The possibility of creating artificial light with electricity was established as early as 1808, when the English chemist Sir Humphry Davy demonstrated that current from batteries can create light either by heating some substance until it glows or by causing an arc of electricity to jump over a gap between two conductors. Arc lighting uses a lot of current and creates a brilliant light and it was limited to the outdoors or large interior spaces. The problem of lighting smaller spaces—which technicians of the nineteenth century called subdividing the light—was to find a lighting material that would not burn or melt when the current ran through it. Carbon and platinum seemed most promising but not ideal: the first does not melt, but it burns easily, while the second resists chemical changes at high temperatures (oxidation) but catches fire if the...