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 impulse derived from the Earth; so that thenceforward I should be entirely free from the influence of the latter, though still sharing that motion of the Earth through space at the rate of nearly nineteen miles per second, which would carry me towards the line joining at the moment of opposition her centre with that of Mars.
All went as I had calculated. I contrived to arrest the Astronaut's motion at the required elevation just about the moment of sunset on the region of the Earth immediately underneath. At 12 P.M., or 24h by the chronometer, I directed a current of the requisite strength into the eastward conductor, which I had previously pointed to the Earth's surface, but a little short of the extreme terrestrial horizon, as I calculated it. At 1 A.M. I found myself, judging by the stars, exactly where I wished to be, and nearly stationary as regarded the Earth. I instantly arrested
