-------- Original Message -------- Subject: Program and Registration for LOC Portolan Conference Date: Wed, 17 Mar 2010 08:08:33 -0400 From: John W. Hessler <[log in to unmask]> The program for the Library of Congress' previously announced conference on Portolan Charts is shown below...the conference is free, but registration is required...to register e-mail me at [log in to unmask] or Pam Van Ee at [log in to unmask] . Re-examining the Portolan Chart: History, Navigation and Science Sponsored by the Philip Lee Phillips Society and the Geography & Map Division of the Library of Congress May 21st, 2010, Coolidge Auditorium Morning Session: History and Navigation, 9:30-11:30 The Marine Chart in the Mappamundi: Mapping the World in the Later Middle Ages Evelyn Edson Professor of History Piedmont University Modern scholars have long been fascinated by the medieval marine chart: “the first, modern scientific map,” rhapsodized Edward L. Stevenson in 1911 in his book on sea charts. The contrast with the mappamundi, with its lively pictures, lengthy legends and unrecognizable geographical outlines, could not be more striking. One is all business, the other closer to fantasy. Yet, recent research, pushing back the origin of the marine chart to 1200, has made it clear that these two map types flourished side by side, and were consulted and even occasionally constructed by the same people. The thirteenth century, the period which shows the first evidence of marine charts, was also the heyday of the great mappaemuindi, such as the one at Hereford Cathedral. Marine charts had a different purpose and scope than a mappamundi. Limited to the well-known world of the Mediterranean and Black Sea basins, and eventually the Atlantic coast, they did not attempt to depict the interior lands, much less the entire world with its terrae incognitae shown on the mappamundi. And yet, looking from one to the other, we can see that the lines separating the two forms are not all that clear. Marine charts may come with explanatory texts, be burdened with legends that have nothing to do with navigation, or be ornamented with images of richly caparisoned kings. Itineraries appear on the Hereford mappamundi, as G. R. Crone observed many years ago, and by the fourteenth century we have what David Woodward called “transitional maps,” and more recently, Ramon Pujades has termed “hybrid maps.” We must look at marine charts and mappaemundi as contemporaneous products, rather than one being “modern” and the other more “medieval.” The Birth and Use of the Navigational Chart Alison Sandman Assistant Professor of History James Madison University In the sixteenth century, Portolan charts were expanded to meet the new navigational needs of the Iberian overseas empires, extending them from the Mediterranean to include first the Atlantic and then the entire world without meaningfully changing their form. This brought into focus several distinct types of problems, which both cartographers and navigators attempted to solve, often in very different ways. The greater extant of the charts highlighted issues of projection, and arguments about the proper way to reconcile compass bearings with first latitudes and (eventually) longitudes. It also forced decisions about information-gathering, most notably what sorts of information were most useful (weather patterns, depths and obstacles around the port, latitudes, landmarks, etc.), who could be trusted to gather that information, and to what extent branch offices in areas such as the Philippines could help in developing both charts and navigators with local expertise, all without experts in the center losing too much control. The surviving debates of the sixteenth and early seventeenth centuries, in revealing the ongoing controversies about cartography and navigation, can help us understand the always fraught connections between those making maps and those using them, even as they took Portolan charts and altered them almost out of all recognition. The Portolan Chart: Dimensions of the Genre Richard Pflederer Independent Scholar Williamsburg, Va. Portolan charts are particularly interesting artifacts of the medieval and renaissance period in that the genre began as plain, functional tools of work-a-day mariners but eventually evolved into a highly stylized and decorative art form. Because these charts were initially intended to be used, abused and discarded, the surviving population represents a small and probably non-representative subset of the total production. Nonetheless, we can extrapolate with some confidence, especially by combining our studies with documentary evidence from a variety of sources, including manuals covering navigational practices of the period. This lecture will offer a definition of portolan charts and touch on the intelligent speculations on the origins of the genre. It will also provide a ‘big picture’ view of the surviving population covering the period from the earliest charts through the 17th century when printed charts began to dominate. It will also outline the evolution of production locations, coverage area and decorative styles throughout the period. Afternoon Session: Analysis and Science, 1:30-3:30 Bi-dimensional Regression Revisited: Studying the Mathematical Structure and Form of the Portolan Chart John Hessler Fellow of the Royal Geographical Society Senior Cartographic Librarian Geography and Map Division Library of Congress One of the major open questions and areas of controversy in the history of the analysis of Portolan Charts is whether or not they are projected. This question has been addressed in the past by several scholars including Waldo Tobler, the inventor of the technique of bi-dimensional regression. In this paper we will look at Tobler’s work and update his mathematical methods using more advanced radial basis functions and thin-plate splines to probe the geometric structure and form of Portolan charts. We will discuss some more modern results, such as those of Joaquim Gaspar, and show how the techniques of distortion grids and scale and rotation isoline surfaces can be adapted for comparative analysis of charts of the period from 1290-1590. I will also highlight how some more advanced metrics, that I have derived from the field of statistical shape analysis on Riemann surfaces, can be used to further determine the error and show the evolution of these early nautical charts. Scientific and Image Analysis of Portolan Charts: Preliminary Results and Methods Fenella France Preservation Scientist Preservation Research and Testing Division Library of Congress The scientific assessment and characterization of a range of Portolan Charts from ca. 1320 - 1665 revealed information about materials used in the construction of these charts. A range of analytical methods were utilized in these studies. Carbon-14 dating confirmed the age of the vellum used. Hyperspectral imaging, which involves taking images of the charts over a range of wavebands - from the ultra-violet, through visible, to infrared - utilizes low light, low heat LEDs for illumination to ensures no damage to the object. Specific non-destructive characterization of inks, pigments and colorants can be achieved, including revealing lost and hidden details, as well as construction marks such as compass points and erasures. This enhances our knowledge of the object by allowing scholars and researchers to gain access to information relating to how the charts were created, including assessments of things like colorants that indicate whether these charts may or may not be commensurate with the suggested timeframe. The characterization of the media on the chart can be further confirmed through the use of additional non-destructive analyses including portable x-ray fluorescence and x-ray diffraction spectroscopy. This minimizes the handling of the artifact, and provides additional information that may allow a source or location for the inks and colorants to be suggested. Saturday There will be an open house in the Geography and Map Division Reading Room, James Madison Building, Room B-01, on Saturday from 9:30 to noon where they will display their Portolan Collection. John W. Hessler Fellow of the Royal Geographical Society Senior Cartographic Librarian Geography and Map Division Library of Congress Washington DC 202-707-7223 Website: http://www.warpinghistory.blogspot.com What any picture, of whatever form, must have in common with reality in order to depict it--correctly or incorrectly-- in any way at all, is logical form, i.e. the form of reality. --Wittgenstein Tractatus Logico-Philosophicus