ut
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 deg.; 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 deg.
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 the eastward current, detaching that conductor from
the apergion; and,