It was a mild evening on the Mediterranean, the wind light, the sea smooth, the temperature—­though the season was that of midwinter—­summer-like in its geniality.  Into the harbor of Tripoli slowly glided a small, two-masted vessel, all her sails set and moderately well filled by the wind, yet moving with the tardiness of a very slow sailer.  A broad bay lay before her, its surface silvered by the young moon whose crescent glowed in the western sky.  Far inward could be dimly seen the masts and hull of a large vessel, its furled sails white in the moonlight.  Beyond it were visible distant lights, and a white lustre as of minaret tops touched by the moonbeams.  These were the lights and spires of Tripoli, a Moorish town then best known as a haunt and stronghold of the pirates of the Mediterranean.  All was silence, all seemingly peace.  The vessel—­the ketch, to give it its nautical name—­moved onward with what seemed exasperating slowness, scarcely ruffling the polished waters of the bay.  The hours passed on.  The miles lagged tardily behind.  The wind fell.  The time crept towards midnight.  The only life visible in the wide landscape was that of the gliding ketch.

But any one who could have gained a bird’s-eye view of the vessel would have seen sufficient to excite his distrust of that innocent-seeming craft.  From the water-side only ten or twelve men could be seen, but on looking downward the decks would have been perceived to be crowded with men, lying down so as to be hidden behind the bulwarks and other objects upon the deck, and so thick that the sailors who were working the vessel had barely room to move.

This appeared suspicious.  Not less suspicious was the fact that the water behind the vessel was ruffled by dragging objects of various kinds, which seemed to have something to do with her slowness of motion.  As the wind grew lighter, and the speed of the vessel fell until it was moving at barely a two-knots’ rate, these objects were drawn in, and proved to be buckets, spars, and other drags which had been towed astern to reduce the vessel’s speed.  Her tardiness of motion was evidently the work of design.

It was now about ten o’clock.  The moon hovered on the western horizon, near its hour of setting.  The wind was nearly east, and favorable to the vessel’s course, but was growing lighter every moment.  The speed of the ketch diminished until it seemed almost to have come to rest.  It had now reached the eastern entrance to the bay, the passage here being narrowed by rocks on the one hand and a shoal on the other.  Through this passage it stole onward like a ghost, for nearly an hour, all around being tranquil, nothing anywhere to arouse distrust.  The craft seemed a coaster delayed by the light winds in making harbor.

The gliding ketch had now come so near to the large vessel in front, that the latter had lost its dimness of outline and was much more plainly visible.  It was evidently no Moorish craft, its large hull, its lofty masts, its tracery of spars and rigging being rather those of an English or American frigate than a product of Tripolitan dock-yards.  Its great bulk and sweeping spars arose in striking contrast to the low-decked vessels which could be seen here and there huddled about the inner sides of the harbor.