Myth

Thomas Alva Edison (1847-1931) invented what we would now recognise today as the electric light bulb. A feat of achievement only managed after many thousands of hours of experiments. His vacuum carbon filament bulb is the basis of all electric bulb technology today.

Reality

Edison neither invented the light bulb or the vacuum carbon filament light bulb. Light bulbs had been around for decades but proved unrealible and not particularly effective. In 1850 Sir Joseph Wilson Swan (1828–1914) began working on a light bulb using carbonized paper filaments in an evacuated glass bulb. By 1860 he was able to demonstrate a working device, and obtained a UK patent covering a partial vacuum, carbon filament incandescent lamp.However, the lack of good vacuum and an adequate electric source resulted in a short lifetime for the bulb and an inefficient light.

Fifteen years later, in 1875, Swan returned to consider the problem of the light bulb and, with the aid of a better vacuum and a carbonized thread as a filament. The most significant feature of Swan's lamp was that there was little residual oxygen in the vacuum tube to ignite the filament, thus allowing the filament to glow almost white-hot without catching fire.

Swan received a British patent for his device in 1878, about a year before Thomas Edison. Swan successfully won a court battle agains Edison and was awarded substantial damages. To resolve these Edison and Swan formed a joint company called Ediswan to market the invention. This company and its technological heritage became General Electric in 1892.

Tags: thomas edison