TABLE 255. 



THERMOELECTRIC POWER. 



The thermoelectric power of a circuit of two metals at mean temperature t is the electromotive force in the circuit 

 for one degree difference of temperature between the junctions. It is expressed by dE j dt = A + Bt, when 

 dE / dt = o, t = A / JS, and this the neutral point or temperature at which the thermoelectric power vanishes. 

 The ratio of the specific heat of electricity to the absolute value of the temperature t is expressed by B for any 

 one metal when the oilier metal is lead. The thermoelectric power of different couples may be inferred from the 

 table, as it is the difference of the tabulated values with respect to lead, which is here taken as zero. The table 

 has been compiled from the results of Becquerel, Matthieson, and Tail. In reducing the results the electromotive 

 forces of the Grove's and the Daniell cells have been taken as 1.95 and 1.07 volts respectively. 



SMITHSONIAN TABLES. 



248 



