Like Adam, Stuart was keenly interested in the archaeological discoveries of the day. In 1750, under the sponsorship of the Society of Dilettanti, he traveled to Greece with Nicholas Revett, an English architect. As late as the Victorian era, a journey there bespoke a spirit of adventure, and in the 18th century it was downright dangerous. Piracy, the plague and attempted murder were some of the dangers Stuart and Revett survived during the two and a half years they spent sketching and measuring the ancient ruins.

On Stuart’s return to England in 1755,  members of the Dilettanti hired him to create furniture based on ancient artifacts. Because the classical world produced only a limited number of forms, Stuart had to innovate. For Spencer House, his most famous commission, he designed a suite of seating furniture based on the Greek throne. “Stuart used the animal legs of the marble throne as a starting point,” says Soros. “Upholstered sofas did not exist in the ancient world, so he invented a sofa form with antique animal legs.”

Stuart was sought after as an architect and antiquarian advisor. His diffused legacy rests, however, on The Antiquities of Athens, the four-volume book he and Revett published, which had an enduring influence on architecture.

As recent sales show, an attribution to Stuart is today worth significantly less than one to Adam. A pair of Rococo armchairs with fluted cabriole legs terminating in Ionic scrolls sold at a Sotheby’s London auction in 2005 for a respectable $82,909. They are believed to be part of a suite that Stuart designed for a fellow member of the Dilettanti. But despite the substantial documentary proof, they sold for only a fraction of what was paid for the Dundas armchairs.

Also on the block in London was a bronze tripod perfume burner, circa 1765, which Stuart is believed to have designed for another member of the Dilettanti. With its pierced bowl supported by fluted sphinxhead supports terminating in animal paws, it is characteristic of the fashion for adapting ancient forms to modern uses. The final bid last spring at Christie’s was $54,545. While not contemptible, it is nowhere near the range for Adam-designed furniture.

Although Stuart had exceptional knowledge of Greek architecture, Adam possessed greater stamina and inventiveness. Less creditably, he copied Stuart’s early work, and maneuvered him out of some commissions. Then again, Stuart could be imprudent and had a reputation for “Epicureanism” (that is, he drank). Accounts of the period neatly (and plausibly) distinguish between Adam the ruthless careerist and Stuart the bohemian flâneur.

There were also artistic differences, though these are less clear-cut. Adam is associated with Roman architecture and Stuart with Greek architecture. But they were not in the replica business; their intention was to make stylish furniture based on Classical models, so they drew on the vestiges of both Greece and Rome.

Moreover, during the late 18th century, it was not always clear what was Greek and what was Roman. The growing awareness of Greek achievements inspired counterarguments in favor of Etruria, the Italian civilization that antedated Rome. Greek art was pretty, so the argument went, but Etruscan art was simple and austere. For proof the Etruscan partisans pointed to the vases then were being excavated in Italy.