Maps and naucal charts in the medieval and early modern ages: two of a kind or different cartographic paradigms? 2016 Jay Kislak Lecures – Library of Congress Joaquim Alves Gaspar Introducon I would like to start my talk by showing, side by side, two different kinds of modern maps depicng the same region of the world, the well-known Chesapeake Bay [2]: a naucal chart, on the leſt, and a topographical map, on the right. The differences are obvious. In the topographic map the informaon is concentrated inland, leaving the wet areas almost totally empty; in the naucal chart most of the informaon is located at sea and in the coastal areas closest to the sea, leaving the dry land virtually blank. The reasons for these differences are, of course, related to the different purposes of the two kinds of maps: while topographical maps are intended to depict all kinds of general informaon relave to the surface of the Earth, naucal charts are constructed with the specific goal of supporng marine navigaon. But, of course, these are old news for those of you who are acquainted with maps and charts. However when we look into the historical evoluon of naucal cartography we realize that the differences between these two types of representaons are much more profound than expected. That is the subject of my presentaon today. I will show – using examples taken from various periods – that, historically, maps and naucal charts not only had different geneses but also were constructed with different purposes and according to different principles. [3] The fundamental difference between maps and charts was, in a limited way, already expressed by the late American cartographer Arthur Robinson, who stated in his well-known book Elements of Cartography that “maps are to be looked at while charts are to be worked on”. Although Robinson’s definion is wonderfully expressive and synthec, it doesn’t tell the whole story or even the most excing parts. 1