398 
Proceedings of Roy cd Society of Edinburgh. [july 18, 
inside two small copper cylinders, and brought to an almost steady 
temperature by the well-screened flame of a spirit-lamp beneath. A 
thermometer was inserted with its bulb touching the junction. The 
cold junction (well varnished) was kept in a large can of water ; the 
temperature of this seldom varied by more than *3 of a degree C. 
Several hours usually elapsed between each reading. The reading 
at each temperature was the mean of four deflections, two to each 
side of the scale. Table IX. gives a set of the measurements : t x is 
the cold temperature, t 2 the hot, and D the mean deflection. The 
third column shows how nearly constant the thermoelectric power 
remains up to about 250° C. 
Table IX. 
| w 
k 
D 
k 
k 
D 
k ~ k 
k~k 
9°-4 C. 
63° -5 C. 
8-627 
9°-5 C. 
167°-1 C. 
8-739 
9°-4 
65° ’3 
8-658 
9°-7 
192° -3 
8-727 
9°-3 
85°-5 
8-734 
9°-6 
205°-l 
8-719 
9°*3 
127°'l 
8-761 
9°-7 
214°-6 
8-715 
9°*6 
152°-1 
8-704 
9°-8 
233°-6 
8-688 
9°*5 
153°-5 
8-675 
9°-8 
245°-7 
8'668 
Similar measurements with the sheet iron and German silver 
used in the experiments described below showed the lines of the 
specimens to be very nearly parallel. The neutral point of the 
nickel and German silver used in the experiments tabulated in 
Tables IY. and V. was carefully redetermined by this method, and 
found to be 252° '3 C., which agrees with Tables IV. and V. even 
more closely than the former determination did. 
§ 4. Comparison of Peltier Effect ivith Thermoelectric Power. 
Further experiments were also made in order to compare the 
measurements of the Peltier effect with those of the thermoelectric 
power in the same specimens. The apparatus here used consisted 
essentially of two thermopiles (one of FeZn and the other of 
FeArg) of the same size and shape, and having the same number 
of junctions each. These were arranged, junction to junction, in as 
symmetrical a manner as possible. 
