Now while the Earth is going on to describe the half-circle C G E, the sun is still pursuing its journey at the rate of about 18,000 miles per hour, only this time in a direction away from the Earth. As, however, the Earth has not yet regained its mean distance of 92,000,000 miles, the centrifugal force is still greater than the centripetal force, so that the centrifugal force is urging the planet away from the sun with greater intensity than the centripetal force is attracting it, as the two forces are only in equilibrium at the mean distance of the Earth.

Thus, as stated, the orbital motion of the sun and the centrifugal forces are now working conjointly together, with the result that the Earth is repelled gradually further and further from its central body, until it reaches its maximum distance of 94,500,000 miles. While, however, the distance is gradually being increased, it is passing into a part of the Aether possessing not only a decreased mass, but also a decreased velocity, with the result that the motive power or kinetic energy of the aetherial currents at the increased distance is gradually lessened, and as a natural result the velocity of the Earth is also decreased; so that by the time the Earth has got to its furthest distance from the sun, its orbital velocity is slowest, because of the decreased momentum of the aetherial currents.

Thus we can account for the difference of velocity of a planet in its orbit by the same electro-magnetic Aether currents working in conjunction with the sun's orbital motion, and that upon a strictly physical basis. This result is in perfect harmony with Kepler's Second Law, which states that equal areas are described by the radius vector in equal times. Newton proved that by the Law of Gravitation Attraction he could account for this second law, as well as all the others, and as we have not destroyed that law, but perfected it by giving it its exact complement and counterpart, the same mathematical reasoning that applies to the centripetal force must equally apply to the centrifugal force, and if it is true that the centripetal force works harmoniously with the second of Kepler's Laws, then it is equally true that the centrifugal force does also, as the two are inseparably and indisputably united together in the atomic Aether. We have, however, a physical basis for this centrifugal force, and we have an equal physical basis for the centripetal force, as we shall see later, and therefore, by the conjoint working of these two forces taken in conjunction with the orbital motion of the sun, we have now a physical conception for the first time of Kepler's Laws, as well as a mathematical conception, that physical conception being derived from the pressure and motions of the universal Aether.

Art. 104. Aether and Kepler's Third Law.--In [Art. 28] we saw that according to the Third Law of Kepler, the square of the periodic time was proportionate to the cube of the mean distance of that planet from its controlling centre. Newton proved that this Third Law was mathematically correct, and that it could be mathematically accounted for by the existence and operation of the universal Law of Gravitation. As the centrifugal force is the exact opposite of that force in intensity, proportion and mode of operation, it follows that mathematically the centrifugal force also bears the same relation to the Third Law that the centripetal force does.

We have, however, a physical basis for the centrifugal force, and it is with the physical conception of this Third Law rather than with its mathematical character that we are now dealing. Kepler by his Third Law showed that the chief regulating factor in the orbital velocity of a planet was its mean distance from the sun.

The great regulator of the velocity of any planet in its orbit is simply planetary distance, and planetary distance alone. If there were no other law which operated in the solar system than the centripetal force, or the attractive force due to gravity, then such factors as mass and density of a planet ought to play a most important part in the orbital velocity of a planet, as the centripetal force directly recognizes the influence of mass, that is, volume and density, but says nothing about mean distances. This fact unmistakably points to the existence, and demands the operation, of another force, which shall explain, and that on a physical as well as a mathematical basis, how it is that the mean distance of a planet from any centre regulates the orbital velocity of that planet.

The only real and true conception of such a force is to be found in the radiating waves and circulating motions of the aetherial medium, which waves, like water waves, increase in their radial outflow and extent with a regular decreasing intensity, and at the same time decrease in their angular velocity as they recede from the sun. With such a regular decrease of kinetic energy, there must necessarily be imparted to the planets, as their mean distance is increased, a decreased velocity of motion, with the natural result, that the further a planet is from the sun, the less will be its orbital velocity, and that in a regular and uniform proportion as the distance is increased.

Now let us view the matter for a moment in its application to the solar system, and by so doing show the simplicity of the explanation, and at the same time give added proof to the existence and operation of the circulating aetherial currents that exist in space. Let us again picture the solar fires burning in all their fierceness and intensity, every atom and particle of the sun being thrown thereby into the most intense state of activity, and by their energy of motion creating electro-magnetic Aether waves in their myriads, which speed away from the sun on every side.

Under their influence, all subordinate worlds would be carried away into space, were it not for the complementary Law of Gravitation Attraction, that is, the centripetal force. But to every planet, by the operation of some governing and determining principle, a mean distance has been given, and at that mean distance the two forces find their equilibrium; and by their conjoint and co-equal working hold each planet at that mean distance with a power that cannot be broken. Each power or force may be modified under certain conditions, as shown in the two preceding articles; but, whether the planet be repelled further away, or attracted nearer to the sun, through the onward motion of the sun, the two forces ever seek to maintain their equilibrium, and to place the planet at its mean position assigned to it in the solar system.

The nearer that mean position is to the sun, the greater is the velocity of the aetherial currents which circulate round the sun; and the greater their mass, volume for volume, on account of the increasing density of the Aether, the nearer it is to the sun. The effect of this increased velocity, and the increased mass of the circulating Aether currents, is to impart to planets nearest to the sun the greatest orbital velocity; while, the greater the distance, the less will be the orbital velocity of the planet. That this is exactly in accordance with observation and experience may be proved by considering the respective mean distances and orbital velocities of the various planets.