Points of the compass

From Wikipedia, the free encyclopedia
(Redirected from Compass points)

Template:Short description Template:DMCA

32-point compass rose

The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each separated by 90 degrees, and secondarily divided by four ordinal (intercardinal) directions—northeast, southeast, southwest, and northwest—each located halfway between two cardinal directions. Some disciplines such as meteorology and navigation further divide the compass with additional azimuths. Within European tradition, a fully defined compass has 32 "points" (and any finer subdivisions are described in fractions of points).[1]

Compass points or compass directions are valuable in that they allow a user to refer to a specific azimuth in a colloquial fashion, without having to compute or remember degrees.[2]

Designations

Page Module:Hatnote/styles.css has no content.

Several terms redirect here. For other uses, see Northeast (disambiguation), Northwest (disambiguation), Southeast (disambiguation), and Southwest (disambiguation).

The names of the compass point directions follow these rules:

8-wind compass rose

8-wind compass rose
  • The four cardinal directions are north (N), east (E), south (S), west (W), at 90° angles on the compass rose.
  • The four intercardinal (or ordinal) directions are formed by bisecting the above, giving: northeast (NE), southeast (SE), southwest (SW), and northwest (NW). In English and many other tongues, these are compound words. Different style guides for the four mandate spaces, dashes, or none.
    • In Bulgarian, Catalan, Czech, Danish, Dutch, English, Esperanto, French, Galician, German, Greek, Hungarian, Ido, Italian, Japanese (usually), Macedonian, Norwegian (both Bokmal and Nynorsk), Polish, Portuguese, Romanian, Romansch, Russian, Serbian, Croatian, Spanish, Swedish, Ukrainian, and Welsh the part meaning north or south precedes the part meaning east or west.[3]
    • In Chinese, Vietnamese, Gaelic, and less commonly Japanese, the part meaning east or west precedes the other.
    • In Estonian, Finnish, Breton, the "Italianate system" (see section "Traditional Mediterranean compass points" below), and many South Asian and Southeast Asian languages such as Telugu, the intercardinals have distinct words.[3]
  • The eight principal winds (or main winds) are the set union of the cardinals and intercardinals. Taken in turn, each is 45° from the next. These form the 8-wind compass rose, the rose at its usual basic level today.

16-wind compass rose

16-point compass rose
  • The eight half-winds are the direction 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). The name of each half-wind is constructed by combining the names of the principal winds to either side, with the cardinal wind coming first and the intercardinal wind second.
  • The eight principal winds and the eight half-winds together form the 16-wind compass rose, with each compass point at a Page Template:Fraction/styles.css has no content.22+1⁄2° angle from its two neighbours.

32-wind compass rose

32-point compass rose

Template:Named absolute bearings

  • The sixteen quarter-winds are the direction points obtained by bisecting the angles between each of the points in the 16 sets of two adjacent points on the 16-wind compass rose (above). The resulting directions, named quarter-winds, are as follows (here arranged by quadrant, or in other words clockwise):[4][5]
    • in NE quadrant: north by east (NbE), northeast by north (NEbN), northeast by east (NEbE), and east by north (EbN);
    • in SE quadrant: east by south (EbS), southeast by east (SEbE), southeast by south (SEbS), and south by east (SbE);
    • in SW quadrant: south by west (SbW), southwest by south (SWbS), southwest by west (SWbW), and west by south (WbS);
    • in NW quadrant: west by north (WbN), northwest by west (NWbW), northwest by north (NWbN), and north by west (NbW)
  • All of the points in the 16-wind compass rose plus the sixteen quarter-winds together form the 32-wind compass rose.
  • If breaking down for study/signalling the subcomponents are called the "principal" followed by the "cardinal" wind/direction. As a mnemonic (memory device), minds familiar encode the meaning of "X by Y" as "one small measure from X towards Y". It can be noted such measure ('one point') is Page Template:Fraction/styles.css has no content.11+1⁄4°. So, for example, "northeast by east" means "one quarter of the gap from NE towards E".

In summary, the 32-wind compass rose comes from the eight principal winds, eight half-winds, and sixteen quarter-winds combined, with each compass point at an Page Template:Fraction/styles.css has no content.11+1⁄4° angle from the next.

Half- and quarter-points

Compass rose from American Practical Navigator, 1916

By the middle of the 18th century, the 32-point system had been further extended by using half- and quarter-points to give a total of 128 directions.[6] These fractional points are named by appending, for example, Page Template:Sfrac/styles.css has no content.⁠1/4⁠east, Page Template:Sfrac/styles.css has no content.⁠1/2⁠east, or Page Template:Sfrac/styles.css has no content.⁠3/4⁠east to the name of one of the 32 points. Each of the 96 fractional points can be named in two ways, depending on which of the two adjoining whole points is used, for example, NPage Template:Sfrac/styles.css has no content.⁠3/4⁠E is equivalent to NbEPage Template:Sfrac/styles.css has no content.⁠1/4⁠N. Either form is easily understood, but alternative conventions as to correct usage developed in different countries and organisations. "It is the custom in the United States Navy to box from north and south toward east and west, with the exception that divisions adjacent to a cardinal or inter-cardinal point are always referred to that point."[7] The Royal Navy used the additional "rule that quarter points were never read from a point beginning and ending with the same letter".[8]

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

Maritime Use

Prior to the modern three-figure method of describing directions (using the 360° of a circle), the 32-point compass was used for directions on most ships, especially among European crews. The smallest unit of measure recognized was 'one point', 1/32 of a circle, or Page Template:Fraction/styles.css has no content.11+1⁄4°.[9] In the mariner's exercise of "boxing the compass", all thirty-two points of the compass are named in clockwise order.[10] This exercise became more significant as navigation improved and the half- and quarter-point system increased the number of directions to include in the 'boxing'. Points remained the standard unit until switching to the three-figure degree method. These points were also used for relative measurement, so that an obstacle might be noted as 'two points off the starboard bow', meaning two points clockwise of straight ahead, Page Template:Fraction/styles.css has no content.22+1⁄2°[9] This relative measurement may still be used in shorthand on modern ships, especially for handoffs between outgoing and incoming helmsmen, as the loss of granularity is less significant than the brevity and simplicity of the summary.

128 compass directions

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" counterclockwise. The final three columns show three common naming conventions: No "by" avoids the use of "by" with fractional points, U.S. Navy increases counterclockwise from a cardinal directly to the previous direction and clockwise elsewhere, and Royal Navy is the same but also uses counterclockwise from S to SbE to SSE and N to NbW to NNW. Colour coding shows whether each of the three naming systems matches the "CW" or "CCW" column.

Traditional Mediterranean compass points

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 (with no obvious connection to the twelve classical compass winds of the ancient Greeks and Romans). 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, which was principally composed of Genoese (Ligurian), mixed with Venetian, Sicilian, Provençal, Catalan, Greek, and Arabic terms, all from languages spoken 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 mariners' 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). Traditional compass roses will typically have the initials T, G, L, S, O, L, P, and M on the 8 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.

Each half-wind name is simply a combination of the two principal winds that it bisects, with the shortest name usually placed first, for example: NNE is "Greco-Tramontana"; ENE is "Greco-Levante"; SSE is "Ostro-Scirocco", etc. The quarter winds are expressed with an Italian phrase, "Quarto di X verso Y" (Script error: No such module "IPA".[11][12][13] 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 closest principal wind always comes first, the more distant one second, for example: north-by-east is "Quarto di Tramontana verso Greco"; and northeast-by-north is "Quarto di Greco verso Tramontana".

The table below shows how the 32 compass points are named. Each point has an angular range of Page Template:Fraction/styles.css has no content.11+1⁄4 degrees where the azimuth midpoint is the horizontal angular direction (clockwise from north) of the given compass bearing; minimum is the lower (counterclockwise) angular limit of the compass point; and maximum is the upper (clockwise) angular limit of the compass point.

Chinese compass points

Navigation texts dating from the Yuan, Ming, and Qing dynasties in China use a 24-pointed compass with named directions. These are based on the twelve Earthly Branches, which also form the basis of the Chinese zodiac. When a single direction is specified, it may be prefaced by the character Script error: No such module "Lang". (meaning single) or Script error: No such module "Lang"..

Ming dynasty 24-pointed compass

Headings mid-way in-between are compounds as in English. For instance, Script error: No such module "Lang". refers to the direction halfway between point Script error: No such module "Lang". and point Script error: No such module "Lang"., or Page Template:Fraction/styles.css has no content.7+1⁄2°. This technique is referred to as a double-needle (Script error: No such module "Lang".) compass.

Point Ordinal Name Angle
Script error: No such module "Lang". zǐ north 0° or 360°
Script error: No such module "Lang". guǐ 15°
Script error: No such module "Lang". chǒu 30°
Script error: No such module "Lang". gěn northeast 45°
Script error: No such module "Lang". yín 60°
Script error: No such module "Lang". jiǎ 75°
Script error: No such module "Lang". mǎo east 90°
Script error: No such module "Lang". yǐ 105°
Script error: No such module "Lang". chén 120°
Script error: No such module "Lang". xùn southeast 135°
Script error: No such module "Lang". sì 150°
Script error: No such module "Lang". bǐng 165°
Script error: No such module "Lang". wǔ south 180°
Script error: No such module "Lang". dīng 195°
Script error: No such module "Lang". wèi 210°
Script error: No such module "Lang". kūn southwest 225°
Script error: No such module "Lang". shēn 240°
Script error: No such module "Lang". gēng 255°
Script error: No such module "Lang". yǒu west 270°
Script error: No such module "Lang". xīn 285°
Script error: No such module "Lang". xū 300°
Script error: No such module "Lang". qián northwest 315°
Script error: No such module "Lang". hài 330°
Script error: No such module "Lang". rén 345°

See also

References

Page Template:Reflist/styles.css has no content.

  1. ^ Page Module:Citation/CS1/styles.css has no content.Evans, Frederick John, ed. (1859). "Notes on the Magnetism of Ships". Pamphlets on British shipping. 1785–1861. p. 8 (p. 433 of PDF). ISBN 0-217-85167-3. 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 {{cite book}}: ISBN / Date incompatibility (help)
  2. ^ Page Module:Citation/CS1/styles.css has no content.Boardman, David (1983). Graphicacy and Geography Teaching. p. 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.
  3. ^ a b See Wiktionary definitions: north; northeast; east; southeast; south; southwest; west; northwest
  4. ^ Page Module:Citation/CS1/styles.css has no content.Webb Aintablian, Xanthe (June 28, 2018). "An Overview and History of the Compass". thoughtco.com. Dotdash. Archived from the original on July 6, 2018.
  5. ^ Page Module:Citation/CS1/styles.css has no content.Lee, Robert E. (2011). "Compass Rose". University of Washington. Archived from the original on February 21, 2015.
  6. ^ E. Chambers. Cyclopaedia: or, an Universal Dictionary of Arts and Science, 5th Ed, 1743, pp. 206–207, "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 circuit, or 11° 15Template:Prime, from each other; hence 5° Page Template:Sfrac/styles.css has no content.⁠37+1/2⁠Template:Prime is the distance of the half points and 2° Page Template:Sfrac/styles.css has no content.⁠48+3/4⁠Template:Prime is the distance of the quarter points.
  7. ^ Page Module:Citation/CS1/styles.css has no content.Bowditch, Nathaniel (1916). American Practical Navigator: An Epitome of Navigation and Nautical Astronomy. United States Hydrographic Office. p. 15.
  8. ^ Page Module:Citation/CS1/styles.css has no content.Kemp, Peter, ed. (1988). "Box the Compass". The Oxford Companion to Ships and the Sea. Oxford University Press. p. 103. ISBN 0-19-282084-2.
  9. ^ a b Page Module:Citation/CS1/styles.css has no content.Johnson, Tony (January 5, 2020). "Nautical Terminator – Points". Tradewinds Sailing Blog. Retrieved June 29, 2024.
  10. ^ 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 ..."
  11. ^ Page Module:Citation/CS1/styles.css has no content."quarto". WordReference.com. Retrieved December 2, 2018. English translation: fourth, quarter
  12. ^ Page Module:Citation/CS1/styles.css has no content."di". WordReference.com. Retrieved December 2, 2018. English translation: of, from...
  13. ^ Page Module:Citation/CS1/styles.css has no content."verso". WordReference.com. Retrieved December 2, 2018. English translation: towards, toward, close to, near to

Page Module:Side box/styles.css has no content.Page Template:Sister project/styles.css has no content.

Page Template:Plainlist/styles.css has no content.
Script error: No such module "Sister project logo".
Wikimedia Commons has media related to Script error: No such module "Commons link"..

Lua error in package.lua at line 80: module 'Module:Navbox/configuration' not found.

de:Himmelsrichtung#Systematik_der_Benennung

Retrieved from "https://cosmopedia.co/index.php?title=Points_of_the_compass&oldid=216532"