Let us begin, then, by supposing that A’s watch commences at 8 o’clock in the evening; the officer and his party remain on deck till midnight, four hours being one period. This is called the First watch. B is next roused up, and keeps the Middle watch, which lasts from midnight till 4 o’clock. C now comes up, and stays on deck till 8, which is the Morning watch. A then returns to the deck, where he walks till noon, when he is relieved by B, who stays up till 4. If C were now to keep the watch from 4 to 8, of course A would again have to keep the First watch on the second night, as he did at first starting; and all the others, in like manner, would have to keep, over again, exactly the same watches, every night and day. In order to break this uniform recurrence of intervals, an ingenious device has been hit upon to produce a constant and equitable rotation. When or where this plan was invented, I do not know, but I believe it exists in the ships of all nations. The period from 4 o’clock in the afternoon till 8 in the evening, instead of constituting one watch, is divided into two watches, of a couple of hours each. These, I don’t know why, are called the Dog watches. The first, which lasts from 4 to 6 o’clock, belongs, on the second day, according to the order described above, to C, who is, of course, relieved at 6 o’clock by A. This alteration, it will be observed, gives the First watch (from 8 to midnight) to B, on the second night; the Middle (from midnight to 4) to C; and the Morning watch (from 4 to 8) to A; the Forenoon watch (from 8 to noon) to B; and the Afternoon (from noon to 4) to C. The first Dog watch (from 4 to 6) will now be kept by A, the second Dog watch (from 6 to 8) by B, and so on, round and round. By this mechanism, it will easily be perceived, the officers, on each succeeding day, have a watch to keep, always one stage earlier than that which they kept on the day before. Thus, if A have the Morning watch one night, he will have the Middle watch on the night following, and the First watch on the night after that again. The distribution of time which this produces is very unequal, when the short period of twenty-four hours only is considered; but the arrangement rights itself in the course of a few days. On the first day, A has ten hours’ watch to keep out of the twenty-four, B eight, and C only six. But on the next day, A has only six hours, while B has ten, and C eight; while, on the third day, A has eight, B six, and C ten hours’ watching; and so on, round and round, from year’s end to year’s end. This variety, to a person in health and spirits, is often quite delightful. Each watch has its peculiar advantages; and I need hardly add, that each likewise furnishes an ample store of materials for complaining, to those discontented spirits whose chief delight is to coddle up grievances, as if, forsooth, the principal object of life was to keep ourselves unhappy, and to help to make others so!