Neon sign, 1930s.
© Science Museum / Science & Society Picture Library
The luminous glow of an electrical discharge through gas at low presure was known in the 19th century, but only put into practical use in the 20th century. Discharge tubes with the 'inert' gases, helium, neon, argon, krypton and xenon have been used for advertising signs since the 1920s, though their colour and low brightnes make them unsuitable for general use. Neon light was invented by French chemist George Claude (1870-1960), and was first displayed to the public in Paris in 1910.