Map of the World in Two Hemispheres f. 30
Cartographer: Rotz, Jean
Medium: Ink and tempera on parchment
This is a map of the two hemispheres of the world. It is from a bound atlas of portolan charts by the cartographer Jean Rotz and dates from 1542. Invented by mariners, portolan charts take their name from the Italian ‘Portolano’, meaning a written description of Catalan and Italian ports along a coastline. The first portolan Charts date from the late 13th century and represent an important change in the use of maps and charts. Until this point, most maps had held a religious significance and purpose, such as the medieval mappa mundi which was based on theological beliefs. The portolan chart contrasts with this tradition as they are based on direct observation and first hand experience and have a practical purpose. Here the hemisphere's have been graduated for longitude and latitude with lines radiating from the central point of the equator. The British Isles are shown but are presented with many inaccuracies. The projections of the Welsh coast line are exaggerated and the Bay of Cardigan is omitted. This omission is typical of a depiction dating from the first half of the 16th century. The Bay of Cardigan was first accurately depicted in printed form by Gerard Mercator in 1564. The hemispheres are surrounded by personifications of the winds.