With contributions from writers on both sides of the science/humanities divide, this is a collection of quirky and offbeat essays on technology, culture and forgotten or imaginary histories. Taking as its starting point Charles Babbage's 'Difference Engine', a machine imagined but never built, the book explores a range of subjects where the imagination and science and technology meet. Essays deal with such topics as the invention of the phonograph, the Victorian delight in automata and the Internet and the British. The result is a work which makes surprising connections and draws intriguing conclusions.