Balloon canvas is a term applied to sails of large dimensions, made of light cotton canvas. The chief balloon sail is the spinnaker used for sailing when the wind is aft. A balloon jib used to fill up the whole space from the bowsprit end, masthead, and mast at deck; a balloon foresail is hanked to the forestay, but the clew extends some distance abaft the mast; in a schooner a balloon maintopmast staysail has an up and down weather leech extending below the lower corner of the sail, which is hanked to the maintopmast stay. It is sheeted on to the end of the main boom. A balloon jib topsail or "Yankee" jib topsail is a useful sail ; all modern balloon head sails are cut very high in the clew, so that the lead of the sheet nearly makes a right angle with the luff of the sail. Balloon jibs have long gone out of fashion. They were succeeded by "bowsprit spinnakers," whilst the bowsprit spinnaker, a low-footed sail, has in turn given place to the higher clewed balloon jib topsail A balloon topsail is another name for a jackyard topsail, or a topsail set with two yards. The upper or "topsail yard" is a vertical continuation of the topmast. The "lower" yard or jackyard is parallel with the gaff and should act as a direct continuation or extension of it. In setting a jackyard topsail a certain amount of "drift" or "space" should be left between the gaff and the lower yard so that there may be play to take up the slack of the sheet.