Instead of placing the magnet perpendicular to the plane of the loop,
it may be placed parallel to its plane. Fig. 14d shows the magnet
and loop both vertical.

The field shows that the magnet will be rotated, and will finally take
for stable equilibrium an axial position, with the N end pointing as
determined by the rule already given.

[Illustration: Fig. 14d.]

If two loops are placed with their axes in the same straight line as
follows, Figs. 14f, 14g, a reproduction of Figs. 14b and 14c
will become evident.

It is obvious from these spectra that the two loops attract or repel
each other according to the direction of the current, which fact may
be shown by bringing a loop near to another loop suspended from the
ring stand, Fig. 9, or by using the ordinary apparatus for that
purpose--De la Rive's battery and Ampere's stand.

[Illustration: Fig. 14f.]

[Illustration: Fig. 14g.]

If two loops are placed in the same vertical plane, as in Figs. 14h
and 14i, there will be attraction or repulsion, according to the
direction of the adjacent currents. The fields become the same as
Figs. 8 and 8a, as may be seen by comparing them with those figures.

[Illustration: Fig. 14h.]