112 MAPS AND THEIR MAKERS 



drawing instrument which could be set at the required angle. 

 But the problem of representing these as straight lines on a 

 flat chart remained to be solved. The claim that Mercator 

 was the first to recognize the true character of loxodromes has 

 been disputed. The celebrated Portuguese mathematician 

 and expert in the science of navigation, Pedro Nunes, was 

 already investigating them, and in view of the close relations 

 between Portugal and Flanders at the time, it is quite probable 

 that Mercator was aware of his work. As far as is known, 

 however, Nunes never reached the stage of projecting a chart 

 on which they could be laid down as straight lines. This was 

 finally done by Mercator through his great world map of 1569, 

 on the projection now known by his name. Nunes, it may be 

 noted, was highly critical of the charts of his time, complaining 

 for instance that the pilots persisted in attempting to express 

 distances in degrees instead of setting down the actual run in 

 leagues, thus introducing endless confusion. 



Before the appearance of his famous world map in 1569, 

 Mercator had achieved an international reputation as a carto- 

 grapher, principally through his map of Europe of 1554, 

 which displayed critical ability of a high order. This map, of 

 which only one copy is now known, was engraved in fifteen 

 sheets, with over- all dimensions of 132x1 59 cms. It was 

 published at Duisburg, where Mercator had established himself 

 as a map maker and lecturer at the university in 1552. The map 

 is a fine piece of engraving, with the lettering in the italic style 

 which he popularized in Western Europe. 



The principal improvement he eifected was in the reduction 

 of the length of the Mediterranean. Ptolemy's figure of 

 approximately 62° had been generally followed by cosmo- 

 graphers. Mercator accepted Ptolemy's position for Alexandria, 

 but established from the marine charts that the Canary Islands, 

 through which the Alexandrian's prime meridian ran, were 

 much further west of the Straits of Gibraltar than had pre- 

 viously been recognized. Consequently by allowing for this 

 and by revising other distances, he reduced the longitudinal 

 length to approximately 52°. This, though still about 10° 30' 

 in excess of reality, was a considerable advance. For over a 

 century and a half, this was not improved upon by map 



