 Bull was soon assigned to work with fellow student Doug Henshaw, and the two were given the task of building a supersonic wind tunnel, which was at that time a relatively rare device.When the Royal Canadian Air Force donated land adjacent to RCAF Station Downsview to the Institute, the operations were quickly moved.During construction, Bull used the wind tunnel as the basis for his September 15, 1949 Master's thesis, on the design and construction of advanced wind tunnels.