CHAPTER VI 



THE CARTOGRAPHY OF THE GREAT 

 DISCOVERIES 



The second great contribution to the revival of cartography- 

 was made by the leaders of overseas expansion ; the seamen of 

 many nations — Italian, Portuguese, Spanish, French, Dutch 

 and English — who in little more than a century opened up the 

 oceans of the world, with the partial exception of the Pacific, 

 and provided the chart makers with the data for the maps of 

 their coastlines. The outstanding stages in this progress are: 

 the rounding of the southern promontory of Africa by Bernal 

 Diaz in 1487; the landfall of Columbus in the West Indies in 

 1493; the attainment of India by Vasco da Gama in 1498; the 

 discovery of Brazil by Cabral in 1500; the capture of Malacca 

 by Alfonso d' Albuquerque in 1511; the arrival of the first 

 Portuguese in the Moluccas in the following year, and the 

 circumnavigation of the globe by Magellan's expedition. 



In order to judge the standard of accuracy of these charts, 

 we must glance rapidly at the methods of navigation practised 

 by these pioneer seamen. 



At the outset of their African voyages, the Portuguese 

 pilots followed the same methods of navigation as the sea- 

 faring peoples of the Mediterranean. From the marine charts 

 they ascertained the direction, or rhumb, of the proposed 

 voyage, and also its distance. With the aid of the mariner's 

 compass and primitive methods of determining the vessel's 

 speed, they tried to keep as close as possible to this track, 

 estimating their position daily. In the Mediterranean, voyages 

 were largely but not exclusively a matter of coastwise sailing, 

 so that much reliance was also placed on acquired knowledge 

 of local winds and currents and on the ability to recognize 

 prominent coastal landmarks, a bold headland, a group of 

 islets, or a distinctively shaped mountain. Pilots in the Medi- 

 terranean therefore rarely troubled to determine their latitude, 



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