Suddenly, as we all sat waiting for the outburst of the threatened storm, a long-drawn, piercing cry pealed out across the water, apparently from a spot at no very great distance from us.  It was, although not very loud, the most appalling, soul-harrowing sound that had ever smote upon my ears, and a violent shudder of horror thrilled me from head to foot, while I felt the hair bristling upon my scalp as I listened to it.  Three times in rapid succession did that dreadful, heart-shaking cry come wailing to our ears, and then all was silence again for perhaps half a minute, when the men about me began to ask, in low, tense whispers, whence it came, and from what creature.  To me, I must confess, the sounds seemed to be such as might burst from the lips of a fellow-creature in the very uttermost extremity of mortal terror. But that could scarcely be, for how could mortal man have approached us within a distance of some two hundred yards in that breathless calm, unless, indeed, in a boat--of which there had certainly been no sign in any direction half an hour before.  And if one were disposed for a moment to admit such a possibility, whence could a boat come?  The pirate brig had been the only craft in sight when darkness fell, and it was scarcely within the bounds of probability that anything then out of sight beneath the horizon could have drawn so near to us during the succeeding hours of darkness.  Or again, admitting such a possibility, what dreadful happening could have wrung from human lips such blood- curdling sounds?  We were all eagerly discussing the matter, some of the men agreeing with me that the sounds were human, while others stoutly maintained that they were supernatural, and boded some terrible disaster to the boats, when our discussion was abruptly broken in upon by the sound of rippling water near at hand, as though a craft of some kind were bearing down upon us at a speed sufficient to raise a brisk surge under her bows, and the next instant the voice of San Domingo pealed out in piercing tones, eloquent of the direst terror: