Ketch Ketch A ketch is a two-masted sailing craft whose mainmast is taller than the mizzen mast (or aft-mast). The name "ketch" is derived from "catch" or fishing boat. Historically the ketch was a northern European square-rigged vessel, often a freighter or fishing boat, particularly in the Baltic and North seas. Nowadays, a ketch tends to be a fore-and-aft rigged pleasure yacht, similar to a yawl; but a ketch's mizzen mast is taller and its mizzen sail is larger than a yawl's. The large fore-and-aft sail on the mainmast is the mainsail, while the sail on the mizzen mast is the
How many angels can dance on the head of a pin? about how many could perch at the same time on the head of a pin"". Dorothy L. Sayers argued that the question was "simply a debating exercise" and that the answer "usually adjudged correct" was stated as, "Angels are pure intelligences, not material, but limited, so that they have location in space, but not extension." Sayers compares the question to that of how many people's thoughts can be concentrated upon a particular pin at the same time. She concludes that infinitely many angels can be located on the head of a pin, since they do not occupy any space there: