SCIENCE OF COMMON THINGS. 245 



Mirrors. Reflection of light. Incidence and reflection. 



If the edge be straight and uniform, the light from 

 all points of the edge will come to the eye regularly 

 and uniformly ; if irregularities, however, exist, they 

 will cause the light to be irregular, and the eye at 

 once notices the confusion and the point which occa- 

 sions it. 



37* What is a mirror f 



Any substance reflecting light. The term is gene- 

 rally applied to glass covered on the back with quiet 

 silver. 



1038 When liglit falls upon a body, in what three ways may it dispose 

 of itself? 



It may be reflected, refracted, or absorbed. 



1039 What do we mean when we speak of light being reflected? 



When a ray of light strikes against a surface, and is 

 caused to turn back or rebound in a direction different 

 from whence it proceeded, it is said to be reflected. 



1040 Why do we see ourselves in a mirror f 



Because the rays of light from our face strike against 

 the glass, and (instead or being transmitted) are reflect- 

 ed, or sent back again to our eye. 



1041 Why are flie rays of light reflected by a mirror ? 



Because they cannot pass through the impenetrable 

 metal with which the back of the glass is covered ; so 

 they rebound back, just as a marble would do if it were 

 thrown against a wall. 



1043 When a marble is rotted towards a waU, what is the path 

 through which it runs called ? 



The line of incidence. 



1043 When a marbk, rebounds back again, what is the path it then 

 describes called? 



The line of reflection. (See 

 Fig. 52.) 



If A B be the line of incidence, 

 then B E is the line of reflection; 

 and vice versa. 



1044 When the light of our face 

 goes to the glass, what is the path 



rough which it goes catted ? 



11* 



