A rare First World War 'Aero Engine Data Book' in two volumes, compiled to provide officers and staff of the Technical Department of Aircraft Production data for all the principal British, French, German, Italian and American aero engines, Book No. 6 covering fifty-three engines and No. 6B covering forty-seven engines, arranged in alphabetical order with data sheet, power curve, photographs, etc, produced in loose leaf form, issued to Major Evans 5-2-1918, with further updates through 1918, together with a group of other publications of aero engine interest, including 'Advisory Committee for Aeronautics Internal Combustion Engine Sub-committee Report No. 23', 'British Anzani Engine Co. Instruction Book 100HP and 125HP Anzani Engines' and 'Ariès Moteurs D'Aviation Licence Hispano-Suiza Brevets Birkigt', and two documents relating to Aubrey Thomas Evans.