Though Thomas Edison is usually credited as the man who invented the lightbulb, the famous American inventor wasn’t the only one who contributed to the development of this revolutionary technology.
Alessandro Volta, Humphrey Davy and Joseph Swan played a critical role in the development of this technology.
Early research & development
The story of the lightbulb begins long before Edison patented the first commercially successful bulb in 1879. In 1800, Italian inventor Alessandro Volta developed the first practical method of originating electricity (opens in new tab), the voltaic pile. Made of alternating discs of zinc and copper (opens in new tab) — interspersed with layers of cardboard soaked in salt water — the pile conducted electricity when a copper wire was connected at either end. Volta’s glowing copper wire is officially considered a precursor to the battery, but is also one of the earliest manifestations of incandescent lighting.
According to Harold H Schobert (“Energy and Society: An Introduction (opens in new tab),” CRC Press, 2014) the Voltaic Pile “made it possible for scientists to experiment with electric currents under controlled conditions” and furthered experiments with electricity (opens in new tab), Not long after Volta presented his discovery of a continuous source of electricity to the Royal Society in London, Davy produced the world’s first electric lamp by connecting voltaic piles to charcoal electrodes.
Davy’s 1802 invention was known as an electric arc lamp, named for the bright arc of light emitted between its two carbon rods, according to “The Life of Sir Humphrey Davy (opens in new tab)” (HardPress Publishing, 2016)
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While Davy’s arc lamp was certainly an improvement on Volta’s stand-alone piles, it still wasn’t a very practical source of lighting. This rudimentary lamp burned out quickly and was too bright for use in a home or workspace. However in a 2012 lecture for the Proceedings of the American Philosophical Society (opens in new tab), John Meurig Thomas wrote that Davy’s other experiments with lighting led to both the miners’ safety lamp, and also street lighting in Paris “and many other European cities.” The principles behind Davy’s arc light were used throughout the 1800s in the development of many other electric lamps and bulbs.
In 1840, British scientist Warren de la Rue developed an efficiently designed lightbulb using a coiled platinum filament in place of copper, but the high cost of platinum kept the bulb from becoming a commercial success, according to Interesting Engineering (opens in new tab), In 1848, Englishman William Staite improved the longevity of conventional arc lamps by developing a clockwork mechanism that regulated the movement of the lamps’ quick-to-erode carbon rods, according to the Institution of Engineering and Technology (opens in new tab), But the cost of the batteries used to power Staite’s lamps also limited their practical applications.
Joseph Swan vs. Thomas Edison
In 1850, English chemist Joseph Swan began trying to make electrical light more economical, and by 1860 he had developed a lightbulb that used carbonized paper filaments in place of those made of platinum, according to the BBC (opens in new tab), Swan received a patent (opens in new tab) in the UK in 1878, and in February 1879 he demonstrated a working lamp in a lecture in Newcastle, England, according to the Smithsonian Institution (opens in new tab),
Like earlier renditions of the lightbulb, Swan’s filaments were placed in a vacuum tube to minimize their exposure to oxygen, extending their lifespan. Unfortunately for Swan, vacuum pumps weren’t very efficient then, and the prototype didn’t work well enough for everyday use.
Edison realized that the problem with Swan’s design was the filament. A thin filament with high electrical resistance would make a lamp practical because it would require only a little current to make it glow. He demonstrated his lightbulb, with a platinum filament in a glass vacuum bulb, in December 1879 in Menlo Park, New Jersey, according to the Franklin Institute (opens in new tab), Swan included the improvement into his lightbulbs and founded an electrical lighting company in England.
Edison sued for patent infringement, but Swan’s patent was a strong claim, at least in the UK, according to CIO (opens in new tab), The two inventors eventually joined forces and formed Edison-Swan United, which became one of the world’s largest manufacturers of lightbulbs, according to the Science Museum Group (opens in new tab),
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First practical incandescent lightbulb
Where Edison surpassed his competition was in developing a practical and inexpensive lightbulb, according to the DOE. Edison and his team of researchers tested more than 3,000 designs for bulbs between 1878 and 1880.
In Nov. 1879, Edison filed a patent for an electric lamp with a carbon filament, according to the National Archives. (opens in new tab) The patent listed several materials that might be used for the filament, including cotton, linen and wood. Edison spent the next year finding the perfect filament for his new bulb, testing more than 6,000 plants to determine which material would burn the longest.
Several months after the 1879 patent was granted, Edison and his team discovered that a carbonized bamboo filament could burn for more than 1,200 hours, according to the Edison Museum (opens in new tab), Bamboo was used for the filaments in Edison’s bulbs until it began to be replaced by longer-lasting materials in the 1880s to early 1900s.
Related: What’s the longest burning lightbulb?
In 1882, Lewis Howard Latimer, one of Edison’s researchers, patented a more efficient way of manufacturing carbon filaments, according to Rutgers University (opens in new tab), And in 1903, Willis R. Whitney invented a treatment for these filaments that allowed them to burn bright without darkening the insides of their glass bulbs, according to the Smithsonian Institution (opens in new tab),
William David Coolidge, an American physicist with General Electric, improved the company’s method of manufacturing tungsten filaments in 1910. Tungsten, which has the highest melting point of any chemical element, was known by Edison to be an excellent material for lightbulb filaments, but the machinery needed to produce super-fine tungsten wire was not available in the late 19th century.
Tungsten is still the primary material used in incandescent bulb filaments today.
Rachel Ross and Callum McKelvie contributed to this article. This article was updated on Nov. 2, 2022.
Read more about Franklin’s invention at the Franklin Institute (opens in new tab), Learn more about Thomas Edison’s life from MIT (opens in new tab), Watch a video about how light bulbs work from minutephysics on YouTube (opens in new tab),