WHAT IS LIGHT? 73 CHAPTER II. THE SOLAR SPECTRUM 84 CHAPTER III. OTHER CAUSES OF COLOUR 94 CHAPTER IV. LUMINOUS, CALORIFIC, CHEMICAL, AND 100 MAGNETIC PROPERTIES OF THE SPECTRUM CHAPTER V. THE LAWS OF REFLECTION.—MIRRORS 106 CHAPTER VI. METALLIC BURNING MIRRORS 117 CHAPTER VII. LENSES 127 CHAPTER VIII. OPTICAL INSTRUMENTS.—THE SIMPLE AND 141 COMPOUND MICROSCOPE. THE SOLAR AND PHOTO-ELECTRIC MICROSCOPE CHAPTER IX. THE TELESCOPES OF GALILEO, GREGORY, 150 NEWTON, HERSCHEL, LORD ROSSE, AND FOUCAULT -------------- PART III. NATURAL MAGIC. CHAPTER I. THE MAGIC LANTERN 173 CHAPTER II. THE PHANTASMAGORIA 183 CHAPTER III. OTHER OPTICAL ILLUSIONS 196 CHAPTER IV. THE PROPERTIES OF MIRRORS 216 CHAPTER V. CHINESE SHADOWS 223 CHAPTER VI. POLYORAMA—DISSOLVING VIEWS—DIORAMA 231 CHAPTER VII. THE STEREOSCOPE 236 CHAPTER VIII. THE CAMERA OBSCURA AND CAMERA LUCIDA 242 CHAPTER IX. THE SPECTROSCOPE 249 CHAPTER X. SPECTRES—THE GHOST ILLUSION 264 ------------------------------------------------------------------------ LIST OF ILLUSTRATIONS. -------------- FIG. PAGE 1. Section of the Eye 24 2. A Camera Obscura 27 3. The Phenakistiscope 54 4. Disc of the Phenakistiscope 55 5. Solar Spectrum Frontispiece 6. Absorption of Light by Sodium Vapour _ib._ 7. Action of a Prism on the Solar Rays _ib._