128 ON THE SEPARATION OF LIGHT AND HEAT, 



The thermometer with 



Naked ball 58x<> 



Whitened ball 58j° 



Blackened ball 63° 



Experiment II. The apparatus being placed all as before, the blackened 



thermometer 

 Black ther. rofe In full red ray in 3', from 58 p to 61°. or 3°. 



m datk = 3 5 ° In c l uite dark in *'* trom 59 ° t0 6l9 - or 3 °* 



White therm. The whitened thermometer 



'"dwk ol" Ll fllU rCd ™y in 3 '' fr ° m 55 ° t0 58G# ° r **' 



Black ther. In quite dark in 3', from 58° to 58f °. or 0-*-°. 



in dark 4? ^he blackened thermometer was now again placed in the 



quite dark, and rofe in 3', from 58° to (SI °. or 4°. 



This is what I expected, as a thick fmoky haze had come 

 on fince the experiments were begun, and incrcafed much 

 towards the end of them. 



Experiment III. April 18, 11, A. M. Sun clear. All the apparatuses before- 



Black ther rofe In ^ confines f the re d. 



in confine of red , . 



ia « Black thermometer in 3 , from 59 v to 71*. 



White do. do. 3? White thermometer in 3', from 57|° to 60\°. Clouds 



came on, and put a flop to the experiments. 



Experiment IV. April 19, 3f, P.M. Sun clear. 



Black ther. rofe |q & f ,j ^ 

 in full red iz p ■/ 



White do. do. Black thermometer in 3', from 66° to 82° 



St*' White thermometer in 3', from 66° to 69|°. 



In confine of red In the confines of the red. 



Black th. iai Black thermometer in 3', from 67° to 79| # . But thin 



Ditto, quite dark ^^ doudg had cQme Qver ^ ^ 



In quite dark, half an inch out of the red. 

 Black thermometer in 3', from 70° to 84°. 

 Tranfitions from W T hen the thermometer was carried into the faint red light, 

 red to dark occa- it funk quickly; and rofe again as quickly when carried into 

 temperature." ° tne dark f° cus : Dut when carried into the dark on the other 

 fide of the red light, it funk very rapidly, and did not appear 

 to receive any heat at all. Thin clouds increafed, and ren- 

 dered the fun's light too faint for further experiments. 

 Experiment V. April 20, from 1 Of to llf, A. M. Sun quite clear. 



Although it could not be fuppofed that effecls of the re- 

 fracted light could differ in the two fpectra, yet, in order to 

 afcertain the fact, the horizontal fpeclrum was ufed in the fub- 

 Jcquent experiments. 



The 



