川 COPYRIGHT, 1912, BY THE MACMILLAN COMPANY. Set up and electrotyped. Published March, 1912. TO VIMU AMBOLIA) Norwood Press Norwood, Mass., U.S.A. PREFACE THIS book owes its existence to a course on meteorology which has been given by the author in Williams College for the last eight years. This course is a Junior and Senior elective course with three exercises a week during a half year. A syllabus, covering both the text-book used and the added material, was prepared for the course. This was at first mimeographed, then revised and printed. Later it was again revised and reprinted. This book follows the order of topics in this last syllabus very closely, and is thus essentially a resumé of the material which has been gathered for the course. This book is essentially a text-book. For this reason, the marginal comments at the sides of the pages, the questions, topics for investigation, and practical exercises have been added. A syllabus of each chapter has been placed at its beginning, and the book has been divided into numbered sections, each treating a definite topic. The book is also intended for the general reader of scientific tastes, and it is hoped that these earmarks of a text-book will not be found objectionable by him. It can hardly be called an elementary treatise, but it starts at the beginning and no previous knowledge of meteorology itself is anywhere assumed. It is assumed, however, that the reader is familiar with the great general facts of science. References have been added at the end of each chapter. These include pamphlets and articles in the periodical literature as well as books. These are the first things which a student would naturally look up in order to gain further information. In appendix IX an attempt has been made to summarize the literature of meteorology. Here the books are arranged in alphabetical order without regard to age or value. Both the metric and English system of units and the Fahrenheit and centigrade thermometer scales have been used in the book. It seems unnecessary in quoting facts and data from many sources to change everything to conform to one set of units. In appendices I, II, and III, the English and metric systems of units and conversion tables have been added. The facts of meteorology have now become so general and accepted that there can be but little that is new in such a book. The originality must lie in the arrangement, use, and perhaps interpretation 236401 of these facts. Whenever a distinctive idea has been introduced by some investigator, credit is always given in the text when this idea is quoted. Such credit has never been intentionally omitted by the author. Although this book has assumed a considerable size, it can lay no claim to completeness. No single volume can be a treatise containing all known facts to date and all the explanations which have been offered. Four aspects or applications of meteorology have been entirely omitted. These are: (1) Mathematical Meteorology. (2) Meteorology applied to living things; including phenology and the influence of climate on man. (3) Meteorology and medicine; including climate and disease. (4) A History of Meteorology; including a biography of the men who have contributed much to its development. To each of these subjects a long chapter could be devoted, and they could easily be expanded so as to become large books. Such topics as "Meteorological Apparatus," "The Daily, Annual, and Irregular Variation in the Various Meteorological Elements," "The Isothermal Layer," etc., could be easily treated at such length as to become a large book. In fact, each chapter in this book could be expanded into a sizable volume. This book, then, makes no attempt at completeness, but it does attempt to give a fairly full presentation of the present state of the science, and also to point the way for further acquisition of information on the part of him who desires it. In the preparation of this book, the author is particularly indebted to the United States Weather Bureau and to Professor Willis L. Moore, its chief. Every opportunity was given to make use of what is probably the largest meteorological library in the world; tables of data to illustrate various points were supplied; and free permission to reproduce and quote much that has appeared in government publications was given. The author is under great obligations to many persons who have helped him in various ways: to Professor William J. Humphreys, Professor of Meteorological Physics, United States Weather Bureau, who has read the entire manuscript and made many helpful and valuable suggestions; to Edward H. Bowie of the forecast division, Preston C. Day and Maitland C. Bennett of the climatological division, C. Fitzhugh Talman in charge of the library, and Cleveland Abbe, Jr., of the library division, for assistance and suggestions during the final revision of this book while in Washington; to Professor Cleveland Abbe, who has read a portion of the manuscript and whose kindly interest is an inspiration to any one who is teaching meteorology or doing research in that subject; to George |