They contain classical, medieval, theological and philosophical works and come wrapped in dust-jackets of a single sombre colour plus white.

ECONOMIST: G?tterd?mmerung postponed

The Triple Smoke is a tasty American single malt whiskey with a golden colour and a peaty butterscotch flavour.

BBC: On and off Kentucky��s beaten Bourbon Trail

These so-called quantitative traits are under the control of a number of different genes acting in concert as opposed to qualitative traits such as human eye colour, where a difference in a single gene produces a single, sharp distinction.

ECONOMIST: A genetic game of chicken

The lighting, camera angles, wall-colour, acoustics and furniture are all designed to make two Halo systems feel like a single room when linked together, and to do away with the 15 minutes of messing around usually required to set up videoconferencing gear.

ECONOMIST: Videoconferencing

WDM, a technique that allows a single optical path to carry thousands of parallel channels, as long as each is encoded in a slightly different colour.

ECONOMIST: Optical communications