Bradford is a small city located in rural McKean County, Pennsylvania, in the United States 78 miles (126 km) south of Buffalo, New York. Settled in 1823, Bradford was chartered as a city in 1879 and emerged as a wild oil boomtown in the Pennsylvanian oil rush in the late 1800s. The area's Pennsylvania Grade crude oil has superior qualities and is free of asphaltic constituents, contains only trace amounts of sulfur and nitrogen, and has excellent characteristics for refining into lubricants. World-famous Kendall racing oils were produced in Bradford. The population peaked at 17,691 in 1940, but as of the 2000 census had dropped to 9,175 and was still declining at mid-decade according to census bureau estimates. Two adjoining townships, home to approximately 9,000 people, make the population of Greater Bradford about 18,000. Famous Bradfordians include opera singer Marilyn Horne and Hall of Fame baseball player Rube Waddell. A famous Perpetual Motion machine hoax was created in Bradford in 1897 by J M Aldrich; it was exposed in the July 1, 1899 issue of the Scientific American magazine, leading to a four month prison sentence in the county jail.