114 MAPS AND THEIR MAKERS 



borne in mind in discussing the work of map makers for at 

 least two centuries after Mercator. 



The unique quaHty of his map of Europe was at once 

 recognized, and for the period the demand was large. A 

 second edition was published in 1572, with considerable 

 improvements especially in the northern regions. There 

 Mercator was able to use the results of the English voyages 

 to the White Sea, and English observations for the latitude 

 of Moscow, combined with itineraries for the interior of 

 Russia. Another important work dating from this period was 

 his map of the British Isles of 1564. Oriented with the west at 

 the top, it measures 129 x 89 cms. The compiler is unfortunately 

 unknown, Mercator merely stating that he engraved it for an 

 English friend. 



Mercator's posthumous fame rests upon his world map 

 published at Duisburg in 1569: 'Nova et aucta orbis terrae 

 descriptio ad usum navigatium emendate accomodata'. This 

 great map, of which only four copies have survived, is made 

 up of twenty-four sheets in all, its full dimensions being 

 131x208 cms. Though the title refers only to its use for 

 navigators, Mercator states that it was also intended to re- 

 present the land surfaces as accurately as possible, and to 

 show how much of the earth's surface was known to the 

 ancients. 



As has been seen above, lines of constant bearing on the 

 surface of the globe must be spirals, which ultimately circle 

 round the Pole. To represent them as straight lines on a flat 

 map, the meridians and parallels must be arranged so that 

 loxodromes cut the meridians at constant angles, i.e. the 

 meridians must be parallel. Since the meridians in fact con- 

 verge, the effect of this is to distort east-west distances, 

 and therefore direction and area at any given point. If however 

 the distances between parallels are increased proportionately 

 to the increase in the intervals between the meridians from the 

 Equator towards the Poles, the correct relationships of angles, 

 i.e. direction, are preserved. This was the solution obtained by 

 Mercator, and charts on his projection were thus said to 

 have 'waxing latitudes'. The projection has a further useful 

 property: since at any point, the angles are correct, the shape 



