CONTENTS. 



I. RADIATION 13 



II. WONDER AND MYSTERY 21 



III. THE VELOCITY OF LIGHT 30 



IV. THE LAW OF THE SQUARES OF THE DISTANCES 36 



V. CANDLES TOO TALL , 44 



VI. INTENSITY OF LIGHT. . r >4 



VII. CANDLES AND LAMPS 60 



VIII. THE ARGAND BURNER 71 



IX. INTERMINGLING OF UNDULATIONS 75 



X. REFLECTED AND TRANSMITTED LIGHT 86 



XI. SPECTRES AND GHOSTS 97 



XII. THE POLYTECHNIC INSTITUTION 105 



XIII. VERY BRIGHT LIGHTS 11G 



XIV. COMBUSTION OF MAGNESIUM 124 



XV. THE MAGNESIUM LAMP 131 



XVI. INCANDESCENCE 130 



XVII. FOLKESTONE 1 4 1 



XVIII. THE CHANNEL AT NIGHT 154 



XIX. THE ELECTRIC LIGHT 163 



XX. THE CORRELATION OF FORCE 1 75 



XXI. FRE8NEL 183 



XXII. COLOR 194 



XXIII. FLIPPY 205 



XXIV. ILLUSIONS EXPLAINED 215 



XXV. FORMATION OF IMAGES 227 



XXVI. LAWS OF REFLECTION AND REFRACTION 240 



XXVII. THE EYE 249 



XXVIII. THE RETURN 263 



XXIX. FAREWELL TO FLIPPY 274 



XXX. UP THE NORTH RIVER 283 



XXXI. LIGHTING BY GAS 295 



XXXII. CONCLUSION SOU 



A 2 



