242 Apparent Radiation of Cold. 



tities radiated and reflected, we shall apply the same principles, 

 and employ a similar notation. 



Let r be the reflecting power of any surface, the £ radiating 

 power, and x any ratio in which the reflecting power of this sur- 

 face is changed or the ratio which it bears to the reflecting power 

 of other surfaces. Then r will be an integer or a proper fraction 

 according as the reflecting power is increased or diminished ; rx 

 will be the resulting reflecting power, rx the radiating povv- 



er> and r l|_^ 2 rx is ^ general formula for expressing in all cases 

 the ratio of the refecting to the absorbent and radiating powers. 



