The big picture: Civil War cyclorama to be restored

In the age before the Imax cinema and big-budget documentaries, there was the cyclorama. In the 19th century, the best way citizens could appreciate the magnitude of great historical events was to see them depicted in lavish, panoramic paintings in the round.

Most of these cycloramas were not made to last. They toured from town to town until their usefulness was exhausted then discarded. But one cyclorama has survived, a depiction of the great American Civil War battle of Gettysburg, which has been on display for years at the national museum on the site of the pivotal 1863 encounter between the Union and the Confederacy.

Now, the canvas is to undergo a facelift. The cyclorama, made by the French painter Paul Philippoteaux and 20 assistants in the early 1880s, will be removed from public view and subjected to a two-year restoration.

The New York Times said the painting has become "as ragged as an old army tent". Many of its original effects, including three-dimensional objects in and around the artwork - wagon wheels, canvas stretchers - have long gone missing. The painting has become faded.

The idea is to move the cyclorama to a new visitor centre where it can be hung against a convex wall to enhance the realism. (In its present location it hangs straight.) The top of the painting will be modified to blends directly into the sky-blue ceiling. Grass, rocks and mud will be placed around the bottom to enhance the sense of realism.

At Gettysburg, General Robert E Lee, the commander of the Southern forces, tried and failed to invade Pennsylvania. His troops flushed the federal troops out of Gettysburg but sent them fleeing to a strategically advantageous hill where they bloodily repelled the Confederate charges.

The cyclorama depicts the worst of these uphill sorties across open fields, known as Pickett's Charge, during which 5,000 men lost their lives in little more than an hour.