1913-14.] The Hall and Transverse Thermomagnetic Effects. 215 
The coefficient R is negative and varies with the field strength in 
practically the same way as S and Q. 
Increase of temperature increases the numerical value of R. 
Temperature coefficient of R in field of 6,400 units = +00025. 
1 | 22,000 „ =+ 0 - 0010 . 
Iron. Thickness of plate = 0*51 mm. 
Thermomagnetic Temperature and Potential Effects . — These were 
measured in magnetic fields varying from 2000 to 22,000 units, and at 
temperatures of 48*6° C., 71*5° C., 97 - 9° C., and 129-2° C. 
Temperature of Plate 
= 48-6° C. 
Temperature of Plate 
= 71-5° C. 
Temperature of Plate 
= 97-9° C. 
Temperature of Plate 
= 129-2° C. 
Field. 
S x 10 7 . 
Q > 
<10 4 . 
Field. 
SxlO 7 . 
Q x 10 4 . 
Field. 
S x 10 7 . 
Q x 10 4 . 
Field. 
S x 10 7 . 
Q x 10 4 . 
2,100 
+ 5-75 
+ 
10*0 
2,000 
+ 6*45 
+ 10-8 
2,100 
+ 7-16 
+ 
12*8 
2,000 
+ 6-05 
+ 10-9 
4,000 
+ 5-44 
+ 
10*2 
4,000 
+ 6-27 
+ 9-7 
4,300 
+ 6-24 
+ 
11-7 
4,500 
+ 6-98 
+ 10-1 
6,500 
+ 5-20 
+ 
10-1 
6,000 
+ 6-00 
+ 10-5 
6,300 
+ 6-10 
+ 
11-5 
6,650 
+ 6-31 
+ 10*4 
8,550 
+ 5-47 
+ 
10-6 
8,300 
+ 5-82 
+ 10-4 
9,250 
+ 6*26 
+ 
10-6 
8,200 
+ 6-25 
+ 10-5 
11,300 
+ 5'54 
+ 
10*9 
11,400 
+ 6*08 
+ 10-3 
11,500 
+ 6-21 
+ 10-3 
14,800 
+ 5-48 
+ 
10-6 
14,900 
+ 5-92 
+ 10-8 
16,400 
+ 5-85 
+ 
ii-6 
14,250 
+ 6-12 
+ 9-9 
17,600 
+ 5-26 
+ 
9-9 
17,550 
+ 5*72 
+ 97 
20,300 
+ 5-65 
+ 
10-5 
19,300 
+ 5-70 
+ 9'2 
22,650 
+ 4-88 
+ 
9-1 
22,500 
+ 5-40 
+ 8*7 
23,300 
+ 5*30 
j. 
9-5 
22,100 
+ 5-39 
+ 8*6 
The coefficients S and Q. are both positive ; they decrease slightly as 
the magnetic field is increased. As the field approaches the value 20,000 
units, a more rapid decrease in the values of S and Q is observed. 
Field. 
Range of 
Temperature. 
Temperature 
Coefficient of S. 
Temperature 
Coefficient of Q. 
22,500 1 
48-6° C.-71-5 0 C. 
71-5° C.-97'9° C. 
97-9° C.-129-2 0 C. 
+ 0-0045 
zero 
zero 
- 0-002 
+ 0-005 
- 0-002 
Up to about 70° C. the value of S increases considerably with 
rising temperature, but between 70° C. and 130° C. it remains nearly 
constant. 
The variation of Q is not so simple. As the temperature is 
increased the value of Q at first decreases, then increases, and finally 
decreases again. 
