Alexander Graham Bell : The Life and Times of the Man Who Invented the Telephone

Edwin Grosvenor writes of Bell's other extraordinary inventions: the first transmission of sound over light waves, metal detector, first practical phonograph, and early airplanes, including the first to fly in Canada. He also examines Bell's humanitarian efforts, including support for women's suffrage, civil rights, and speeches about what he warned would be a "greenhouse effect" of pollution causing global warming.