remain this way until 1March 1945, when the SAM Laboratories were taken over by Union Carbide. The expansion of the SAM Laboratories led to a search for more space. The Nash Garage Building at 3280 Broadway was purchased by Columbia University. Originally an automobile dealership, it was just a few blocks from the campus. Major Benjamin K. Hough Jr. was the Manhattan District's Columbia Area engineer, and he moved his offices here too. Kellex was in the Woolworth Building at 233 Broadway in Lower Manhattan. In January 1943, Lieutenant Colonel James C. Stowers was appointed New York Area Engineer, with responsibility for the entire K-25 Project. His small staff, initially of 20 military and civilian personnel, but which gradually grew to over 70, was co-located in the Woolworth Building. The Manhattan District had its offices nearby at 270 Broadway until it moved to Oak Ridge, Tennessee, in August 1943. Codename The codename "K-25" was a combination of the "K" from Kellex, and "25", a World War II-era code designation for uranium-235 (an isotope of element 92, mass number 235). The term was first used in Kellex internal reports for the end product, enriched uranium, in March 1943. By April 1943, the term "K-25 plant" was being used for the plant that created it. That month, the term "K-25 Project" was applied to the entire project to develop uranium enrichment using the gaseous diffusion process. When other "K-" buildings were added after the war, "K-25" became the name of the original, larger complex. Research and development Diffusers The highly corrosive nature of uranium hexafluoride presented several technological challenges. Pipes and fittings that it came into contact with had to be made of, or clad with nickel. This was fine for small objects, but impractical for the large diffusers, the tank-like containers that had to hold the gas under pressure. Nickel was a vital war material, and although the Manhattan Project could use its overriding priority to acquire it, making the diffusers out of solid nickel would deplete the national supply. The director of the Manhattan Project, Brigadier General Leslie R. Groves Jr., gave the contract to build the diffusers to Chrysler. In turn, its president, K. T. Keller assigned Carl Heussner, an expert in electroplating, the task of developing a process for electroplating such a large object. Senior Chrysler executives called this "Project X-100". Electroplating used one-thousandth of the nickel of