America’s birth certificate—the only known copy of cartographer Martin Waldseemüller’s 1507 world map depicting the continental landmasses in the Western Hemisphere and naming them “America”—survived out of sight in southwestern Germany for nearly five centuries. Through the combined efforts of Librarian of Congress James H. Billington; Margrit Krewson, the Library’s former German and Dutch area specialist, and other members of the Library’s staff over a 15-year-period, the map was able to leave Germany and come to the Library of Congress in April 2007. (See Information Bulletin, June 2007.)
To preserve and protect the map while millions view it in the “Exploring the Early Americas” exhibition, the Library is displaying it in a sealed oxygen-free encasement filled with argon, an inert gas.
A crane was used to hoist the map case into the Thomas Jefferson Building, where it took its place as part of the “Early Americas” exhibition. - Dianne van der Reyden
The Library’s Preservation Directorate experts and National Institute of Standards and Technology (NIST) engineers spent nearly a year designing the encasement. Although NIST developed the same technology for the National Archives to preserve and display the Declaration of Independence, the Constitution, the Bill of Rights and their transmittal letters, this will be “the largest encasement ever built for a single paper document,” according to Dianne L. van der Reyden, the Library’s director for preservation.
Printed from inked wood blocks onto 12 sheets of sturdy rag paper, the “America” map measures 4-by-8 feet when the sheets are assembled. According to van der Reyden, the challenge was to fabricate an encasement large enough to house the map, light enough to meet Jefferson Building floor-load limits and flexible enough to withstand atmospheric pressure changes.
The answer was an aluminum monolithic block, which was machined to create the encasement base that van der Reyden said “can be best described as a tray.”
A team of conservators mounted the map on an archival-quality backing board, which in turn was mounted to an aluminum platform, secured within the encasement base and covered with a sheet of laminated, tempered, nonreflective glass.
An aluminum frame holding the glass was secured to the base with 96 bolts; when tightened, the bolts seal the case. The encasement measures about 116-by-73-by-4 inches and weigh about 2,200 pounds; the glass alone weighs between 400 and 500 pounds.
The base containing the map rests on a specially designed support structure that will enable the map to be displayed upright.
Library preservationists supervised installation of the map within the encasement, which was assembled and tested at NIST in August and September and then transported to the Library and hoisted through a second-floor Jefferson Building window. Installation and final testing were completed the end of October.
The hermetically sealed encasement includes valves for the replacement of oxygen with argon gas. (Oxygen reacts with and degrades organic material such as the map’s paper and ink.) The encasement contains monitoring devices to measure internal environmental conditions. The seals are expected to last a minimum of 20 years.
The Waldseemüller Support Fund, established by Virginia Gray and the Gray family in memory of Martin Gray, provided funding for the design and fabrication of the map encasement. The Alcoa Company, the world’s largest aluminum producer, donated the monolithic aluminum blocks from which the encasement base and frame were machined. The Alcoa Foundation provided funds to help fabricate the encasement and enable the Library to incorporate the needed environmental monitoring capabilities.