At five o'clock P.M. being engaged in regenerating the atmosphere within the chamber, I took that opportunity of observing the cat and kittens through the valve. The cat herself appeared to suffer again very much, and I had no hesitation in attributing her uneasiness chiefly to a difficulty in breathing--but my experiment with the kittens had resulted very strangely. I had expected of course to see them betray a sense of pain, although in a less degree than their mother; and this would have been sufficient to confirm my opinion concerning the habitual endurance of atmospheric pressure. But I was not prepared to find them, upon close examination, evidently enjoying a high degree of health, breathing with the greatest ease and perfect regularity, and evincing not the slightest sign of any uneasiness whatever. I could only account for all this by extending my theory, and supposing that the highly rarefied atmosphere around might perhaps not be, as I had taken for granted, chemically insufficient for the purposes of life, and that a person born in such a medium might possibly be unaware of any inconvenience attending its inhalation, while, upon removal to the denser strata near the earth, he might endure tortures of a similar nature to those I had so lately experienced. It has since been to me a matter of deep regret that an awkward accident at this time occasioned me the loss of my little family of cats, and deprived me of the insight into this matter which a continued experiment might have afforded. In passing my hand through the valve with a cup of water for the old puss, the sleeve of my shirt became entangled in the loop which sustained the basket, and thus, in a moment, loosened it from the button. Had the whole actually vanished into air it could not have shot from my sight in a more abrupt and instantaneous manner. Positively there could not have intervened the tenth part of a second between the disengagement of the basket and its absolute and total disappearance with all that it contained. My good wishes followed it to the earth, but, of course, I had no hope that either cat or kittens would ever live to tell the tale of their misfortune.
At six o'clock 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 view 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 circumstance, although of course fully anticipated, did not fail to give me an infinite deal of pleasure. It was evident that, in the morning, I should behold the rising luminary many hours at least 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, would I enjoy the light of the sun for a longer and a longer period. I now determined to keep a journal of my passage, reckoning the days from one to twenty-four hours continuously, without taking into consideration the intervals of darkness.