Created in France by Georges Claude in the early 1900s, neon signs became extremely popular throughout Europe in the 1920s. They were first used in 1923 by a Los Angeles Packard automobile dealer. Their attention getting features quickly assured their popularity.
Most neon signs were extremely large outdoor signs used to attract attention from quite a distance. Since these large signs are almost impossible for the collector to transport, now-a-days, window neon signs and neon clocks are popular among collectors.
Most neon signs are made by hand. The fragile glass tube is bent by hand and an inert gas is sealed in the air tight tube. When electrified at a high voltage, the gas gives off a color. Neon gas gives off an orange/red color. Argon gas gives off a blue color. Other colors are the result of tinting the glass or adding other chemicals to the inside. A transformer is used to achieve the voltage necessary to make the gas light up.
Jean Picard is better known as the astronomer who first accurately measured the length of a degree of a meridian (longitude line) and from that computed the size of the Earth. A barometer is a device used to measure atmospheric pressure, there are two main types of barometers: mercury and aneroid. Evangelista Torricelli invented the barometer in 1643.
Even though barometric light was not yet understood, it was investigated. When the principles of electricity were discovered, scientists moved forward towards the invention of various forms of lighting. By 1855, there was the geissler tube named after Heinrich Geissler, a German glassblower. Gas in the tube was placed under low pressure and electrical voltage was applied, the result was that the gas glowed. After electrical generators were invented, many people experimented with applying electric power to tubes of gas. Several electric discharge lamps or vapor lamps were invented from 1900 onwards in Europe and the United States. Simply defined the electric discharge lamp is a lighting device consisting of a transparent container within which a gas is energized by an applied voltage, and thereby made to glow.
The French engineer, chemist, and inventor Georges Claude was the first to apply an electrical discharge to a sealed tube of neon gas to create a lamp. The word neon comes from the Greek "neos," meaning "the new gas." Georges Claude displayed the first neon lamp to the public on December 11, 1910, in Paris. In 1923, Georges Claude and his French company Claude Neon, introduced neon gas signs to the United States, by selling two to a Packard car dealership in Los Angeles. Earle C. Anthony purchased the two signs reading "Packard" for $24,000. Neon lighting quickly became a popular fixture in outdoor advertising. Visible even in daylight, people would stop and stare at the first neon signs dubbed "liquid fire."
History Note: Before there were neon signs in America, there were commercial sign tubes that used a carbon dioxide fill. The carbon dioxide signs were made by a man called Moore. Neon gas was discovered by William Ramsey and M. W. Travers in 1898 in London. Neon is a rare gaseous element present in the atmosphere to the extent of 1 part in 65,000 of air. It is obtained by liquefaction of air and separated from the other gases by fractional distillation.
Making a Neon Sign
Hollow glass tubes used to make neon lamps come in 4, 5 and 8 ft lengths. To shape the tubes, the glass is heated by lit gas and forced air. Several compositions of glass are used depending on the country and supplier. What is called 'Soft' glass has compositions including lead glass, soda-lime glass, and barium glass. "Hard" glass in the borosilicate family is also used. Depending on the glass composition, the working range of glass is from 1600' F to over 2200'F. The temperature of the air-gas flame depending on the fuel and ratio, is approximately 3000'F using propane gas.
The tubes are scored (partial cut) while cold with a file and then snapped apart while hot. Then the artisan creates the angle and curve combinations. When the tubing is finished, the tube must be processed. This process varies depending on country; the procedure is called "bombarding" in the US. The tube is partial evacuated of air. Next, it is short circuited with high voltage current until the tube reaches a temperature of 550 F. Then the tube is evacuated again until it reaches a vacuum of 10-3 torr. Argon or neon is back filled to a specific pressure depending on the diameter of the tube and sealed off. In the case of an argon-filled tube, additional steps are taken for the injection of mercury; typically, 10-40ul depending on tube length and climate it is to operate in.
Red is the color neon gas produces, neon gas glows with its characteristic red light even at atmospheric pressure. There are now more than 150 colors possible; almost every color other than red is produced using argon, mercury and phosphor. Neon tubes actually refer to all positive-column discharge lamps, regardless of the gas filling. The colors in order of discovery were blue (Mercury), white (Co2), gold (Helium), red (Neon), and then different colors from phosphor-coated tubes. The mercury spectrum is rich in ultraviolet light which in turn excites a phosphor coating on the inside of the tube to glow. Phosphors are available in most any pastel colors.