GETTING UP AND DOWN; MODELS AND GLIDERS; AEROPLANE DETAILS.--Launching.--Descending.-- Gliders.--Models.--Balancing.--Weights.-- Miscellaneous.--Things to Look After 121 SOME AEROPLANES.--SOME ACCOMPLISHMENTS 143 THE POSSIBILITIES IN AVIATION.--The Case of the Dirigible.--The Orthopter.--The Helicopter.--Composite Types.--What is Promised 170 AERIAL WARFARE 189 LIST OF ILLUSTRATIONS PAGE The Fall of Icarus _Frontispiece_ The Aviator 3 The Santos-Dumont "_Demoiselle_" 4 View from a Balloon 9 Anatomy of a Bird's Wing 10 Flight of a Bird 11 In a Meteoric Shower 13 How a Boat Tacks 15 Octave Chanute 18 Pressure of the Wind 19 Forces Acting on a Kite 20 Sustaining Force in the Aeroplane 23 Direct Lifting and Resisting Forces 24 Shapes of Planes 26 Balancing Sail 28 Roe's Triplane at Wembley 30 Action of the Steering Rudder 31 Recent Type of Wright Biplane 31 Circular Flight 33 The Aileron 35 Wing Tipping 36 Wing Warping 37 The Gyroscope 39 Diurnal Temperatures at Different Heights 45 Seasonal Variation in Wind Velocities 47 The Wind Rose for Mt. Weather, Va. 49 Diagram of Parts of a Drifting Balloon 51 Glidden and Stevens Getting Away in the "_Boston_" 52 Relative and Absolute Balloon Velocities 53 Field and Speed 53 Influence of Wind on Possible Course 54 Count Zeppelin 55 Buoyant Power of Wood 57 One Cubic Foot of Wood Loaded in Water 58 Buoyant Power of Hydrogen 59 Lebaudy's "_Jaune_" 60 Air Balloon 62 Screw Propeller for Altitude Control 66