six p.m.
Up to this we had all been working so hard that we had deemed it hardly worth while to sacrifice our hours of rest for the very doubtful advantage of maintaining a night watch ; but with the conclusion of what we considered our heaviest task , so far as actual labour was concerned , we decided that it might be of advantage to keep a look-out at night time , at least during the moonlit nights . We should then be able to see a passing ship at such a distance as would enable us to attract her attention by means of a flare . Accordingly it was arranged that four of us , namely , Julius , the two stewardesses , and I , should each take one watch in succession . In that latitude , which was only a few degrees north of the Line , day and night were approximately of equal length , and for all practical purposes the night might be reckoned as beginning at six p.m. , and ending at six a.m. Therefore if each of us kept a watch of three hours , we should cover the twelve hours between us . But by this arrangement the same person would keep one particular watch every night , and , of course , the least arduous of the watches would be that from six o'clock to nine o'clock p.m. ; I therefore decided to split this watch into two dog-watches of one and a half hours each , by which arrangement the regularity would be broken , and each of us would get the benefit of the first dog-watch in succession , which seemed to be not only a fair but a desirable thing . To keep a night watch , however , without possessing the means to attract the notice of a passing ship , would be useless . I therefore constructed a sort of framework consisting of four twelve-foot planks , which I set up on edge in the form of a square enclosure on the after extremity of the poop , securing them firmly to the deck planking by means of battens .