REFLECTION 



329 



A glass of water W is placed behind a piece of plate glass MN and 

 a lighted candle in front of the glass, behind a shield B, the open 

 side of the shield facing 

 the glass. The observer 

 stands behind the shield B. 

 The image of the candle 

 appears in the glass of 

 water. Virtual images of 

 this type are used to pro- 

 duce stage ghosts, etc. 



Why images are seen 

 in plain mirrors. Any 

 smooth surface, such as 

 glass, water, polished wood 

 or polished materials, pro- 

 duces images because the 

 rays of light striking the 

 smooth surface are re- 

 flected back. If the sur- 

 face is irregular the rays 

 of light are reflected at 

 all angles and diffused. 



Light shining on . the 

 objects about us, such as 

 plants, houses and animals, 

 is reflected into the eyes 

 and enables us to see the 

 various objects about us. 

 The moon is seen because 

 sunlight is reflected from 

 its surface to the earth. 



Different phases of the 

 moon depend upon the 

 amount of surface toward 

 us which is reflecting light. 

 The new moon is reflecting light 

 toward us. 







FIG. 200. In this picture we see how the peri- 

 scope works. The ship on the waves is seen 

 by the lens of the periscope, and the picture is 

 reflected down the tube on the table. 



Courtesy Child's Book of Knowledge. 



with one-half of its surface 



