Kunstmann III: The Oldest Known Nautical Chart Incorporating Latitudes

Abstract

Among the few Portuguese charts surviving from the turn of the sixteenth century, the now lost Kunstmann III chart is the most enigmatic. Not only is it undated and unsigned but also its cartographical style differs greatly from the best-known contemporary Portuguese charts, namely those by Jorge de Aguiar and Pedro Reinel, as well as the Cantino planisphere. Although Kunstmann III has been studied by various twentieth-century authors, none has addressed in depth its distinctive features: the presence of four different handwritings, the depiction of a latitude scale for the Northern Hemisphere only, and the geometry of the African coastline. Contradicting the usually accepted dating of ‘after 1506’, we argue that the Kunstmann III chart was most probably started around 1500 and remained a living document for some years thereafter, with new places-names added by other individuals at later times. We further show, based on the assessment of its geometry and a comparison with other charts, that Kunstmann III is the oldest known chart incorporating observed latitudes of places and containing a primitive non-astronomical depiction of the southwestern and southern coasts of Africa, based on the first voyage of Vasco da Gama to India in 1497. This makes Kunstmann III a hitherto unrecognized link in the transitional period between two different cartographical models.