Later Years

After the mining failure, Edison adapted some of the machinery to process Portland cement. A roasting kiln he developed became an industry standard. Edison cement was used for buildings, dams, and even Yankee Stadium.In the early years of the automobile industry there were hopes for an electric vehicle, and Edison spent the first decade of the twentieth century trying to develop a suitable storage battery. Although gas power won out, Edisons battery was used extensively in industry.In World War I the federal government asked Edison to head the Naval Consulting Board, which examined inventions submitted for military use. Edison worked on several problems, including submarine detectors and gun location techniques.By the time of his death in 1931, Edison had received 1,093 U.S. patents, a total still untouched by any other inventor. Even more important, he created a model for modern industrial research.