Changes in the environment cause dimensional changes in objects which in turn can lead to damage - controlling humidity and temperature for storage and display is essential for long term stability of the collections. All materials used for storage must be stable for decades, if not longer, and not adversely affect the artifacts. Exhibition designers in concert with conservators analyze the materials used for exhibit cases to ensure that they do not have detrimental effects on the objects. Light can also cause damage so it must be carefully controlled.
Conservation involves examination, scientific analysis, and research to determine the original structure, materials and extent of loss of the artifacts. Conservation also encompasses the structural and chemical treatment to stabilize the object and delay any future deterioration. NMAH has four conservation laboratories dedicated to the preservation of our collections.
Steps taken to display the Jefferson bible illustrate some of our preservation work. The light levels are kept low and the page to which it is displayed is changed every three months to prevent fading of the printing or discoloration of the paper. The binding is very brittle so a special cradle supports the bible. Aside from protecting the Bible from dimensional changes, temperature and humidity are kept at a specified level in order to keep the glue in the binding from desiccating if the humidity is too low or from mold growing if the humidity is too high.
Preservation is a very complicated and involved process. Protecting and caring for the national collections is a major focus of the National Museum of American History.
How did Smithsonian get these things? Were they purchased or donated?
The Smithsonian acquires almost all of its collections as gifts. Donors understand that placing much loved and often valuable artifacts in the national collections means that they will be accessible to a broad public and cared for and preserved for perpetuity.
While most donations have come from the owners themselves, some of the National Museum of American History's most prized objects have been “inherited” from other institutions, such as the desk on which Thomas Jefferson drafted the Declaration of Independence. It was given by Jefferson to his favorite granddaughter, Eleanora Wayles Randolph Coolidge, and her husband, Joseph Coolidge Jr., as a wedding present in 1825. For over 50 years the desk was much revered by the family and occasionally exhibited in Boston. Upon the death of Joseph in 1879 (Ellen had died in 1876), the children presented the desk to President Rutherford Hayes as a gift to the country. For more than 40 years it was displayed at the Department of State as an icon of American democracy. In 1921 Secretary of State Charles Hughes transferred the desk to the Smithsonian, recognizing that the museum could better preserve and display this treasure.
A full list of individuals and organizations who donated artifacts featured in the Treasures exhibition is provided on the Muhammad Ali donated his boxing gloves, and Alexander Graham Bell donated his telephone, for example – as well as ordinary Americans who generously chose to share their treasures with the nation.
When the museum reopens, can we still see everything in the exhibit?
When the museum reopens in 2008 many of the artifacts in the Treasures of American History exhibition will go back on display in exhibitions like Price of Freedom and The American Presidency. However some of the objects will go back into storage.