Made on pseudocylindrical projections, which were precursors to the Bonn variation that gained prominence in eighteenth-century France, maps of this type were drawn from concentric arcs, with each arc displaying a consistent, if distinct scale. In displaying proportionally correct area throughout, the projection could also preserve shape along one of these arcs and along the central meridian. Here, Peter Apian selected the northern Tropic to be distortion-free, allowing the greatest measure of clarity to fall in its vicinity. Accordingly, the narrowness of the presumably undistorted North American continent reveals how little recognized its true scale really was.
At the top, the Holy Roman Emperor Charles V appears in ancient Roman dress, alongside Zeus; styling indicative of the humanist movement. At the time, the most notable champion of humanism was Desiderius Erasmus (1466–1536), a Catholic priest and theologian who advocated for positions more moderate than those developing on either side of the divide opening between Catholics and reform-minded Protestants. His influential Handbook for a Christian Knight had been dedicated to the young Charles. The twelve traditional wind heads appear along the edges. The skeletal ones at bottom reflect a belief that plague-bearing winds came from the South.