the hour of ten
No doubt you will wonder how I came by this knowledge -- since I had kept no time for the first hundred hours after getting aboard , and there was then , in the complete darkness that surrounded me , no means of distinguishing the one from the other . I had a means of telling , however , and it was this : During all my life I had been trained to the habit of going to bed at a particular hour -- ten o'clock at night -- and also of rising at six exactly . 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 .