Dominating the Freemasons' Hall's new exhibition, Freemasonry and the French Revolution, a giant chair, all puffed up with majesty and pomp, looms over the display cases - an effect rather undermined by its resemblance to an oversized, over-pimped prop in a novelty Hip Hop video, and its having been designed to be disassembled and moved around like eighteenth-century flat pack. Still, it's clear what it's trying to say: built for the Prince of Wales (later George IV), who was elected Grand Master in 1790, it reflects the extraordinary prestige and respectability accorded to English Freemasonry by the late eighteenth century.