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