Term used in its widest meaning to refer to luminous devices containing neon, mercury vapour, argon or other inert gases and their combinations used in electric signs or lamps generally tubular in shape. This extended definition is also applied in an artistic context. In its narrower, more technical sense, neon (from Gr. neos: ‘new’) is a rare inert gas that was discovered in 1898 and that was immediately recognized as a new element by its unique glow when electrically stimulated. The vapour-tube device filled with neon gas was invented by Georges Claude in Boulogne-Billancourt near Paris in 1910. When a high voltage was applied to the two electrodes at either end of the tube, it emitted a deep red light. With other gases, mercury vapour and their mixtures, a small range of colours was obtained in the following years in tubes that could be cut to any length, bent and formed by skilled craftsmen into almost any shape and used for signs that had, however, a very limited lighting capacity. When industrially produced, low-tension fluorescent straight tubing of white (and occasionally coloured) light in standardized sizes came into use in the 1930s, results approaching natural lighting were obtained.