A year before the Manhattan Project began, the S-1 Section of the Office of Scientific Research and Development asked Kellogg to work with John R. Dunning and other scientists at Columbia University to ascertain the feasibility of gaseous diffusion.

Several technical challenges needed to be met before gas extraction techniques could be effectively applied to separation of uranium.

These included a pilot gaseous diffusion plant built at Columbia University in the Nash Garage Building at 3280 Broadway, New York, NY.

[8] Scientists and engineers were developing technology for the proposed production plant at the same time that architects were designing a building to house it.

[4] The mile-long, U-shaped plant covered 44 acres (18 ha), was four stories high and contained hundreds of miles of specially coated, hermetically sealed pipes and equipment.