xii ILLUSTRATIONS. 



Pag 



Light-house on a Rock .^ 1 77 



Magneto-electric Machine.' ; . . .". . * . k 1* 



Parabolic Reflector lf 



Flashing Light by Reflectors 186 



Convergence of Rays 1* 



Fresnel's Idea 188 



Signal Lantern 190 



Effect of the Prisms 191 



Pole seeming to be bent 195 



Refraction of Solar Ray ! 196 



Recomposition of Light 197 



Newton's Disk 198 



Lines of the Solar Spectrum 199 



The Spectroscope 200 



The Gardens of the Tuileries 208 



Masts of near and distant Ships 217 



Near and distant Birds 218 



Reflection from the inner Surface 222 



The Plane Mirror 229 



Seeing through a Stone 234 



Image reversed 236 



Enlargement in a Concave Mirror 237 



Distorted Picture reflected true 238 



Diagram. Law of Reflection 243 



Reflection from a Concave Surface 244 



Diagram. Law of Refraction 245 



Image of the Lily 251 



Section of the Eye 252 



Camera Obscura in a Box 254 



Camera Obscura in its own Building 255 



Camera Obscura in a Tent 257 



Photographic Room 259 



The Thaumatrope 2G1 



Atmospherical Refraction 2G5 



Blowing Bubbles 2G9 



Newton's Bubble 271 



Rough Plays 277 



Flippy when he was little 279 



Ancient Lake filled up 291 



A Wagon-load of Gas 303 



TL^ Locomotive OAQ 



