t for such a rotation, and if there be a physical cause, then the
problem to be solved is--find the physical cause to account for the
continuous and ever-recurring rotation of all the planets and the sun on
their axes, which shall be so effective and continual that, year in and
year out, the rotation of all the planets may be continued as observed.
In solving this problem we have to revert to our reason why the earth is
a magnet. In Art. 91 we learned that the earth and all the other
planets, and indeed all stellar bodies, were electro-magnets, because
the electro-magnetic Aether was constantly circulating round them.

If, by accepting this explanation, we can at the same time solve the
problem of the rotation of the planets, and the sun, on their axes, then
we shall have further evidence that our hypothesis is the correct one.
Now let me ask, What is the effect of an electric current continually
circulating round any magnet in the same way that the electro-magnetic
Aether continually circulates round the earth, which is a magnet?

To find out what the effect is, we must resort to experiment. Professor
Lodge, in his _Modern Views of Electricity_, shows us the effect of any
circulating current of electricity revolving round a magnet. In his
chapter on Electro-Magnetism he writes as follows: "How does a current
act on a magnetic pole? Two currents attract or repel each other, two
poles attract or repel each other, but a current and a pole exert a
mutual force which is neither attraction nor repulsion. It is a rotatory
force. They tend neither to approach nor to recede, they tend to revolve
round each other." "A singular action this and at first sight unique"
(p. 135). "The two things will revolve round each other for ever. This
affords and has afforded a fine field for the perpetual motionist, and
if only the current would maintain itself without a sustaining power,
perpetual motion in fact would be attained."

Faraday has shown by experiment the action of a current on the magnet,
and _vice versa_. Faraday, in his description of an electro-magnetic
apparatus for the exhibition of rotatory motion, shows how the rotation
of a current round a magnet, and a magnet round a current, may be
experimentally proved. With the apparatus used he shows that the current
of electricity may be made to revolve round the pole of the magnet in
the direction dependent on the pole used, and further, illustrates how
the magnet may be made to r