The sunset that evening was clear, promising a fine night, while the wind held steady and fair.  We were consequently all in high spirits at the prospect of a quick and pleasant passage to Sierra Leone.  But as the night advanced a bank of heavy cloud gradually gathered on the horizon to the northward, and the wind began to back round and freshen somewhat, so that about midnight it again became necessary to double- reef our canvas, while the sea once more rose to such an extent that the boats were soon shipping an unpleasant quantity of water over the weather bow.  Moreover the wind continued to back until we were broken off a couple of points from our course; so that, altogether, it finally began to look very much as though we were in for another unpleasant night, though perhaps not quite so bad as the one that had preceded it. It is true that we were not just then in any actual danger, for, after all, the strength of the wind was no more than that to which the _Shark_ would show single-reefed topsails.  But it was more than enough for us, under the canvas which we were carrying, and I had just given the order to haul down a third reef when one of the men who was engaged upon the task of shortening sail suddenly paused in his work and gazed out intently to windward under the sharp of his hand.  The next moment he shouted excitedly: