waves of light with a finite velocity.

Apart, therefore, from atomicity of some kind or other, elasticity of
the Aether is an assumption philosophically incorrect, as it is contrary
to that simplicity of conception laid down by Newton, and is also
contrary to all experience, and thus violates the second Rule of
Philosophy.

Aether therefore must be said to be perfectly elastic; so perfectly
elastic, that it is susceptible to the least touch of any natural thing,
so that even an atom, so small that it cannot be seen with the most
powerful microscope, yet so elastic is this Aether medium, that the
least motion or vibration of one of these atoms, though the motion did
not exceed the 20- or 40-millionth part of an inch, yet even this would
create in the aetherial ocean, Aether-waves, just as a body moving in
water creates water-waves, which, radiating from the place of their
birth, beget and create others, the process continuing until they reach
the margin of the water in which they were generated. It is precisely
so with these Aether-waves, when once generated and set in motion. They
create others, the process being continued and perpetuated; and, unless
arrested in their course, may continue until they reach the very limits
and confines of material immensity and space.

It is, perhaps, only necessary to say, regarding the perfection of the
elasticity of the Aether medium, that though it takes from 40,000 to
69,000 waves to complete the space of one inch in extent, yet it is done
with such miraculous rapidity, as to speed the distance of 186,000 miles
in the short space of a second of time; or, taking the number of
Aether-waves to complete an inch as 50,000, its elasticity is such that
it makes 50,000 x 186,000 x 12 x 5280 vibrations in one second of time.

We have already seen in Art. 39, that according to Boyle and Marriotte's
Law, the velocity of a wave-motion, as sound in the air, is determined
by the relation of the elasticity of the medium to its density. If the
temperature of the atmosphere remains the same, then the _elasticity_
varies in the same proportion as its density.

According to Art. 45, Aether is gravitative, and that fact produces
different degrees of density in the aetherial atmosphere of an atom or
planet or meteor, sun or star; that part of the Aether being densest
nearest the central body, and rarer the further we go away from that
body.

Now the question at once arises, what is the effect of