An alternative route to mapping history.

• Author: Harley, J. Brian

From the mappaemundi to the Ptolemaic grid, maps have been both mirrors and catalysts of their times

THE SIXTEENTH-CENTURY GEOGRAPHER Hulsius once wrote, "Maps may be called the light or eye of history." It is in this role, as the primary documents for locating historical events, that early maps are still most used by the historians of the late-twentieth century. Nowhere are these uses more visible than in the study of the maps what is sometimes still called the first great age of European exploration. J. A. Williamson, the distinguished historian of the Cabots, wrote discerningly in 1937 that "old maps are slippery witnesses." But for many researchers maps still hold out the prospect of locating the elusive landfalls of a Columbus or a Drake, of reconstructing the routes of navigators or tracks of the explorers, or perhaps of identifying a place described ambiguously in written texts. Maps are the coordinates of history.

During our researches inn connection with the History of Cartography project and the Maps and the Columbian Encounter Exhibition program, we have come to understand the place of maps in early American history in some alternative ways. Maps can still be analyzed as credible and articulate witnesses to some aspects of the European voyages and explorations to America and in that sense we continue to interrogate them as traditional record of events. But we are also discovering - as we re-read them as a visual language to uncover new meanings - that they have yet more to contribute to a richer history of the Columbian encounter.

First, we are seeking a new perspective that focuses on the use of maps and on the social consequences of their making. The key question is "What happened when particular maps were made?" The research has shifted from a theoretical consideration of what maps were designed to do to what they actually did in society.

Inasmuch as Renaissance maps straddle a major transition in the history of European cartography - from the medieval to the modern - this question is especially fascinating. The dramatic shift in ways of thinking about the world, and in the way that vision was constructed, can be seen by comparing two of the dominant traditions of fifteenth-century cartography. The first tradition, the medieval mappaemundi, was allegorical, historical, and literary - a representation of the space of Christianity. Often centered on Jerusalem, these maps were introverted to the interior of the classical and medieval world by a circumscribing ocean sea. Beyond the pillars of Hercules there was nothing: Ne plus ultra (Nothing more beyond). The second tradition - represented by the rediscovered world maps of Ptolemy - by popularizing coordinates of latitude and longitude, led to a major conceptual shift in ways of fixing geographical positions and hence in visualizing and controlling the world. From the early fifteenth century onwards, after Ptolemy's Geography had been translated into Latin, the system of latitude and longitude - the symbol of modern cartography -began its ascendancy.

The coordinate system derived from Ptolemy was quickly appropriated as an instrument of the first great age of European expansion into the overseas world. Whether or not such a seemingly humble innovation was a necessary condition for that expansion we cannot be sure. But by reversing the introspection of the mappaemundi, the Ptolemaic world map projected an image of extroversion. The numbered sequence of latitude and longitude values, known as the graticule, explicitly recognized the other half of the world. Even if it was not an accurate prediction of what was there, it was a rhetorical visualization of the unknown, an invitation to fill the blank space, and to explore that previously inauspicious West beyond the ocean sea.

The importance of...