CONTENTS

PART I I. Introductory … 1 II. Preliminary … 5 Experiments with small models … 6 Abbreviations and symbols employed … 14 Experiments with Aerodromes Nos. 30 and 31 … 16 III. Available motors … 21 India rubber … 21 Steam engine … 24 Gunpowder, hot-water, compressed air … 25 Gas, electricity … 26 Carbonic-acid gas … 28 IV. Early steam motors and other models … 30 V. On sustaining surfaces … 41 Experiments in the open wind … 42 Relation of air to weight and power … 43 VI. Balancing the aerodrome … 45 Lateral and longitudinal stability … 45 VII. History of construction of frame and engines of aerodromes … 53 1893 … 53 1894 … 64 1895 … 75 1896 … 79 VIII. History of construction of sustaining and guiding surfaces of aerodromes 4, 5, and 6 … 80 Introduction … 80 1893, 1894 … 81 1895 … 85 1896 … 89 IX. History of launching apparatus and field trials of aerodromes 4, 5, and 6 … 92 1892 … 92 1893 … 93 Field trials … 93 1894 … 96 1895 … 101 1896 … 106 X. Description of the launching apparatus of aerodromes Nos. 5 and 6 … 110 Description of Aerodrome No. 5 … 111 Description of Aerodrome No. 6 … 120

PART II I. Introductory … 123 II. General considerations … 128 III. Experiments with models … 133 Condensed record of flights of aerodromes Nos. 5 and 6, from June 7 to August 3, 1899 … 135 June 7—aerodrome No. 6 … 135 June 13—aerodrome No. 6 … 137 June 22—aerodrome No. 6 … 139 June 23—aerodrome No. 6 … 140 June 27—aerodrome No. 5 … 140 June 30—aerodrome No. 5 … 141 July 1 to July 8 … 142 July 11 to July 14—aerodrome No. 5 … 143 July 19—aerodrome No. 5 … 144 July 27—aerodrome No. 6 … 145 July 28—aerodrome No. 6 … 146 July 29—aerodrome No. 5 … 147 August 1—aerodrome No. 5 … 148 August 3—aerodrome No. 5 … 149 IV. House-boat and launching apparatus … 156 V. Construction of frame of large aerodrome … 164 Transverse frame … 174 Propellers … 178 Aviator’s car … 185 VI. Construction of supporting surfaces … 188 VII. Equilibrium and control … 207 VIII. The experimental engine … 218 IX. The quarter-size model aerodrome … 226 X. Construction and tests of the large engine … 234 XI. Shop tests of the aerodrome … 251 XII. Field trials in 1903 … 255 Statement made by Mr. Manly to associated press … 266 Report of War Department, January, 1904 … 276 Langley aerodrome, Official Report of Board of Ordnance, October, 1904 … 278 Statement to the Press … 280 Present status of the work … 281 Blériot Machine of 1907 on Langley type … 283 Appendix. Study of American Buzzard and “John Crow” … 285 Instructions to assistants … 294 Data sheets 1 to 12 … 297

Index … 309