ARGONNE NATIONAL LABORATORY / SCIENCE PHOTO LIBRARY ARGONNE NATIONAL LABORATORY / SCIENCE PHOTO LIBRARY
Contemporary sketch of the atomic pile in Chicago in which the first self-sustaining nuclear chain reaction occurred on December 2, 1942. At bottom left is physicist George Weil operating the main control rod. The pile was built by a team led by the Italian physicist Enrico Fermi in a squash court underneath Chicago University's Stagg Field. The pile consisted of a complex lattice of bricks of graphite & "slugs" of uranium. It was encased in a tent of balloon fabric to minimise the loss of neutrons from the pile. Part of this tent is seen above and to the left of the pile, but was eventually found not to be needed.
Model release not required. Property release not required.