ating in, each case the effect of the lines of
force of each magnet upon one another. The iron filings strewed over the
magnet are magnetized by induction, with the result that the North pole
of one filing attracts the South pole of the next one to it, and this is
continued along the whole of one line of force, as revealed by the united
iron filings. Faraday believed in the real physical existence of these
lines of force, and that belief has been perfected by Clerk Maxwell in two
papers which he wrote on "Physical Lines of Force," which will be
considered in another article. We will simply deal with them at present
as indications of the existence of the magnetic forces in the medium
surrounding any magnet.

Let us apply these facts to the solar system and see what the
application yields. We have the sun revolving in the Aether medium
represented by the circle _S_ in Fig. 19. Then we have the lines of
force extending in curved lines _E._ and _W._, but in almost straight
lines North and South. We will suppose the axis of the sun to be
vertical for the sake of simplicity. It may be asked, how far will these
lines of force stretch out into space? The reply is that they stretch
and extend throughout the whole solar system, and far away into the
depths of space, though with ever-decreasing intensity according to the
law of inverse squares. Wherever the aetherial light waves are
manifested, there the electro-magnetic waves, with all that they imply,
are manifested also. We know that the light waves are existent at least
as far as Neptune, a distance of 2800 millions of miles, therefore at
least to that extent the electro-magnetic waves are manifested; and
wherever the electro-magnetic waves to which the sun has given birth are
manifested, there we have the existence of the electro-magnetic field,
which is co-existent and co-extensive with the electric field of the
sun. Further, wherever we get the magnetic field, there we get the lines
of force which are as real as air or ocean currents, and are caused, as
Maxwell indicated (Art. 44), by the motions of the atomic Aether.
Wherever these lines of force are closest together, there the intensity
of the magnetic force is at its greatest.

[Illustration: Fig: 19.]

By actual experiment, it can be demonstrated that the lines of force are
closest together nearest to the magnet, and therefore applying that fact
to the solar magnetic field, the lines of force should be closest
togeth