This Christmas, the BBC has opted to avoid the troubles of our current world by plunging us into the recent past. Amid the usual round of tinsel-bedecked episodes of sitcoms, soaps and panel games, there are three period dramas. On Christmas Eve, the prime BBC1 slot is devoted to an adaptation of Norman Hunter’s Professor Branestawm books, which some may remember from childhood. In a piece of inspired casting, the lead role in The Incredible Adventures of Professor Branestawm is played by the comedian Harry Hill, in his first dramatic role. I have only seen clips, but he looks and sounds just right. The film is set in the 1950s, and the Professor’s mad machines, illustrated by Heath Robinson in the ­original books, have been ­lovingly re-imagined. One of the inventions