There’s a rude gesture in Pickwick that I don’t quite understand. Mr Jackson, a young lawyer’s clerk in conversation with Mr Pickwick, ‘applying his left thumb to the tip of his nose, worked a visionary coffee-mill with his right hand, thereby performing a very graceful piece of pantomime (then much in vogue, but now, unhappily, almost obsolete) which was familiarly denominated “taking a grinder”’.