Mill Green Museum in Hatfield, Herts (tel 0707 271362), is currently featuring an exibition called “Birkin’s Bentleys”, which majors on the firm of Birkin & Couper in nearby Welwyn Garden City. From 1929 to 1932, this was the centre of Birkin’s attempt to keep a British car ahead of the Continental pack, and the works supercharged machines are all described, along with the story of the ill-fated partnership with W M Couper. It’s a small show, only one room, but I learned some new information from it (there are details of the model electric racing set the company manufactured, for instance), and the Museum itself is a working watermill complete with miller in attendance. The show runs until November 13, and entry is free. G C