226 



GENERAL SCIENCE 



from the tip of the flame strike the mirror at all points, 

 but only the ray which strikes the mirror at F is reflected 

 to the eye. Why ? It is the same with the rays of light 

 from other points on the object OA ; for example, only 

 the ray from A which strikes the mirror at B will reach 

 the eye. The eye sees the image of at 0', since the 

 line O'F is a continuation of the direction from which 

 the ray from entered the eye. 



It is to be noted that as you face the mirror the left 

 side of the face appears as the right side in the mirror. 

 It is difficult to tell the time of day by looking at the 

 image of the clock in the mirror for this reason. Writing 

 to be read in the mirror must be written backwards. 



Diffused or Scattered Light. - - The snow reflects the 

 sunlight in countless directions. This sort of reflection 

 is called diffusion. The " glare " of the sun upon the 

 snow, which is so painful to weak eyes, is due to the fact 

 that no matter which way we turn we encounter strong 

 reflected light. Most objects do not have a mirror-like 



surface and hence diffuse the 

 light which strikes them in all 

 directions. It is by the aid of 

 this diffused light that we see 

 these objects. Mirrors are some- 

 times difficult to see because the 

 reflection of the light upon them 

 is so nearly perfect. Rooms with 

 mirrored walls may seem to be 

 very large rooms. 



Refraction of Light. A number of familiar phenomena 

 are due to the refraction of light or the bending of a ray 

 of light as it passes from one transparent medium to 

 another. If a pencil be placed in a tumbler of water, 



