cam panus of Novara (1303). Terres trial globes, however, are not re ferred to.
Map-making Among the Arabians and Other Nations of the East.—Baghdad early be came a famous seat of learning. Indian astronomers found apt pupils there among the Arabs; the works of Ptolemy were translated into Arabic, and in 827, in the reign of the caliph Abdullah al Mamun, an arc of the meridian was measured in the plain of Mesopotamia. Most famous among these Arabian astronomers were Al Batani (d. 998), Ibn Yunis of Cairo (d. 1008), Zarkala (Azarchel), who determined the meridian dis tance between his observatory in Toledo and Baghdad to amount to 51° 3o', an error of 3° only, as compared with Ptolemy's error of 18°, and Abul Hassan (123o) who reduced the great axis of the Mediterranean to Further materials serviceable to the compilers of maps were supplied by numerous Arabian travellers and geographers, among whom Masudi (915-940), Istakhri (950), Ibn Haukal Al Biruni (d. 1038), Ibn Batuta (1325-1356) and Abul Feda (1331-1370), occupy a foremost place, yet the few maps which have reached us are crude in the extreme. Neither Idrisi's map of
the world (fig. 7), engraved for King Roger of Sicily upon a silver plate, nor the rectangular map in 7o sheets which accompanies his geography (Nusha t-ul Mushtat) take rank with Ptolemy's work.
The Arabians are not known to have produced a terrestrial globe, but several of their celestial globes are to be found in our collections. The oldest of these globes was made at Valentia, and is now in the museum of Florence. Another globe (of 1225) is at Velletri ; a third by Ibn Hula of Mosul (1275) is the property of the Royal Asiatic Society cf London; a fourth (1289) from the observatory of Maragha, in the Dresden museum ; two globes of uncertain age at Paris, and another in London. All these globes are of metal (bronze).
The charts in use by the mediaeval navigators of the Indian Ocean—Arabs, Persians or Dravidas—were equal in value if not superior to the charts of the Mediterranean. Marco Polo men tions such charts; Vasco da Gama (1498) found them in the hands of his Indian pilot, and their nature is fully explained in the Mohit or encyclopaedia of the sea compiled from ancient sources by the Turkish admiral Sidi Ali Ben Hosein in 1554. These charts are covered with a close network of lines intersecting each other at right angles. The horizontal lines are parallels, depending upon the altitude of the pole star, the Calves of the Little Bear and the Barrow of the Great Bear above the horizon. This alti tude was expressed in isbas or inches each equivalent to I° 42' 50". Each isba was divided into zams or eighths. The interval between two parallels thus only amounted to 2' These intervals were mistaken by the Portuguese occasionally for degrees, which account for Malacca, which is in lat. 2' 13" N., being placed on Cantino's chart (1502) in lat. 14' S. It may have been a map of this kind which accounts for Ptolemy's moderate exaggerations of the size of Taprobana (Ceylon). A first meridian, separating a lee ward from a windward region, passed through Ras Kumhari (Comorin) and was thus nearly identical with the first meridian of the Indian astronomer which passed through the sacred city of Ujjain (Ozere of Ptolemy) or the meridian of Azin of the Arabs. Additional meridians were drawn at intervals of zams, supposed to be equal to three hours' sail.