360 THE POPULAR SCIENCE MONTHLY. 



surface receiving liglit, every little grain and fiber acting as a 

 reflector to send it out again. Reflection and re-reflection are tak- 

 ing place with enormous rush and intricacy. But the extent of 

 complication is not yet reached. These various lights are not 

 all white. Each substance has its effect upon the light that it 

 reflects. Some of the light undulations are absorbed, and those 

 reflected give the effect of color characteristics of the object. The 

 colored lights are then flashing back and forth, continually chang- 

 ing as they leave the different surfaces. Neither is this a com- 

 plete statement of the situation. Each surface is illuminated by 

 a variety of colored lights, depending upon the surfaces opposite 

 it. The color of any one material depends upon the color of the 

 light striking it, as well as upon its own nature. Hence possibly 

 none of the surfaces in the street are seen in their true tones, the 

 hues belonging to them when illuminated by pure white sun- 

 light. They are slightly off color, modified by the colored lights 

 that strike them. All this wonderful play of lights darting across 

 the street is put in action by the steady, powerful, pure white 

 flood of light coming from the sun. 



It may be questioned why this condition of affairs is not more 

 noticeable. Why are not the bright hues of the rainbow seen in 

 all directions ? The absence of brilliant coloring is briefly ac- 

 counted for by the large amount of surface reflection taking 

 place, through which we see objects as if a gray glazing had been 

 washed over them. 



However, conditions will occur when there is a very noticeable 

 flush of color cast over objects which is not their normal hue, and 

 it can be traced to the predominating influence of some one of the 

 reflecting surfaces. Occasionally most striking effects of this 

 character are seen during the sunset hour. Sun-illumined clouds 

 are in the west holding their bright color when all other sources 

 of light in sky and earth are waning. The predominating power 

 of their colored light is enough to make a modest little sunset 

 in the east, and the sky there will glow with a soft tint sympa- 

 thetic with the display in the opposite part of the heavens. The 

 western sky may even give a glamour of colored light to the land- 

 scape, casting a weird, strange effect over meadow and hillside, 

 ere they disappear in the darkness. 



" Where the quiet-colored end of evening smiles miles and miles on the 

 solitary pastures. ..." 



Those who use colored parasols understand perfectly the result, if 

 not the theory, when the lining of the parasol is selected so as to 

 add to natural charms by casting a soft flush of color over the 

 complexion. 



But illustration of the influence of the effect of surfaces upon 



