In 1809, British chemist David invented the arc light, humanity has entered the era of electric lighting. In the United States in 1879, the California Theatre The first human use of arc lights (electric arc light). In 1906, Edison tungsten filament invention of electric light bulbs. With After, incandescent, fluorescent, energy saving lamps, neon signs, and a variety of high-tech lights of contemporary high-tech invention mushroomed on the lighting dance Units. Greatly facilitate the people's production and life. The Edison Electric greatest contribution is the design of the filament. Within two years, he tried more than 6000 kinds of replacement filament, spent $ 40,000 into the Line experiments up to 1200 times. After testing various materials around the world, Edison found that platinum is the most effective. However, this material is very Ngong Expensive and limited, and its efficiency as a practical filament. Finally, Edison tried a carbonized cotton filament. October 19, 1879, Sunday Evening, Edison and his assistant, the cotton filament energized and observed rotation around the clock. After more than 40 hours, the cotton filament remains in the light-emitting , Edison knew he had to solve the problem. Bulb sales in 1880, while in London, the first comprehensive introduction of Edison Illuminating System as early as 1882 Holburn the Viaduct, through the central city power GE Lighting era began in September 1882 4 Day, New York's Pierre Street Station. The face of questions from reporters, Edison "I've completed what I promised."