COMPASS ROSE

A common compass rose as is found on a nautical chart showing both true and magnetic north with magnetic declination

A compass rose is a figure displaying the orientation of the cardinal directions, north, south, east and west on a map or nautical chart. Today the use and idea of a compass rose is found on or featured in almost all navigation systems, including nautical charts, NDB and VOR systems, some GPS sets and similar.

Contents
History
Modern depictions
In popular media
Gallery
External links

History


A 16-point compass rose

Naming all 32 points on the rose is called boxing the compass.
Replica of a 32 points wind rose from a chart by Jorge de Aguiar (1492), the oldest person signed and dated Portuguese nautical chart

The "rose" term arises from the fairly ornate figures used with early compasses. A fleur-de-lis figure, evolved from the initial 'T' in the north wind's name ''Tramontane'', is sometimes used to indicate the north direction. Similarly, on old maps the east was marked with an 'L' for ''Levante'', or with a '+' indicating the direction of Jerusalem from the point of view of western Europe's countries.
Early roses were depicted with 12 points at 30º each, as was favored by the Romans. In the Middle Ages map makers moved to the 16 point rose complaining that sailors did not have the education to understand the previous design. The 16 point rose has the uncomfortable number of 22 1/2º between points, but is easily found by halving divisions and may have been easier for those not using a 360º circle. Using gradians, the sixteen-point rose will have exactly twenty-five gradians per point in.
A ''Rose of the Winds'' is an ancient version of a compass rose which personified compass directions as winds with individual names, such as the west wind Zephyrus and the east wind Eurus.
A fountain in Taranto, Italy was inspired by and named after the Rose of the Winds.

Modern depictions


The contemporary compass rose appears as two rings, one smaller and set inside the other. The outside ring denotes 'true' cardinal directions while the smaller inside ring denotes 'magnetic' cardinal directions. 'True north' refers to the geographical location of the north pole while 'magnetic north' refers to the direction towards which the north pole of a magnetic object (as found in a compass) will point. The angular difference between 'true' and 'magnetic' north is called variation, which varies depending on location. The angular difference between magnetic heading and compass heading is called deviation which varies by vessel and its heading.
Pedro Reinel was the first person to draw a standard compass rose.

In popular media


HMS ''Compass Rose'' is the name of a fictional Royal Navy corvette in the novel ''The Cruel Sea''.
In the interactive fiction game, Beyond Zork, a compass rose is a flower that can control the direction of the wind.
''The Compass Rose'' is the name of a significant tavern in Mercedes Lackey's Valdemar fantasy novels.

Gallery



External links



Origins of the Compass Rose

The Rose of the Winds - An example of a rose with 26 directions.

Wind rose

Rose of Piedro Reinel, 1504 - an example of a 32-point rose with cross for east (the Christian Holy Land) and fleur-di-lis for north.

The Compass Rose in St. Peter's Square

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