The air which surrounds us, so intangible and so commonplace that it seldom arrests our attention, is in reality a vast, unexplored ocean, fraught with future possibilities. Even now, the pioneers of a countless fleet are hovering above us in the sky, while steadily, surely these wonderful possibilities are unfolded.

The Publishers take pleasure in acknowledging their indebtedness to the Scientific American for their courtesy in permitting the use of many of the illustrations appearing in this book.

New York, October 20, 1910.

CONTENTS

CHAPTERPAGE
[Preface]7
I.[Introductory]11
II.[The Air]20
III.[Laws of Flight]37
IV.[Flying Machines]55
V.[Flying Machines: The Biplane]78
VI.[Flying Machines: The Monoplane]112
VII.[Flying Machines: Other Forms]141
VIII.[Flying Machines: How to Operate]151
IX.[Flying Machines: How to Build]174
X.[Flying Machines: Motors]193
XI.[Model Flying Machines]215
XII.[The Glider]241
XIII.[Balloons]257
XIV.[Balloons: The Dirigible]296
XV.[Balloons: How to Operate]340
XVI.[Balloons: How to Make]351
XVII.[Military Aeronautics]363
XVIII.[Biographies of Prominent Aeronauts]379
XIX.[Chronicle of Aviation Achievements]407
XX.[Explanation of Aeronautical Terms]452

HOW IT FLIES

Chapter I.
INTRODUCTORY.