As my first object was to ascertain whether there were sentinels at that time at that precise point, I saw that I was approaching the end of my experiment. Could I have once reached the causeway unnoticed, I could have lurked in the water beneath its projecting timbers, and perhaps made my way along the main shore, as I had known fugitive slaves to do, while coming from that side. Or had there been any ripple on the water, to confuse the aroused and watchful eyes, I could have made a circuit and approached the causeway at another point, though I had already satisfied myself that there was only a narrow channel on each side of it, even at high tide, and not, as on our side, a broad expanse of water. Indeed, this knowledge alone was worth all the trouble I had taken, and to attempt much more than this, in the face of a curiosity already roused, would have been a waste of future opportunities. I could try again, with the benefit of this new knowledge, on a point where the statements of the negroes had always been contradictory. Resolving, however, to continue the observation a very little longer, since the water felt much warmer than I had expected, and there was no sense of chill or fatigue, I grasped at some wisps of straw or rushes that floated near, gathering them round my face a little, and then, drifting nearer the wharf in what seemed a sort of eddy, was able, without creating further alarm, to make some additional observations on points which it is not best now to particularize. Then, turning my back upon the mysterious shore which had thus far lured me, I sank softly below the surface and swam as far as I could under water. During this unseen retreat, I heard, of course, all manner of gurglings and hollow reverberations, and could fancy as many rifle-shots as I pleased. But on rising to the surface all seemed quiet, and even I did not create as much noise as I should have expected. I was now at a safe distance, since they were always chary of showing their boats, and they would hardly take personally to the water. What with absorbed attention first, and this submersion afterwards, I had lost all my bearings but the stars, having been long out of sight of my original point of departure. However, the difficulties of the return were nothing; making a slight allowance for the flood-tide, which could not yet have turned, I should soon regain the place I had left. So I struck out freshly against the smooth water, feeling just a little stiffened by the exertion, and with an occasional chill running up the back of the neck, but with no nips from sharks, no nudges from alligators, and not a symptom of fever-and-ague.