The electric light bulb was invented by Joseph Swan in Tyneside, north east England, in 1879. It works by the electricity, when the supply has been turned on, passing through a thin filament heats it which makes it glow brightly. At first the filaments were made of carbon which made them expensive, but in around 1910 they started to be produced with a tungsten filament which made them more affordable. The chemical symbol for tungsten is W, hence it being used in the name and advertising for the new light bulbs.
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