Multi-spectral imaging, a technique that has only been developed in the past decade, captures multiple images at specific frequencies of light, including ultraviolet and infrared, which are then combined to reveal information that is not visible to the human eye. See the image gallery for an example of how multi-spectral imaging enhances the legibility of a darkened papyrus fragment, from a recent NEH-funded project at Brigham Young University. This particular fragment, P. Tebt. 254, contains a petition to Asklepiades, overseer of the revenues, from the royal farmers of Kerkeosiris, ca. 113 BCE and was recovered from a crocodile mummy exhumed at the ancient site of Tebtunis, Egypt in 1900 CE. Compare the legibility of the fragment, photographed with standard photography (on the left) and with multi-spectral imaging (on the right). It is especially valuable for recovering text that has been obscured by fading, water damage, over-painting, and palimpsesting. Notably, the technique does not expose the already fragile map to destructive light rays.
The Martellus map project team consists of Michael Phelps of the Early Manuscripts Electronic Library, an organization based in Los Angeles, California, that uses digital technologies to make manuscripts and other historical source materials accessible for study and appreciation; Gregory Heyworth, of the Lazarus Project at the University of Mississippi, which facilitates the recovery of manuscripts through multi-spectral imaging, and another member of the Lazarus Project, Roger Easton, Professor of Imaging Science at the Rochester Institute of Technology in Rochester NY; Kenneth Boydston, a digital imagery pioneer and CEO of MegaVision; and Chet Van Duzer, a specialist in the history of cartography at the Early Manuscripts Electronic Library, and the director of the project.
Van Duzer and his colleagues transported a custom-designed multi-spectral imaging system (see images in gallery) from Oxford, Mississippi, to New Haven, where they are working closely with the curators and the digital technology team at the Beinecke Library. They divided the Martellus map into 55 overlapping regions, or tiles, and took 22 images at varying wavelengths per tile. When the project is completed next year, digital processing should reveal any previously illegible text and images on the map. With metadata assigned to the images, information will be made available about the content and imaging conditions. Images of the Martellus map and metadata will be made freely available to the public in early 2015 via the Beinecke Digital Library Web site. National Geographic is also planning an article on the Martellus map with publication of the multi-spectral images. Thanks to NEH funding, the public will shortly have access to a set of technical images of the map that will reveal knowledge about map making and geography at a critical moment of global exploration.
Support for this project was awarded through the Humanities Collections and Reference Resource grant program from NEH’s Division of Preservation and Access: PW-51707-14 to the Early Manuscripts Electronic Library, Los Angeles, CA. Support for the multi-spectral imaging of Egyptian papyrus fragments was awarded through the Humanities Collections and Reference Resource grant program from NEH’s Division of Preservation and Access: PW-50427-09 to Brigham Young University, Provo.