508 



Mr. J. J. Waterston on Solar Radiation, 



ing to be studied easily without fractional parts or interpola- 

 tion : — 



Thus, 53 being the last observation of the vacuum-cooling, 

 corresponds with r=5°; then 



At r - 5 we have 843 beats Difference 



r = 10 

 r = 20 



r = 40 



549 

 255 

 ■ 32 



294 



294 Mean Difference 2917 



287 



Again, beginning with r=7°, 



At r = 7 we have 704 beats niffprpnpp 2 qa 



r = 14 „ 406 „ JJitterence^ys Mean Difference 294| 

 r = 28 „ 115 „ » * JL 



And beginning with r=9°, 

 At r = 9 we have 594 beats Difference 296 



r=18 

 r = 3G 



298 

 12 



28G 



Mean Difference 291 



The numbers in the column of differences ought to be the 

 same if the law of cooling in a vacuum is perfectly true, if the 

 vacuum is complete, and if the graduation of the thermometer 

 is correct. The difference between them is so snTall that the 

 result must, I think, be deemed satisfactory. 



