228 PROCEEDINGS OF THE AMERICAN ACADEMY 



T.h (1) 

 T.k (2) 



Notes. — The silvered surface of the mirror reflects the yellow 

 color of the candle, while the mercury amalgam mirror gives a more 

 grayish color. Hence, the convenient method of viewing the spot on 

 both sides at once by a mirror, is no longer accurate. 



Silvered Mirror (Glass Surface). 



Ratios. Averages. 

 T^t) 



Tiri 



T.T*) 



Tiri 



Percentage 775 



Notes. — The back surface of the silvered mirror gives successive 

 reflections. 



Gkneral Result. — The face of the silvered mirror has been 

 found to reflect more light than any of the six surfaces tried above, 

 and it would probably be found to reflect more than auy other surface 

 on account of the superior whiteness of the metal. The double 

 transmission through the glass costs the difference between 80 and 

 77.5, or 2.5 per cent, disregarding the amount reflected from the 



