As part of a university-wide reorganization, the University of Chicago's Division of the Physical Sciences was formed to incorporate the Departments of Astronomy, Chemistry, Geology, Mathematics, Military Science and Physics. During the 1940s, the division included the Departments of Astronomy and Astrophysics, Chemistry, Geography, Geology, Mathematics, Meteorology and Physics, as well as the Institute for the Study of Metals and the Institute for Nuclear Studies. The astronomer Walter Bartky served as dean of the division during this time. Some of the most critical scientific developments of the 20th century took place under the Division of the Physical Sciences during the 1940s, most famously Enrico Fermi's 1942 achievement of the first self-sustaining nuclear chain reaction. Further research and training programs in the physical sciences were supported by government contracts in the interest of national defense.