The story of the light bulb begins long before Edison ___(1)___ the first commercially successful bulb in 1879. In 1800, Italian inventor Alessandro Volta developed the first practical method of generating electricity, the voltaic pile. Made of alternating discs of zinc and copper — interspersed with layers of cardboard soaked in saltwater — the pile conducted electricity when a copper wire was connected at either end. While actually a ___(2)___ of the modern battery, Volta's glowing copper wire is also considered to be one of the earliest ___(3)___ of incandescent lighting.
Not long after Volta presented his ___(4)___ of a continuous source of electricity to the Royal Society in London, Humphry Davy, an English chemist and inventor, produced the world's first electric lamp by connecting voltaic piles to charcoal electrodes. Davy's 1802 invention was known as an electric arc lamp, named for the bright arc of light emitted between its two carbon rods.
While Davy's arc lamp was certainly an improvement on Volta's stand-alone piles, it still wasn't a very practical source of lighting. This ___(5)___ lamp burned out quickly and was much too bright for use in a home or workspace. But the principles behind Davy's arc light were used throughout the 1800s in the development of many other electric lamps and bulbs.