On the night of December 20, in the same year of the mutiny of the _Mowbray_, a large full-rigged ship, homeward bound, was, to the north of the Equator, stealing silently through the dusk. The hour was about half-past nine. The moon rode high and shone gloriously, and the edge of the plain of ocean came in two sweeps of ebony to the clasp of splendour under the satellite. The ship lifted a cloud of sail to the stars. The night-wind was lightly breathing, and every cloth was asleep, stirless as alabaster mouldings, curving from each yard-arm, and climbing with the whiteness of the moon into three spires. This ship was the _Alfred_, but not the famous Thames East Indiaman of that name. She was about sixteen hundred tons, with an abundant crew, a captain and four mates. She was carrying a valuable cargo and a number of passengers from India to London, and once only had she halted--at Simon's Bay, where she put a lieutenant of Marines and fifteen men ashore, and then proceeded, after filling her fresh-water casks. She was a flush-decked ship, and when you stood at the wheel your eye ran along a spacious length of deck, rounding with the exquisite art of the shipwright into flaring bows which sank into the true clipper lines, high above the keen and coppered forefoot. A number of ladies and gentlemen sat and moved about the decks. The awnings were furled, and the moonshine glistened upon these people, and sparkled in the jewellery of the ladies, and silvered the whiskers of the gentlemen. On the weather side of the long quarter-deck walked the commander of the ship, Captain Barrington. A lady's hand was tucked under his arm, and he frequently looked to windward whilst he talked. To leeward paced the mate, and a little distance forward, in the deep shadows of the main-rigging, stood a group of midshipmen. Right aft, upon the taffrail, sat three gentlemen. One smoked a pipe, the others cheroots. Captain Barrington permitted his guests--as he, with facetious politeness, called his passengers--to smoke upon the quarter-deck after five bells in the first watch. A considerable surface of grating stretched betwixt these three gentlemen and the wheel. The wheel was something forward of the grating, and the helmsman, therefore, absorbed in the business of keeping the ship to her course, could hear little more than the rumble of the tones of the gentlemen who conversed on the taffrail. 'I say, Parry,' said one of the gentlemen, who was, indeed, no less a personage than the surgeon of the ship, casting his eyes up at the moon, and tasting his tobacco, with slow enjoyment, in the discharge of each little cloud of it; 'did it ever occur to you to consider that all the great processes of this world--that all creation, in short, is based on circles?' 'Why do you address yourself to me?' said Captain Parry. 'What do I know about circles?'