z6o 



Dr. Herschei/s 



Investigation of the Powers 



No. 2. 







No. 3. 



44 



- 



- 



44 



46 



- 



- 



44 



4Pi - 



- 



- 



43i 



47 



- 



- 



43i 



47 



- 



- 



43 



And here the thermometer, exposed to red, rose in five 

 minutes 4 degrees. 

 Jtb Experiment. In green rays. 



No. 2. No. 3. 



43? - 431 



44i - - - 43t 

 442- 43 



This made the thermometer rise, in the green rays, i£ 

 degree. 

 8th Experiment. Again in green rays. 



No. 2. No. 3. 



43 " - - 43 

 44i ~ 4 2 1 



44i " 4 2 f 



Here the rising, by the green rays, was 2 degrees. 



From these experiments, we are authorised to draw the fol- 

 lowing results. In the red rays, my thermometer gave 6 £ 

 degrees in the 1st, and 7 degrees in the 2d, for the rising of 

 the quicksilver : a mean of both is 6^. In the 3d experiment, 

 we had 3^ degrees, for the rising occasioned by the green rays ; 

 from which we obtain the proportion of 55 to 26, for the power 

 of heating in red to that in green. The 4th experiment gave 





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