Mercator's Southern Continent: Its Origins, Influence and Gradual Demise*

One of the most puzzling features on many world maps of the sixteenth and seventeenth centuries is the vast southern continent known as TERRA AVSTRALIS ("The Southern Land"), often with the addition of the words INCOGNITA ("Unknown") or RECENTER INVENTA SED NONDVM PLENE COGNITA ("Recently discovered but not yet fully known").