1872,] 



for Heat in Absolute Measure. 



93 



Second Series. 



Atmosphere moist. Copper Ball blackened. 

 Ten sets of Observations. 



i. 



Mean 

 deflections 

 of ten sets 

 of observa- 



tions. 



631-85 

 558-46 

 492-92 

 435-27 

 384-29 

 339-49 

 300-20 

 266-11 

 236-12 

 209-65 

 186-59 

 166-14 

 148-16 

 132-46 

 118-29 

 105-97 

 94-79 

 84-59 



Difference 

 of 



tempera- 

 ture, 

 D- 



67-44 

 58-68 

 51-06 

 44-52 

 38-86 

 33-98 

 29-78 

 26-20 

 23-08 

 20-37 

 18-03 

 15-98 

 14-19 

 12-64 

 11-25 

 1004 

 896 

 7-98 



logi 



IV. 



^ l ogipD'-logioD" 



,D. 



•82893 

 •76849 

 •70808 

 •64856 

 •58950 

 •53122 

 •47392 

 -41830 

 •36324 

 •30899 

 •25600 

 •20358 

 •15198 

 ■10165 

 •05104 

 •00186 

 •95240 

 •90195 



•01511 

 •01510 

 •01488 

 •01476 

 ■01460 

 •01433 

 •01391 

 •01377 

 •0J358 

 •01325 

 •01311 

 •01290 

 •01258 

 •01265 

 •01230 

 •01236 

 •01261 



!o ?e D'-log e D' 

 4 



c. 



VI. 



Heat emitted 

 per second 

 by observa- 

 tion. 



VII. VIII. 

 Mean difference , Heat emitted 

 of tempera- per second, 

 ture, calculated by 



i[D'-D"], formula, 

 (<). (*)• 



•03478 



•000326 



63-06 



•000328 





W\JO—\J 



o-± o i 



UvJUO-o 



•03426 



•000322 



47-79 



•000325 



•03399 



•000319 



41-69 



•000321 



•03362 



•000315 



36-42 



•000315 



•03300 



•000310 



31-88 



•000311 



•03202 



•000301 



27-99 



•000303 



•03170 



•000297 



24-64 



•000298 



•03126 



•000293 



21-72 



•000292 



•03050 



•000286 



19-20 



•000287 



•03018 



•000283 



17-00 



•000283 



•02970 



•000279 



15-09 



•000279 



•02896 



•000272 



13-41 



•000274 



•02902 



•000272 



11-94 



•000271 



•02832 



•000266 



10-70 



•000268 



•02846 



•000267 



9-50 



•000265 



•02903 



•000272 



8-47 



•000262 



Formula for calculating column VIII. :—- 



-000238 + '00000306* - '000000026* 8 . 



The following Table gives the results calculated by the formula for 

 every fifth degree within the limits of the experiments : — 









Ratio of 





Heat emitted. 



emissive 



Difference 







power 

 of polished to 



of 











temperature. 



Polished 

 surface. 



Blackened 

 surface. 



that of 

 blackened 

 surface. 



5 



•000178 



•000252 



•707 



10 



•000186 



•000266 



•699 



15 



•000193 



•0C0279 



•692 



20 



•000201 



•000289 



•695 



25 



•000207 



•000298 



•694 



30 



•000212 



•000306 



•693 



35 



•000217 



•000313 



•693 



40 



•000220 



•000319 



•693 



45 



•000223 



•000323 



•690 



50 



•000225 



•000326 



•690 



55 



•000226 



•000328 



•690 



60 



•000226 



•000328 



•690 



