Edison's filament lamp, American, 1879.
© Science Museum / Science & Society Picture Library
Made by Thomas Alva Edison (1847-1931), this lamp has a single loop of carbon which glowed when a current flowed through it. The glas bulb (made by the glas blower, Boehm) was evacuated so that there was so little oxygen in the bulb that the filament could get white hot without burning. This lamp was made one year after Joseph Swan's pioneering electric light bulb, but both were obsolete by the time Swan and Edison joined forces in Britain in 1883 to form the Edison and Swan United Electric Light Company.