554 
ME. G-. GOEE ON ELECTEOTOESION. 
and the wire did not remain twisted ; on repeating the currents in the same direction, 
the very large torsion in the original direction was again produced ; and any number of 
such torsions could be consecutively obtained without any intervening reversal of the cur- 
rents. It is evident therefore that the coercive force or condition within the bar, which 
retains the iron in a twisted state after the passage of alternate coil- and axial currents, 
is either overcome or does not operate when simultaneous currents are employed. 
As simultaneous currents produced very much larger torsions than alternate ones, 
and appeared to aid each other, and notwithstanding coil-currents destroy the effect of 
axial ones, and vice versa, , their influences, although dissimilar, are not contradictory, 
but appear to act upon the principle of “ composition of forces.” 
The very much greater magnitude of the torsions obtained by this method was pro- 
bably a consequence of the two magnetic conditions being very much stronger during 
the continuance of the currents than after their cessation. Not unfrequently, with an 
iron wire T75 mm. thick, the first movement of the index exceeded 25 millimetres. The 
torsional push is not limited to a small angle, but continues through the entire range 
of the largest arc through which the pointer can be made to swing, even though that 
exceeds one third of a circle. 
36. Torsions yielded by simultaneous and divided currents. 
With the two currents commenced together and terminated also simultaneously, the 
index made a very large movement at the commencement of the currents, remained 
considerably (though much less) deflected during their continuance, and returned nearly 
to zero on their cessation, provided the two currents were of proper relative degrees of 
strength. In all the experiments in which currents simultaneous in their commence- 
ment were employed (and they were very many), the direction of torsion agreed with 
the law (see Section 6), probably because such a method of applying them largely 
removes at once all interfering residuary influences. 
Eight series of experiments, including sixty distinct and different orders of succession 
of currents, were made — passing simultaneous currents after single ones, both coil and 
axial, and single currents after simultaneous ones; employing an iron wire l 1 75 mm. 
diameter, and currents from six cells arranged as three upon each circuit. In fifty-four 
of these cases the directions of the torsions agreed with the law, and the magnitudes 
of them agreed with the results usually obtained. In the other six, all instances in 
which single currents following simultaneous ones were employed, and associated only 
with coil-currents producing a north pole below, no movements took place on making , 
but small detorsions occurred on breaking the contact. 
Although the two currents of each pair of simultaneous ones in these experiments 
were not of proper relative strength, the coil one being in excess, the average magnitude 
of all the torsions produced by a single coil-current, after repeated simultaneous ones, 
was only 1 mm., and by a single axial one after them was 1-5 mm. By comparing these 
results with those obtained by means of alternate single currents under nearly similar 
