By the time the Fourth of July is over this year, the Declaration of Independence and the Constitution will have vanished, authorities say.

And the Bill of Rights? That will be missing too.

But it won't be because of thievery or the crumbling of democracy — it's just that the glass housing the treasured documents needs repair.

For the next two years, the original copies of the Declaration, Constitution and Bill of Rights at the National Archives in Washington will be out of the public eye while experts examine them and mend the chipping glass display.

"The deterioration is not readily visible under current exhibition conditions," said an Archives report, "but eventually the glass will become opaque and block the visibility of the documents."

The last holiday visitors were to be ushered out of the rotunda at 6 p.m. EDT on Independence Day, much earlier than the usual 9 p.m. closing. At that time, the three documents were to be lowered 22 feet into the building's concrete and steel vault.

That's customary. But instead of being raised for view again Thursday morning, the documents will be prepared for transfer in a month to a laboratory in suburban College Park, Md., for their first close examination since 1952. There is evidence that the glass enclosing them has been flaking.

Experts have decided that the documents should not be shown and stored vertically, as they now are. Their new cases of gold-plated titanium will display them at an angle, convenient for children and the disabled. The cases will be filled with argon, an inert gas, and glass will no longer touch the parchment.

And when they return, all four pages of the Constitution will be on display for the first time, not just the opening and final ones.

"We hope to create a place where visitors will find it easy to look at the Charters of Freedom, not just because the glass is clear, but because the perspective is fresh and visitors young and old can find something new to rekindle their civic pride," said John W. Carlin, archivist of the National Archives and a former governor of Kansas.

Experts will also renovate two large 65-year-old murals by Barry Faulkner in the rotunda of the Archives. They depict the presentation of the Declaration of Independence to John Hancock, president of the Continental Congress, and James Madison presenting his final draft of the Constitution to George Washington.

All day Wednesday there will be traditional ceremonies by the Joint Services Color Guard, the 3rd U.S. Infantry Fife and Drum Corps and costumed actors representing Washington, Thomas Jefferson and other leading figures of the late 1700s.

For the occasion, Archives officials have brought in an internationally known calligrapher — Brody Neuenschwander of Houston, who lives in Belgium. He will demonstrate how the authors of the documents sharpened their goose-quill pens and scratched the words in ink made of oak galls and vitriol. A new computer program will enable any visitor to add his or her signature to a copy of the Declaration, in Hancock's famous bold handwriting.

Also, on Wednesday, the 225th anniversary of the nation's founding, one of the 200 original prints of the Declaration will be displayed in Philadelphia as part of a celebration that includes a staged reading.

The document will hit the road, traveling to presidential libraries, museums and schools throughout the country during the next three years to encourage interest in history and political activism.

The print is on loan from television producer and liberal activist Norman Lear, of All in the Family fame. Lear stood in front of the Jefferson Memorial — which honors the nation's third president and main author of the Declaration of Independence — to announce the tour. He said he expects it will cost about $6 million, given by foundations and private donors,  for his print to travel the country.

Fox News' Catherine Donaldson-Evans and The Associated Press contributed to this report.