Compass rose two adjacent cardinal directions. For example, North-by-east (NbE) is one quarter wind from North towards East, Northeast-by-north (NEbN) is one quarter wind from Northeast toward North. Naming all 32 points on the rose is called "boxing the compass". The 32-point rose has the uncomfortable number of 11° between points, but is easily found by halving divisions and may have been easier for those not using a 360° circle. Using gradians, of which there are 400 in a circle, the sixteen-point rose will have twenty-five gradians per point. Linguistic anthropological studies have shown that most human communities have four points of
Compass equivalence theorem only a collapsing compass and no straightedge. There are several proofs of the correctness of this construction and it is often left as an exercise for the reader. Here is a modern one using transformations. Compass equivalence theorem The compass equivalence theorem is an important statement in compass and straightedge constructions. The tool advocated by Plato in these constructions is a "divider" or "collapsing compass", that is, a compass that "collapses" whenever it is lifted from a page, so that it may not be directly used to transfer distances. The "modern compass" with its fixable aperture can be used to