For the same reason which led me to start so long before the date of the opposition, I resolved, having regard to the action of the Earth's rotation on her axis, to start some hours before midnight. Taking leave, then, of the two friends who had thus far assisted me, I entered the Astronaut on the 1st August, about 4.30 P.M. After sealing up the entrance-window, and ascertaining carefully that everything was in order—a task which occupied me about an hour—I set the generator to work; and when I had ascertained that the apergion was full, and that the force was supplied at the required rate, I directed the whole at first into the main conductor. After doing this I turned towards the lower window on the west—or, as it was then, the right-hand side—and was in time to catch sight of the trees on the hills, some half mile off and about two hundred feet above the level of my starting-point. I should have said that I had considerably compressed my atmosphere and increased the proportion of oxygen by about ten per cent., and also carried with me the means of reproducing the whole amount of the latter in case of need. Among my instruments was a pressure-gauge, so minutely divided that, with a movable vernier of the same power as the fixed ones employed to read the glass circles, I could discover the slightest escape of air in a very few seconds. The pressure-gauge, however, remained immovable. Going close to the window and looking out, I saw the Earth falling from me so fast that, within five minutes after my departure, objects like trees and even houses had become almost indistinguishable to the naked eye. I had half expected to hear the whistling of the air as the vessel rushed upward, but nothing of the kind was perceptible through her dense walls. It was strange to observe the rapid rise of the sun from the westward. Still more remarkable, on turning to the upper window, was the rapidly blackening aspect of the sky. Suddenly everything disappeared except a brilliant rainbow at some little distance—or perhaps I should rather have said a halo of more than ordinary rainbow brilliancy, since it occupied, not like the rainbows seen from below, something less than half, but nearly two-thirds of a circle. I was, of course, aware that I was passing through a cloud, and one of very unusual thickness. In a few seconds, however, I was looking down upon its upper surface, reflecting from a thousand broken masses of vapour at different levels, from cavities and hillocks of mist, the light of the sun; white beams mixed with innumerable rays of all colours in a confusion, of indescribable brilliancy. I presume that the total obscuration of everything outside the cloud during my passage through it was due to its extent and not to its density, since at that height it could not have been otherwise than exceedingly light and diffuse. Looking upward through the eastern window, I could now discern a number of brighter