For enthusiasts of Britain’s Georgian period—and a good cup of tea—the London dealer Philip Mould has a treat in store. He is selling a collection of 45 works by the 18th-century miniaturist John Smart (1741-1811). Smart was working at the same time as Thomas Gainsborough and Joshua Reynolds and displays the same skills in bringing the contemporaneous merchant class to life—on a much smaller scale. Mould and his team have worked hard to dig out more details on both Smart and his sitters to pull together the exhibition, “A Genius Magnified” (until 9 December). Their research has unearthed that Smart, who is recorded as being from Norfolk, was in fact from the Soho area of London. Among his sitters are Richard Twining, who entered his family’s tea business at only 16. Prices for the pieces from the collection, which was amassed in Germany over the past 30 years, begin at £4,000 (for Smart’s preparatory drawings) to £55,000.