Ketch mizzen sheet. So on a ketch, the dual purpose of the mizzen sail is to both propel and balance the vessel, while on a yawl, the smaller mizzen mainly serves the purpose of trim or balance. Yawls tend to have mainsails almost as large as those of comparable sloops. A ketch may be distinguished from a cutter or a sloop by virtue of having two masts rather than one, though a ketch with two foresails is sometimes called a "cutter-rigged ketch". Both the ketch and the yawl differ from the two-masted schooner, whose aft mainmast is taller than the foremast.
How many angels can dance on the head of a pin? How many angels can dance on the head of a pin? The question "How many angels can dance on the head of a pin?" (alternatively ""How many angels can stand on the "point" of a pin?"") is a reductio ad absurdum of medieval scholasticism in general, and its angelology in particular, as represented by figures such as Duns Scotus and Thomas Aquinas. It is first recorded in the 17th century, in the context of Protestant apologetics. The question has also been linked to the fall of Constantinople, with the imagery of scholars debating about minutiae while the Turks besieged the