With contributions from both sides of the science/humanities divide, this is a quirky collection of essays on science and the imagination. It springs from the Science Museum's construction of Charles Babbage's difference engine, the mechanical computer which he designed in the 1830s but never built. The essays deal with topics such as the invention of the phonograph, the Victorian delight in robots and automata such as the steel tarantula spider which crawls out of its box and runs around, microphotography and the minuscule, and the Internet and the British.