• Collection of Whittle provisional patent specifications relating to the propulsion of aircraft (9 items) - No.347,206 Improvements relating to the propulsion of aircraft and other vehicles. No.347,766 Improvements relating to centrifugal compressors & pumps. No.375,104 Improvements relating to the supercharging of aircraft internal combustion engines. No.456,976 Improvements relating to centrifugal compressors. No.457,972 Improvements relating to the electrical transmission of mechanical power. No. 461,887 Improvements relating to internal combustion turbines.