Suddenly a shrill whistle pealed out from somewhere in the fog away on our port hand, followed, the next instant, by a thin, whirring sound in the air all about the ship, accompanied by sharp, crisp thuds here and there along the bulwarks, and a thin, reedy pattering on the decks.  An object of some sort fell close to my feet, and, upon groping for it, I found that it was an arrow.  At the same moment a loud, fierce, discordant yell burst out all round the ship, and the rattling splash of innumerable paddles dashed into the water, reached our ears.