CARTOGRAPHY OF THE GREAT DISCOVERIES 93 



The duty of revising it as exploration progressed was entrusted 

 to the officials of the Casa da Contrataci6n at Seville. Un- 

 fortunately, no authenticated copy has survived, but there are 

 charts by official cartographers, which undoubtedly embody 

 its main features. Owing to the presence of Portuguese chart 

 makers in Spain, much Portuguese work found its way into 

 these charts — in fact our knowledge is largely based on copies 

 by Diego Ribero — and they may be regarded as joint Hispanic- 

 Portuguese productions. Ribero, a Portuguese by birth, was 

 expelled from his native country, and in 1519 was at Seville 

 in contact with the Reinels when preparations were being 

 made for Magellan's voyage. Five years later, described as "our 

 cosmographer and master maker of charts, astrolabes and other 

 navigation instruments", he was a technical adviser to the 

 Spanish representatives at the Conference of Badajoz, when 

 the attempt to negotiate an agreement with Portugal on the 

 ownership of the Moluccas failed, both sides firmly maintaining 

 their claims. Ribero reached a position of considerable eminence 

 in the Spanish service, in which he remained until his death 

 in 1533. By a royal decree of 1526, he was to be provided with 

 all material for a chart and world map portraying all the dis- 

 coveries, evidently a revision of the Tadron Real', and the 

 following year he was appointed an examiner of pilots during 

 the absence of Sebastian Cabot on an expedition. 



Three world charts similar in type have survived out of all 

 his work, and in view of his official position they may be 

 assumed to be based upon the Tadron Real'. One, dated 1527, is 

 unsigned, but there are two signed copies, dated 1529. Some 

 comments on the 1529 chart, now in Rome, may fittingly con- 

 clude this account of the fundamental Lusitano-Hispanic 

 contribution to the mapping of the world. 



Ribero's chart is a landmark in the development of know- 

 ledge of the world, comprehending the whole circuit of the 

 globe between the Polar circles, with the East Indian archi- 

 pelago appearing in both the west and the eastern margins. 

 The placing of the continents in latitude and longitude is on 

 the whole good. The exaggeration of the easterly extent of 

 Asia, however, is still allowed to stand. Canton being placed 

 about 20° long, too far to the east. The area around Canton, 



