National Museum of Nuclear Science & History
George I. Ray worked for the G.G. Ray Company.
Opaline Calhoun was a laboratory technician at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project.
Robert Francis worked for Hanley & Company.
Arthur Weisberg was a mechanical engineer with the Special Engineer Detachment assigned to the Metallurgical Lab at the University of Chicago.
