about ten o'clock
This was a rule in my father 's house , as well as that of my uncle -- in the latter , indeed , I was compelled to observe it with a stern exactitude . The consequence of this habit was , that whenever the hour of ten drew nigh , I naturally felt the inclination for sleep ; and the habit had grown so fixed , that , notwithstanding the change of circumstances , it still continued . This I was not slow to observe . I felt the desire to sleep come upon me at regular periods , and I concluded , therefore , that whenever I had this feeling upon me it was about ten o'clock of the night . I had discovered , too , by registering the time with my watch , that I usually slept about eight hours , and then I felt no desire to remain asleep any longer . When I awoke it would be six in the morning ; and , in this belief , I regulated my watch to that hour . So convinced was I of these facts , that I felt confident I could have counted the days without the watch ; but fearing that some change might occur in my habitual hours of rest , in consequence of the altered circumstances in which I was placed , I resolved always to keep the time-piece going .