Measurement of the Peltier Effect. 

 the junctions during the steady state : 



Qi + CfVi-PC^^ . . 



and for a reversed current C 2 : 



L>2 V\ + rt'o = /til>2 • • 



These equations give 



P= (CTr#^ +(( * ° 2) U*7W 1 + 



459 



(1) 

 (2) 



(4) 



fc, +/■•■> 



• 2 -n)} 

 (5) ' 



In the experiment Q! was made nearly equal to Q 2 * In 

 this case the maximum value of the second term, as deduced 

 from the observations, was about O'OOl of the first term, and 

 is therefore negligible. The second term may be made to 

 vanish by making C 2 = Ci; but this necessitates an approxi- 

 mate value of the ratio of k t to k 2 to evaluate the first term. 



Thus 



Qi + Q 2 



P = 



(6) 



2(C 1 4-C 2 )- ; • 



The tables below contain some of the results of experiments 

 with different currents and at slightly different temperatures. 

 The thermoelectric powers of the copper-bismuth junction as 

 calculated from the relation 



cm 



P = T 



dT 



are also given. 



Heating 

 Current. 



Junction 

 Current. 



Mean Temp, 

 of junction. 



Peltier 

 Coeificient. 



Thermoelectric 

 Power, 



a +0*125 amp. 

 a -01 25 

 6+0-130 

 6-0-130 



« +01)70 

 ^ -0-070 

 6+0*072 

 6-0-072 



c— 1-466 amp. 



.. 1*431 

 d- 1-366 



>, 1*330 



22°-4 C. 



0-01590 volt 



53-8xl0~ h volt 



o -0461 



„ 0-455 



d-0'426 



„ 0-411 



20°-6 



0-01573 volt 



53'6xi0~ 6 volt 



a + 0-100 

 a -0100 

 6+0-102 



6-0-102 



c- 1-040 



„ 1-018 



rf- 0-892 



„ 0-868 



8°-l 



'0-01462 volt 



52iOxlO~ 6 vol1 



The resistance of coil a = 2*780 ohms. 

 6=2*6,92 

 :2 11 2 



