TRI DUC ENGLISH - The Development of the Lightbulb TRI DUC ENGLISH Reading Practice: The Development of the Lightbulb Thomas Edison is generally credited with the invention of the lightbulb. In fact, he was just one inventor among many involved in the process of moving the concept of incandescent light from inspiration to marketable reality. What he actually invented in 1879 was a carbon filament that lasted for forty hours. In 1880, he improved his idea, producing a filament derived from bamboo that burned for 1,200 hours. The first person to successfully produce light with electricity was Humphry Davy, who connected a carbon filament to a battery in 1809. Other inventors worked on refinements of this idea. In 1835, James Lindsay unveiled an electric lamp, which cast enough light to read a book one and a half feet away. In 1854, Henrich Globel created the first actual lightbulb—a glass bulb containing a filament that glowed when electrical current passed through it. However, it burned out too quickly to have any commercial value. Then, Hermann Sprengel developed the Sprengel Pump, a device that used mercury to create a vacuum. Reducing the oxygen in the bulb allowed the filament to glow longer before burning out. In 1874, Henry Woodward and Matthew Evans filed a patent for a light specifically described as "a shaped piece of carbon held between two electrodes enclosed in a glass vessel." Woodward and Evans attempted to raise the necessary money to improve and market their invention; however, as entrepreneurs, they had little success finding anyone to back them financially. Eventually they sold the rights to their patents to Thomas Edison. Edison had already been working on the same idea, but for him money was not a critical issue. He was no longer a solitary inventor working in his basement, but the head of a laboratory with the support of investors. He worked to refine the Woodward and Evans light because its filament burned out too quickly. Edison set about testing every material possible for use as a filament. "Before I got through," Edison recalled, "I tested no fewer than 6,000 vegetable growths, and ransacked the world for the most suitable filament material." He even considered using tungsten, which is the material curr...