42 PROCEEDINGS OF THE AMERICAN ACADEMY 



F. 



Corrected value 787.0 



or 442.8 at 15° C. on the air thermometer. 



The other experiment, on sperm oil, made at this time, is probably 

 hardly worth reducing. The experiments of 1850 are of the highest 

 importance, and should be accurately reduced. 



In the experiments with water the capacity of the calorimeter is 

 corrected as follows: — 



778.0 



or 426.8 on the air thermometer in the latitude of Baltimore at the 

 temperature of 14° C, nearly. 



In the next experiment, with mercury, Joule determined the capa- 

 city of the apparatus by experiment. The mean of the experiments 

 was that the apparatus lost 20°.33155 F. in heating 143430 grains of 

 water 3°. 13305 F. To reduce these to the air thermometer we must 

 divide respectively by 1.0042 and 1.0056. Therefore the capacity 

 must be divided by 1.0014. Therefore the corrected values are: — 



779.2 781.4 



