Produced by The Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive.) SHILLING SCIENTIFIC SERIES [Illustration: DR. AITKEN'S DUST-COUNTER. R is the test-receiver; P the air-pump; M the measuring apparatus; L the illuminating arrangements; G the Gasometer; A the pipe through which the tested air is drawn.] METEOROLOGY; OR, WEATHER EXPLAINED. BY J. G. M'PHERSON, Ph.D., F.R.S.E., GRADUATE WITH FIRST-CLASS HONOURS, AND FOR NINE YEARS EXTENSION LECTURER ON METEOROLOGY AND MATHEMATICAL EXAMINER IN THE UNIVERSITY OF ST. ANDREWS; AUTHOR OF "TALES OF SCIENCE," ETC. LONDON: T. C. & E. C. JACK, 34 HENRIETTA STREET, W.C. AND EDINBURGH. 1905. THE SHILLING SCIENTIFIC SERIES _The following Vols. are now ready or in the Press_:-- BALLOONS, AIRSHIPS, AND FLYING MACHINES. By GERTRUDE BACON. MOTORS AND MOTORING. By Professor HARRY SPOONER. RADIUM. By Dr. HAMPSON. TELEGRAPHY WITH AND WITHOUT WIRES. By W. J. WHITE. ELECTRIC LIGHTING. By S. F. WALKER, R.N., M.I.E.E. LOCAL GOVERNMENT. By PERCY ASHLEY, M.A. _Others in Preparation_ Printed by BALLANTYNE, HANSON & CO. At the Ballantyne Press CONTENTS CHAP. PAGE I. INTRODUCTION 9 II. THE FORMATION OF DEW 13 III. TRUE AND FALSE DEW 17 IV. HOAR-FROST 20 V. FOG 23 VI. THE NUMBERING OF THE DUST 26 VII. DUST AND ATMOSPHERIC PHENOMENA 29 VIII. A FOG-COUNTER 31 IX. FORMATION OF CLOUDS 34 X. DECAY OF CLOUDS 37 XI. IT ALWAYS RAINS 40 XII. HAZE 43 XIII. HAZING EFFECTS OF ATMOSPHERIC DUST 47 XIV. THUNDER CLEARS THE AIR 49 XV. DISEASE GERMS IN THE AIR 53 XVI. A CHANGE OF AIR 55 XVII. THE OLD MOON IN THE NEW MOON'S ARMS 58 XVIII. AN AUTUMN AFTERGLOW 62 XIX. A WINTER FOREGLOW 65 XX. THE RAINBOW 68 XXI. THE AURORA BOREALIS 71 XXII. THE BLUE SKY 74 XXIII. A SANITARY DETECTIVE 78 XXIV. FOG AND SMOKE 80 XXV. ELECTRICAL DEPOSITION OF SMOKE 83 XXVI. RADIATION FROM SNOW 86 XXVII. MOUNTAIN GIANTS 88 XXVIII. THE WIND 92 XXIX. CYCLONES AND ANTI-CYCLONES 95