English: Photograph of the original "Richards box" built by Frederic M. Richards at Oxford in 1968. It uses a half-silvered mirror at 45° to visually superimpose an image of the sheets of crystallographic electron-density contours onto the molecular model of the protein being built in the lower compartment. The photo was given by Richards (now deceased) to Eric Martz in 2001, with provision to make it publicly available.