Book excerpt: In September 1878, Thomas Alva Edison brashly—and prematurely—proclaimed his breakthrough invention of a workable electric light. That announcement was followed by many months of intense experimentation that led to the successful completion of his Pearl Street station four years later. Edison was not alone—nor was he first—in developing an incandescent light bulb, but his was the most successful of all competing inventions. Drawing from the documents in the Edison archives, Robert Friedel and Paul Israel explain how this came to be. They explore the process of invention through the Menlo Park notes, discussing the full range of experiments, including the testing of a host of materials, the development of such crucial tools as the world's best vacuum pump, and the construction of the first large-scale electrical generators and power distribution systems. The result is a fascinating story of excitement, risk, and competition. Revised and updated from the original 1986 edition, this definitive study of the most famous invention of America's most famous inventor is completely keyed to the printed and electronic versions of the Edison Papers, inviting the reader to explore further the remarkable original sources.