EXPLORING ANTARCTIC SEAS 



the Old and New Worlds are fairly well represented in 

 latitude (north to south), there is a good deal of error 

 in the east-west direction. This is of course primarily 

 due to the difficulty of obtaining longitude before the 

 accurate use of chronometers was possible. Hence all 

 the known continents are too wide. There is no sign 

 of Australia, save a huge ''hump" in the hypothetical 

 land which occupies so large a part of the Southern 



Fig. 2a. — Mercator's world-map, 1587. 



For some 300 years explorers were reducing the large ruled 

 "Southern Continent" to its true size, shown in black. (True 

 position of Australia and East Asia indicated.) 



Hemisphere. The only basis for this large area was 

 perhaps the view of Tierra del Fuego seen by Magel- 

 lan in 1520, when his voyage around the world clearly 

 showed that Ptolemy's Terra Incognita was not joined 

 to South America. Moreover, in 1578 Drake had 

 been driven as far to the south of Tierra del Fuego 

 as 57° and sailed through the broad strait now known 

 by his name. This gap of some four hundred and fifty 

 miles was apparently not known to Mercator. 



13 



