INTENSITY OF LIGHT. 



421 



intensity of light diminishes as the square of the 

 distance from the source of light increases ; in other 

 words : the intensity of light is inversely proportional to 

 the square of the distance. 



FIG. 241 ( real size ; A and B an. proj.). 



A luminous body at a greater distance from a surface 

 cannot illuminate the latter with the same intensity as 



