Aeroplanes by J. S. Zerbe Scanned by Charles Keller with OmniPage Professional OCR software AEROPLANES This work is not intended to set forth the exploits of aviators nor to give a history of the Art. It is a book of instructions intended to point out the theories of flying, as given by the pioneers, the practical application of power to the various flying structures; how they are built, the different methods of controlling them; the advantages and disadvantages of the types now in use; and suggestions as to the directions in which improvements are required. It distinctly points out wherein mechanical flight differs from bird flight, and what are the relations of shape, form, size and weight. It treats of kites, gliders and model aeroplanes, and has an Interesting chapter on the aeroplane and its uses In the great war. All the illustrations have been specially prepared for the work. Every Boy's Mechanical Library AEROPLANES BY J. S. ZERBE, M. E. Author of Automobiles--Motors COPYRIGHT, 1915, BY CUPPLES & LEON COMPANY NY CONTENTS INTRODUCTORY CHAPTER I. THEORIES AND FACTS ABOUT FLYING The "Science" of Aviation. Machine Types. Shape or Form not Essential. A Stone as a Flying Machine. Power the Great Element. Gravity as Power. Mass and Element in Flying. Momentum a Factor. Resistance. How Resistance Affects Shape. Mass and Resistance. The Early Tendency to Eliminate Momentum. Light Machines Unstable. The Application of Power. The Supporting Surfaces. Area not the Essential Thing. The Law of Gravity. Gravity. Indestructibility of Gravitation. Distance Reduces Gravitational Pull. How Motion Antagonizes Gravity. 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.