Suddenly, the simultaneous discharge of three or four of our main-deck guns was followed by a cheer of delight from our lads, and, jumping upon the carriage of one of the quarter-deck guns, I was just in time to see the French ship's mizenmast fall forward, dragging down the main-topgallant-mast with it and passing through the main topsail and mainsail in its fall, splitting them from head to foot.  There was at once great confusion on board the Frenchman, and, being thus deprived in a moment of all her after-sail, she immediately fell square off before the wind, or about three points more to the eastward than the course we were steering.