BULB

In truth, the question has a less obvious answer than many people believe. In reality, in fact, to be extremely precise, the true father of the light bulb was the Englishman Joseph Wilson Swan, whose patent is dated 1878. Swan's light bulb was built with a very thick carbon filament which, when heated, it emitted light and gas. The problem, however, was the excessive soot that this filament gave off, which in a short time - a matter of minutes - covered the entire bulb of the light bulb, blackening it and therefore making the light bulb unusable.