1 A.M.
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 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 .