Harry W. Bull (1909-1971) was an American rocketry pioneer who conducted more than 800 individual tests during the period from 1926 to 1934, as well as building and successfully riding a rocket-propelled sled in 1931. Bull was credited by James Hart Wyld with being the first American to design and build a regeneratively-cooled rocket motor and the first to experiment with a monopropellant rocket motor. Bull also did extensive research on steam propulsion as well as various types of propellants. Bull financed his education by lecturing on rocketry, and by selling photos of his successful rocket sled experiments to various news outlets. Bull also was able to use publicity generated by the sled run to produce and sell a copyrighted specification booklet. Bull graduated from the College of Applied Science at Syracuse University with a Bachelor of Science degree in mechanical engineering in 1932. After graduating, Bull was employed by Church and Dwight Company to design and test packaging machines, then went to work in 1935 with the Tennessee Valley Authority where he was involved in aerial mapping. Bull joined The Dow Chemical Company in 1937 as a design engineer, becoming a packaging coordinator in 1954, and he was named Director of Packaging in 1962. Bull retired from Dow in 1968 due to ill health. Bull was a member of the American Interplanetary Society, the American Society of Mechanical Engineers, and was a charter member of the American Rocket Society, as well as belonging to various organizations relating to his work in packaging.