The displacement of the Earth on the Sun’s face proved it to be necessary that the apergic current should be directed against the latter in order to govern my course as I desired, and to recover the ground I had lost in respect to the orbital motion. I hoped for a moment that this change in the action of the force would settle a problem we had never been able to determine. Our experiments proved that apergy acts in a straight line when once collected in and directed along a conductor, and does not radiate, like other forces, from a centre in all directions. It is of course this radiation— diffusing the effect of light, heat, or gravity over the surface of a sphere, which surface is proportionate to the square of the radius—that causes these forces to operate with an energy inversely proportionate, not to the distance, but to its square. We had no reason to think that apergy, exempt as it is from this law, would be at all diminished by distance; and this view the rate of acceleration as I rose from the Earth had confirmed, and my entire experience has satisfied me that it is correct. None of our experiments, however, had indicated, or could well indicate, at what rate this force can travel through space; nor had I yet obtained any light upon this point. From the very first the current had been continuous, the only interruption taking place when I was not five hundred miles from the Earth’s surface. Over so small a distance as that, the force would move so instantaneously that no trace of the interruption would be perceptible in the motion of the Astronaut. Even now the total interruption of the action of apergy for a considerable time would not affect the rate at which I was already moving. It was possible, however, that if the current had been hitherto wholly intercepted by the Earth, it might take so long a time in reaching the Sun that the interval between the movement of the helm and the response of the Astronaut’s course thereto might afford some indication of the time occupied by the current in traversing the 96-1/2 millions of miles which parted me from the Sun. My hope, however, was wholly disappointed. I could neither be sure that the action was instantaneous, nor that it was otherwise.
At the close of the third day I had gained, as was indicated by the instruments, something more than two millions of miles in a direct line from the Sun; and for the future I might, and did, reckon on a steady progress of about one and a quarter million miles daily under the apergic force alone—a gain in a line directly outward from the Sun of about one million. Henceforward I shall not record my observations, except where they implied an unexpected or altered result.