CHAPTER II 



THE EVOLUTION OF 

 THE MEDIEVAL SEA CHART 



Towards the end of the thirteenth century there came into 

 use in western Europe a type of chart which was a great 

 advance upon any other product of medieval cartography so 

 far considered. In their essentials these charts marked a com- 

 plete break with tradition: their fundamental feature was that 

 they were based on direct observation by means of a new instru- 

 ment, the mariner's compass. On them the coasts of the Black 

 Sea, the Mediterranean, and south-west Europe were laid down 

 with considerable accuracy, and the outline thus established 

 was followed by map makers for several centuries, without sub- 

 stantial modification until the fixing of position by astronomical 

 observation became general in the eighteenth century. 



These charts are frequently referred to as portolans, but 

 as the term portolano is properly applied only to written sailing 

 directions, this usage is confusing. Some would call them simply 

 medieval sea charts without distinction, but, to indicate the 

 particular type characteristic of the fourteenth and fifteenth 

 centuries, it is convenient to compromise with the term 

 *portolan chart'. 



These charts have survived as single examples or as 'atlases'. 

 The latter are in the main merely the standard chart divided 

 into sections, sometimes bound with a calendar, world map, 

 or astronomical data. The total number of charts surviving 

 from the fourteenth century is not great: probably not many 

 more than a score, and only seven draughtsmen can be iden- 

 tified with certainty; of these three, Petrus Vesconte, Angellino 

 de Dalorto, and Johannes de Carignano, worked at Genoa; 

 two, Perrinus Vesconte and Francesco Pizigano, at Venice; 

 and two, Angellino Dulcert^ and Guillelmus Soleri at Majorca. 



^Dulcert is probably the Catalan rendering of Dalorto, and these two 

 names are generally assumed to refer to the same cartographer. 



29 



