EFFECTS OF IRON CORE IN THE PRIMARY COIL 49 
According to this method increases in the primary current 
represent corresponding decreases in the stimulating 
efficiency of the inductorium. 
TABLE III 
Experimental Proof that Stimulation Intensity shows Greater 
Variation in the " Critical Region " when the Iron Core is 
Absent than when it is Present. Break Shocks 
Iron core absent. 
Iron core present. 
Date of experiment. 
Position of 
secondary 
Primary 
current, 
Per- 
centage 
increase 
Primary 
current. 
Per- 
centage 
increase 
in centi- 
amperes. 
in cur- 
amperes. 
in cur- 
rent. 
rent. 
Dec. 21, 1906 . . 
8.0 
O OIQ 1 ? 
0.00187 
12. 
w wx VO 
0.0505 
159 
0.00463 
148 
16.0 
0.260 
415 
O.O22 
375 
Dec. 24, 1906 
8.0 
o 00^76 
o . 0008 
12.0 
\S . W*M^ 1 \J 
0.01523 
164 
O.OOI97 
146 
16.0 
0.091 
432 
0.00934 
374 
Apr. i;, 1007. . 
8.2 
O OI7 
0.0036 
11.28 
w / 
0-035 
107 
0.0063 
75 
12.45 
0-0535 
50 
O.OO92 
46 
14.0 
0.107 
TOO 
0.016 
74 
16.2 
0.2485 
132 
0.034 
112 
