However, as the known world widened and trade grew, inventions by private ship-owners continually improved the rigging, though it would be hard to find a class of men slower to change old ways for new than the seamen. Columbus’s “caravel” had four short masts, the forward one having a square lug-sail and the three after masts lateens. It was very gradually, indeed, that lateens were given up, and most curious combinations of sails were to be seen in this transition period of the fifteenth and sixteenth centuries. The old-fashioned Mediterranean barca, for example, had as foremast the forward-raking “trinchetto” of the felucca, with a huge lateen, while the mainmast bore three square sails and the mizzen two lugs; and in addition to this two banks of oars were provided! In fact, it was not until 1800 that English frigates substituted a spanker for the lateen-rigged mizzen. Another curiosity of rigging possessed by these solidly built, beautifully carved vessels (no such exterior decoration has been seen since as adorned the ships of the sixteenth and seventeenth centuries) was the quaint little spritsail-topmast. By this time the single heavy pole-mast had been superseded by the three built-up masts and topmasts, braced by stays, made accessible by rope ladders (shrouds), and carrying several tiers of topsails instead of only one. A bowsprit had been added, also, and this became almost a fourth mast, so loaded were it and its stays with various small sails. Its outer end bore this miniature spritsail-mast, with topmast, shrouds, and tiny sails all complete, surmounted by a pole-head, or jack-staff, upon which was hoisted the flag since known as the jack, and always now carried at the prow of any national boat or ship, even such as the shapeless monitors. But gradually, out of the experience of long voyages, the competition of merchants, and as an effect of improved gunnery and consequent changes in naval tactics, the lofty deck-structures, great tops, needless outworks, and odd sails, like this spritsail, were got rid of, and vessels were trimmed down and equalized until they became, as now, “ship-shape, Bristol-fashion.” The rigging of modern sailing-vessels is divided into “standing” and “running”; the former includes the masts, their stays, now generally made of wire, and such other rope-work as is not adjustable. The sails, also, may be assigned to two classes: first, those attached to a mast, with or without boom and gaff, or to a stay, which are called fore-and-aft sails because they may be ranged lengthwise of the ship; and, second, those suspended by their upper and lower edges to or between spars or “yards” swung across the mast, and known as “square” sails, the lowermost of which are really lugs. All the variations of shape seen in America, except the rare and local lateens, can be counted in one or the other of these classes.