The geographical ideas which prevailed at the time Columbus started in search of Cathay may be most readily gathered from two contemporary globes, the one known as the Laon globe be cause it was picked up in 186o at a curiosity shop in that town, the other produced at Nuremberg in 1492 by Martin Behaim. The information which it furnishes, in spite of a legend intended to lead us to believe that it presents us with the results of Portu guese explorations up to the year is of more ancient date. The Nuremberg globe (fig. 9), a work of a more ambitious order, was undertaken at the suggestion of George Holzschuher, a trav elled member of the town council. The work was entrusted to Martin Behaim, who had resided for six years in Portugal and the Azores, and was believed to be a thoroughly qualified cosmog rapher. The globe is of pasteboard covered with whiting and parchment, and has a diameter of 5o7mm. (2o inches). The author followed Ptolemy not only in Asia, but also in the Mediterranean. He did not avail himself of the materials available in his day. Not even the coasts of western Africa are laid down correctly, although the author claimed to have taken part in one of the Portuguese ex peditions. The ocean separating Europe from Asia is assumed as being only 126° wide, in accordance with Toscanelli's ideas of 1474. Very inadequate use has been made of the travels of Marco Polo, Nicolo de' Conti, and of others in the east.
The maritime discoveries and surveys of that age of great dis coveries were laid down upon so-called "plane-charts," that is, charts having merely equidistant parallels indicated upon them, together with the equator, the tropics and polar circles, or, in a more advanced stage, meridians. For his longitude the mariner was dependent upon dead reckoning. Errors of 3o° in longitude were by no means rare. It was only after the publication of Kep ler's Rudolphine Table (1626) that more exact results could be obtained. A further difficulty arose in connection with the variation of the compass, which induced Pedro Reinel to introduce two scales of latitude on his map of the northern Atlantic (15o4).
The chart of the world by Juan de la Cosa, the companion of Columbus, is the earliest extant which depicts the discoveries in the New World (1500), and there is the map which Alberto Can tino caused to be drawn at Lisbon for Hercules d'Este of Ferrara (1502), illustrating in addition the recent discoveries of the Por tuguese in the East. Other cosmographers of distinction were Pedro Reinel (1504-42), Nuno Garcia de Toreno (152o), to whom we are indebted for 21 charts, illustrating Magellan's voy age, Diogo Ribero (maps of the world 1527, 1529), Alonzo de Santa Cruz, of Seville, whose Isolario general includes charts of all parts of the world (1540, John Rotz or Rut (1542), Sebastian Cabot (1544), as also Nicolas Desliens, Pierre Desceliers, G. Breton and V. Vallard, all of Argues, near Dieppe, whose charts were compiled between 1541 and The Strasbourg Ptolemy of 1513 has a supplement of as many as 20 modern maps by Martin Waldseemiiller or Ilacomilus, several among which are copied from Portuguese originals. Wald
seemiiller was one of the most distinguished cartographers of his day. He published in 1507 a map of the world, in 12 sheets, to gether with a small globe of a diameter of I iomm., the segments for which were printed from wood-blocks. On these documents the new world is called America, after Amerigo Vespucci.
Equally interesting with these Ptolemaic supplements are col lections like that of Anton Lafreri, which contains reprints of 142 maps of all parts of the world originally published between 1556 and 1572 (Geografica tavole moderne, Rome, n.d.), or that of J. F. Camocio, published at Venice in 1576, which contains 88 reprints. The number of cartographers throughout Europe was considerable. Germany is represented by G. Glockendon, the author of an interesting road-map of central Europe 0500, Sebastian Munster (1489-1552), Elias Camerarius, whose map of the mark of Brandenburg won the praise of Mercator; Wolf gang Latz von Lazius, to whom we are indebted for maps of Austria and Hungary 0560, and Philip Apianus, who made a survey of Bavaria (1553-63), which was published 1568 on the reduced scale of :144.00o, and is fairly described as the topo graphical masterpiece of the 16th century. For maps of Switzer land we are indebted to Konrad Tiirst (1495-97), Johann Stumpf (1548) and Aegidius Tschudi (1538). A map of the Netherlands from actual survey was produced by Jacob of Deventer (1536-39). Leonardo da Vinci, the famous artist, while in the service of Cesare Borgia as military engineer, made surveys of several dis tricts in central Italy. New maps of Spain and Portugal ap peared in 156o, the former being due to Pedro de Medina, the latter to Fernando Alvarez Secco and Hernando Alvaro. Among the French map-makers of this period may be mentioned Oronce Finee (Finaeus), who in 1525 published a map of France, and Jean Jolivet (c. 156o). Gregorio Lilly (1546) and Humphrey Lhuyd of Denbigh (d. 151o) furnished maps of the British Isles, Olaus Magnus of Scandinavia, Anton Wied (1542), Sigis mund von Herberstein (1549) and Jenkinson (1562) of Muscovy.
The cylindrical and modified conical projections of Marinus and Ptolemy were still widely used, the stereographical projection of Hipparchus was for the first time employed for terrestrial maps in the 16th century, but new projections were introduced in addi tion to these. A trapeziform projection with equidistant parallels, by D. Nicolaus Germanus (1466), led to Flamsteed's projection. Joh. Stabius (r 502) and his pupil J. Werner (1514) devised three heart-shaped projections, one of which was equal-area. Petrus Apianus (1524) gave his map an elliptical shape. H. Glareanus (I 5 io) first employed an equidistant zenithal polar projection.