Nigel, Thomas Edison was the DC man who "proved" how dangerous AC was when he pointed out that the electric chair at Sing Sing prison was powered by AC. It was George Westinghouse who, with Nikola Tesla, built the first hydroelectric AC generator (3-phase) at Niagra Falls. That plant supplied far more power than was currently being used in the entire northeastern part of the U.S. Tesla had worked for Edison for a very short period of time and didn't much like Tom's hit-and-miss method of invention preferring a more analytical (sometimes read "anal") engineering approach.