[Illustration: Fig. 61. Six of Twelve Terrestrial Globe Gores by Gerhard Mercator, 1541.] The ecliptic, the tropics, and the polar circles are represented at their proper intervals, with other parallels at intervals of ten degrees, and meridians at intervals of fifteen degrees. As in his double cordiform map of 1538, his prime meridian passes through the island of “Forte Ventura,” one of the Fortunate Islands of the ancients, but which had long been known as the Canary Islands. To his globe map he added a feature of special value to seamen. From the numerous compass or wind roses, distributed with some regularity over its surface, he drew loxodromic lines, or curved lines cutting the meridians at equal angles.[273] This feature could not have failed to win the approval of navigators, since they well knew that the previous attempts to represent these rhumbs as straight lines on maps drawn on a cylindrical projection, led to numerous errors in navigation. A second somewhat curious and interesting feature of his globe, a feature which I do not recall to have noticed in any other, is the representation in various localities on land and on sea of certain stars, his idea being that he could thus assist the traveler to orient himself at night. In his list of stars on his globe map, we find, for example, “Sinister humerus Boötes” near latitude 40 degrees north, longitude 210 degrees; “Corona septentrionalis” near latitude 29 degrees north, longitude 227 degrees; “Cauda Cygni” near latitude 44 degrees north, longitude 305 degrees; “Humerus Pegasus” near latitude 12 degrees north, longitude 340 degrees; “Crus Pegasi” near latitude 26 degrees north, longitude 339 degrees; six of the important stars in “Ursa Major,” including “Stella Polaris,” and in the present California, somewhat strangely prophetic, “Caput Draconis.”