448 
DR. J. HOPKINSON ON MAGNETIC AND OTHER PHYSICAL 
Tables 5-8. 
■ 
Table 5, Curve VI. 
Table 6, Curve VII. 
Table 7, Curve VIII. 
Table 8, Cun^e IX. 
! 
Resistance of second-'! 
ary before experi- > 2'CL 
ment J 
Temperature of se-1 
condary before ex- > 722° C. 
periment J 
Resistance of second- 1 
ary after experi- > 2‘61 
ment J 
Temperature of se-"] 
condary after ex- >722°C. 
periment J 
2-47 
670° C. 
2-47 
670° C. 
2-29 
603° C. 
2-21 
573° C. 
2-0 
494° C. 
1-94 
472° C. 
Magnetising 
■ force. 
Indiiclion per 
sq. cm. 
Magnetising 
force. 
Induction 
per sq. cm. 
1 
Magnetising 
force. 
Induction 
per sq. cm. 
Magnetising 
force. 
Induction 
per sq. cm. 
0-075 
0-15 
0-.30 
0-6 
2-2 
7-6 
47-2 
/ 163 
1 125 
/ 305 
1 278 
/ 762 
[ 726 
4,004 
[ 8,952 
1 8,895 
10,410 
/ 11,224 
111,111 
0-075 
0-16 
0-3 
0-6 
2-2 
7-6 
47-8 
77 
162 
427 
1,516 
9,381 
11,562 
12,859 
- 
0-075 
0-15 
0-30 
0-60 
2-2 
7-6 
50-6 
/ 68 
1 50 
/ 128 
1 -108 
/ 307 
1 275 
/ 908 
1 8.34 
9,604 
11,992 
14,470 
0-075 
0-15 
0-3 
0-6 
2-2 
7-6 
5.3-5 
/ 54-7 
1 35-8 
/ 98 
1 5^-5 
/245 
1195 
/ 742 
\590 
9,433 
12,273 
15,201 
At this stage the ring was allowed to cool down, and on the following day a 
determination was made of the curve at oi’dinary temperature of 9°’6 C. (Curve X.) 
Magnetising force . 0'075 0T5 0'3 0'6 1'2 2‘2 4‘0 6‘8 11'4 17'3 57'0 
Induction per sq. cm. 21-61 41T1 1161 SOS') 1,482 6,912 10,.341 12,410 13,640 14,255 15,623 
13-0 / 32'0/ 93/ 273 / 
The ring was next heated till the resistance reached about 2 ' 4 , was allowed to cool 
somewhat, and a curve was determined (Curve XL) at a resistance of 1‘69 to 1'64. 
Temperature 378° C. to 354° C. 
Magnetising force 
0-075 
0-15 
0-3 
0-6 
1-2 
2-2 
4-0 
7-6 13-1 51-7 
Induction per sq. cm. 
38-1 
931 
26.3 
874 
4,288 
8,818 
11,296 
12,589 13,404 15,174 
44/ 
101 / 
Tn addition to the variation of magnetisability depending on the temperature, these 
numbers show one or two interesting facts. Where two observations are given these 
are the results of successive reversals in opposite directions. After each experiment 
the ring was demagnetised by reversals of current ; thus currents successively 
diminishing in amount were passed through the primary, each current being reversed 
