He hurried on, flashing his torch along the blind fronts of the shops in a perfunctory manner.

He was especially nervous when he came to corners.

And he was glad when he issued from the little street into the wider one that was well lighted.
How could he have been expected to notice a very trifling incongruous detail as he passed the log cabin?
Indeed many a keener-eyed and entirely valorous night watchman might have neglected to observe that the leathern latch-string of the cabin's closed door was no longer hanging outside..