Charm is as invisible as the circus but as undeniably present in Le Cirque Invisible, an adorable little presentation for which parents should go miles with children to see this month. Charlie Chaplin’s fourth daughter and her husband are not young things any more, and their two-person show is at least 40 years old in its various guises - but they simply keep adding and subtracting gags, costumes, dressing-up box illusions, magic tricks, rabbits, soap-bubbles, locking down a hall of children and parents for two and a half hours in raptures.