PLATE XXI 252 Montgomery’s Aëroplane. PLATE XXII 258 Santos-Dumont’s Biplane. Santos-Dumont’s _Demoiselle_. PLATE XXIII 260 Farman Biplane, 1908. Farman Biplane, 1909. Harmon in Farman Biplane. PLATE XXIV 264 The _Red Wing_. Curtiss Biplane. Curtiss Biplane with Pontoons. PLATE XXV 268 Blériot Flying Over Toury-Artenay Circuit. Blériot Monoplane _No. VIII_. Blériot Monoplane _No. IX_. PLATE XXVI 272 Wright Biplane of 1908. Standard Wright Biplane of 1910. Wright Racing Biplane of 1910. PLATE XXVII 286 _Blériot XI_ With Moisant Aviator on Mexican Border. _Blériot XII._ PLATE XXVIII 288 _Antoinette_ Monoplane of 1909. _Antoinette_ Monoplane of 1910. PLATE XXIX 302 Esnault-Pélterie Monoplane, Early Pattern. Esnault-Pélterie Monoplane of 1910. PLATE XXX 304 Grade Monoplane. Cody Biplane. PLATE XXXI 332 Fabre Hydro-aëroplane. Paulhan Hydro-aëroplane. Moisant Metal Monoplane. PLATE XXXII 482 Curtiss Starting from the Water. Curtiss Biplane for Land and Water. Curtiss Triplane Risen from the Water. LIST OF ILLUSTRATIONS IN TEXT FIG. PAGE 1.—Da Vinci’s designs for human flying-gear 9 2.—A possible air-scout 12 3.—Blanchard’s flying-machine 17 4.—Lana’s proposed vacuum balloon 24 5.—Montgolfier’s experimental balloon 34 6.—Charles’ first hydrogen balloon 36 7.—Montgolfier’s passenger balloon 39 8.—Charles’ passenger balloon 43 9.—La Flesselle 50 10.—_The Great Balloon of Nassau_ 55 11.—Car of Nadar’s balloon 61