midnight
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 .