1887 .] Mr A. Campbell on Measurement of Peltier Effect. 393 
values of DJCf where Dj = deflection in HiArg circuit, C 1 = 
battery current, and t = absolute temperature. In both tables the 
correction for increase in specific heat was introduced. 
Table IV. 
Table V. 
(Battery Current through NiArg.) 
Temp. C. 
D 
C t 
Temp. C. 
D 
C t 
1 — i 
o 
OO 
*0683 
220°-0 
•0321 
19°‘0 
•0691 
222° -0 
*0304 
64°T 
•0637 
223° -8 
•0308 
69°-0 
•0689 
225° -3 
•0293 
70°-0 
•0686 
226°-9 
•0314 
75 ° *7 
•0657 
228° -5 
•0310 
81°-8 
•0657 
230°-l 
•0267 
98°-0 
•0649 
231 0, 9 
•0258 
101°-0 
•0659 
233° -2 
•0253 
1 1 8 ° *8 
•0632 
234 ° *5 
•0234 
121°-0 
•0657 
235 ° -8 
•0235 
124°-9 
•0652 
237° -2 
•0223 
206° -2 
•0471 
237° -9 
*0190 
208° -8 
•0439 
254°-3 
- -0006 
210 ° 7 
•0431 
283 ° 
- -0153 
212°-9 
•0435 
284 ° 
- -0208 
21 4° ‘8 
•0390 
285 °"4 
- -0228 
216°-4 
•0369 
300°i 
- -0640 
218°-4 
•0335 
(Battery Current through 
FeArg pile.) 
Temp. C. 
Di 
C y t 
23°’0 
•134 
114°-5 
•143 
153° -3 
•134 
157 ° 3 
•123 
166°-3 
•0982 
169 ° *9 
•1023 
173°-8 
•0975 
1 77 ° *4 
•0915 
181°-0 
•0925 
210° -8 
•0740 
254° -3 
- '0012 
O 
o 
CO I 
N ! 
- -0204 
275 ° -6 
- -0392 
278° -0 
- '0527 
290 °? 
- -0614 
302 ° 
- *0879 
330 ° ? 
- -16 
The neutral point of the NiArg, found by heating up a junction 
in oil, was 250 0, 6 C. The curve drawn from Table IV. shows a 
vanishing of the Peltier effect at 2 5 3° *7, while from Table V. the 
thermoelectric 'power vanishes at 2 5 3° ’4. Ho measurement was 
made exactly at the directly observed neutral point, but the small- 
