EFFECTS OF IRON CORE IN THE PRIMARY COIL 45 
produced by each carefully noted. Then with the stand- 
ard inductorium the values of S giving these same de- 
flections are determined. Although at first the ratio 
of S to / remains constant, as the values of / begin to 
exceed o.i ampere the ratio steadily increases. It is 
evident, therefore, that large currents are producing 
relatively greater deflections than small ones. By mul- 
tiplying the different values of S by the ratio of S to /, 
which was constant, we obtain a series of computed values 
of 7 representing the currents which would be required 
to produce the observed galvanometer deflections if no 
iron core were present. These are, of course, the values 
of I which are to be employed in computing the strengths 
of stimuli according to the expression 
LI 
Table I, column 3, gives the values of / computed 
from a series of observed values of / and S in actual 
experiments. 
TABLE I 
Value of 7 ob- 
served in am- 
peres. 
Value of 5 ob- 
served. 
Value of / com- 
puted in am- 
peres. 
Ratio computed 
value of / to its 
observed value. 
Decimal part 
of ratio divided 
by observed 
value of /. 
0.01 
0.005 
O.OI 
.O 
0.05 
0.025 
0.05 
.O 
.... 
O. IO 
0.05 
O.IO 
.O 
.... 
O.2O 
0.1044 
0.2088 
044 
.22 
0.30 
0.1597 
0.3194 
.065 
.217 
0.40 
0.2180 
0.4360 
.OQO 
.225 
0.50 
0.2782 
0.5564 
113 
.226 
O.6O 
0.3396 
0.6792 
I.I32 
.22 
