Radiant Heat and Light 



163 



FIG. 92. When the wheel is rapidly whirled the colors blend to make white. 



here shown illustrates how the prism breaks up the single 

 beam of white light into different-colored beams of light. 



Experiment 51. Rotate the color disk on the rotator 

 and watch it. Make it go faster and faster until all the 

 colors are perfectly merged. What color do you get by 

 combining all the colors of the rainbow? If the colors on 

 the disk were perfectly clear rainbow colors, in exactly the 

 same proportion as in the rainbow, the whirling would give 

 a white of dazzling purity. 



Since you can break up pure white light into all the 

 colors, and since you can combine all the colors and get 

 pure white light, it is clear that white light is made up 

 of all the colors. 



As we have already said, light is probably vibrations 

 or waves of ether. Light made of the longest waves 



