Points of the compass

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"ENE" and "Compass point" redirect here. For the company with the former ticker symbol ENE, see Enron. For other uses, see Compass Point (disambiguation).
"Southeastern" redirects here. For the British TOC, see Southeastern (train operating company).
A 32-point compass rose

The points of the compass are points on a compass, specifically on the compass rose, marking divisions of the four cardinal directions: North, South, East, West. The number of points may be only the 4 cardinal points, or the 8 principal points adding the intercardinal (or ordinal) directions northeast (NE), southeast (SE), southwest (SW), and northwest (NW). In meteorological usage further intermediate points are added to give the sixteen points of a wind compass.[1] Finally, at the most complete in European tradition, are found the full thirty-two points of the mariner's compass.[2] In ancient China 24 points of the compass were used.[citation needed]

The mariner's practice of boxing the compass is the action of naming all thirty-two points of the compass in order clockwise.[3] The names of intermediate points are formed by the initials of the cardinal directions and their intermediate ordinal directions, and are very handy to refer to a heading (or course or azimuth) in a general or colloquial fashion, without having to resort to computing or recalling degrees. For most applications, the minor points have been superseded by degrees measured clockwise from North.

32 cardinal points[edit]

# Compass point Abbr. Traditional wind point minimum middle maximum
1 North N Tramontana 354.38° 0.00° 5.62°
2 North by east NbE Qto Tramontana verso Greco 5.63° 11.25° 16.87°
3 North-northeast NNE Greco-Tramontana 16.88° 22.50° 28.12°
4 Northeast by north NEbN Qto Greco verso Tramontana 28.13° 33.75° 39.37°
5 Northeast NE Greco 39.38° 45.00° 50.62°
6 Northeast by east NEbE Qto Greco verso Levante 50.63° 56.25° 61.87°
7 East-northeast ENE Greco-Levante 61.88° 67.50° 73.12°
8 East by north EbN Qto Levante verso Greco 73.13° 78.75° 84.37°
9 East E Levante 84.38° 90.00° 95.62°
10 East by south EbS Qto Levante verso Scirocco 95.63° 101.25° 106.87°
11 East-southeast ESE Levante-Scirocco 106.88° 112.50° 118.12°
12 Southeast by east SEbE Qto Scirocco verso Levante 118.13° 123.75° 129.37°
13 Southeast SE Scirocco 129.38° 135.00° 140.62°
14 Southeast by south SEbS Qto Scirocco verso Ostro 140.63° 146.25° 151.87°
15 South-southeast SSE Ostro-Scirocco 151.88° 157.50° 163.12°
16 South by east SbE Qto Ostro verso Scirocco 163.13° 168.75° 174.37°
17 South S Ostro 174.38° 180.00° 185.62°
18 South by west SbW Qto Ostro verso Libeccio 185.63° 191.25° 196.87°
19 South-southwest SSW Ostro-Libeccio 196.88° 202.50° 208.12°
20 Southwest by south SWbS Qto Libeccio verso Ostro 208.13° 213.75° 219.37°
21 Southwest SW Libeccio 219.38° 225.00° 230.62°
22 Southwest by west SWbW Qto Libeccio verso Ponente 230.63° 236.25° 241.87°
23 West-southwest WSW Ponente-Libeccio 241.88° 247.50° 253.12°
24 West by south WbS Qto Ponente verso Libeccio 253.13° 258.75° 264.37°
25 West W Ponente 264.38° 270.00° 275.62°
26 West by north WbN Qto Ponente verso Maestro 275.63° 281.25° 286.87°
27 West-northwest WNW Maestro-Ponente 286.88° 292.50° 298.12°
28 Northwest by west NWbW Qto Maestro verso Ponente 298.13° 303.75° 309.37°
29 Northwest NW Maestro 309.38° 315.00° 320.62°
30 Northwest by north NWbN Qto Maestro verso Tramontana 320.63° 326.25° 331.87°
31 North-northwest NNW Maestro-Tramontana 331.88° 337.50° 343.12°
32 North by west NbW Qto Tramontana verso Maestro 343.13° 348.75° 354.37°

16 cardinal points[edit]

Cardinal Direction abbreviation minimum azimuth maximum azimuth (degrees)
North N 348.75º 11.25º
North-northeast NNE 11.25º 33.75º
Northeast NE 33.75º 56.25º
East-northeast ENE 56.25º 78.75º
East E 78.75º 101.25º
East-southeast ESE 101.25º 123.75º
Southeast SE 123.75º 146.25º
South-southeast SSE 146.25º 168.75º
South S 168.75º 191.25º
South-southwest SSW 191.25º 213.75º
Southwest SW 213.75º 236.25º
West-southwest WSW 236.25º 258.75º
West W 258.75º 281.25º
West-northwest WNW 281.25º 303.75º
Northwest NW 303.75º 326.25º
North-northwest NNW 326.25º 348.75º

Compass point names[edit]

"Southwest" redirects here. For the airline, see Southwest Airlines. For other uses, see Southwest (disambiguation).
"Northeast", "Northwest", and "Southeast" redirect here. For other uses, see Northeast (disambiguation), Northwest (disambiguation), and Southeast (disambiguation).
A 16-point compass rose
A 32-wind compass card, with English names

The names of the 32-wind compass rose follow these rules:

- The cardinal directions are North (N), East (E), South (S), West (W), at 90° angles on the compass rose.

- The ordinal (or intercardinal) directions are Northeast (NE), Southeast (SE), Southwest (SW) and Northwest (NW), formed by bisecting the angle of the cardinal winds. The name is merely a combination of the cardinals it bisects.

- The eight principal winds (or main winds) are the cardinals and ordinals considered together, that is N, NE, E, SE, S, SW, W, NW. Each principal wind is 45° from its neighbour. The principal winds form the basic eight-wind compass rose.

- The eight half-winds are the points obtained by bisecting the angles between the principal winds. The half-winds are North-northeast (NNE), East-northeast (ENE), East-southeast (ESE), South-southeast (SSE), South-southwest (SSW), West-southwest (WSW), West-northwest (WNW) and North-northwest (NNW). Notice that the name is constructed simply by combining the names of the principal winds to either side, with the cardinal wind coming first, the ordinal wind second. The eight principal winds and the eight half-winds together yield a 16-wind compass rose, with each compass point at a 2212° angle from the next.

- The sixteen quarter winds are the direction points obtained by bisecting the angles between the points on a 16-wind compass rose. The sixteen quarter-winds are North by east (NbE), Northeast by north (NEbN), Northeast by east (NEbE), East by north (EbN) in the first quadrant, East by south (EbS), Southeast by east (SEbE), Southeast by south (SEbS), South by east (SbE) in the second quadrant, South by west (SbW), Southwest by south (SWbS), Southwest by west (SWbW), West by south (WbS) in the third quadrant, and finally West by north (WbN), Northwest by west (NWbW), Northwest by north (NWbN) and North by west (NbW) in the fourth quadrant.[4][5]

The eight principal winds, eight half-winds and sixteen quarter winds together yield a 32-wind compass rose, with each compass direction point at 1114° angle from the next.

The name of a quarter-wind is typically "X by Y", where X is a principal wind and Y is a cardinal wind. As a mnemonic device, it is useful to think of "X by Y" as a shortcut for the phrase "one quarter wind from X towards Y", where a "quarter" is 1114°, X is the nearest principal wind, and Y the next (more distant) cardinal wind. So "Northeast by east" means "one quarter from NE towards E", "Southwest by south" means "one quarter from SW towards S". The title of the Alfred Hitchcock 1959 movie, North by Northwest, is actually not a direction point on the 32-wind compass, but the film contains a reference to Northwest Airlines.

Traditional names[edit]

The traditional compass rose of eight winds (and its 16-wind and 32-wind derivatives) was invented by seafarers in the Mediterranean Sea during the Middle Ages (the ancient Greco-Roman 12 classical compass winds have little to do with them). The traditional mariner's wind names were expressed in Italian - or, more precisely, the Italianate Mediterranean lingua franca common among sailors in the 13th and 14th centuries, that was principally composed of Genoese (Ligurian), mixed with Venetian, Sicilian, Provençal, Catalan, Greek and Arabic terms from around the Mediterranean basin.

32-wind compass with traditional names (and traditional colour code).

This Italianate patois was used to designate the names of the principal winds on the compass rose found in mariner compasses and portolan charts of the 14th and 15th centuries. The "traditional" names of the eight principal winds are:

  • (N) - Tramontana
  • (NE) - Greco (or Bora in some Venetian sources)
  • (E) - Levante (sometimes Oriente)
  • (SE) - Scirocco (or Exaloc in Catalan)
  • (S) - Ostro (or Mezzogiorno in Venetian)
  • (SW) - Libeccio (or Garbino, Eissalot in Provençal)
  • (W) - Ponente (or Zephyrus in Greek)
  • (NW) - Maestro (or Mistral in Provençal)

Local spelling variations are far more numerous than listed, e.g. Tramutana, Gregale, Grecho, Sirocco, Xaloc, Lebeg, Libezo, Leveche, Mezzodi, Migjorn, Magistro, Mestre, etc. Traditional compass roses will typically have the initials T, G, L, S, O, L, P, and M on the main points. Portolan charts also colour-coded the compass winds: black for the eight principal winds, green for the eight half-winds and red for the sixteen quarter-winds.

In the English compass, all wind names are constructed on the basis of the cardinal four names (N, E, S, W). In the traditional compass, one needs to memorize eight basic names - one for each of the eight principal winds. While there are more names to memorize, the payoff is that the name construction rules for the 32-wind compass are more straightforward. The half-winds are just a combination of the two principal winds it bisects, with the shortest name usually coming first (e.g. NNE is "Greco-Tramontana", ENE is "Greco-Levante", SSE is "Ostro-Scirocco", etc.). The quarter winds are phrased "Quarto di X verso Y" (one quarter from X towards Y) or "X al Y" (X to Y) or "X per Y" (X by Y). There are no irregularities to trip over: the nearest principal wind always comes first, the more distant one second, e.g. North-by-east is "Quarto di Tramontana verso Greco", Northeast-by-north "Quarto di Greco verso Tramontana". The names are perfectly symmetric.

Half- and quarter-points[edit]

Compass Rose from "American Practical Navigator" 1916

By at least the middle of the eighteenth century the 32-point system had been further extended with the use of half- and quarter-points to give a total of 128 directions.[6] These fractional points are named by appending, for example 1/4east, 1/2east, or 3/4east to the name of one of the 32 points. Each of the 96 fractional points can be named in two ways, depending of which of the two adjoining whole points is used, for example, N3/4E is equivalent to NbE1/4N. Either form is easily understood but differing conventions as to correct usage developed in different countries and organisations.

The table below shows how each of the 128 directions are named. The first two columns give the number of points and degrees clockwise from north. The third gives the equivalent bearing to the nearest degree from north or south towards east or west. The "CW" column gives the fractional-point bearings increasing in the clockwise direction and "CCW" counter clockwise. The final three columns show three common naming conventions: No "by" avoids the use of "by" with fractional points; "USN" the system used by US Navy;[7] and "RN" the Royal Navy.[8] The colour coding illustrates where each of the three naming systems matches the "CW" and "CCW" columns.

Compass roses very rarely named the fractional points and only showed small, unlabelled markers as a guide for helmsmen.

See also[edit]

References[edit]

  1. ^ David Boardman Graphicacy and Geography Teaching 1983 - Page 41 "In particular they should learn that wind direction is always stated as the direction from which, and not to which, the wind is blowing. Once children have grasped these eight points they can learn the full sixteen points of the compass."
  2. ^ Pamphlets on British shipping. 1785-1861 1785- Page 50 "A deviation table having been formed by any of the processes now.so generally understood, either on the thirty-two points of the compass, the sixteen intermediate, or the eight principal points"
  3. ^ George Payn Quackenbos A Natural Philosophy: Embracing the Most Recent Discoveries 1860 "Mentioning the mariner's compass: the points of the compass in their order is called boxing the compass. — The compass box is suspended within a larger box by means of two brass hoops, or gimbals as they are called, supported at opposite ..."
  4. ^ Compass rose at geography.about.com
  5. ^ Washington Education
  6. ^ E. Chambers Cyclopaedia: or, an Universal Dictionary of Arts and Science, 5th Ed, 1743, pp.206-7, "Points of the Compass, or Horizon, &c, in Geography and Navigation, are the points of division when the whole circle, quite around, is divided into 32 equal parts. These points are therefore at the distance of the 32d part of the circult, or 11°15', from each other; hence 5°371/2' is the distance of the half points and 2°483/4' is the distance of the quarter points.
  7. ^ Nathaniel Bowditch, American Practical Navigator: An Epitome of Navigation and Nautical Astronomy, 1916, p. 16, "It is the custom in the United States Navy to box from North and South toward East and West, excepting that divisions adjacent to a cardinal or inter-cardinal point are always referred to that point;"
  8. ^ Henry Raper, The Practice of Navigation and Nautical Astronomy, 10th Ed., 1870, p. 65, "A half-point, which is the middle division between two points, is called after that one of its adjacent points which is either a cardinal point, or is nearest to a cardinal point [...] In naming the half and quarter points it is advisable in some cases to sacrific system to simplicity. Thus, for example, seamen commonly say NNE1/2E instead of NE by N1/2N; "

External links[edit]