ten o’clock
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 . `` 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 atmosphere in the chamber be regenerated in the interim ? To breathe it for more than an hour , at the farthest , would be a matter of impossibility , or , if even this term could be extended to an hour and a quarter , the most ruinous consequences might ensue . The consideration of this dilemma gave me no little disquietude ; 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 .