on the terrestrial Rays that occasion Heat. 501 



1000 rays of heat, and 1000 of light, then will black paper scat- 

 ter 767 rays of heat, and 420 of light. 



201st Experiment. 



White paper. Black muslin scattering. 



°' 73i 73f 



5 77% 77- "4i'3i =*«S*8 



This scatters 813 rays of heat; and, when it is suspended so 



that the rays which pass through it may not be reflected, it 



scatters only 64, rays of light. 



202d Experiment. 



As my intention at present was to find a black substance that 

 should scatter more heat than a white one, I thought it would 

 be the readiest way to examine the white and black objects 

 separately, that of all the white ones I might afterwards take 

 that which scattered least, and compare it with the black one 

 which scattered most. 



White paper. White linen scattering. 



°' 74i 75 



5 79 79i — 4i : 4i= 1 >°°° 



These objects scatter heat equally, and very nearly also light; 



for our table gives for linen 1008. 



203^ Experiment. 



White paper. White cotton scattering. 



°' 74i 741 



5 7§| 7H--3i-3i=i>o°° 



These objects scatter heat equally. White cotton scatters 

 1054 rays of light. 

 mdccc 3 T 



