The relation of this decrease of velocity to the mean distance is exactly determined by Kepler's Third Law, in which he states that the square of the periodic time is proportionate to the cube of the mean distance. That this is true has already been proved in Art. 28. In conclusion on this point, let me ask the reader to try to conceive any other physical explanation for this decrease of orbital velocity as the mean distance is increased, than the one given here, namely, the decrease in the velocity and mass of the radiating and circulating Aether currents, and if such attempt is made, I premise that its only result will be utter failure. No other physical conception to account on a physical basis for all Kepler's Laws can be given or conceived, than that which finds its origin in the universal electro-magnetic Aether, which by its pressures, tensions and motions gives rise to all the phenomena incidental to, and associated with, planetary and stellar phenomena. Therefore, inasmuch as all the laws of motion, and all Kepler's Laws can be accounted for by a gravitating and rotatory Aether medium, those facts alone, apart from the explanation of other phenomena associated with light and heat, would stamp the circulating Aether medium as the physical cause of all the motions and phenomena associated with the whole of the celestial mechanism. ART. 105. _Orbital Motions of Satellites and Planets._--According to Kepler's First Law, the Earth and all the other planets move round the sun in orbits which are in the shape of an ellipse. Not only, however, is the first law true of planetary motion, it is equally true of the motions of all satellites moving round their primary planets. I wish, however, to point out, and prove in an indisputable manner, that Kepler's First Law does not sufficiently explain and determine the exact orbit of any satellite as it revolves around its primary planet, or even of any planet as it revolves around the sun. Simply because, if any satellite or planet is to perform a perfect ellipse as it revolves around its central body, that central body must only move for a time and must then come to rest, or partly return in its journey in order for a perfect ellipse to be formed, as shown in a previous figure. Now we know from observation that such a thing as rest in space by any planet, or by the sun, is absolutely unknown in the celestial mechanism.