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vity. A Tangent. Tangential Motion Represents Centrifugal Pull. Equalizing the Two Motions. Lift and Drift. Normal Pressure. Head Resistance. Measuring Lift and Drift. Pressure at Different Angles. Difference Between Lift and Drift in Motion. Tables of Lift and Drift. Why Tables of Lift and Drift are Wrong. Langley's Law. Moving Planes vs. Winds. Momentum not Considered. The Flight of Birds. The Downward Beat. The Concaved Wing. Feather Structure Considered. Webbed Wings. The Angle of Movement. An Initial Movement or Impulse Necessary. A Wedging Motion. No Mystery in the Wave Motion. How Birds Poise with Flapping Wings. Narrow- winged Birds. Initial Movement of Soaring Birds. Soaring Birds Move Swiftly. Muscular Energy Exerted by Soaring Birds. Wings not Motionless.
CHAPTER II.
PRINCIPLES OF AEROPLANE FLIGHT Speed as one of the Elements. Shape and Speed. What "Square of the Speed" Means. Action of a "Skipper." Angle of Incidence. Speed and Surface. Control of the Direction of Flight. Vertical Planes.
CHAPTER III.
THE FORM OR SHAPE OF FLYING MACHINES The Theory of Copying Nature. Hulls of Vessels. Man Does not Copy Nature. Principles Essential, not Forms. Nature not the Guide as to Forms. The Propeller Type. Why Specially-designed Forms Improve Natural Structures. Mechanism Devoid of Intelligence. A Machine Must Have a Substitute for Intelligence. Study of Bird Flight Useless. Shape of Supporting Surface. The Trouble Arising From Outstretched Wings. Density of the Atmosphere. Elasticity of the Air. "Air Holes." Responsibility for Accidents. The Turning Movement. Centrifugal Action: The Warping Planes.
CHAPTER IV.
FORE AND AFT CONTROL The Bird Type of Fore and Aft Control. Angle and Direction of Flight. Why Should the Angle of the Body Change. Changing Angle of Body not Safe. A Non-chan
