Produced by Chris Curnow, Josephine Paolucci and the Online Distributed Proofreading Team at http://www.pgdp.net. (This file was produced from images generously made available by The Internet Archive.) Nature's Miracles _Familiar Talks on Science_ BY ELISHA GRAY, PH. D., LL. D. VOL. I World-Building and Life EARTH, AIR, AND WATER NEW YORK FORDS, HOWARD, & HULBERT COPYRIGHT, 1899, BY FORDS, HOWARD & HULBERT. THE MERSHON COMPANY PRESS, RAHWAY, N. J. CONTENTS. CHAPTER PAGE INTRODUCTION, v EARTH. I. WORLD-BUILDING AND LIFE, 1 II. LIMESTONE, 12 III. COAL, 22 IV. SLATE AND SHALE, 31 V. SALT, 36 AIR. VI. THE ATMOSPHERE, 42 VII. AIR TEMPERATURE, 51 VIII. CLOUD FORMATION, 60 IX. CLOUD FORMATION (_Continued_), 69 X. WIND--WHY IT BLOWS, 79 XI. WIND (_Continued_), 88 XII. LOCAL WINDS, 100 XIII. WEATHER PREDICTIONS, 110 XIV. HOW DEW IS FORMED, 115 XV. HAILSTONES AND SNOW, 124 XVI. METEORS, 129 XVII. THE SKY AND ITS COLOR, 134 XVIII. LIQUID AIR, 146 WATER. XIX. RIVERS AND FLOODS, 152 XX. TIDES, 161 XXI. WHAT IS A SPONGE? 167 XXII. WATER AND ICE, 177 XXIII. STORED ENERGY IN WATER, 182 XXIV. WHY DOES ICE FLOAT? 192 XXV. GLACIERS, 198 XXVI. EVIDENCES AND THEORIES OF AN ICE AGE, 207 XXVII. GLACIAL AND PREGLACIAL LAKES AND RIVERS, 217 XXVIII. SOME EFFECTS OF THE GLACIAL PERIOD, 230 XXIX. DRAINAGE BEFORE THE ICE AGE, 239 INTRODUCTION. Dear Reader: Please look through this "Introduction" before beginning with the regular chapters. It is always well to know the object, aim, and mode of treatment of a book before reading it, so as to be able to look at it from the author's view-point. First: A word about the title--"Nature's Miracles." Some may claim that it is unscientific to speak of the operations of nature as "miracles." But the point of the title lies in the paradox of finding so many wonderful things--as wonderful as any miracle that was ever recorded--subservient to the rule of law.