518 MAP was defended by a fence of thorns or of flames, and, being considered tho highest place in the world, was always introduced at the top of the map ! The positions of Jerusalem and Paradise served to fix the other points. How long this conception remained in vogue appears from Oriens. Septen- trio. Paradisus. Seni. Asia. Hierusalem. Occidens. Fig. 2. the fact that in 1422 Leonardo Dati, in a poem on the sphere (Delia Spera), wrote, "AT within an O shows the design " (Uu T dent re a uno mostra il disegno), thus . In this way the whole science of cartography sank back below the level attained by the Ionian Greeks. 5. Map-making among the Arabians. The first develop ment of geographical science among the Arabs took place at Baghdad about 772 A.D., in the reign of the caliph Mansiir, and under the influence of an Indian astronomer ani mathematician; and, not long after the works of Euclid, Archimedes, Aristotle, and Ptolemy were translated into Arabic, by orders of the caliph Mamun (813-833), a degree was measured in Mesopotamia in the plain of Sinjar, and a system of the world (Rasm el-ard) was constructed by his librarian Mohammed ben Musa of Khiva (Alcharesmius), in which every place was to be determined by longitude and latitude in the style of Ptolemy. But the science split up only too soon into a practical and a theoretical (astronomical) section the one treating geography (jarafiya) as the doctrine of routes and provinces, the other as the doctrine of latitudes and longitudes. Astronomy contented itself with the astronomical determination of the position of places without drawing maps or exerting any influence on their projection ; travellers and topographers on the other hand did not trouble themselves about astronomy, but like Istakhri (c. 750) or Ibn Haukal (c. 750) added maps to their descriptions which were destitute of any system of degrees, and betrayed by the roughness of their outlines the clumsi ness of the draughtsman. Ultimately, like Dimishki(1327), they left mathematical geography completely out of their works, Ibn Haukal having already declared that mathemati cal division only brought confusion into geography. Only Edrisi s map, engraved for King Roger II. of Sicily upon a silver plate (1161), forms an exception; but, as it was not drawn according to the Ptolemaic projection, but simply indicated the seven climates, it was after all but an unsuc cessful copy of Ptolemy. G. Nautical Maps. The nautical (loxodromic or compass) maps, which make their first appearance in Italy in the 13th century, indicate a gratifying improvement in cartography after a long period of stagnation. These maps were constructed with the aid of the compass, and took the name of compass-maps because they are covered with the figure of a compass from which numerous straight lines radiate out in all directions over the sheet. The fact that the magnet turns towards the north is first mentioned in 1187. Flavio Gioja of Amalfi was perhaps the first to make a mariner s compass and to teach seamen the use of that important instrument. The Italians divided the compass into eight parts (venti), assigning 45 to each Tramontane (N.), Greco (N.E.), Levante (E.), Sirocco (S.E.), Ostro (S.), Libeccio or Garbino (S.W.), Ponente (W.), Maestro (N.W.). Every division had four quarters (quarte di vento), each of 11|- degrees. The maps were produced as follows. The courses of individual ships were first of all inserted as straight lines, calculated according to the distances traversed, from particular ports, as Genoa or Venice, to other ports, and when a good supply of such material had been collected and a series of diagonals drawn in accordance therewith, the most important points on the coast and in the islands were fixed. The lines by which the meridians were cut at the same angle were called loxodromes ; they gave a correct indication when they cut the true astronomical meridian, a false one when they cut the magnetic meridian. On the Italian charts the loxodromes were drawn as straight lines. The numerous radii of the compass shown on the maps enabled the seaman to find the direction which he had to take to reach his goal. Hence the title loxodromic maps. Charts on which the degrees were marked became neces sary only when navigation extended to the ocean ; they were introduced by the Portuguese, probably at the sugges tion of Prince Henry the Navigator. They are " plane charts" with lines of longitude and latitude. The oldest loxodromic charts which have been preserved come from Pisa, Genoa, and Venice. The earliest, the so-called Pisan chart, belongs probably to the middle of the 13th century, and already comprises the whole Mediterranean. As this representation of the whole must of necessity have been preceded by surveys of the several portions, the beginning of the chart may be placed at least as far back as the first part of the 13th century. Next in point of age comes (2) the Luxoro Atlas in Genoa about the year 1300, in the possession of the Cavaliere Tomas Luxoro. Then follow (3) Petrus A r esconte, 1311, in the national archives at Florence, including the eastern Mediterranean (Petrus Vesconte do Janua fecit ista carta ann dni JHCCCXI), see fig. 3 ; (4) Marino Sanudo, a map of the world representing the Mediterranean and the Atlantic coasts as far as Flanders, probably drawn between 1312 and 1321 several copies in Borne (the Vatican), Venice, and Brussels ; (5) an atlas of Petrus Vesconte s about 1318 (in Venice, in eight sheets ; in Milan, ten sheets) ; (6) Perrinus Vesconte, 1327, in the Laurentian Library at Florence ; (7) Joannes da Carignano, between 1306 and 1333, in the archives of Florence (Prcsbiter Joannes rector sancti Marci dc portu Januse me fecit) ; (8) a map of 1346 in the Castilian tongue, in the National Library at Paris ; (9) the Medicean atlas of 1351 in the Laurentian Library at Florence, eight sheets, which represents also the Caspian Sea, and, remarkable enough, the whole of Africa ; (10) Pizigani, 1367, in the National Library at Parma, a map of the world which extends as far as Persia, with numerous entries not only on the coasts but also in the interior; (11) an atlas of Pizigani, of date 1363, nine sheets in folio, in the Ambrosian Library in Milan, comprising the Mediterranean and the Ocean as far as Jutland (M.CCCLXXIII a die VIII di zuyno franzescho piziganij veniziano in veniexia me fecit) ; (12) the famous Cata- lonian map of the world of 1375, in four sheets, in the National Library at Paris; (13) a map by Guill. Solerio of Majorca, 1385, in the public archives in Florence ; and (14) atlas by some un known hand, four sheets folio, in the Biblioteca Marciana at Venice. Several of these Italian maps give indubitable evidence that as early as the 14th century the Azores and Canaries had been dis covered, as well as the coast of Africa as far as beyond Cape Bojador. With the middle of the century the coast maps developed into maps of countries with trade routes, pictorial figures, and numerous inscriptions. Maps preserved from the 15th century are still more numerous : (15) a map by the Venetian Nicolao, of date 1408, in Vienna ; (16) Mecia de Villa destes, 1413, in the National Gallery at Paris ; (17) a map of the world of 1417, in the National Library at Florence ; (18) Francesco de Cesanis, 1421, in the Museo Correr at Venice ; (19) a map of 1424 at Weimar ; (20) atlases by Gia- como de Giraldi, 1426-43, in Venice and Milan ; (21) Gabriel de Valsecqua, 1434, ironVMajorca;( 22) Francesco Beccario, three maps, in tae British Museum ; (23) two maps by Battista Beccario in Munich (1426) and Parma (1435) ; (24) Andrea Bianco, 1436, an atlas of ten sheets, where for the first time the mediaeval circular
maps are accompanied by the Ptolemaic maps, in the Biblioteca