In 1894, Elwood Haynes successfully tested his one-horsepower, one-cylinder vehicle at 6 or 7 mph at Kokomo, Indiana. He was an American pioneer whose vehicle was one of the first automobiles built. Now on exhibition at the Smithsonian Institution, Washington, D.C., Hayne's vehicle is the oldest American-made automobile in existence. He manufactured automobiles 1898-1925. He was a trained engineer and chemist who discovered several alloys, including a stainless steel (discovered 1911, patented 1919). He was the first to use aluminum in an automobile engine.