Dez 152010

Surprisingly, neon tubes are almost as old as incandescent bulbs. One hundred years ago, the first neon tube was lit in Paris. Today, ‘neon light’ is everywhere, from flashing billboards to energy-saving lamps – only that it’s not neon anymore.

The columns of the Grandpalais glowed red. An otherworldly light, emitted by long, thin glass tubes, welcomed the visitors to the Paris Motor Show on the 11th December, 1910. What a spectacle; the strange, crimson shine was visible even in broad daylight. Soon this so-called ‘neon light’ would become the talk of the town. Quite a feat considering that by 1910 Parisians were used to all sorts of electric light shows: In 1843, the Place de la Concorde became the first public place to be illuminated by arc lights, and the nights of the World Fair in 1900 were turned into days by thousands and thousands of the new incandescent bulbs. But this new light was different: it was warm and cold at the same time and seemed to float in its tube, almost like a liquid fire.

Neon displays in Tokyo.

Those first neon tubes not only advertised the Motor Show, but even more so the genius of their designer George Claude. Not only had he created a new kind of light, but he had also found a clever and, as it turned out, very profitable way to deal with what essentially was a waste product. Born in 1870 and trained as a chemist and physicist, the Frenchman Claude was a busy inventor, some even called him the ‘French Edison’. Besides experiments with ocean thermal energy conversion, his greatest feat was the liquefaction of air and the separation into its component parts on an industrial scale. Like his German competitor Carl von Linde, he managed to turn his process into a successful business. In 1902, he founded L’Air Liquide, which today is a multinational corporation.

The mass production of liquid oxygen and nitrogen left Claude with considerable amounts of all the other gases which make up our atmosphere. Among them, besides carbon dioxide, argon and many others, was neon, literally a ‘new’ element.

Neon – a New and Shining Element

Neon was discovered in 1898 by Sir William Ramsay and Morris William Travers. They, too, were working on the liquefaction of air and the distillation into its components, but more for scientific reasons. In the process they had already discovered a new group of chemical elements, the inert or noble gases. Their first findings, argon and helium, suggested another element in between those two. After years of research they finally spotted in their atomic spectrometer a “blaze of crimson light … a sight to dwell upon and never forget”, as Travers put it. In stark contrast to this emotional outburst, they rather unimaginatively christened their discovery ‘neon’ after the Greek word ‘neos’, meaning new.

Aware of the commercial value of their discovery, Ramsay and Travers were, however, unable to obtain significant amounts of ‘their’ element, and so Ramsay contacted George Claude. Claude not only had the technology to economically produce neon in large quantities, he also knew exactly how to let it shine.

The physics behind the lighting-up of neon as well as other gases is called gas discharge. Free electrons, accelerated by an electric field, bump into gas atoms and ‘excite’ their electrons, i.e. lift them to a higher energy state. When these electrons fall back to their original level, they emit a photon – the gas lights up. The colour of this light corresponds directly to the difference in energy levels, so each gas shines with a characteristic spectrum of colours. Unaware of all the theory, the French astronomer Jean Picard was the first one to describe this phenomenon in 1676. He observed a faint blue shimmer when he shook his mercury barometer. The mercury running off the glass created static electricity, which in turn excited the mercury vapour. Not knowing any better, he called this effect ‘barometric light’.

French inventor George Claude built the first Neon tube in 1910.

Two centuries later, the process was understood well enough to inspire the German glassblower Heinrich Geissler to experiment with various gases and different shapes of glass tubes and electrodes. In the 1850’s, he created a series of ‘Geissler tubes’, which were almost pieces of art with their different colours and fancifully shaped tubes and bulbs.

While Geissler’s interest was mainly scientific or artistic, the American Daniel McFarlan Moore thought more about the practical use of Geissler tubes for general lighting purposes. Although Moore worked for the Edison company, he obviously never liked his employer’s approach to lighting and called the incandescent bulb “too small, too hot and too red.” By 1898 he had created an alternative. The Moore lamp was a thick glass tube up to 70 metres long and filled with carbon dioxide, which was lit up by a high voltage fed through two electrodes at either end of the lamp. It produced a good white light with an efficiency well above that of Edison’s incandescent bulb. Unfortunately, the carbon dioxide, not being an inert gas, reacted with the electrodes and had to be replenished constantly. Unreliable as it was, the Moore lamp was never a commercial success and was soon forgotten. It is an irony of fate that another one of Moore’s inventions, something “small and red”, has survived almost to this date: the glow lamp. Moore observed that in a small bulb filled with neon the negative electrode would glow red even at low voltages. Before the advent of the LED, the glow lamp was therefore used in all kinds of electrical equipment as an indicator light.

Based on his experience with the glow lamp, Moore encouraged Claude to experiment with neon on a larger scale. After a series of tests and some improvements to the electrodes, Claude was finally ready for the big show at the Grandpalais. Its red glowing columns heralded a new age.

The Scarlet Whore of the Advertising World

But it wasn’t a new age of general lighting – yet. Obviously no-one wanted to illuminate their home with a bright scarlet light – except for those practicing some old profession, perhaps. But the neon light was perfect for something else: advertising. The light and the colour of the liquid fire caught people’s attention and Claude instantly realised the potential of the thin glass tubes, which could be bent into any shape. The age of the neon sign had begun.

In 1911, Claude founded the Claude Neon company, which soon sold the first neon sign to a barber in Paris. Quite a humble beginning for what rapidly would become a whole new industry. In 1913, Claude installed a one-metre high “Cinzano” lettering on the Champs-Élysées. In 1919, the entrance to the Paris Opera House was decorated with neon tubes and in 1923, the first neon signs in the USA advertised a Packard dealer in Los Angeles. Two years later another car manufacturer put its name on a world-famous landmark, thus creating the largest billboard ever. When brightly glowing tubes spelled out ‘Citroen’ on the Eiffel Tower, neon signs had already started to conquer the world. Soon they would become synonymous with flashy, colourful advertisements.

Free electrons from a glowing electrode are accelerated, bump into the argon atoms and stimulate the gas to emit light.

But in the beginning it wasn’t so colourful at all. Neon gas produces a red light, argon blue and helium a sort of pinkish gold – these were all the colours available to the early ‘tubebenders’, as the neon sign makers call themselves. It took Claude and his competitors more than a decade before they came up with the idea of fluorescent coating, which allowed them to produce all sorts of colours, including white. Luminous or fluorescent minerals had been known for centuries. It was the Irish physicist Sir George Gabriel Stokes who in 1852 examined the effect, named it after the mineral Fluorite, and stated that the outgoing light has a longer wavelength than the incoming. Again, some sort of atomic excitation is at work.

The best fluorescent effect is achieved with ultraviolet light. So, after filling a tube with argon and a bit of mercury, which produces a strong ultraviolet light, the challenge is simply to find the right mineral for a certain colour and apply it to the inside of the tube – a technology which was developed in the 1930’s. This split the development of ‘neon tubes’ into two different branches and, strictly speaking, marked their demise.

Rise and Fall of the Neon Tube

From now on the sign industry tried to produce more and more colours – over 50 to date – while the lighting industry sought after brighter and brighter white light. Suddenly, the liquid fire was everywhere. Neon signs started to illuminate shopping streets around the globe and fluorescent lamps entered first our offices and then our homes. In the 1950’s and 60’s, neon lived up to its name and became the promise of modernity, of a ‘new’ beginning. Everything bright and flashy was called ‘neon’ – only that it wasn’t neon anymore. Although those blinking billboards are called neon signs and we commonly refer to the shine of fluorescent lamps as ‘neon light’, only a small percentage of the former and none of the latter contain neon anymore. Argon, xenon and other mixtures of inert gases have long since replaced it. But that hasn’t deterred tubebenders of all kinds from creating more and more complex signs or squeezing more and more lumen from a fluorescent energy-saving lamp.

However, every light has its shadow. And so has neon. George Claude, the bright mind that lit up its fire got stuck in the dark ages. During the occupation of France he collaborated with the Germans, was put into jail after the war and fell into disgrace.

With neon out of use and the father of the neon lamp forgotten, it seems that the liquid fire’s birthday party will be held without the guests of honour.

Matthias Meier
Einige Artikel zur Geschichte des Neonschilds.
Ausführliche Artikelserie zum Thema Neon.
Deutschsprachiger Podcast über George Claude, den Erfinder der Neonröhre
Zwei Beschreibungen, wie ein Neonschild hergestellt wird.
Ausführliches, englisches Glossar zum Thema Neonschild.
Webseite von Air Liquide, dem Unternehmen, das George Claude vor fast 100 Jahren gegründet hat.



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