s, and I consequently surveyed at that time an extent of
the earth's area amounting to no less than one three-hundred-and-twentieth
part of the entire surface.

At half-past nine, I tried the experiment of throwing out a handful of
feathers through the valve. They did not float as I had expected, but
dropped down like a bullet and with the greatest velocity, being out of
sight in a very few seconds. It occurred to me that the atmosphere was
now far too rare to sustain even feathers; that they actually fell, as
they appeared to do, with great speed, and that I had been surprised by
the united velocities of their descent and my own rise.

At six o'clock P. M., I perceived a great portion of the earth's visible
area to the eastward involved in thick shadow, which continued to
advance with great rapidity, until at five minutes before seven the
whole surface in sight was enveloped in the darkness of night. It was
not, however, until long after this time that the rays of the setting
sun ceased to illumine the balloon, and this fact, although, of course,
expected, did not fail to give me great pleasure. In the morning I
should behold the rising [v]luminary many hours before the citizens of
Rotterdam, in spite of their situation so much farther to the eastward,
and thus, day after day, in proportion to the height ascended, I should
enjoy the light of the sun for a longer and longer period. I now
resolved to keep a journal of my passage, reckoning the days by
twenty-four hours instead of by day and night.

At ten o'clock, feeling sleepy, I determined to lie down for the rest of
the night; but here a difficulty presented itself, which, obvious as it
may appear, had escaped my attention up to the very moment of which I
am now speaking. If I went to sleep, as I proposed, how could the air in
the chamber be renewed in the meanwhile? To breath it more than an hour
at the farthest would be impossible; or, even if this term could be
extended to an hour and a quarter, the most ruinous consequences might
ensue. This dilemma gave me no little anxiety; and it will hardly be
believed that, after the dangers I had undergone, I should look upon
this business in so serious a light as to give up all hope of
accomplishing my ultimate design, and finally make up my mind to the
necessity of a descent.

But this hesitation was only momentary. I reflected that man is the
slave of custom and that many things are deemed essential which are only
th