500 Dr. Herschel's Experiments on the solar, and 



lggtb Experiment. 



Sun. Black paper scattering. 



65I 66 



79| 68 . . . 4|- : s = ,410 



This paper scatters 993 rays of heat, and 420 of light. 



From these experiments it seems to be evident, that in scat- 

 tering heat, the colour of the object is out of the question ; or, 

 at least, that it is no otherwise concerned than as far as it may 

 influence the texture of the surface of bodies. For here we find 

 that pale-green, which is brighter, or scatters more light, than 

 dark-green, yet scatters less heat. Even black, so generally 

 known to scatter but little light, scatters much heat. But, in 

 order to put this surmise to a fairer trial, I made the following 

 experiments with my new machine. 



Qootb Experiment. 



I covered one of the tablets with white paper, and the other 

 with black. The quantity of sunshine admitted through the 

 two openings, of \\ inch in diameter each, being equal, I found 

 the heat scattered on both thermometers to be as follows. 



>774 







White pape: 



r. Black paper 



scattering. 



0' 





7ii 



72 





5 





75f 



75 •• 



■3l'3 



turned 



now 



the tablets, 



and had, 









Black paper 



White paper 



scattering. 



0' 





7Si 



hi 





5 75f 75i-- af • 3i = >7<So 



These results, agreeing sufficiently well together, shew that 

 if we make white paper our standard, and suppose it to scatter 



