328 



BRIDGMAN. 



At atmospheric pressure the thermal behavior against lead is 

 given by formulas: 



E = (-17.61^-0.0178^2) X 10-6 volts, 



P = (-17.61 -0.0356 it + 273) X 10"^ volts, 



a = -0.0356(^ + 273) X lO'^ volts/°C. 



The measurements under pressure went without incident except 

 for somewhat greater irregularities than usual due to imperfection 



40° 60° 

 Temperature 



80° 1 00° 20° 

 Nickel 



40° 60° 

 Temperature 



Figure 24. Nickel. On the left, the heat absorbed by unit quantity of 

 electricity in flowing from uncompressed metal to metal compressed to the 

 pressure indicate on the curves, as a function of temperature. On the right, 

 the excess of Thomson heat in metal compressed to the pressure indicated on 

 the curves over uncompressed metal, as a function of temperature. 



of temperature control already mentioned. The pressure manipula- 

 tion of this substance was a matter of some difficulty, because tempo- 

 rary effects due to elastic drag are easy to get. There was no evidence 

 of incomplete internal equilibrium. The maximum zero correction 

 was 1% of the total effect, and the maximum departure of any single 



