text: “The axle was made six times more stout than was needed to be safe. Ferris' axle, the weight of a large locomotive, was at that time the heaviest piece of steel ever forged.” Credit: The Dream City: a portfolio of photographic views of the World's Columbian Exposition/ with an introduction by Professor Halsey C. Ives, Published weekly by St. Louis, MO.: N. D. Thompson Co., 1893-189, found on Ferris Wheel Inventor Historical Marker. ExplorePAhistory.com