[Illustration: ORVILLE WRIGHT IN THE 80-MILE-AN-HOUR “BABY WRIGHT” RACER.] How It Flies or, THE CONQUEST OF THE AIR The Story of Man’s Endeavors to Fly and of the Inventions by which He Has Succeeded By RICHARD FERRIS, B.S., C.E. Illustrated by Over One Hundred and Fifty Half-tones and Line Drawings, Showing the Stages of Development from the Earliest Balloon to the Latest Monoplane and Biplane New York THOMAS NELSON AND SONS 381-385 Fourth Avenue Copyright, 1910, by THOMAS NELSON & SONS THE TROW PRESS, NEW YORK PREFACE In these pages, by means of simple language and suitable pictures, the author has told the story of the Ships of the Air. He has explained the laws of their flight; sketched their development to the present day; shown how to build the flying machine and the balloon, and how to operate them; recounted what man has done, and what he hopes to do with their aid. In a word, all the essential facts that enter into the Conquest of the Air have been gathered into orderly form, and are here presented to the public. We who live to-day have witnessed man’s great achievement; we have seen his dream of ages come true. Man has learned to _fly_! 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 CHAPTER PAGE 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