Four neon lights, c 1920

Four neon lights, c 1920. Four of the earliest neon lights are shown here (clockwise) and include a neon lamp of about 1922; an Osram `Glimmelamp', a lamp shaped to show a letter 'E';; and a beehive-type neon lamp. Scientists in the 19th century were the first to discover that they could produce a luminous glow by passing an electrical discharge through gas at low pressure, but this was only put into practical use in the 20th century when discharge tubes containing the 'inert' gases, helium, neon, argon, krypton and xenon started toæ be used for advertising signs since the 1920s, though their colour and low brightness 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. ©SSPL/Science Museum