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Our Charters of Freedom

Created date

May 30th, 2009

Keeping them safe for the public eye

By Michael G. Williams In June 1776, John Adams remarked to a friend that they were "in the midst of revolution, the most . . . remarkable of any in the history of the world." Eight weeks later, he signed a piece of parchment that declared the colonies free from British rule. This Declaration of Independence set the course for a national Constitution and Bill of Rights establishing liberties that today give credence to Adams s words. Known collectively as the Charters of Freedom, these articles have brought millions of people to the Rotunda of the National Archives Building in Washington, D.C., all eager to see the compacts that started a system of government unlike any other. Damaging effects over time While the principles outlined in their pages are as strong now as they were two centuries ago, the iron gall ink and animal skin parchments used to record them are not. The Charters spent their first 150 years rolled up, framed, in storage, and on display in various government buildings with little protection from the damaging effects of light, moisture, and temperature change. Not until 1952 did they find a more stable environment, with each parchment sealed in a helium-filled encasement of bronze and glass. There they remained under Archives conservators careful monitoring, which, from 1988 to 1995, revealed microscopic signs of deterioration that sparked one of the most important preservation projects in U.S. history. "Because you couldn t open the 1950s encasements without destroying their seals, we had to examine the documents through the glass using a high-resolution digital scanner called the Charters Monitoring System," explains Catherine Nicholson, deputy director of the National Archives Document Conservation Laboratory. "The scans showed that little crystals had formed between the exterior glass and the glass resting directly on the parchment, which was the earliest sign of glass deterioration." The only solution was to transfer the Charters from their original containers to new, state-of-the-art encasements that would better preserve them a process that took five years of off-and-on work to complete. As Nicholson recalls, one of the more nerve-racking steps was opening the old encasements, which first required them to use a specially designed tool to cut through the lead ribbon that sealed each one on all four sides. "There was some uncertainty since the encasements had never been opened," she says. "We weren t sure what would happen to the parchments when the air hit them or whether they would stick to the glass, but we just took each step slowly and everything went well." Nicholson and her colleagues never underestimated the truly historic nature of the task. Their eyes were the first in over half a century to view the Charters without the cover of glass, their hands the first to hold them. Painstaking work Even so, they worked on each parchment with detached focus, microscopically examining every letter of every page, reattaching flaking ink, mending tears, and removing surface dirt. The construction of the new encasements was a feat of scientific collaboration in which the fields of conservation, engineering, optics, and metallurgy came together to produce containers capable of preserving the Charters for centuries. Each parchment s encasement consists of an aluminum base, covered with a 3/8-inch-thick piece of high-grade, non-reflective glass, bolted and gasketed to a frame of commercially pure, gold-plated titanium. The parchment rests on an aluminum platform covered in a special paper that absorbs and releases moisture. After sealing the encasements, conservators fill them with inert argon gas that provides a constant level of humidity. "Parchment is extremely responsive to moisture," Nicholson explains. "It gets very soft and expands when it s damp, and it contracts and hardens when it dries out. This can distort the document, so you need to maintain an optimal middle range of humidity to avoid that." For the Charters, that middle range is a relative humidity of 40% and a temperature of 67 degrees Fahrenheit. Conservators can track the humidity, temperature, and oxygen levels using an optical monitoring system housed under the document s platform. By 2003, each parchment was in its new encasement, and the Declaration of Independence, the Bill of Rights, and the four pages of the Constitution went back on permanent exhibit in the newly renovated Rotunda. "These are documents that every generation should be able to see," Nicholson says. "Knowing that we ve made them so much more accessible, and in a way that will preserve them well beyond our lifetimes, is the most rewarding aspect of the whole project." And when people visit the shrine, gazing intently at Jacob Shallus s artful penmanship in the Constitution s opening phrase, "We the People," they share in her fulfillment. '