Columbia University

Working at Columbia University from 1939 to 1942, Enrico Fermi and Herbert Anderson furthered their collaborative research on fission, constructing a series of exponential piles to test their theories. Fermi concluded that it should be possible to sustain a chain reaction in uranium which, under the right conditions, might multiply fast enough to cause a nuclear explosion. Along with physicist Leo Szilard, Fermi proposed placing the uranium in a matrix of graphite, forming a cubical lattice with potential for inducing a self-sustaining controlled reaction.

Portrait of Leo Szilard
Leo Szilard

Photograph

University of Chicago Library, Special Collections Research Center, Archival Photographic Files, apf1-11212
Portrait of Herbert Anderson
Herbert Anderson at Columbia

Photograph
A typed letter
Vannevar Bush to Enrico Fermi, letter, August 19, 1941

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
The second page of the typed letter with Vannevar Bush's signature
Vannevar Bush to Enrico Fermi, letter, August 19, 1941

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Pages from Fermi's notebook, handwritten in pencil on graph paper and including places where he scribbled over mistakes
Enrico Fermi, Notebook D15, November 1941

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
A black and white photo of the cube-shaped pile
Exponential test pile, Columbia University, photograph, undated

Herbert L. Anderson Papers, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Pages from Herbert Anderson's meeting notes, handwritten in blue pen on graph paper
Herbert Anderson, notebook, 1942

Herbert L. Anderson Papers, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Pages from Herbert Anderson's meeting notes, handwritten in blue pen on graph paper
Herbert Anderson, notebook, 1942

Herbert L. Anderson Papers, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
The first page of Fermi's paper. The page has a stamp in red ink in the upper right corner that reads "secret" in capital letters, which was then stamped over with a black stamp to cross it out. On the left edge of the page, it is stamped "declassified" in black ink and dated 1/26/54.
Enrico Fermi, "Neutral Reproduction in a Lattice of Uranium andm Graphite," paper, Mrach 17, 1942

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
The first page of the paper. It was stamped "secret" in the upper right hand corner in red ink, which was then stamped over in black to cross it out. On the bottom of the page, it was stamped "declassified" and dated 1/26/54.
H. L. Anderson, B. Feld, E. Fermi, G. Weil, and W. Zinn, "Neutron Reproduction in a Lattice of Uranium Oxide and Graphite: Exponential Experiemnt," paper, March 26, 1942

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Fermi's personal diary, with equations jotted down under each daily entry.
Enrico Fermi, personal diary, March 1942

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Fermi's personal diary, with equations jotted down under each daily entry.
Enrico Fermi, personal diary, March 1942

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago