"And my soul from out that shadow that lies floating on the floor Shall be lifted - nevermore! "

Each line of Edgar Allan Poe's The Raven still has the power to send a chill down the spine. Now Charles Dickens' pet raven called Grip - the little known, real-life inspiration behind one of literature's most terrifying poems -  has been put on display to commemorate the author's 200th birthday. The bird, which Dickens has a taxidermist preserve, has been given pride of place in a new exhibition in Philadelphia's public library.