April 22, 2010 Re-Examining the Portolan Chart: History, Navigation and Science

To the historian of cartography, the invention of the portolan chart is a major revolutionary moment in the history of mapping. This early map began as the workaday navigational tool of medieval mariners and later developed into a highly stylized and decorative art form. Yet the origin and development of the portolan chart is shrouded in mystery.

The Library of Congress will bring together scholars in an attempt to shed light on these important but poorly understood early maps. "Re-Examining the Portolan Chart: History, Navigation and Science" will be held from 9:30 a.m. to 3:30 p.m. on Friday, May 21, in the Coolidge Auditorium on the basement level of the Thomas Jefferson Building, 10 First St. S.E., Washington, D.C.

The conference is sponsored by the Library's Geography and Map Division and the Philip Lee Phillips Society. The event is free and open to the public, but reservations are required. For reservations, call 202-707-5218 or send an e-mail to specialevents@loc.gov.

The conference will include two sessions. The morning session, "History and Navigation," from 9:30 a.m. to 11:30 p.m., will feature three scholars who have conducted extensive historical research on portolan charts:

• Evelyn Edson, professor emerita of history at Piedmont College, will present "The Marine Chart in the Mappamundi: Mapping the World in the Later Middle Ages."
• Alison Sandman, assistant professor of history at James Madison University, will present "The Birth and Use of the Navigational Chart."
• Richard Pflederer, an independent scholar from Williamsburg, Va., will present "The Portolan Chart: Dimensions of the Genre."

The afternoon session, "Analysis and Science," from 1:30 p.m. to 3:30 p.m., will feature two experts from the Library of Congress who apply the modern tools of imaging science and mathematical modeling to try to unlock some of the long-standing mysteries associated with these charts.

• John Hessler, senior reference librarian in the Geography and Map Division, will present "Bi-dimensional Regression Revisited: Studying the Mathematical Structure and Form of the Portolan Chart." Hessler uses computer models and newly developed Riemannian metrics and radial basis functions to probe the accuracy and geometric form of portolan charts in a way never before attempted.
• Fenella France, preservation scientist in the Preservation Research and Testing Division, will present "Scientific and Image Analysis of Portolan Charts: Preliminary Results and Methods." France will focus on hyperspectral imaging, X-ray fluorescence spectroscopy and the carbon dating of the Geography and Map Division's portolan collection.

The Philip Lee Phillips Society was established in 1995 as an association of collectors, geographers, historians and map enthusiasts, with a shared interest in supporting and promoting the programs and activities of the Geography and Map Division. The society's mission is to encourage financial donations, gifts and bequests to make the division's collections more widely known, and to help the division and its staff develop and preserve the cartographic collections of the Library of Congress.

The Library of Congress has the largest and most comprehensive collection of maps and atlases in the world, some 5.2 million cartographic items that date from the 14th century to the present time. The Library's map collections contain coverage for every country and subject, and include the works of the most famous mapmakers throughout history -- Ptolemy, Waldseemüller, Mercator, Ortelius and Blaeu. For more information, visit www.loc.gov/rr/geogmap/.