28
KINETIC ENERGY OF ELECTRICITY IN MOTION [I]
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differs from the calculated ratio 5-330 only by 1/250. The
difference certainly is less than the unavoidable errors of
observation.
It is to be remarked that in the above results all observa-
tions without exception have been included.
SECOND SERIES OF EXPERIMENTS WITH RECTILINEAR WIRES.
A second series of observations with rectilinear wires was
made, which differed from the preceding one only in that the
German-silver resistance A'B was replaced by a resistance of
Bunsen gas carbon, and in that a thicker copper wire was
chosen for the circuit giving the current. This change was
intended to remove a danger to be apprehended in the preceding
experiment, viz. that the small changes of temperature attending
the reversal itself might produce an apparent alteration in the
strength of the extra-current, and so might hide any deviation
of it from the induction law. In order to render these and
similar disturbances observable, the experiments were made
with as many different values as possible of the primary
current. The deviations of the integral flow of the extra-
currents from proportionality to the strength of the primary
necessarily had their origin in such disturbances.
The diameter of the wire used was 0.6482 mm.; the
distance between the two branches was 3.441 mm. The
inductances were calculated exactly as above, and were found
to be
P' 920,956 mm.,
=
P185,282 mm.
The self-inductance of the opposing carbon resistance was
P=2997 mm.,
and hence the calculated ratio of the extra-currents was
P'-P
P-P
=
5.0367