LIST OF ILLUSTRATIONS xvii 



FIGURE CHAPTER XII PAGE 



131. Diagram of Varying Light Intensities 282 



132. The Pinhole Camera 284 



133. The Camera Obscura 285 



134. Reflection in a Plane Mirror 287 



135. Horizontal Section of Eyeball 288 



136. Reflection from a Convex Mirror 290 



137. Images Seen in Curved and Plane Mirrors . . . . . 290 



138. Diagram of an Object Magnified by a Spherical Concave Mirror, 



Object Being Inside of Focus 291 



139. Figure of Coin in a Bowl of Water, to Show Refraction . . 293 



140. Diagram of a Ray of Light Entering Glass 293 



141. Diagram of Light Coming Out of Glass 294 



142. The Action of the Burning Glass ........ 295 



143. The Conjugate Foci of a Convex Lens 296 



144. Lenses of Several Shapes 297 



145. Diagram Showing How* a Magnifying Glass Magnifies . . 297 



146. Diagram of a Compound Microscope 298 



147. A Compound Microscope, Showing Parts ..... 300 



148. Diagram Showing Operation of a Telescope 301 



149. A Telescope and Its Mount 302 



150. Diagram of the Stereopticon 303 



151. Diagram of Refraction by a Prism . . . . . . . 304 



152. The Correction of a Convex Lens by a Concave Lens . . . 305 



153. Diagram of Wave Motion 305 



154. Diagram of Marching Men 306 



155. Formation of Rainbow 308 



CHAPTER XIII 



156. A Box Camera, the Brownie 309 



157. A Plate Camera on Its Tripod 310 



158. An Exposure Meter 312 



159. Front of Camera Lens to Show Device for Setting the Time and 



Diaphragm 314 



1 60. Diagram of a Reflecting Camera 316 



161. Some Darkroom Equipment 318 



1620 and b. A Negative and a Print from the Same . . . ' . 321 



163. Handling the Film ; 322 



164. A Lantern Slide 323 



CHAPTER XIV 



165. Vibration of a Taut String 326 



1 66. Sound Waves Radiating from a Bell 327 



