the poles or from the poles toward the equator. If the earth is a sphere then why could a map so draughted as truly to represent the surface of a sphere not be counted the most acceptable? This must have been the argument of those who especially applied themselves to the designing of maps suitable for a spherical surface, that is, for application to a globe ball. Who first conceived the idea of fashioning globe gore maps we do not know. Fiorini cites evidence[190] that Francesco Rosselli (1445-1510), a printer of large and small maps in Florence, included in his productions gore maps to be used in globe construction, and this probably before the year 1507, but none of his work of this character has come down to us. The so-called Waldseemüller gores are the oldest known, of which but one copy is extant.[191] By some they are thought to have been constructed for his globe to which he refers in his ‘Cosmographiae Introductio,’ but they are unsigned and undated. They are somewhat crude and much manipulation would be required to fit them to the surface of a sphere. Before the first quarter of the sixteenth century had passed other globe gore maps made their appearance, such as those undoubtedly the work of Schöner or of the Schönerian school, or such as the gores of Boulengier[192] exquisitely engraved and printed, though so far as we know never used in covering the surface of a sphere. [Illustration: Fig. 134. Globe Gores of Henricus Glareanus, 1527.] The artist Albrect Dürer (1471-1528), as we are informed, was one of the earliest to set himself to the solution of the problem having to do with the development of a spherical surface into a flat surface, yet he never seems to have thought an exact mathematical solution possible. It was a problem, he realized, in which there could be but an approximate solution. In trying to illustrate what he thought to be the nearest approach to the same he found himself led to the idea of the globe gore.[193] Of his illustration, he said, “Die sphera oder ein Kugel wenn man sie durch jr mittag linien zerschneydet, und in Planum legt, so gewinnt sie ein Gestalt eines Kam, wie ich das hie hat auffgerissen.” “Should one divide the sphere or ball on the line of the equator and lay this out as a plane, one has the figure of a comb, as is here shown.” Dürer worked out a simple rule for the construction of the globe biangles,[194] which rule served measurably well for the purpose intended. While it would not be inappropriate to give here a résumé of his formula, as well as the formulae of others who set themselves to a like task, we should in so doing be carried into a field rather more technical than seems fitting for our purpose.[195]