TRANSCRIBER’S NOTE Italic text is denoted by _underscores_. Bold text is denoted by =equal signs=. Footnote anchors are denoted by [number], and the footnotes have been placed at the end of the book. The tables in this book are best viewed using a monospace font. Some minor changes to the text are noted at the end of the book. THE NEW AIR WORLD [Illustration: FIG. 4.—INSTRUMENT SHELTER. Frontispiece. (_Page 66_)] THE NEW AIR WORLD _The Science of Meteorology Simplified_ BY WILLIS LUTHER MOORE, SC.D., LL.D. PROFESSOR METEOROLOGY GEORGE WASHINGTON UNIVERSITY, EIGHTEEN YEARS CHIEF UNITED STATES WEATHER BUREAU [Illustration: (colophon)] BOSTON LITTLE, BROWN, AND COMPANY 1922 _Copyright, 1922_, BY LITTLE, BROWN, AND COMPANY. _All rights reserved_ Published October, 1922 PRINTED IN THE UNITED STATES OF AMERICA AFFECTIONATELY DEDICATED TO A FRIEND OF MANY AND PLEASANT YEARS A BELOVED TEACHER AND A GREAT CHEMIST DR. CHARLES E. MUNROE, PH.D. INTRODUCTION The author’s “Descriptive Meteorology” (Appleton, 1914) is designed for the teaching of those who intend to make Meteorology a profession. This book is planned for the reading of those who desire to know something of the wonders of the New Air World into which man is just now entering, for those who desire to become weatherwise and make forecasts for themselves, and to apply their knowledge to their business, their health, and their happiness; and for the reading of the more advanced pupils of the public schools. So far as possible technical terms are avoided and an effort made to tell a simple story that will awaken curiosity and lead the reader to wish to know more and more of the mysteries of the atmosphere, of which practically nothing was known at the time of the landing of the Pilgrims, Torricelli not having discovered the barometer until twenty-three years later. It will be made plain how atmospheric air was formed, how long it will remain, whither it will go, how it is heated, cooled, and lighted; where and how storms, cold waves, clouds, frosts, and fair-weather conditions originate and how move; how the cyclone, the tornado, and the thunderstorm may be recognized on the Daily Weather Map of the Government and their future activities forecast; how a fund of simple yet wonderful information that will be of inestimable value may be acquired by any intelligent person.