Sitting thus, I gradually fell into a somewhat sombre reverie, in the course of which I reviewed the events that had befallen me during the short period that had elapsed since the _Dolphin_ and the _Eros_ had parted company.  I went over again, in memory, all the circumstances connected with the loss of the brigantine, the hours I had spent alone in the longboat, her destruction and my somewhat dramatic appearance among the crew of _La Mouette_, my reception by her mad captain, and then fell to conjecturing what the future might have in store for me, when I was suddenly aroused to a consciousness of my immediate surroundings by a sort of impression it was no more than that--that I had heard the sound of a ship's bell struck four times--_ting-ting_, _ting-ting_--far away yonder in the heart of the thick darkness.  So faint, such a mere ghost of a sound, did it seem to be that I felt almost convinced it was purely imaginary, an effect resulting from the train of thought in which I had been indulging; yet I rose to my feet and, walking over to the skylight, peered through it at the cabin clock to ascertain what the time might actually be.  _It was on the stroke of two o'clock_!  Therefore if, as I had assured myself, the sounds were imaginary, it was at least a singular coincidence that they should have reached me just at that precise moment.  I walked to the fore end of the poop, upon the rail guarding which the ship's bell was mounted, and sharply struck four bells, after which I again called to the crew forward to maintain a sharp look-out.