HANDBOOK OF METEOROLOGY A Manual for C o o p e r a t i v e O b s e r v e r s and Studefzts - 1921 - PREFACE - This text-book has been prepared for the use of cooperative observers and for the instruction of students in meteorology and aeronautics. It is essentially a laboratory manual. Part I is an elementary synopsis of the general principles of air science, but is not wholly restricted thereto. The subject of atmospheric transparency and the principles of visibility may not be logically a part of tgeteorology, but it is one of great importance, not only to air men, but also to every one engaged in transportation. The chapter on the dust content of the air in part summarizes the researches of author in this field. Part I1 is descriptive of the instruments used in meteorology and the construction and care of them. The methods of observation discussed is a resume of the experience of many observers covering a period of half a century. This part of the text is specifically designed for the use of cooperative observers and students. The Appendix contains conversion and other useful tables that are not included in the Circulars of Instruction published by the U. S. Weather Bureau. English units of measurement are used throughout the book, but the metric equivalents are used when necessary. In the final revision of the text, the author desires to express his appreciation for the counsel received from James H. Scarr, forecaster in charge of the New York City Weather Bureau Office, and to J. H. Kimball of the same office in charge of marine work. Acknowledgments are due to Dr. Charles F. Brooks, editor of the Monthly Weather Review, for the cloud photographs used, and also for his critical knowledge of cloud science to Dr. W. J. Humphreys for the use of illustrations in his Physics of the Air and to Charles Scribners Sons for the use of illustrations taken from Redways Physical Geography. METEOROLOGICALLA BORATORY Mount Vernon, N. Y. iii TABLE OF CONTENTS PART I GENERAL PKINCZPLES PAGE I . THE A TMOSPHER A E N D ITS CONSTITUEN . T . S . . . . . . . . . . . . . . . . . I 11 . FORMS AN D PROPERTIE O S F I. T. EK IN RELATION TO ME TEOROLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 I11 . HEAT I TS NATURE P , ROPERTI A E X S D DIFFUSIO . N . . . . . . . . . . . . . 16 IV . THE A IR DISTRIBUTIO OF N W ARMT . H . . . . . . . . . . . . . . . . . . . . . . . 23 V . THE A IR DISTKIBUTI O O F K P RESSUR . E . . . . . . . . . . . . . . . . . . . . . . 39 V1 . THE A IR MAJOR C IRCULATIOLNO C AL W ISDS . . . . . . . . . . . . . . . . 49 V11 . THEM OISTURE OF THE AIR Ev-ZPORATI . I O ND N CONDENSATI . O N 60 VIII . THEM OISTURE O F THE AIR FOGS A SD CLOUD . S . . . . . . . . . . . . . 68 IX . THE M OISTURE O F THE AIR RECIPIT. TION . . . . . . . . . . . . . . . . . . 93 X . ATMOSPHERI E C L ECTRIC I TOYPT ICAL P HEKOME . N . A . . . . . . . . . . . 108 XI . THED UST C ONTENT OF THE AIR . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 XI1 . THEP RINCIPLE O S F ATMOSPHERI V C I SIBILITY . . . . . . . . . . . . . . . . . I33 XI11 . THE D AILY W EATHER M AP STORM . . S . . . . . . . . . . . . . . . . . . . . . . 146 XIV . FORECAST T IN HE G W EATHER F OLKLO . R . E . . . . . . . . . . . . . . . . . . . 164 PART II INSTRUMENTS AND MEASUREMENT XV . THE M EASUREMEN OF T TEMPERATU T R H E E H MOMP . I . T . E . . K . . S . 177 XVI . THE M EASUREMEN O T F PRESSUR M E E RCURY RA KO JIETER . S . . . . 193 XVII . THE IEASUREME OF N PTR ESSUR A E N EROID B AKOJIETER . S . . . . . 206 XVII I . THE M EASUREMEN O T F HUMIDITY H Y GROMETP . I . K . . S . . . . . . . ...