esimal order.

Further, if we are to be strictly correct, in our analogy between the
earth and the aetherial atom, its polar diameter must be shorter than
its equatorial diameter, as that is one of the facts observable
regarding the shape of our earth, so that the shape of the aetherial
atom will not be strictly spherical, but its actual shape would be that
of an oblate spheroid, being flatter at the poles, and bulging out in
the equatorial regions.

This exact analogy between the earth and an aetherial atom may not at
present seem of very great importance, but its importance will be seen
later on, when we come to deal with the phenomena of heat, light, and
electricity.

Here, then, is our conception of an aetherial atom in the rough, based
not upon any imaginative hypothesis, but rather upon that strict
conformity to observation and experience, which is the very groundwork
of all true Philosophy.

For, after all, what is the earth but an atom on a large scale? In
comparison with illimitable space, with its infinite distances, that can
alone be measured by the velocity of light, our own earth is but a speck
of dust, a very atom that helps to make up the universe, and, as such,
should teach us the shape and properties of other atoms of which the
same universe is composed.

We have therefore to conceive of the all-space-pervading Aether as being
composed of infinitesimal portions of Aether, which are nearly spherical
in shape, and ever in a state of rotation; this state of rotation
differentiating the atom of Aether from the free Aether, if such an
entity exists. So that an atom of Aether would simply be an
infinitesimal portion of the Aether in a state of rotation.

If, by any means, we could stop the rotation, we should at once destroy
the atom, in the same way that the smoke vortex ring would cease to be a
ring, if its rotation were stopped. The cessation of the rotation I,
however, believe to be impossible. So that even in the ultimate atom of
that universal medium the Aether, we have an illustration of the
combination of those two forms which are inseparably connected
throughout the whole universe, viz. matter and motion, and it is the
combination of these two that gives to the aetherial atom its form, and
its very existence, without which it has no life, and ceases to exist.

It may be necessary in the development of this work as we proceed, to
slightly modify our conception of the aetherial atom, but that