nine in the evening
For himself he had accomplished the object for which he came , and presently after bade me farewell . The next day , the keepers , I know not for what reason , were more than usually industrious in their search , saying , though without assigning any ground for their suspicion , that they were sure I had some tool in my possession that I ought not ; but the depository I had chosen escaped them . I waited from this time the greater part of a week , that I might have the benefit of a bright moonlight . It was necessary that I should work in the night ; it was necessary that my operations should be performed between the last visit of the keepers at night and their first in the morning , that is , between nine in the evening and seven . In my dungeon , as I have already said , I passed fourteen or sixteen hours of the four-and-twenty undisturbed ; but since I had acquired a character for mechanical ingenuity , a particular exception with respect to me was made from the general rules of the prison . It was ten o'clock when I entered on my undertaking . The room in which I was confined was secured with a double door .