Incandescent lamp with carbon filament

Thomas Edison’s many inventions included his improvements to the incandescent lamp beginning in 1878. But although simple in principle it was less so in practice. Subjected to an electric current, a filament in a vacuum inside a glass bulb heats and becomes incandescent and luminous. Edison found a way of creating the vacuum inside the bulb using a Sprengel pump. For the filament, he experimented with various materials capable of resisting high temperatures without breaking: platinum, Bristol board, and finally carbonised bamboo fibre. He successfully showed this type of lamp at the International Electricity Exhibition in Paris in 1881. Edison’s research into electric lighting and his acute business acumen ensured the major success of this lamp as the use of electricity grew both in industry and the home.