The wind, though light, was sufficiently to the southward to enable us to stand for Plymouth; but we kept close-hauled, that we might have a good offing, should the wind shift to the westward, when it would be in our teeth.  Darkness was creeping over the face of the water.  The Dolphin was about two cables length ahead of us.  We had just gone down to tea, and Oliver was pouring out a cup for papa, when we were startled by a loud shout uttered by Truck: