DOCSLIB.ORG

Chapter 6 Magnetic Compass Adjustment

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chapter 6 Magnetic Compass Adjustment CHAPTER 6 MAGNETIC COMPASS ADJUSTMENT GENERAL PROCEDURES FOR MAGNETIC COMPASS ADJUSTMENT 600. Introduction f. Alignment of magnets in binnacle. g. Alignment of heeling magnet tube under pivot This chapter presents information and procedures point of compass. for magnetic compass adjustment. Sections 601 and 613 h. See that corrector magnets are available. cover procedures designed to eliminate compass errors satisfactorily. Refer to Figure 607 for condensed infor- 2. Physical checks of gyro, azimuth circle, and peloruses. mation regarding the various compass errors and their a. Alignment of peloruses with fore-and-aft line of correction. ship (section 610). The term compass adjustment refers to any change of b. Synchronize gyro repeaters with master gyro. permanent magnet or soft iron correctors to reduce normal c. Ensure azimuth circles and peloruses are in good compass errors. The term compass compensation refers to condition. any change in the current slupplied to the compass compen- sating coils to reduce degaussing errors. 3. Necessary data. a. Past history or log data which might establish 601. Adjustment Check-Off List length of Flinders bar (sections 610 and 623). b. Azimuths for date and observer’s position (section If the magnetic adjustment necessitates (a) movement 633 and Chapter 17). of degaussing compensating coils, or (b) a change of c. Ranges or distant objects in vicinity if needed (lo- Flinders bar length, check also the coil compensation per cal charts). section 646. d. Correct variation (local charts). Expeditious compass adjustment depends on the appli- e. Degaussing coil current settings for swing for resid- cation of the various correctors in an optimum sequence ual deviations after adjustment and compensation designed to minimize the number of correction steps. Cer- (ship’s Degaussing Folder). tain adjustments may be made conveniently at dockside, simplifying the at sea adjustment procedures. 4. Precautions. Moving the wrong corrector wastes time and upsets all a. Determine transient deviations of compass from previous adjustments, so be careful to make the correct ad- gyro repeaters, doors, guns, etc. (sections 636 and justments. Throughout an adjustment, special care should 639). be taken to pair off spare magnets so that the resultant field b. Secure all effective magnetic gear in normal seagoing about them will be negligible. To make doubly sure that the position before beginning adjustments. compass is not affected by a spare magnet’s stray field, c. Make sure degaussing coils are secured before be- keep them at an appropriate distance until they are actually ginning adjustments. Use reversal sequence, if inserted into the binnacle. necessary. d. Whenever possible, correctors should be placed A. Dockside tests and adjustments. symmetrically with respect to the compass. 1. Physical checks on the compass and binnacle. 5. Adjustments. a. Remove any bubbles in compass bowl (section a. Place Flinders bar according to best available infor- 610). mation (sections 610, 622 through 625). b. Test for moment and sensibility of compass nee- b. Set spheres at mid-position, or as indicated by last dles (section 610). deviation table. c. Remove any slack in gimbal arrangement. c. Adjust heeling magnet, using balanced dip needle d. Magnetization check of spheres and Flinders bar if available (section 637). (section 610). e. Alignment of compass with fore-and-aft line of B. Adjustments at sea. Make these adjustments with the ship ship (section 610). on an even keel and steady on each heading. When using 81 82 MAGNETIC COMPASS ADJUSTMENT the gyro, swing slowly from heading to heading and check Fore-and-aft and athwartship magnets Quadrantial spheres Flinders bar Deviation Easterly on east Westerly on east Deviation E. on NE, W. on NE, Deviation change E. on E. and W. on W W. on E. and E. on W and westerly on and easterly on E. on SE, E. on SE, with latitude when sailing toward when sailing toward west. west. W. on SW, W. on SW, change equator from north equator from north and andE. on NW. latitude or away from Spheres latitude or away from Magnets (+B error) (-B error) W. on NW. (-D error) equator to south Bar equator to south latitude. (+D error) latitude. No fore and aft Place magnets red Place magnets red No spheres on Place spheres Place spheres fore Place required of bar Place required amount magnets in forward. aft. binnacle. athwartship. and aft. No bar in holder. forward. of bar aft. binnacle. Fore and aft Raise magnets. Lower magnets. Spheres at Move spheres toward Move spheres Increase amount of bar Deacrease amount magnets red athwartship compass or use outwards or remove. Bar forward of binnacle. forward. of bar forward. forward. position. larger spheres. Fore and aft Lower magnets. Raise magnets. Spheres at fore and Move spheres Move spheres toward Decrease amount of Increase amount of magnets red aft. aft position. outward or remove. compass or use Bar aft of binnacle. bar aft. bar aft. larger spheres. Deviation Easterly on north Westerly on north Deviation E. on N, W. on N, W. on E. and E. on W. E. on E. and W. on W. and westerly on and easterly on W. on E, E. on E, when sailing toward when sailing toward south. south. E. on S, W. on S, Bar equator from south equator from south Magnets Spheres and and latitude or away from latitude or away from (-C error) W. on W. E. on W. Deviation change equator to north equator to south latitude (+C error) (+E error) (-E error) with latitude latitude. change No athwartship Place athwartship Place athwartship No spheres on Place spheres at port Place spheres at Heeling magnet magnets in magnets red magnets red port. binnacle. forward and starboard starboard foreward (Adjust with changes in magnetic latitude) binnacle. starboard. aft intercardinal and port aft If compass north is attracted to high side of ship when rolling, raise positions. intercardinal the heeling magnet if red end is up and lower the heeling magnet if blue positions. end is up. Athwartship Raise magnets. Lower magnets. Spheres at Slew spheres Slew spheres If compass north is attracted to low side of ship when rolling, lower magnets red athwartship clockwise through counter-clockwise the heeling magnet if red end is up and raise the heeling magnet if blue starboard. position. required angle. through required end is up. angle. NOTE: Any change in placement of the heeling magnet will affect the Athwartship Lower magnets. Raise magnets. Spheres at fore and Slew spheres counter- Slew spheres deviations on all headings. magnets red port. aft position. clockwise through clockwise through required angle. required angle. Figure 601. Mechanics of magnetic compass adjustment. gyro error by sun’s azimuth or ranges on each heading to half of any observed deviation by moving the ensure a greater degree of accuracy (section 631). Be sure C magnets. gyro is set for the mean speed and latitude of the vessel. The cardinal heading adjustments should now be Note all precautions in section A-4 above. Fly the “OSCAR complete. QUEBEC” international code signal to indicate such work 6. Come to any intercardinal magnetic heading, e.g., is in progress. Section 631 discusses methods for placing northeast (045°). Correct any observed deviation the ship on desired headings. by moving the spheres in or out. 7. Come to the next intercardinal magnetic heading, 1. Adjust the heeling magnet while the ship is rolling e.g., southeast (135°). Correct half of any ob- on north and south magnetic headings until the os- served deviation by moving the spheres. cillations of the compass card have been reduced to an average minimum. This step is not required The intercardinal heading adjustments should now be if prior adjustment has been made using a dip nee- complete, although more accurate results might be ob- dle to indicate proper placement of the heeling tained by correcting the D error determined from the magnet. deviations on all four intercardinal headings, as discussed 2. Come to a cardinal magnetic heading, e.g., east in section 615. (090°). Insert fore-and-aft B magnets, or move the existing B magnets, to remove all deviation. 8. Secure all correctors before swinging for residual 3. Come to a south (180°) magnetic heading. Insert deviations. athwartship C magnets, or move the existing 9. Swing for residual undegaussed deviations on as C magnets, to remove all deviation. many headings as desired, although the eight car- 4. Come to a west (270°) magnetic heading. Correct dinal and intercardinal headings should be half of any observed deviation by moving the sufficient. B magnets. 10. Should there still be any large deviations, analyze 5. Come to a north (000°) magnetic heading. Correct the deviation curve to determine the necessary MAGNETIC COMPASS ADJUSTMENT 83 corrections and repeat as necessary steps 1 the unlike poles will attract each other. through 9 above. Magnetism can be either permanent or induced.A 11. Record deviations and the details of corrector positions bar having permanent magnetism will retain its magnetism on the deviation card to be posted near the compass. when it is removed from the magnetizing field. A bar hav- 12. Swing for residual degaussed deviations with the ing induced magnetism will lose its magnetism when degaussing circuits properly energized. removed from the magnetizing field. Whether or not a bar 13. Record deviations for degaussed conditions on the will retain its magnetism on removal from the magnetizing deviation card. field will depend on the strength of that field, the degree of hardness of the iron (retentivity), and also upon the amount The above check-off list describes a simplified method of physical stress applied to the bar while in the magnetiz- of adjusting compasses, designed to serve as a workable ing field.
Load more

Recommended publications
  • Acnmanual.Pdf
    Advanced Coastal Navigation Coast Guard Auxiliary Association Inc. Washington, D. C. First Edition..........................................................................1987 Second Edition .....................................................................1990 Third Edition ........................................................................1999 Fourth Edition.......................................................................2002 ii iii iv v vi Advanced Coastal Navigation TABLE OF CONTENTS Introduction...................................................................................................ix Chapter 1 INTRODUCTION TO COASTAL NAVIGATION . .1-1 Chapter 2 THE MARINE MAGNETIC COMPASS . .2-1 Chapter 3 THE NAUTICAL CHART . .3-1 Chapter 4 THE NAVIGATOR’S TOOLS & INSTRUMENTS . .4-1 Chapter 5 DEAD RECKONING . .5-1 Chapter 6 PILOTING . .6-1 Chapter 7 CURRENT SAILING . .7-1 Chapter 8 TIDES AND TIDAL CURRENTS . .8-1 Chapter 9 RADIONAVIGATION . .9-1 Chapter 10 NAVIGATION REFERENCE PUBLICATIONS . .10-1 Chapter 11 FUEL AND VOYAGE PLANNING . .11-1 Chapter 12 REFLECTIONS . .12-1 Appendix A GLOSSARY . .A-1 INDEX . .Index-1 vii Advanced Coastal Navigation viii intRodUction WELCOME ABOARD! Welcome to the exciting world of completed the course. But it does marine navigation! This is the fourth require a professional atti tude, care- edition of the text Advanced Coastal ful attention to classroom presenta- Navigation (ACN), designed to be tions, and diligence in working out used in con cert with the 1210-Tr sample problems. chart in the Public Education (PE) The ACN course has been course of the same name taught by designed to utilize the 1210-Tr nau - the United States Coast Guard tical chart. It is suggested that this Auxiliary (USCGAUX). Portions of chart be readily at hand so that you this text are also used for the Basic can follow along as you read the Coastal Navigation (BCN) PE text. We recognize that students course.
    [Show full text]
  • Barry Lawrence Ruderman Antique Maps Inc
    Barry Lawrence Ruderman Antique Maps Inc. 7407 La Jolla Boulevard www.raremaps.com (858) 551-8500 La Jolla, CA 92037 [email protected] Il Disegno Della Terza Parte Dell' Asia Stock#: 55879 Map Maker: Gastaldi Date: 1561 Place: Rome Color: Uncolored Condition: VG+ Size: 29 x 19 inches Price: $ 64,500.00 Description: First State of the Most Influential Map of Eastern Asia Published in the Sixteenth Century Rare and highly influential map of India, China, and Southeast Asia by Giacomo Gastaldi, one of the most celebrated Italian cartographers of the sixteenth century. The present map, the last in a set of three maps of Asia produced by Gastaldi between 1559 and 1561, comprises the easternmost section of the continent. The map is interesting for its considerable impact on sixteenth-century mapping of Asia, as well as for its important geographical and toponymic content—for example, this is the first use the modern name of the Philippines on a European map. In the lower right of the map, above the scale bar, it is noted that the map was created based on a fifteen- year privilegio, or copyright protection, granted by Pope Pius IV. Also in this area, Fabio Licinio is named as the map’s engraver. On the right border of the map, a large table lists ancient and modern place names. While the first and second maps in Gastaldi’s three-part Asia series contained this information in a separate gazetteer, here they are included on the map itself. The map is bounded in the west by the Arabian Sea and in the east by China and the East China Sea (Mare de Mangi, from Marco Polo’s use of Mangi as the name for southern China).
    [Show full text]
  • Barry Lawrence Ruderman Antique Maps Inc
    Barry Lawrence Ruderman Antique Maps Inc. 7407 La Jolla Boulevard www.raremaps.com (858) 551-8500 La Jolla, CA 92037 [email protected] La Descrittione Della Prima Parte Dell' Asia Con i nomi antichi & moderni Di Jacopo Gastaldi Piemontese comografo . L'Anno MDLXI Stock#: 55880 Map Maker: Gastaldi Date: 1561 Place: Venice Color: Uncolored Condition: VG+ Size: 31.5 x 20.5 inches Price: $ 19,500.00 Description: The Most Influential Map of the Ottoman and Persian Empires Published in the Sixteenth Century Rare and highly influential two-sheet map of the Ottoman and Persian Empires by Giacomo Gastaldi, one of the most celebrated Italian cartographers of the sixteenth century. It depicts Turkey, the Middle East, and Central Asia. The present map, the first in a set of three maps of Asia produced by Gastaldi between 1559 and 1561, comprises the westernmost section of the landmass. It is bounded by the Black Sea (Mare Maggiore) and the Mediterranean in the west, with Moscow and present-day Moldova (Moldavia) to the northwest and Egypt (Egit) and the northern Red Sea to the southwest. To the east the map is bounded by Central Asia, with Gujarat (Guzarate) to the southwest and a desert, Care, likely in present-day Kyrgyzstan, to the northeast. In the Black Sea, the Crimean Peninsula (Gazaria) juts down from the north, and Constantinople can just be seen to the southwest. South of Turkey (Natolia), the island of Cyprus is prominent in the Mediterranean. The Caspian Sea is depicted interestingly in an oval shape, as was common until the 1730s.
    [Show full text]
  • Download Mariners Compass Stars Free Ebook
    MARINERS COMPASS STARS DOWNLOAD FREE BOOK Carol Doak | 114 pages | 30 Oct 2007 | C & T Publishing | 9781571204059 | English | Concord, United States Mariner's Compass Star Patterns and Quilts I quickly abandoned this method and devised an easier method for assembling the large pointed arcs which I'll talk about later. This meant I could layer and quilt each wedge individually which made things much easier. Comments Beautiful work! See below. Please help improve this section by adding citations to reliable sources. Philadelphia: University Museum, University of Philadelphia. Features see all. Cozy up with Sarah and her friends for more murder, quilting, and community. Brass Antique Maritime Compasses. When navigating in the Northern Hemispherespecial techniques can be used with Polaris to determine latitude or gyrocompass error. Only two of its point names OstroLibeccio Mariners Compass Stars Classical etymologies, the rest of the names seem to be autonomously derived. This suggests the mariner's rose was probably acquired Mariners Compass Stars southern Italian seafarers not from their classical Roman ancestors, but rather from Norman Sicily in the 11th to 12th centuries. Polaris [8]. Quilting Daily has the best resources for quilters including quilt patterns, how-to quilt videos, quilting magazines, and more. Footer My Guide Whatever you do, do your work heartily, as for the Lord rather than for men. Today, a form of compass rose is found on, or featured in, almost all navigation systems, including nautical chartsnon-directional beacons NDBVHF Mariners Compass Stars range VOR systems, global-positioning systems GPSand similar equipment. Nonetheless, both systems were gradually conflated, and wind names came eventually to denote cardinal directions as well.
    [Show full text]
  • Barry Lawrence Ruderman Antique Maps Inc
    Barry Lawrence Ruderman Antique Maps Inc. 7407 La Jolla Boulevard www.raremaps.com (858) 551-8500 La Jolla, CA 92037 [email protected] Carte de L'Amerique Nouvellement dressee suivant les Nouvelles descouvertes . 1661 [and] Carte Nouvelle de L'Europe Asie & Afrique Nouvellement . Stock#: 74198 Map Maker: Tavernier Date: 1661 Place: Paris Color: Hand Colored Condition: VG+ Size: 24 x 12 inches Price: $ 3,400.00 Description: Rare pair of eastern and western hemispheric maps, published by Melchior Tavernier. Tavernier's map provides a fine blend of contemporary cartographic information with unique details in the concentric circles outside of the geographical hemisphere. In the outermost circle, Tavernier names the 32 compass point directions in French. In the center circle, are the names of the 12 Classical Winds described by Timothenes of Rhodes (circa 282 BC) in both Latin and the original Greek spellings (see below). In the innermost circle, the 8 Winds of the Mediterranean (the modern compass points) are named (Tramontane, Greco (Grecale), Levante, Sirocco, Austral (Ostro or Mezzogiorno), Sebaca (Libeccio or Garbino), Ponent (Ponente) and Maestral (Mistral or Maestro). Cartographically, the map is a marvelous blend of information and conjecture. Tavernier treats the massive northwestern landmass to the north of California as conjecture, employing a lighter coastal outline to signify that the lands depicted are not known with certainty. California is shown as a curiously shaped island, not consistent with either the Briggs or Sanson models. A single Great Lake is depicted. In the Arctic regions, a notation describes Thomas Button's search for a Northwest Passage. In South America, there is a small Lake Parime in Guiana, and both the Amazon and Rio de la Plata flow from the large interior Lago de los Xarayes.
    [Show full text]
  • Compass Rose a Compass Rose Is a Tool That Is Found on Maps to Show Directions
    Compass Rose A compass rose is a tool that is found on maps to show directions. It contains cardinal directions, north, south, east, and west. You will see these abbreviated on the compass rose with the capital letters, N, S, E, and W. North will always point toward the North Pole and South points toward the South Pole. You may also see intermediate directions on a compass rose. These directions are northwest, northeast, southwest, and southeast. They are abbreviated NE, SE, NW, and SW. The intermediate directions are located between each of the cardinal directions as a way to be more specific. Cut out and glue each each direction onto the correct place on the compass rose. Then, color each section of the compass rose using the key below. KEY North – Red South – Blue East – Orange West – Purple Northeast – Pink Northwest – Gray Southeast – Yellow Southwest - Green NE W SW N E NW S SE Compass Rose QUIZ 1. Why is it important to include a compass rose on a map? _______________________________________________________________________________________ 2. What are the cardinal directions? Please write the whole word. ____________________, ____________________, ____________________, ____________________ 3. What are the intermediate directions? Please write the whole word. ____________________, ____________________, ____________________, ____________________ 4. Label the compass wrote with both the cardinal and intermediate directions. You may use the abbreviations. using a Compass Rose Use the map and compass rose to answer the questions. N NW NE W E SW SE S 1. Which state is northeast of Oklahoma? ______________________________ 2. Which state is east of Illinois? ______________________________ 3. Which state is southwest of Wyoming? ______________________________ 4.
    [Show full text]
  • CITY LANDMARK ASSESSMENT REPORT SANTA MONICA AIRPORT COMPASS ROSE 3223 Donald Douglas Loop SANTA MONICA, CALIFORNIA
    CITY LANDMARK ASSESSMENT REPORT SANTA MONICA AIRPORT COMPASS ROSE 3223 Donald Douglas Loop SANTA MONICA, CALIFORNIA Prepared for: City of Santa Monica City Planning Division 1685 Main Street, Room 212 Santa Monica, CA 90401 Prepared by: Jan Ostashay Principal Ostashay & Associates Consulting PO BOX 542 Long Beach, CA 90801 SEPTEMBER 2019 THIS PAGE INTENTIONALLY BLANK CITY LANDMARK ASSESSMENT REPORT SANTA MONICA AIRPORT COMPASS ROSE Santa Monica Airport 3223 Donald Douglas Loop Santa Monica, CA 91423 APN: 4272-016-903 (compass rose northern half) APN: 4272-015-900 (compass rose southern half) INTRODUCTION This landmark assessment and evaluation report, completed by Ostashay & Associates Consulting (OAC) for the City of Santa Monica, documents and evaluates the local landmark eligibility of the functional navigational art feature located at the Santa Monica Airport and herein referred to as the Santa Monica Airport Compass Rose (or the subject property). This assessment report was prepared at the request of the City and includes a discussion of the survey methodology utilized, a concise description of the feature (subject property); a summarized historical context of the Santa Monica Airport, compass rose, and related themes; evaluation for significance under the City of Santa Monica landmark criteria; photographs and other applicable supporting materials. OAC evaluated the subject property, the Santa Monica Airport Compass Rose, to determine whether it appears to satisfy one or more of the statutory landmark criteria pursuant to Chapter 9.56 (Landmarks and Historic Districts Ordinance) of the Santa Monica Municipal Code. The evaluation assessment and this report were prepared by Jan Ostashay, principal with OAC, who satisfies the U.S.
    [Show full text]
  • Do Modern Winds Equal Ancient Winds? William M
    DO MODERN WINDS EQUAL ANCIENT WINDS? WILLIAM M. MURRAY Mediterranean Historical Review, 2, (1987),p 139-167 (published online: 02 Jun 2008) INTRODUCTION Today, most of us routinely ignore the presence or absence of the wind unless we are caught in a violent storm or swelter in the heat of a still day. Nevertheless, the wind - its varying strength and direction- was a critically important matter for maritime civilizations before the advent of steam. The winds had a strong influence over human interaction with the sea, and for the ancient cultures of the Mediterranean basin this had far-reaching effects. The winds determined the ease or difficulty of sea-borne communications between cities of the same coast, between the mainland and the islands, and indeed, between the different regions of the Mediterranean basin. Places easily reached on the prevailing winds were visited frequently, and if the presence of sufficient resources warranted, were settled in preference to other areas less open to the sea lanes.1 This recurring tendency helped to shape settlement patterns, and on a smaller scale, determined the precise placement of harbours and the sites of the cities they serviced.2 In addition, the winds determined both coastal and offshore sailing routes, defined navigational hazards, and at times, affected the outcomes of naval battles.3 It follows that our knowledge of their precise behaviour in a particular area might help to locate ancient harbours and wreck sites, to explain anomalies in settlement patterns and to 'flesh out' or even explain confusing accounts of ancient sea battles.4 Stated simply, understanding a coastal area's wind regime (its recurring, annual wind patterns) could be an important factor in helping to reconstruct and evaluate the record of human activity along that coast.
    [Show full text]
  • Barry Lawrence Ruderman Antique Maps Inc
    Barry Lawrence Ruderman Antique Maps Inc. 7407 La Jolla Boulevard www.raremaps.com (858) 551-8500 La Jolla, CA 92037 [email protected] Tabula Anemographica seu Pyxis Nautica ventorum nomina sex linguis repraesentans Stock#: 74241 Map Maker: Jansson Date: 1650 Place: Amsterdam Color: Hand Colored Condition: VG+ Size: 21.5 x 17 inches Price: $ 4,500.00 Description: The Medieval 32 Point Compass Rose Finely engraved wind chart, surrounded by wind heads and with the compass divided into 32 parts and text in six languages. The wind heads are arranged in successive ages from young to old, and four large heads, blowing winds on the compass and seasons. The corners are decorated with large allegorical representations of the four seasons. The 32 Point Compass Rose in Medieval Navigation The map illustrates the classical 32 point compass rose, as used in Medieval times by mariners at sea. Arab navigators in the Red Sea and the Indian Ocean, who depended on celestial navigation, were using a 32-point sidereal compass rose before the end of the 10th century. In the northern hemisphere, the steady Pole Star (Polaris) was used for the N-S axis; the less-steady Southern Cross had to do for the southern hemisphere, as the southern pole star, Sigma Octantis, is too dim to be easily seen from Earth with the naked eye. The other thirty points on the sidereal rose were determined by the rising and setting positions of fifteen bright stars. The western half of the rose would be the same stars in their setting position. The true position of these Drawer Ref: Celestial 1 Stock#: 74241 Page 1 of 2 Barry Lawrence Ruderman Antique Maps Inc.
    [Show full text]
  • Design a Compass Rose for the Cottonwood Municipal Airport!
    A CALL TO ARTISTS Design a Compass Rose for the Cottonwood Municipal Airport! The City of Cottonwood Municipal Airport is calling all local artists to submit an original design for an aeronautical compass rose. The winner will paint their compass rose on the ramp at the Airport at approximately 50 feet in diameter as part of the national airmarking program. In addition to aesthetic appeal and creativity, the design must also incorporate the technical requirements of a usable compass rose. Artists are encouraged The History of the Compass Rose to provide a design that The Compass Rose first appeared on ships’ navigational charts around 1300. The term “rose” incorporates the essence stems from the fact that the design looks like rose petals. The now-standard 32-point compass of Cottonwood. rose has a fleur-de-lis indicating north, and the cross indicating east (long thought to be the direction to paradise), evolved around the time of Christopher Columbus. The compass rose on Theme Ideas: a map or navigational chart provides directional information. An airport compass rose is used to calibrate the aircraft’s magnetic compass. It is also often • The Heart of Arizona a unique airfield identifier found at many general aviation airports. It is typically part of the Wine Country airport’s “airmarking” program, a system devised in the 1930s to identify airports. • Inspiring a Vibrant Take a look at the following page for some reference materials, and to see some examples of compass rose designs and actual airport compass roses. Community Contest Rules • The City of Cottonwood Eligibility: Artists must live or work in the Verde Valley.
    [Show full text]
  • Barry Lawrence Ruderman Antique Maps Inc
    Barry Lawrence Ruderman Antique Maps Inc. 7407 La Jolla Boulevard www.raremaps.com (858) 551-8500 La Jolla, CA 92037 [email protected] Carte de L'Amerique Nouvellement dressee suivant les Nouvelles descou=vertes . 1661 Stock#: 45099 Map Maker: Tavernier Date: 1661 Place: Paris Color: Uncolored Condition: VG+ Size: 14 x 13 inches Price: SOLD Description: Rare Western Hemisphere map showing California as an island, published by Melchior Tavernier. Tavernier's map provides a fine blend of contemporary cartographic information with unique details in the concentric circles outside of the geographical hemisphere. In the outermost circle, Tavernier names the 32 compass point directions in French. In the center circle, are the names of the 12 Classical Winds described by Timothenes of Rhodes (circa 282 BC) in both Latin and the original Greek spellings (see below). In the innermost circle, the 8 Winds of the Mediterranean (the modern compass points) are named (Tramontane, Greco (Grecale), Levante, Sirocco, Austral (Ostro or Mezzogiorno), Sebaca (Libeccio or Garbino), Ponent (Ponente) and Maestral (Mistral or Maestro)). Cartographically, the map is a marvelous blend of information and conjecture. Tavernier treats the massive northwestern landmass to the north of California as conjecture, employing a lighter coastal outline to signify that the lands depicted are not known with certainty. California is shown as a curiously Drawer Ref: America Stock#: 45099 Page 1 of 3 Barry Lawrence Ruderman Antique Maps Inc. 7407 La Jolla Boulevard www.raremaps.com (858) 551-8500 La Jolla, CA 92037 [email protected] Carte de L'Amerique Nouvellement dressee suivant les Nouvelles descou=vertes .
    [Show full text]
  • The Art and Science of the Compass Rose by Eliane Dotson
    Collector's Corner: The Art and Science of the Compass Rose by Eliane Dotson Often the central focal point of a map, the compass rose has played an important role through the centuries with regards to both cartography and navigation. However, one must first know a little of the history of the compass before one can understand the origin of the compass rose. History of the Compass Although the exact origin is unknown, there were several discoveries that led to the creation of the compass. The basic compass requires a magnet that reacts to the earth's magnetized field, and will physically align itself with the magnetic poles (in a north/south orientation). The only naturally occurring mineral on earth to exhibit strong magnetic properties is magnetite, and a magnetized piece of magnetite is called a lodestone. The magnetic properties of the lodestone were known to the ancients, as evidenced by the writings of Plato and Euripides, and were also known independently by the Chinese, possibly as early as 1100 BC. The first primitive compasses using lodestones were believed to have been created by the Chinese around 140 AD to be used for the purposes of spiritual life. Various rudimentary forms of compasses were used over the next millennium, both for spiritual aligning and for basic orientation and navigation. Knowledge of the compass is believed to have made its way to the Mediterranean around the 12th century, with Italy presumed to be the entry point. The first written description of a freely pivoting compass needle (in contrast to earlier known floating apparatus) came from Petrus Peregrinus de Maricourt, a French scholar, in 1269.
    [Show full text]