ody. If it were possible to move a planet
along one of these lines of force, its path would be that of a straight
line. If on the other hand a planet moved at right angles to one of
these lines of force, that is, along the surface of an equipotential
sphere, then no work would be done against the electric force, as on
such a sphere the electric force would be of the same intensity.

So that from Hertz' experiments it can be demonstrated, that if there be
any electric force existent in the Aether, due to the action of the sun
upon the Aether, then such a force is directed along the path of a
straight line into space with the velocity of light, which, as already
pointed out, is the path taken by a ray of radiant heat and light, and
coincides with the path taken by the centripetal force.

It has been demonstrated that such electric force is accompanied by a
repulsive force, or more correctly a pressure, so that here we have
further evidence of the existence of a centrifugal force which finds its
generating source in the sun, which is also the centre of the attractive
force of Gravitation in the solar system.

The application of Hertz' experiments may be made not only to the sun,
but also to every planet and satellite that exists in space with the
same result; and, further, may be extended to every particle and atom
that exists throughout the universe. For, according to Art. 43, we have
learned that Aether is universal, and we have seen that it is
gravitative, and have learned from the electro-magnetic theory of light
that it has an electro-magnetic basis. Therefore, to be thoroughly
consistent, we must not stop in the application of this principle at any
point in the whole universe.

Either the whole principle is of universal application, or it ceases to
be a universal law. Therefore, if there is this centrifugal force
operating along a straight line from the centre of an electrified body,
such centrifugal force must be in its application universal, in order to
be complete, and in order to satisfactorily form the counterpart of the
centripetal force which is also universal, and operates along the
straight line joining the centres of gravity of any two bodies.

[Footnote 32: Hertz on _Electric Waves_.]

ART. 84. _Law of Inverse Squares._--We have learned therefore from the
preceding Arts., that the solar system may be looked upon as an electric
field, with the sun as the electrified body occupying the centre. We
hav