LONDON — The venerable British Museum has always been almost as famous for its visitor-unfriendly layout as for treasures like the Rosetta Stone. Galleries were hard to reach and clogged with foot traffic, and the main courtyard was filled with a jumble of outbuildings.
Now an ambitious $150 million renovation — with a breathtaking glass roof the size of Buckingham Palace as its centerpiece — is being hailed as an architectural triumph to rival I.M. Pei's glass pyramid that transformed the Louvre in Paris.
The museum's new Great Court, which was to be inaugurated Wednesday by Queen Elizabeth II, also features a loving restoration of the Reading Room, the domed reference library that was the haunt of writers and thinkers from Charles Dickens to Virginia Woolf to Karl Marx. For the first time, it will be open to the public, not just to holders of coveted reading tickets.
But in keeping with Britain's millennium jinx, the seven-year project produced at least one embarrassing goof.
The building contractor used the wrong shade and type of stone to rebuild one of the courtyard's columned Georgian porticos, and wrangling over the error could wind up in the courts.
Britain's tabloids had a field day with the mix-up. But in the mainstream press, attention centered on the soaring steel-and-glass roof that creates Europe's largest enclosed plaza, flooded with natural light even on a typically gray London day.
Critics were bowled over by the honeycombed structure, calling it a feat of engineering as well as a work of art.
"Mesmerizing geometry," said The Guardian. "That thud you hear," said the Daily Telegraph, "will be the sound of jaws dropping." The Independent rhapsodized about the "sky above seen through prisms . . . the best of both worlds, shelter and expansiveness."
Though weighing 800 tons, the roof, mounted on sliding bearings, appears to float above the museum's two-acre inner courtyard repaved in pale stone with the drum-shaped Reading Room at its heart.
The closing in 1997 of the 150-year-old Reading Room — and the moving of its enormous collection to the new British library a mile away — was widely acknowledged as a necessary modernization, but nonetheless mourned as the end of an era.
The structure was a shrine of literary and scholarly pursuit; Gandhi, George Bernard Shaw and T.S. Eliot all wrote and studied there. E.M. Forster used it as a setting in one of his novels.
Because of the weight of history and sentiment associated with the old Reading Room, purists welcomed a sensitive restoration that left intact its circular, book-lined walls and familiar blue-leather desks.
The room's original color scheme — eggshell-blue, cream and gold — was uncovered, with delicate and painstaking repair of the dome's papier-mache interior.
Architect Sir Norman Foster, whose restorations have included that of the Reichstag in Berlin, spoke of the room's "historic fabric ... so full of memories."
"We felt it was important that that was respected," he said.
Curators said the restoration of the central courtyard — previously crammed with outbuildings housing the Reading Room's book stacks — alleviates the British Museum's biggest problem: its maddeningly maze-like quality.
Previously, there was no short-cut to and from opposite sides of the sprawling four-winged building. So galleries doubled as corridors, resulting in exhibition spaces that seemed more "like traffic roundabouts," said Suzanna Traverne, the museum's director.
Over the years, the building, designed in 1853, has had many additions and alterations, but never one so sweeping as this. The museum was originally meant to accommodate 100,000 visitors a year; today, it draws around 6 million annually.
The restoration's apparent success might occasion some quiet sighs of relief, after the misfortunes that plagued Britain's other high-profile public projects in this millennium year.
The Millennium Dome on the banks of the Thames is limping through its final weeks. After a much-ballyhooed opening last New Year's Eve, it is finishing the year shunned by visitors and millions of dollars in the red.
The Millennium Bridge, the first footbridge across the River Thames, was praised for the beauty of its design, but had to be closed for repairs after its pronounced side-to-side sway terrified many of those crossing it.