Man’s Mundane Mistake Threatens 15th-Century Italian Architectural Marvel

Heaven, it is said, so envied Brunelleschi’s brick red dome soaring above Florence that it hurled down lightning bolts in hopes of destroying the eight-sided architectural marvel that crowns the city’s cathedral.

The ribbed cupola has weathered many a storm since it was built atop the green, white and red marbled duomo in 1438. Now man threatens to shorten its glorious life.

“Brunelleschi’s masterpiece risks, with time, to split itself open like a gigantic melon,” wrote Europeo, an Italian newsmagazine.

Four major cracks, more or less symmetrical, run up and down the dome. They are getting wider every year, alarming architects, engineers and art historians who have studied the 300-foot-high vault-within-a-vault, which stands without the help of outside buttresses.

Plugged With Concrete

The problem, it seems, began in the winter of 1979 when some workers plugged up 48 square holes with concrete.

Brunelleschi, the first great architect of the Italian Renaissance, had apparently left the holes to anchor scaffolding needed for the decoration of the dome. A Florentine who devoted the later years of his life to building the dome, he hoped to decorate its interior with dazzling mosaics. Instead, Giorgio Vasari and Federico Zuccari were charged with covering the inside with frescoes.

When authorities decided nearly a decade ago to restore the frescoes, planners took advantage of the holes--six on each side running along the base, each space two feet by two feet--to erect their own scaffolding.

They built a kind of metal shell, shaped to fit inside the inner vault, as a framework for the scaffolding, but the metal rods didn’t stay still in the holes. Someone decided to fill the spaces with concrete to hold the poles tightly.

‘Irreparable Damage’

“It’s a criminal affair,” says Alessandro Parronchi, an art historian who lives in Florence. “The dome has suffered irreparable damage.”

Almost since its completion, the dome has had cracks, some blamed on lightning strikes. About 50 years ago, Pier Luigi Nervi, an architect and a pioneer in the use of reinforced concrete, noticed that the dome’s cracks closed up in summer’s heat and widened in winter’s cold, a kind of regular respiration for its brick and stone.

But after the holes were stopped up, measurements showed that the cracks were widening and not closing up in summer.