Now what will be the effect of these circular or rotatory Aether currents on the bodies situated within their field? It must be remembered that we are no longer dealing with a frictionless medium, but with a medium which possesses inertia and kinetic energy the same as any other moving matter. Therefore, as soon as it is set in motion, it will impress its motions upon all planets that come under its control and influence, with the result that as the impressed force is ever directed in a circular form, the planet will be pushed along through space by the moving Aether, and the path it describes will be circular also. Thus the actual result of the rotatory electro-magnetic Aether currents will be, that all dependent and associated planets under their influence will be carried by them around the central body which generates the Aether currents. So that they will literally and truly have an orbit, and the circle they describe will be, in its size and circumference, regulated by the mean distance of each planet, which mean distance will form the radius of the circular orbit. Further, as we shall see later, if the sun were always stationary, and had no orbital motion of its own, then the orbit of each planet would always be circular, each planet always occupying its mean distance from the sun, because at that mean distance the centripetal and centrifugal forces are equal. That the actual path of any planet is a circle has been proved by Sir W. R. Hamilton. Tait, in his _Natural Philosophy_, on this point writes (Art. 38): "The Hodograph for the motion of a planet or comet is always a circle, whatever be the form and dimensions of the orbit." This path has been termed the Hodograph. So that we have in the circling electro-magnetic Aether currents a physical explanation for the Hodograph of any planet. In applying the rotatory Aether currents to the various planets, and in endeavouring to find out the quantity of the force impressed upon the various planets at their mean distances, by those currents, we have to take into consideration, as we have already seen, two facts, viz. the mass of the Aether at any point in space, and the velocity of the Aether at the same point. We will first take the effect of the difference in mass. We have seen that at the distance of Mercury from the sun the density of the Aether is greater than at the distance of Venus, and that the density at Mars is greater than the aetherial density at the Earth, the aetherial density decreasing the further the Aether recedes from the sun. What, therefore, is the effect of the decreased density of the Aether on each planet? Even supposing the velocity of the moving Aether is the same at the respective mean planetary distances, which it is not, the total impressed force at the respective mean planetary distances will gradually be decreased upon the various planets, proportionate to the decrease in the mass and density of the Aether.