1574 Ruscelli map of the World According to Ptolemy

This is Girolamo Ruscelli's 1574 edition of a foundational work of Renaissance cartography: the map of the known world as understood at the time of the Roman Empire. Claudius Ptolemy's 2nd-century innovation in representing the three-dimensional world projected on a grid via mathematical formulae provided the basis of all modern cartography. Consequently, his Geographia and the maps derived from it remained canonical and continued to be printed well into the 17th century. This is the first appearance of this specific map in Ruscelli's Ptolemy.

The Projection

Ptolemy's work is most important in that it distinguishes between chorography - regional mapping - and geography, which was concerned with understanding and measuring the known world, and representing those measurements graphically. Ptolemy proposed two new types of projection to represent the spherical world in two dimensions. The first, conic projection, is based on a cone tangent to the Earth at the 36° parallel, showing the meridians as straight lines that tend to close towards the poles, and showing parallels as concentric arcs. The second, more complex projection modifies the conic projection by presenting the meridians as curving inwards towards the poles. The latter was the model used for the map appearing in Ruscelli's 1561-1564 edition, prior to its replacement with this plate.

A Closer Look

Employing the former, conic projection, the present map is the simpler and clearer of the two and is better suited to the educational role for which it was intended. It labels Ptolemy's latitudes and longitudes at the top, bottom, and right-hand borders. Along the left-hand border are more detailed labels of the climate zones, including the hours of daylight at the solstice at given latitudes.

Ptolemy's Grid

Ptolemy's great innovation was in the idea that features of the world - cities, mountains, rivers, seas, and so forth - could have their relative locations fixed by measuring the distances between them, and that these could be marked on a grid, thus providing a mathematically correct representation of the globe on a flat surface. All modern cartography developed from this understanding. Ptolemy's data reflected that available to a second-century Alexandrian: with the result that Ptolemy's work painted a picture using second century European place names, limited by that era's European exploration and knowledge of the world, and the era's limited ability to accurately measure distances. The picture of the world thus presented is necessarily distorted, despite the utility and importance of the methodology.

The Map

The Ptolemaic 'world map' is a representation of only the known inhabited world, the Oikoumene. Its westernmost limit is the 'Fortunate Isles' (Fortunatae) in the Atlantic Ocean and to the east, the projection ends at China (Sinarum Situs). The map shows from 63 degrees north, to 14 degrees south: thus encompassing the British Isles as the northernmost limit of Europe, while the southern limits of the map pass far beyond those areas familiar to second-century travelers, and well into the realm of speculation and legend.

The Indian Ocean and the Sinus Magnus

The Indian Ocean is presented as a massive, inland sea. Note that at the southern limits of eastern Africa, Ptolemy's 'Prassum Promont', the coastline turns sharply to the east and continues until it turns north, ultimately meeting the Asian coastline at China beyond the Malay Peninsula and 'India Beyond the Ganges.' The portion of the Indian Ocean enclosed beyond the peninsula, Ptolemy termed the Great Bay, or 'Magnus Sinus.' The Portuguese journeys around Africa proved that the land connection between China and Africa around the Indian Ocean did not exist: what, then, was the extent of the Magnus Sinus? Did land reach around it to the south from China? Was the ocean discovered by Magellan's voyage the same body of water as this? Was the mysterious coastline at the eastern limit of Ptolemy's knowledge the same as the west coast of the Americas? All European geographical thinking about the Pacific Ocean and the nature of the American discoveries began from a foundation of knowledge encapsulated in this map.

Africa and The Nile

Northern Africa was nearly as well understood by Ptolemy as was Europe itself: all fell within the bounds of the Roman Empire, and after all, the Greco-Roman Ptolemy was, himself, a native of Alexandria. Beyond the great African deserts, however, lay mysteries which remained poorly illuminated well beyond the Age of Discovery. Ptolemy's sources told him of the sources of the Nile - found in the lakes of the Mountains of the Moon. This representation remained unchallenged on maps of Africa until the end of the 17th century.

The Mysteries of Scythia and the East

The Indies and Africa were not the only lands draped in obscurity for classical Alexandrian scholars. Beyond the Black Sea to the north and east, Ptolemy's geography grows less and less detailed. The regions of Scythia, Serica, and the Imaum mountains were - to Ptolemy's era - the domain of little-known nomadic peoples, often reputed to be cannibals. The Persian kingdoms of Sogdiana, Bactriana, Parthia, and so on are accurately placed, but the Caspian, or Hyrcanian, Sea is shown distorted into an east-west oval which would not be corrected in European geography until the 18th century.

Publication History and Census

This map was first engraved for publication in the 1574 Ziletti edition of Ruscelli's La Geographia di Claudio Tolomeo…, and it continued in use for later editions of the work. The present example conforms typographically to the 1574 edition. We see five examples of this issue of the separate map listed in institutional collections. It appears on the market from time to time.