Sir Joseph Wilson Swan (October 31, 1828 – May 27, 1914) was an English physicist and chemist, most famous for the invention of the light bulb.

Swan was born in 1828 at Pallion Hall in Bishopwearmouth (now Sunderland), and he served an apprenticeship with a pharmacist there. He later became a partner in Mawson's, a firm of manufacturing chemists in Newcastle upon Tyne. This company existed as Mawson, Swan and Morgan until 1973, formerly located on Grey Street in Newcastle-upon-Tyne near Grey's Monument. The premises are now owned by Waterstones and can be identified by a line of Victorian-style electric street lamps in front of the store on Grey Street.

In 1850 he began working on a light bulb using carbonised paper filaments in an evacuated glass bulb. By 1860 he was able to demonstrate a working device, and obtained a UK patent covering a partial vacuum, carbon filament incandescent lamp. However, the lack of a good vacuum and an adequate electric source resulted in an inefficient bulb with a small, uncontinued lifetime.

Fifteen years later, in 1875, Swan returned to consider the problem of the light bulb with the aid of a better vacuum and a carbonised thread as a filament. The most significant feature of Swan's improved lamp was that there was little residual oxygen in the vacuum tube to ignite the filament, thus allowing the filament to glow almost white-hot without catching fire. However, his filament had low resistance, thus needing heavy copper wires to supply it.

Swan received a British patent for his device in 1878, about a year before Thomas Edison. Swan had reported success to the Newcastle Chemical Society and at a lecture in Newcastle upon Tyne in February 1879 he demonstrated a working lamp. Starting that year he began installing light bulbs in homes and landmarks in England. His house Underhill on Kells Lane in Low Fell, Gateshead was the first in the nod. In 1881 he had started his own company, The Swan Electric Light Company, and started commercial production.

In America Edison had been working on copies of the original Swan patent, trying to make them more efficient. Though Swan had beaten him to this goal, Edison obtained patents in America for a fairly direct copy of the Swan light, and started an advertising campaign which claimed that he was the real inventor. Swan, who was less interested in making money from the invention, agreed that Edison could sell the lights in America while he retained the rights in Britain.

In 1883 the Edison & Swan United Electric Light Company was established. Known commonly as "Ediswan" the company sold lamps made with a cellulose filament that Swan had invented in 1881. Variations of the cellulose filament became an industry standard, except with the Edison Company. Edison continued using bamboo filaments until the 1892 merger that created General Electric, and that company then shifted to cellulose.

When working with wet photographic plates, Swan noticed that heat increased the sensitivity of the silver bromide emulsion. By 1871 he had devised a method of drying the wet plates, initiating the age of convenience in photography. Eight years later he patented bromide paper, developments of which are still used for black and white photographic prints.

Three years later, while searching for a better carbon filament for his light bulb, Swan patented a process for squeezing nitro-cellulose through holes to form fibres. The textile industry has used his process.

Swan was knighted in 1904. He died in 1914 at Warlingham in Surrey.

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*Tyne & Wear Archives Service Joseph Swan collection