At this point I had to cut off the greater part of the apergy and check my speed, for reasons that will be presently apparent. I had started in daylight in order that during the first hundred miles of my ascent I might have a clear view of the Earth's surface. Not only did I wish to enjoy the spectacle, but as I had to direct my course by terrestrial landmarks, it was necessary that I should be able to see these so as to determine the rate and direction of the Astronaut's motion, and discern the first symptoms of any possible danger. But obviously, since my course lay generally in the plane of the ecliptic, and for the present at least nearly in the line joining the centres of the Earth and Sun, it was desirable that my real journey into space should commence in the plane of the midnight meridian; that is, from above the part of the Earth's surface immediately opposite the Sun. I had to reach this line, and having reached it, to remain for some time above it. To do both, I must attain it, if possible, at the same moment at which I secured a westward impulse just sufficient to counterbalance the eastward impulse derived from the rotation of the Earth;—that is, in the latitude from which I started, a thousand miles an hour. I had calculated that while directing through the main bar a current of apergy sufficient to keep the Astronaut at a fixed elevation, I could easily spare for the eastward conductor sufficient force to create in the space of one hour the impulse required, but that in the course of that hour the gradually increasing apergic force would drive me 500 miles westward. Now in six hours the Earth's rotation would carry an object close to its surface through an angle of 90°; that is, from the sunset to the midnight meridian. But the greater the elevation of the object the wider its orbit round the Earth's centre, and the longer each degree; so that moving eastward only a thousand miles an hour, I should constantly lag behind a point on the Earth's surface, and should not reach the midnight meridian till somewhat later. I had, moreover, to lose 500 miles of the eastward drift during the last hour in which I should be subject to it, through the action of the apergic force above-mentioned. Now, an elevation of 330 miles would give the Astronaut an orbit on which 90° would represent 6500 miles. In seven hours I should be carried along that orbit 7000 miles eastward by the impulse my Astronaut had received from the Earth, and driven back 500 miles by the apergy; so that at 1 A.M. by my chronometer I should be exactly in the plane of the midnight meridian, or 6500 miles east of my starting-point in space, provided that I put the eastward apergic current in action exactly at 12 P.M. by the chronometer. At 1 A.M. also I should have generated a westward impulse of 1000 miles an hour. This, once created, would continue to exist though the force that created it were cut off, and would exactly counterbalance the opposite rotation