rom the sun, the density of the Aether at the mean distance of
Mercury, 35,900,000 miles, would not be so great as near the sun's
surface; while the density of the aetherial medium at the distance of
Venus, 67,000,000 miles, would be less than the density of the aetherial
medium at the distance of Mercury. This principle may be applied right
through the sun's aetherial electro-magnetic field, until we come to the
mean distance of Neptune, which is 2,780,000,000 miles, and there the
density of the Aether would be less than at any other part of the
aetherial electro-magnetic field around the sun.

So that the mass of the Aether at Mercury, which is equal to the number
of aetherial atoms per unit volume, is greater than the mass at Venus.
Thus the impressed force which the aetherial medium at the mean distance
of Mercury can exert upon any body in its neighbourhood, is greater than
the impressed force which the Aether can exert upon any body at the
distance of Venus, because of its decreased mass at that distance. In
the same way it can be proved that the impressed force which the
electro-magnetic Aether exerts on any body at the distance of Venus, is
greater than the impressed force which the Aether exerts upon a body at
the mean distance of the Earth. So that at the respective mean distances
of Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, the
electro-magnetic Aether, if in motion, would exert less force at each
of the mean distances of these planets exactly proportionate to the
decreased mass and decreased velocity of the Aether.

Now what is the motion which the Aether possesses, so far as the sun is
concerned? because, upon the particular kind of motion which it
possesses will depend the direction in which the impressed force will be
exerted according to the second law of motion.

In Art. 98 we supposed the sun and planets to be stationary in the solar
system, each planet being at its respective mean distance, from which it
cannot move owing to the equality of the two forces. Now give to the
central sun from whence the electro-magnetic Aether waves flow, a
rotatory motion on its own axis, which it really possesses, as it
rotates on its axis once in every twenty-six days nearly, and this will
give to the Aether medium a circular or rotatory motion. This circular
or rotatory motion the Aether has already been proved to possess (Art.
91, where we learned that all solar magnets were caused by
electro