t 
182 S&. P. Langley—Selective Absorption of Solar Energy. 
greatly modify our usual estimates not only of the sun’s heat 
radiation but of his effective temperature. 
The sun to an eye without our atmosphere would appear of 
a bluish tint. 
n spite of the care with which the experiments on which 
the above conclusions rest have been conducted, owing to the 
: ep 
sound, we ought to find like results, by actually ascending to 
