Thomas Edison invented the incandescent light bulb in 1879, patenting it the following year. Before getting the right design for a long-burning, pleasant light for indoor use, he experimented with more than 1,600 different bulbs.
To make safer electric lights comfortable to use inside the home, Edison needed to find a pleasant light with a long-burning filament. He experimented with everything from coconut fibers to human hair, finally hitting on carbonized bamboo as the ideal centerpiece for his new bulb. The first successful large-scale test of Edison's bulb was in October 1882, when 25 buildings in the New York City financial district were lit with electric light bulbs.
While electric lighting already existed during Edison's time, they were arc lights, too bright to be comfortable indoors and impractical for everyday use. Hence, most houses used candles, lanterns or gas lights, all of which were dangerous due to their open flames.