A hand compass (also hand bearing compass or sighting compass) is a compact magnetic compass capable of one-hand use and fitted with a sighting device to record a precise bearing or azimuth to a given target or to determine a location.[1][2] Hand or sighting compasses include instruments with simple notch-and-post alignment ("gunsights"), prismatic sights, direct or lensatic sights,[3] and mirror/vee (reflected-image) sights. With the additional precision offered by the sighting arrangement, and depending upon construction, sighting compasses provide increased accuracy when measuring precise bearings to an objective.[4]
Parts of a hand compass
The term hand compass is used by some in the forestry and surveying professions to refer to a certain type of hand compass optimized for use in those fields, also known as a forester or cruiser compass.[5][6] A hand compass may also include the various one-hand or 'pocket' versions of the surveyor's or geologist's transit.
A standard Brunton Geo, used commonly by geologists
While small portable compasses fitted with mechanical sighting devices have existed for a few hundred years, the first one-hand compass with a sighting device appeared around 1885.[7] These soon evolved into more elaborate and specialized models such as the Brunton Pocket Transit patented in 1894.[8] Hand compasses were soon widely employed in the practice of forestry, geology, archaeology, speleology, preliminary cartography and land surveying.
Compass used by engineering geologists
In the United States, the hand compass became very popular among foresters seeking a compass to plot and estimate stands of timber. While the Pocket Transit was more than adequate for such work, it was relatively expensive. Consequently, a new type of hand compass was introduced: the forester or cruiser compass. Traditionally, cruiser compasses featured a sighting notch, a mechanically-damped[9] or "dry" needle, adjustable declination and a large dial marked in individual degrees using counterclockwise calibration (reversed east and west positions). A screw base for a tripod or jacob staff (monopod) was often fitted as well.[10]
By the late 1960s many foresters had begun using more modern liquid-damped compass designs, including mirror-sight protractor models such as the Silva Type 15 Ranger or the Suunto MC-1 (later, the MC-2). These compasses were fast to use, particularly along straight cruise lines and were sufficiently accurate for most forestry applications.[11] On the other hand, geologists, speleologists, archaeologists, ornithologists, and foresters engaged in precision survey work often used direct-reading models such as the Suunto KB-14, prismatic compasses such as Suunto KB-77 or the traditional Brunton Pocket Transit.[12][13] Many models featured an optional quadrant (0-90-0 degree) scale instead of an azimuthal (0-360 degree) system.[14]
By using a hand compass in combination with aerial photographs and maps a person can determine his/her location in the field, determine direction to landmarks or destinations, estimate distance, estimate area, and find points of interest (marked boundary lines, USGS marker, plot centers). For increased accuracy, many professional hand compasses continue to be fitted with tripod mounts.[15] While the hand compass continues to be widely employed in such work, it has been increasingly supplanted in recent years by use of the GPS, or Global Positioning System receiver.
Marine hand bearing compassedit
Floating-card compass with prismatic sight (bearing 220° through eyepiece)
The marine hand compass, or hand bearing compass|hand-bearing compass as it is termed in nautical use, has been used by small-boat or inshore sailors since at least the 1920s to keep a running course or to record precise bearings to landmarks on shore in order to determine position via the resection technique.[16][17] Instead of a magnetized needle or disc, most hand bearing compasses feature liquid damping with a floating card design (a magnetized, degreed float or dial atop a jeweled pivot bearing).[18] Equipped with a viewing prism, the hand bearing compass allows instant reading of forward bearings from the user to an object or vessel, and some provide the reciprocal bearing as well.[19][20] Modern examples of marine hand bearing compasses include the Suunto KB-14 and KB-77, and the Plastimo Iris 50.[21][22] These compasses frequently have battery-illuminated or photoluminescent degree dials for use in low light or darkness.[23][24]
Notesedit
^Frazer, Persifor, A Convenient Device to be Applied to the Hand Compass, Proceedings of the American Philosophical Society, Vol. 22, No. 118 (Mar., 1885), p. 216
^Johnson, Mark, The Ultimate Desert Handbook: A Manual for Desert Hikers, Campers, and Travelers, McGraw-Hill Professional (2003), ISBN0-07-139303-X, 9780071393034, p. 134: A direct-sighting compass uses a magnifying viewfinder mounted in the compass body to directly view a degreed dial and superimposed indicator line; it therefore differs from a lensatic sight (which uses a simple magnifying lens on a folding arm positioned over the dial), or a prismatic sight (which uses a magnifying optical prism).
^Suunto Oy, The Suunto KB-14 Story, Article 2008-04-09 at the Wayback Machine
^Rutstrum, The Wilderness Route Finder, University of Minnesota Press (2000), ISBN0-8166-3661-3, pp. 47-55, 64-72
^Mooers Jr., Robert L. Finding Your Way In The Outdoors, Outdoor Life Press (1972), ISBN0-943822-41-6, p. 47: The term cruiser compass derives from the practice of foresters cruising or estimating the value of a stand of timber by taking compass readings to ascertain the size of the stand.
^Frazor, Persifor, A Convenient Device to be Applied to the Hand Compass, Proceedings of the American Philosophical Society, Vol. 22, No. 118 (Mar., 1885), p. 216
^Hudson, William J., The Brunton Pocket Transit, 26 January 2005 Article
^Mooers Jr., Robert L. Finding Your Way In The Outdoors, Outdoor Life Press (1972), ISBN0-943822-41-6, pp. 48-49: Most of the traditional designs used a momentary button lock mechanism that froze the needle in position to stop excessive swing and permit a reading.
^Dickison, Dan, Powerboat Reports Guide to Powerboat Gear: Take the Guesswork Out of Gear Buying, Globe Pequot Press (2006), ISBN1-59228-069-2, ISBN978-1-59228-069-8, pp. 91-93
Johnson, Mark, The Ultimate Desert Handbook: A Manual for Desert Hikers, Campers, and Travelers, McGraw-Hill Professional (2003), ISBN0-07-139303-X, 9780071393034
Mooers Jr., Robert L. Finding Your Way In The Outdoors, Outdoor Life Press (1972), ISBN0-943822-41-6
Rutstrum, The Wilderness Route Finder, University of Minnesota Press (2000), ISBN0-8166-3661-3
January 01, 1970
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A hand compass also hand bearing compass or sighting compass is a compact magnetic compass capable of one hand use and fitted with a sighting device to record a precise bearing or azimuth to a given target or to determine a location 1 2 Hand or sighting compasses include instruments with simple notch and post alignment gunsights prismatic sights direct or lensatic sights 3 and mirror vee reflected image sights With the additional precision offered by the sighting arrangement and depending upon construction sighting compasses provide increased accuracy when measuring precise bearings to an objective 4 Parts of a hand compass The term hand compass is used by some in the forestry and surveying professions to refer to a certain type of hand compass optimized for use in those fields also known as a forester or cruiser compass 5 6 A hand compass may also include the various one hand or pocket versions of the surveyor s or geologist s transit Contents 1 History and use 1 1 Marine hand bearing compass 2 Notes 3 ReferencesHistory and use edit nbsp A standard Brunton Geo used commonly by geologists While small portable compasses fitted with mechanical sighting devices have existed for a few hundred years the first one hand compass with a sighting device appeared around 1885 7 These soon evolved into more elaborate and specialized models such as the Brunton Pocket Transit patented in 1894 8 Hand compasses were soon widely employed in the practice of forestry geology archaeology speleology preliminary cartography and land surveying nbsp Compass used by engineering geologists In the United States the hand compass became very popular among foresters seeking a compass to plot and estimate stands of timber While the Pocket Transit was more than adequate for such work it was relatively expensive Consequently a new type of hand compass was introduced the forester or cruiser compass Traditionally cruiser compasses featured a sighting notch a mechanically damped 9 or dry needle adjustable declination and a large dial marked in individual degrees using counterclockwise calibration reversed east and west positions A screw base for a tripod or jacob staff monopod was often fitted as well 10 By the late 1960s many foresters had begun using more modern liquid damped compass designs including mirror sight protractor models such as the Silva Type 15 Ranger or the Suunto MC 1 later the MC 2 These compasses were fast to use particularly along straight cruise lines and were sufficiently accurate for most forestry applications 11 On the other hand geologists speleologists archaeologists ornithologists and foresters engaged in precision survey work often used direct reading models such as the Suunto KB 14 prismatic compasses such as Suunto KB 77 or the traditional Brunton Pocket Transit 12 13 Many models featured an optional quadrant 0 90 0 degree scale instead of an azimuthal 0 360 degree system 14 By using a hand compass in combination with aerial photographs and maps a person can determine his her location in the field determine direction to landmarks or destinations estimate distance estimate area and find points of interest marked boundary lines USGS marker plot centers For increased accuracy many professional hand compasses continue to be fitted with tripod mounts 15 While the hand compass continues to be widely employed in such work it has been increasingly supplanted in recent years by use of the GPS or Global Positioning System receiver Marine hand bearing compass edit nbsp Floating card compass with prismatic sight bearing 220 through eyepiece The marine hand compass or hand bearing compass hand bearing compass as it is termed in nautical use has been used by small boat or inshore sailors since at least the 1920s to keep a running course or to record precise bearings to landmarks on shore in order to determine position via the resection technique 16 17 Instead of a magnetized needle or disc most hand bearing compasses feature liquid damping with a floating card design a magnetized degreed float or dial atop a jeweled pivot bearing 18 Equipped with a viewing prism the hand bearing compass allows instant reading of forward bearings from the user to an object or vessel and some provide the reciprocal bearing as well 19 20 Modern examples of marine hand bearing compasses include the Suunto KB 14 and KB 77 and the Plastimo Iris 50 21 22 These compasses frequently have battery illuminated or photoluminescent degree dials for use in low light or darkness 23 24 Notes edit Frazer Persifor A Convenient Device to be Applied to the Hand Compass Proceedings of the American Philosophical Society Vol 22 No 118 Mar 1885 p 216 SCFC Get Acquainted With Forestry Tools Article Johnson Mark The Ultimate Desert Handbook A Manual for Desert Hikers Campers and Travelers McGraw Hill Professional 2003 ISBN 0 07 139303 X 9780071393034 p 134 A direct sighting compass uses a magnifying viewfinder mounted in the compass body to directly view a degreed dial and superimposed indicator line it therefore differs from a lensatic sight which uses a simple magnifying lens on a folding arm positioned over the dial or a prismatic sight which uses a magnifying optical prism Suunto Oy The Suunto KB 14 Story Article Archived 2008 04 09 at the Wayback Machine Rutstrum The Wilderness Route Finder University of Minnesota Press 2000 ISBN 0 8166 3661 3 pp 47 55 64 72 Mooers Jr Robert L Finding Your Way In The Outdoors Outdoor Life Press 1972 ISBN 0 943822 41 6 p 47 The term cruiser compass derives from the practice of foresters cruising or estimating the value of a stand of timber by taking compass readings to ascertain the size of the stand Frazor Persifor A Convenient Device to be Applied to the Hand Compass Proceedings of the American Philosophical Society Vol 22 No 118 Mar 1885 p 216 Hudson William J The Brunton Pocket Transit 26 January 2005 Article Mooers Jr Robert L Finding Your Way In The Outdoors Outdoor Life Press 1972 ISBN 0 943822 41 6 pp 48 49 Most of the traditional designs used a momentary button lock mechanism that froze the needle in position to stop excessive swing and permit a reading Rutstrum pp 47 55 64 72 Bonner Soil amp Water Conservation District Idaho State Forestry Contest October 2004 p 25 Article Archived 2008 12 15 at the Wayback Machine Nix Steve The Best Forestry Field Compass Article Archived 2008 08 07 at the Wayback Machine Suunto Oy The Suunto KB 14 Story Rutstrum pp 47 55 197 199 Rutstrum p 72 Casey Don Using a Hand Bearing Compass Article Seidman David The Complete Sailor Learning the Art of Sailing McGraw Hill Professional 1995 ISBN 0 07 057131 7 ISBN 978 0 07 057131 0 pp 190 194 Dickison Dan Powerboat Reports Guide to Powerboat Gear Take the Guesswork Out of Gear Buying Globe Pequot Press 2006 ISBN 1 59228 069 2 ISBN 978 1 59228 069 8 pp 91 93 Seidman pp 190 194 Dickison pp 91 93 Suunto Oy The Suunto KB 14 Story Dickison pp 91 93 Dickison pp 91 93 Suunto Oy The Suunto KB 14 StoryReferences editAvery T E Burkhart H E Forest Measurements 5th ed New York McGraw Hill 2002 Johnson Mark The Ultimate Desert Handbook A Manual for Desert Hikers Campers and Travelers McGraw Hill Professional 2003 ISBN 0 07 139303 X 9780071393034 Mooers Jr Robert L Finding Your Way In The Outdoors Outdoor Life Press 1972 ISBN 0 943822 41 6 Rutstrum The Wilderness Route Finder University of Minnesota Press 2000 ISBN 0 8166 3661 3 Retrieved from https en wikipedia org w index php title Hand compass amp oldid 1147174899, wikipedia, wiki, book, books, library,
