The dome of the National Museum of Natural History’s rotunda is one of several area buildings (and one of several hundred nationwide) that boast tiled vault ceilings by the Guastavino company . (Michael Freeman)

“Palaces for the People” is essentially an exhibition about grand ceilings. Though the subtitle of the National Building Museum show, “Guastavino and America’s Great Public Spaces,” emphasizes the rooms under those ceilings, it’s evident that the highlighted spaces — the Boston Public Library, the Oyster Bar in New York’s Grand Central Terminal, the Rotunda of the National Museum of Natural History and its Baird Auditorium, among many others — derive much of their greatness from what’s up top.

What those gracefully curving tiled ceilings — and hundreds of others like them — have in common is that they were designed and built by a single company, a family business run by Spanish immigrant Rafael Guastavino (1842-1908) and his son, Rafael Jr. (1872-1950), using the Old World technique of structural tiling.

The show, curated by M.I.T. architecture professor John Ochsendorf, includes new and archival photos, architectural drawings and examples of Guastavino tiles, along with a modern half-scale replica of the Boston Public Library’s vault ceiling. That replica features a cutaway section revealing the technique behind the iconic structure, which resembles a gently billowing parachute, albeit one made of a layer-cake-like structure of terra cotta tiles.

The technical aspect alone is fascinating. A vault ceiling works without horizontal support beams, directing the downward force of gravity outward toward the walls so that the structure, in essence, holds itself up. (Imagine forcing a flexible panel with a surface area of 100 square feet into an opening that’s 50 square feet. It fits only because it’s curved, and the compression of the curved surface keeps it from falling down.)

The Guastavino company not only designed, engineered and built these engineering marvels, but it also manufactured the beautiful tiles, at a rate of about 900,000 a year at the company’s peak in 1915. The business folded in 1962, the victim of changing tastes, which favored modernism over the late-19th-century and early-20th-century evocation of ancient Rome, according to Ochsendorf. Much of the documentation on display at the Building Museum was rescued from the Guastavino company’s dumpster by art historian George Collins of Columbia University, which worked to catalogue the material.

The show contains many interesting details that shed light on the ingenuity and marketing savvy of the Guastavinos, including material related to the creation of a patented acoustical tile, called Akoustolith, made from a porous, graded aggregate and binder. Coarser particles of crushed rock, brick, sand or other material were used at the front surface of the tile, absorbing low-frequency sound, with finer particles used at the back to absorb high frequencies.

The Guastavinos’ advertising also made much of the fact that structural tile was fireproof, which was a huge selling point in the late 19th century, given several devastating, high-profile fires. It therefore seems ironic, at first, to read of the 1997 Oyster Bar fire, which damaged much of that restaurant’s 1913 Guastavino tile ceiling.

In fact, says Ochsendorf, most of the damage was cosmetic, not structural. After what Ochsendorf calls a “face-lift,” the restaurant was back in business, mere months after the fire.

The takeaway from the story has less to do with the durability of Guastavino tile ceilings than with their enduring aesthetic appeal. Although hundreds of Guastavino buildings were demolished in the 20th century, including New York’s Penn Station in 1963, there has been a recent resurgence of appreciation for their beauty.

“Palaces for the People” should only fuel that.

The Story Behind the Work

Although we know of some 600 surviving Guastavino ceilings out of more than 1,000 that were built around the country, more are being discovered today. According to exhibit curator John Ochsendorf, potential additions have come in at the rate of about one a week since “Palaces” opened last September at the Boston Public Library, the show’s first stop before traveling to the Building Museum.

How is that possible?

Ochsendorf says the hidden Guastavinos are the result of lost construction records and incomplete record-keeping. In 1910, the firm was working on more than 100 projects. “They might have been building a schoolhouse somewhere,” Ochsendorf says, “when a builder on another project walks by and says, ‘That looks good. Can you add one to mine?’ ”

While you’re at the Building Museum, pick up a handout listing 11 publicly accessible D.C. sites that feature Guastavino ceilings, such as the Washington National Cathedral and the National Academy of Sciences. But don’t stop there. Ochsendorf encourages anyone who thinks they may have stumbled upon a lost Guastavino to e-mail him at

Don’t be shy, either. Ochsendorf says that he recently heard from a person who believed that his high school in Topeka had a Guastavino ceiling. “Yeah, yeah, it’s a curving ceiling,” he remembers thinking skeptically. But then the man sent Ochsendorf a picture that proved the ceiling’s authenticity. When he hears about discoveries like that, Ochsendorf says, “I still get a chill.”

— Michael O'Sullivan