The skipper, in setting the new course, had displayed what commended itself to me as sound judgment.  We were at such a distance from the strangers of whom we were now in chase that even our most lofty canvas was--and would, for some little time longer, remain--invisible from their decks.  This was highly desirable, since the nearer we could approach them without being discovered, the better would be our chance of ultimately getting alongside them.  The only likelihood of a premature discovery of our proximity lay in the possible necessity, on the part of one or the other of them, to send a hand aloft; but this we could not guard against.  Captain Bentinck, therefore, hoping that _no_ such necessity would arise, had shaped a course not directly for them, but at an intercepting angle to their own course, by which means he hoped not only to hold way with them, but also to lessen very considerably the distance between them and ourselves before the sight of our canvas, rising above the horizon, would reveal our unwelcome presence to the two slavers, as we believed the strange craft to be.  It was also of the utmost importance that we should have instant knowledge of their discovery of our presence in their neighbourhood, and of the action that they would thereupon take; hence the necessity for my remaining aloft to maintain a steady and careful watch upon their movements.