324 



BRIDGMAN, 



This electrolytic copper did not differ greatly in thermo-electric 

 properties from commercial copper. The thermal e.m.f. of electro- 

 lytic against commercial copper was found to be given by the ex- 

 pression : 



E = (0.03468 i + 0.0000133^2) >< iQ-e volts. 



The measurements under pressure went satisfactorily, but the re- 

 sults were somewhat more irregular than usual because of the smallness 



20° 40° 60° 

 Temperature 



80° 100° 20° 

 Copper 



40° 60° 80° 100'° 

 Temperature 



Figure 22. Copper. On the left, the heat absorbed by unit quantity of 

 electricity m flowing from uncompressed metal to metal compressed to the 

 pressure indicated 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 the effect. The maximum zero correction was 1.5% of the maxi- 

 mum effect; this was also the maximum departure of any point from 

 a smooth curve. The a^■erage arithmetical departure of all the ob- 

 served points from a smooth curve was 0.31%. The maximum read- 

 justment necessary in passing from the constant temperature to the 

 constant pressure curves was 0.8%. 



