CHAPTER XIII 



COLOR 



126. The Rainbow. One of the most beautiful and well- 

 known phenomena in nature is the rainbow, and from time 

 immemorial it has been considered Jehovah's signal to man- 

 kind that the storm is over and that the sunshine will remain. 

 Practically every one knows that a rainbow can be seen only 

 when the sun's rays shine upon a mist of tiny drops of water. 

 It is these tiny drops which by their refraction and their scat- 

 tering of light produce the rainbow in the heavens. 



The exquisite tints of the rainbow can be seen if we look 

 at an object through a prism or chandelier crystal, and a very 

 simple experiment enables us to produce on the wall of a 

 room the exact colors of the rainbow in all their beauty. 



127. How to produce Rainbow Colors. The Spectrum. 

 If a beam of sunlight is admitted into a dark room through 

 a narrow opening in the shade, and is allowed to fall upon 



a prism, as shown in 

 Figure 86, a beautiful 

 band of colors will appear 

 on the opposite wall of 

 the room. The ray of 

 light which entered the 

 room as ordinary sun- 

 light has not only been 

 refracted and bent from its straight path, but it has been 

 spread out into a band of colors similar to those of the rainbow. 



134 



FIG. 86. White light is a mixture of lights of 

 rainbow colors. 



