Several large vessels now have four masts, in which case they are called "four-masters." When all the masts are square-rigged, the names are bowmast, foremast, main and mizzen. If the aftermost mast is not square-rigged, the order is foremast, main, mizzen and jigger. In some four-masters the masts are named fore, first-main, second-main and mizzen. Should the vessel be three-masted, and have yards only on the two front masts, she is a "bark;" and, by-the-way, the spanker of a bark is her "mizzen." Should she have yards only, as the foremast, she is a "barkentine;" should she be a two-master, and have yards on both, she is a "brig;" should she have yards on the foremast only, she is a "brigantine." With regard to this, however, a few words of explanation are necessary. A century or so ago, a favorite rig was the "snow," pronounced so as to rhyme to "now." The snow was a bark with a lateen mizzen, or rather a brig with the "driver," a lateen one, on a jigger mast, just a little abaft the mainmast. When this jigger was abolished the sail retained its lateen shape, got on to the mainmast, and became what we may call a main crossjack, thereby rendering a square mainsail impossible. When the crossjack was replaced by a gaff, the larger vessels started the square mainsail, and became "brigs," while the smaller kept the spanker as their mainsail, and became "brigantines," so that a genuine old brigantine is a brig without a square mainsail. Soon, however, vessels appeared with no yards at all on their mainmasts, and these were called "hermaphrodite brigs," and were found to be so handy that they crowded the old brigantines off the sea and took their name. But here a qualification must come in. Perhaps you have seen a two-masted vessel with yards on her foremast and none on her main. She is a "topsail-schooner." In what does she differ from the brigantine? The brigantine has a foremast of three spars from the old snow, and a mainmast of two from the hermaphrodite; the topsail-schooner has both foremast and mainmast of two spars, and the foresail on a gaff instead of on a yard, and in other ways is different, but a glance at the foremast is enough to distinguish her from a brigantine. A "three-masted schooner" has only lower masts and topmasts, and each mast is rigged for fore-and-aft sails, but more often than not these vessels carry yards at the fore and sometimes at the main. With the "ketch" begins what has been called the mast-and-a-half division of sailing vessels. The tall mast is the mainmast, the short mast is the mizzen; some ketches carry square sails on the main, some carry a topsail on the mizzen--the distinctive mark of the ketch being that the mizzen is a pole-mast and stepped in front of the stern-post. If the mizzen be stepped abaft the stern-post the vessel becomes a "dandy" or "yawl."