Dominating the end wall of the first room of Dürer To Van Dyck, a new exhibition at the Royal Scottish Academy in Edinburgh, is a photograph, blown up so it reaches from floor to ceiling. Taken around 1890, it shows the South Sketch Gallery at Chatsworth House in Derbyshire, seat since 1549 of the aristocratic Cavendish family whose scions include the current 12th Duke of Devonshire, Peregrine Cavendish.