22 D. Sears—Magnetism of Soft Tron. 
In the following experiments the soft iron bar, instead of 
forming the core common to both magnetizing helices A and 
B, formed their arma- 
ture. A coil of fine g 
wire was slipped upon 
the iron bar, which was 
connected with a 
flecting galvanometer. 
: Bo | 
C being thus at right ~ 
The coils of the bobbin 
angles to those of the 
magnetizing helices A and B, the effects of the induction b 
the current circulating through A and B were obviated and the ’ 
induced current which arose in C on making the magnetizing 
circuit was due to the magnetism of the iron bar alone. This 
method has great advantages over that of the proof bar. 
- TaBue I. TABLE II. 
from A and B me pc sam SE Defiections. cee hak Popa a Deflections 
rae 14 8 860 
2 13 9 328 
3 10.5 10 308 
4 9 11 278 7 
Table IT. represents the results obtained when two north or 
two south poles were opposed. , 
In the latter case observations for the first four centimeters : 
former, at points remote from 
er, the magn 
int midway 
_B are denoted by «, and the 
