"Only in Italy,” says Vincent Buonanno ’66, “would a dealer write off a piece like this because it was made in the eighteenth century, not the sixteenth.”

Buonanno was referring to a dome that appeared in a 1999 exhibition of architectural models in Turin, Italy, and was withdrawn from the show after art historian Henry Millon determined that the dome in question was 200 years younger than had been previously thought.

Millon, who was then at the National Gallery in Washington, D.C., had recognized the dome from a rare pamphlet by Italian architect Gaetano Chiaveri, which Millon had found in the gallery’s collection. Chiaveri’s model was among the proposals submitted to repair stress cracks that had been discovered in 1750 in St. Peter’s monumental dome in Rome.

When Buonanno, an art collector, discovered that the model had been withdrawn, he made a beeline to Italy and bought it. The dome was restored to the exhibition when it moved to the National Gallery and now resides in Chicago, where Buonanno, a Brown trustee, lives. It is on loan in Providence this summer as part of a joint exhibition at the RISD Museum and the John Hay Library inspired by a student seminar. “The Theater That Was Rome” uses books and maps from Buonanno’s collection to show how two centuries of popes used architecture to dramatize their glory.