on, proved that Africa was almost entirely surrounded by sea, and that the Indian Ocean was accessible from both west and east. These discoveries reduced the area where the continent could be found; however, many cartographers held to Aristotle's opinion. Scientists such as Gerardus Mercator (1569) and Alexander Dalrymple as late as 1767 argued for its existence, with such arguments as that there should be a large landmass in the south as a counterweight to the known landmasses in the Northern Hemisphere. As new lands were discovered, they were often assumed to be parts of the hypothetical continent. The German cosmographer and mathematician Johannes Schöner (1477–1547) constructed a terrestrial globe in 1515, based on the world map and globe made by Martin Waldseemüller and his colleagues at St. Dié in Lorraine in 1507. Where Schöner departs most conspicuously from Waldseemüller is in his globe's depiction of an Antarctic continent, called by him Brasilie Regio. His continent is based, however tenuously, on the report of an actual voyage: that of the Portuguese merchants Nuno Manuel and Cristóvão de Haro to the River Plate, and related in the Newe Zeytung auss Presillg Landt ("New Tidings from the Land of Brazil") published in Augsburg in 1514. The Zeytung described the Portuguese voyagers passing through a strait between the southernmost point of America, or Brazil, and a land to the south west, referred to as vndtere Presill (or Brasilia inferior). This supposed "strait" was in fact the Rio de la Plata (or the San Matias Gulf). By "vndtere Presill", the Zeytung meant that part of Brazil in the lower latitudes, but Schöner mistook it to mean the land on the southern side of the "strait", in higher latitudes, and so gave to it the opposite meaning. On this slender foundation he constructed his circum-Antarctic continent to which, for the reasons that he does not explain, he gave an annular, or ring shape. In an accompanying explanatory treatise, Luculentissima quaedam terrae totius descriptio ("A Most Lucid Description of All Lands"), he explained:The Portuguese, thus, sailed around this region, the Brasilie Regio, and discovered the passage very similar to that of our Europe (where we reside) and situated laterally between east and west. From one side the land on the other is visible; and the cape of this region about away, much as if one were sailing eastward through the Straits of Gibraltar or Seville and