The Poughkeepsie was only a sloop-of-war, or a corvette, in construction, number of her guns, and rate; but she was a ship of the dimensions of an old-fashioned frigate, measuring about one thousand tons. The frigates of which we read half a century since, were seldom ever as large as this, though they were differently built in having a regular gun-deck, or one armed deck that was entirely covered, with another above it; and on the quarter-deck and forecastle of the last of which were also batteries of lighter guns. To the contrary of all this, the Poughkeepsie had but one armed deck, and on that only twenty guns. These pieces, however, were of unusually heavy calibre, throwing thirty-two pound shot, with the exception of the Paixhans, or Columbiads, which throw shot of even twice that weight. The vessel had a crew of two hundred souls, all told; and she had the spars, anchors, and other equipments of a light frigate. In another great particular did the Poughkeepsie differ from the corvette-built vessels that were so much in favour at the beginning of the century; a species of craft obtained from the French, who have taught the world so much in connection with naval science, and who, after building some of the best vessels that ever floated, have failed in knowing how to handle them, though not always in that. The Poughkeepsie, while she had no spar, or upper deck, properly speaking, had a poop and a topgallant-forecastle. Within the last were the cabins and other accommodations of the captain; an arrangement that was necessary for a craft of her construction, that carried so many officers, and so large a crew. Without it, sufficient space would not be had for the uses of the last. One gun of a side was in the main cabin, there being a very neat and amply spacious after-cabin between the state-rooms, as is ordinarily the case in all vessels from the size of frigates up to that of three-deckers. It may be well to explain here, while on this subject of construction, that in naval parlance, a ship is called a single-decked vessel; a _two-_decker, or a _three-_ decker, not from the number of decks she actually possesses, but from the number of _gun-_decks that she has, or of those that are _fully_ armed. Thus a frigate has four decks, the spar, gun, berth, and orlop (or haul-up) decks; but she is called a “single-decked ship,” from the circumstance that only one of these four decks has a complete range of batteries. The two-decker has two of these fully armed decks, and the three-deckers three; though, in fact, the two-decker has five, and the three-decker six decks. Asking pardon for this little digression, which we trust will be found useful to a portion of our readers, we return to the narrative.