4 0 c m
30cm
actual image size: 22cm x 32cm
Description
The English chemist Joseph Swan (1828-1914) demonstrated his lamp in February 1879. It had a carbon filament which glowed when a current flowed through it. The glass bulb contained a partial vacuum; there was so little oxygen in the bulb that the filament could get very hot without catching fire.
Image Details
Image Ref.
10462942
© Science Museum / Science & Society Picture Library