ON STANDARDS OF ELECTRICAL RESISTANCE. 



521 



The correction to be applied to the air-registering thermometer, as deduced 



from the radiation experiments of this third series, is found from — ■ 



16-26 



= _— — '-' whence x, the quantity to be added to the observed tempera- 

 ture of the air in the thermal experiments, =2-81. The temperature of the 

 air was therefore virtually 6-073 higher than that of the -water. The results 

 also show that the unit of effect on the calorimeter was produced by a differ- 

 ence of temperature of 11-64.5. 



Hence .31-0266 — — — =30-.5051 ; and adding -077 for the unimmersed 

 11-645 



part of the thermometer stem, the corrected thermal effect in the third series 



is found to be 30-.5821. 



The average capacity of the calorimeter was equal to that of 93859 grs. 

 of water, being made up of 91531 grs. distilled water, 22.364 grs. of copper, 

 486 grs. of tin (the weight of the coating next the calorimeter), 52 grs.' silk 

 net (half that emploved), the thermometer, coil, and corks. 



1867. ' 2 N 



