140 Years of Incandescent Light
If you ask the average person, “Who invented the light bulb,” the answer will likely be “Thomas Edison.”
However, it’s not quite that simple. The earliest patent
was granted 140 years ago to English chemist, Joseph
Swan, and even his invention was built upon earlier
achievements by Alessandro Volta and Humphry Davy.
An early light bulb designed by Warren de la Rue worked
reasonably well but used a coiled platinum filament,
which was too expensive to allow commercial success. It
also had high conductance, which limited its working life.
In 1860, Swan partially solved the cost problem by
replacing the platinum with a carbonized paper filament,
and he received a patent in the UK in 1878. This version,
however, proved impractical because vacuum pumps in
that era were not efficient enough to create a strong
vacuum. A year later, Edison demonstrated his bulb,
which featured a better vacuum and incorporated a thin
filament with high electrical resistance, thus requiring
only a small current to make it glow.
Swan adopted Edison’s improvements and started his
own electrical lighting company in England. After losing a
patent infringement suit against Swan, the two joined
forces and created Edison & Swan Electric Light Co. Ltd.,
which became one of the world’s largest light bulb
manufacturers. The rest, as they say, is history. ;
INDUSTRY and the PROFESSION
; Joseph Wilson Swan, co-inventor of the light bulb.
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