Atmospheric Phenomena—Thunder and Lightning—Aurora Borealis—The Rainbow—Mock-Suns and Mock-Moons—Halos—Fata Morgana—Reflection and Refraction—Mirage—Spectre of the Brocken 642 CHAPTER L.—PHYSICAL GEOGRAPHY. CLIMATOLOGY. Weather; Climate, and Temperature—Isothermal Lines—Isobars, Weather Forecasts, and Signs of the Sky 651 CHAPTER LI.—BIOLOGY. PART I.: BOTANY. Plants and Animals—Structure of Plants—Flowering Plants—The Stem—The Leaves—Forms of Leaves 658 CHAPTER LII.—FLOWERING PLANTS. Organs of Increase and Reproduction—The Flower—The Calyx—The Corolla—The Stamen—The Pistil 675 CHAPTER LIII.—FLOWERING PLANTS (_Continued_). The Floral Axis—Inflorescence—Fruit—Seed—Nutrition of Plants—Absorbtion of Constituents 679 CHAPTER LIV.—ZOOLOGY. Classification of Animals—Vertebrates and Invertebrates—Protozoa—Hydrozoa—Actinozoa 700 CHAPTER LV.—ECHINODERMATA—ANNULOSA—ENTOZOA—INSECTA. Sea-Urchins—Star-Fishes—Feathery Stars—Sea-Cucumbers—Worms—Leeches— Rotifers—Tape Worms—Insects 712 CHAPTER LVI.—THE ANALYSIS OF CHANCE AND MATHEMATICAL GAMES. Magic Squares—The Sixteen Puzzle—Solitaire—Equivalents 726 CHAPTER LVII.—GAMES (_Continued_). The Magic Top—The Gyroscope and Scientific Games 740 CHAPTER LVIII.—SCIENCE AT HOME. Scientific Objects for the Household 747 CHAPTER LIX.—DOMESTIC SCIENCE. Science and Domestic Economy 757 CHAPTER LX.—CURIOUS INVENTIONS. Some Curious Modes of Transit 770 SCIENTIFIC RECREATIONS. CHAPTER I.—INTRODUCTORY. SCIENCE AND RECREATION—THE BOOK OF NATURE—THE SENSES—NATURAL HISTORY—NATURAL PHILOSOPHY—MATTER—OBJECTS—PROPERTIES OF MATTER. It may at the first glance appear paradoxical to combine Science and Recreation, but we hope to show that true scientific recreation is anything but the dry bones of learning. To those who study science with us, we will point out first how easy and pleasant it is to watch the sky and the plants and Nature generally in the open air. Then we will carry our readers along with us, and by means of illustrations and diagrams instruct them pleasantly in the _reasons for_ things. “How?” and “Why?” will be questions fully answered. Not only will the usual scientific courses be touched upon, but we will show how Science is applied to Domestic Economy. We will have Chemistry put before us without needing a laboratory, and we will experiment in Physics without elaborate apparatus. We will have, in short, a complete Encyclopædia of Science free from dryness and technicalities—an amusing volume suited to old and young who wish to find out what is going on around them in their daily life in earth and sea and sky. Bernard Palissy used to say that he wished “no other book than the earth and the sky,” and that “it was given to all to read this wonderful book.”