New York - Its days may be numbered yet the traditional light bulb does deserve a retrospective on the way to technical redundancy.

The incandescent light bulb first saw the light of day in October 1879 after prolific American inventor Thomas Alpha Edison (1847-1931) produced a carbon filament that burned for 40 hours.

A mere three months later, on January 27, 1880 to be exact, 32-year-old Edison acquired the patent and mass production began. It spelt the death knell for gas lighting and candles as a source of household and industrial artificial light but was the climax of many years of experiments by other inventors dating back to 1802. However, until Edison got to grips with the problem no-one had managed to create a practical light bulb.

Previous light bulb versions stayed alight for only a few hours at a time but Edison achieved a breakthrough by using "a carbon filament or strip coiled and connected ... to platina contact wires"
- as described in his patent application. Success was compounded by creating a vacuum inside the glass bulb.

Edison presented his idea to the public on December 31, 1879 when Christie Street in the town of Menlo Park became the first street in the world to be illuminated using electric lighting. Menlo Park was the site of Edison's first industrial laboratory and the town some 50 kilometres from Manhattan assumed his name in 1954. A tall tower was erected in his honour with a pinnacle which is meant to represent an incandescent light bulb.

Edison's laboratory in Menlo Park (New Jersey) was a forerunner of modern technology parks and he paid for it with the proceeds of his first telephone system. The research facility also saw the birth of the first phonograph, a device which recorded sound on a grooved cylinder and later gave way to the first gramophone records. After the invention Menlo Park became officially the "Birthplace of Recorded Sound." Edison later oversaw a pioneering electric railway system using overhead gantries and wires, as the annals of the town recall.

More than 400 of the inventions which arose from Edison's experiments in Menlo Park were patented. His wife Mary Stilwell died in 1884 aged only 29 and this prompted the inventor to move north to West Orange (New Jersey), where he continued to research for another 47 years before he died aged 84 in October 1931.

At his death Edison had 41,093 US patents to his name. His light bulb later turned out to be one of the least efficient forms of lighting since most of the electricity it uses is wasted in the form of heat rather than visible light. The European Union has already begun phasing out the incandescent light bulb which is due to vanish from shops completely over the next few years in favour of more energy-efficient fluorescent lamps and light-emitting diodes (LEDs). (dpa)