Report presenting an experimental investigation of thrust augmentation of a 4000-pound-thrust axial-flow-type turbojet engine by interstage injection of water-alcohol mixtures into the compressor at sea-level, zero-ram conditions. the number, size, and arrangement of interstage nozzles were varied to produce a satisfactory augmentation system of minimum complication. Results regarding the unaugmented performance with and without interstage-injection nozzles, augmented performance with three-stage system, augmented performance with other injection systems, temperature surveys, and engine operation are provided.