Magnetic compasses the size of softballs trembled periodically as trains rumbled underground.
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Dr Dreyer and Dr Warrant suggest that bogongs use a combination of magnetic compasses and topography.
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They had no magnetic compasses, and no way to ward off stretches of heavy clouds or fog that made it difficult to navigate by sun.
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Alongside GPS, navigational systems utilized by satellites, aircraft, ships, submarines and other vehicles rely on magnetic compasses to ensure they're traveling in the correct direction.
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That way, navigation systems that use magnetic compasses, like those used by airplanes, can be more accurate and correct for the difference between the magnetic poles and the geographic ones.
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That change of address cannot be ignored, given that magnetic compasses still underpin modern navigation, from the systems used by civilian and military airplanes to those that orient your iPhone.
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Some magnetic compasses include means to manually compensate for the magnetic declination, so that the compass shows true directions.
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By the 12th to 13th centuries AD, magnetic compasses were used in navigation in China, Europe, the Arabian Peninsula and elsewhere.
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Jean Alexander Heinrich Clapier de Colongue (; ) (–) was a Baltic German marine engineer and founder of a theory of magnetic deviation for magnetic compasses, living and working in Imperial Russia.
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Another important part of marine electronics is the navigation equipment. Here compasses, which includes both gyro compasses and magnetic compasses make up for equipment that is used by the entire shipping industry.
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C. Weilbach & Co. A/S's Legatfond, was established and it has served as the sole owner of the company since 2005. With the advent of electronic navigation in the twentieth century, magnetic compasses gradually lost ground to gyro compasses and global positioning systems. Iver C. Weilbach & Co. A/S never engaged in the production of electronic navigational systems, which was mainly based on know-how developed in the military industry. The company however continued to produce magnetic compasses until 2009-10 and employees of the company performed compass correction until the 1990s.
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While there are not maintained trails in the area, the peak, which is in Joshua Tree Wilderness, is listed by the Angles Chapter of the Sierra Club as a recommended outing. Magnetite formations near the summit are known to disrupt magnetic compasses.
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The Albemarle was a mid-wing, cantilever monoplane with twin fins and rudders. The fuselage was built in three sections; the structure being unstressed plywood over a steel tube frame.Flight 27 January 1944, p. 89 The forward section used stainless steel tubing to reduce interference with magnetic compasses.
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Gyroscopes can be used to construct gyrocompasses, which complement or replace magnetic compasses (in ships, aircraft and spacecraft, vehicles in general), to assist in stability (bicycles, motorcycles, and ships) or be used as part of an inertial guidance system. MEMS gyroscopes are popular in some consumer electronics, such as smartphones.
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However, it was not until the time of Shen Kuo that the earliest magnetic compasses would be used for navigation. In his written work, Shen Kuo made the first known explicit reference to the magnetic compass-needle and the concept of true north.Needham (1986), Volume 4, Part 1, 249–250.Hsu (1988), 102.
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Exploratory flights were made to obtain information necessary to establish commercial airline service over the Arctic. When the squadron arrived in Alaska, large areas of the territory and northern Canada were largely unexplored. The squadron developed means of polar navigation necessary due to the unreliability of magnetic compasses, and many existing maps of the region were unreliable.
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Lodestones, suspended so they could turn, were the first magnetic compasses. The earliest known surviving descriptions of magnets and their properties are from Greece, India, and China around 2500 years ago. The properties of lodestones and their affinity for iron were written of by Pliny the Elder in his encyclopedia Naturalis Historia.Pliny the Elder, The Natural History, BOOK XXXIV.
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The intersection of the meridian plane with the horizontal defines the true north-south direction found in this way. Unlike magnetic compasses, gyrocompasses are able to find true north, the surface direction toward the north pole. A gyrotheodolite will function at the equator and in both the northern and southern hemispheres. The meridian is undefined at the geographic poles.
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The firm was based at 58 Oxford Street, Digbeth, Birmingham. The factory was built for Thomas Walker & Son by Buckland & Farmer of Birmingham in 1912. It is a Grade II 'Listed building'. In 2002 Lilley & Gillie Ltd, manufacturer of magnetic compasses, acquired Thomas Walker & Son Ltd (Walker Marine), adding Walker's electromechanical speed logs and anemometers to the firm's list of products.
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Needham (1986), Volume 4, Part 1, 279. However, Zhu Yu's book recounts events back to 1086, when Shen Kuo was writing the Dream Pool Essays; this meant that in Shen's time the compass might have already been in navigational use. In any case, Shen Kuo's writing on magnetic compasses has proved invaluable for understanding China's earliest use of the compass for seafaring navigation.
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A compass and map The Earth has a magnetic field which is approximately aligned with its axis of rotation. A magnetic compass is a device that uses this field to determine the cardinal directions. Magnetic compasses are widely used, but only moderately accurate. The north pole of the magnetic needle points towards the geographic north pole of the earth and vice versa.
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Sperry found another use for his gyroscopes in 1908. Magnetic compasses on steel battleships at the time had issues with maintaining magnetic north with the variations of the magnetic field they experienced. Working with Hannibal C. Ford, Sperry began work on a gyrocompass to replace the magnetic compass. In 1910 he founded the Sperry Gyroscope Company in Brooklyn, New York on the basis of this innovation.
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Cheap compasses with bad bearings may get stuck because of this and therefore indicate a wrong direction. Magnetic compasses are influenced by any fields other than Earth's. Local environments may contain magnetic mineral deposits and artificial sources such as MRIs, large iron or steel bodies, electrical engines or strong permanent magnets. Any electrically conductive body produces its own magnetic field when it is carrying an electric current.
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Some compasses feature a special needle balancing system that will accurately indicate magnetic north regardless of the particular magnetic zone. Other magnetic compasses have a small sliding counterweight installed on the needle itself. This sliding counterweight, called a 'rider', can be used for counterbalancing the needle against the dip caused by inclination if the compass is taken to a zone with a higher or lower dip.
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After observing the success of her attack, Ambra moved away. While Hereward was rescuing the survivors, Stuart, who was missed by the third torpedo, detected Ambra with ASDIC and commenced a series of depth charge attacks against the submarine. Hereward soon joined in, and attacks lasted for several hours until approximately 6:30. The submarine suffered damage to a variety of her equipment, including both gyroscopic and magnetic compasses.
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Company Profile: PT Uwatec Batam of Indonesia, January 3, 2008, retrieved March 27, 2012 The discontinued Silva 424 Wrist Sighting Compass was made for Johnson Outdoors by Suunto Oy of Finland, while the Silva Lensatic 360 compass is made in Taiwan. JO ceased all distribution of Silva brand magnetic compasses in 2018. In 2018, JO sold its North America rights to the Silva brand to Silva of Sweden AB.
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Aokigahara has been falsely portrayed as a place where navigational compasses go haywire. Needles of magnetic compasses will move if placed directly on the lava, aligning with the rock's natural magnetism, which varies in iron content and strength by location. However, a compass behaves as expected when held at a normal height. The Japan Ground Self-Defense Force has conducted its ranger courses including navigation training in the forest since 1956.
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He also designed the Finsen Sun Compass to be used by armoured vehicle drivers in the desert campaigns. The standard magnetic compasses were useless owing to the large amount of metal in the vehicles. Finsen also developed a stomach contents sampler at the request of a specialist physician. Shaped like a pill, once swallowed the small device would open inside the patient's stomach after a pre-determined time and sample the stomach contents.
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Evidence for the orientation of buildings by the means of a magnetic compass can be found in 12th-century Denmark: one fourth of its 570 Romanesque churches are rotated by 5–15 degrees clockwise from true east–west, thus corresponding to the predominant magnetic declination of the time of their construction. Most of these churches were built in the 12th century, indicating a fairly common usage of magnetic compasses in Europe by then.
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Although Brunton, Inc. makes many other types of magnetic compasses, the Brunton Pocket Transit is a specialized instrument used widely by those needing to make accurate navigational and slope-angle measurements in the field. Users are primarily geologists, but archaeologists, environmental engineers, mining engineers and surveyors also make use of the Brunton's capabilities. The United States Army has adopted the Pocket Transit as the M2 Compass for use by crew-served artillery.
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Polar aviation refers to aviation in the polar regions of the Earth. Specifically, one may speak of Arctic aviation and Antarctic aviation in the Arctic and Antarctic respectively. The major factors which define the character of polar aviation include remoteness from major populated areas, specific physical geography and climate. Specific factors include low temperatures, frequent changes of meteorological conditions, polar night, the uncertainty of magnetic compasses, difficulties in radio communication, and lack of landmarks.
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Mazzoleni also helped Galileo produce other instruments, including hydrostatic balances, air thermometers, magnets and magnetic compasses for ships, and various kinds of drawing compasses for engineers and architects. For his services, Galileo paid Mazzoleni a meager salary of six crowns per year (in addition to room and board). Mazzoleni continued to work with Galileo even after the latter's return to Florence in 1610. In 1612, Mazzoleni became regulator of the clock of the University of Padua's Palazzo del Bo'.
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The oldest precursors of the luopan are the or , meaning astrolabe or diviner's board—also sometimes called liuren astrolabes—unearthed from tombs that date between 278 BCE and 209 BCE. These astrolabes consist of a lacquered, two-sided board with astronomical sightlines. Along with divination for Da Liu Ren the boards were commonly used to chart the motion of Taiyi through the nine palaces. The markings are virtually unchanged from the shi to the first magnetic compasses.
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A number of early cultures used lodestone so they could turn, as magnetic compasses for navigation. Early mechanical compasses are referenced in written records of the Chinese, who began using it for navigation sometime between the 9th and 11th century, "some time before 1050, possibly as early as 850." At present, according to Kreutz, scholarly consensus is that the Chinese invention used in navigation pre-dates the first European mention of a compass by 150 years.Kreutz, p.
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The voyages were possible through certain technological advancements such as astrolabes, magnetic compasses, and triangular sails as well as more reliable maps and mapping systems. Many of the technological knowledge of these advancements were developed elsewhere and borrowed by European crews. The technologies improved and the grasp of geography grew with further explorations. Ming China was also expanding its naval knowledge during the 1400s, but in 1436 the emperor outlawed more voyages after reaching East Africa.
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These combine some miles downstream to form the River Derwent, flowing through Borrowdale to Derwentwater and Keswick. South-east of the summit of Esk Pike is Ore Gap, the col separating it from Bow Fell. The soil here is red due to haematite, and climbing lore suggests that magnetic compasses cannot be trusted in this locality.Alfred Wainwright: A Pictorial Guide to the Lakeland Fells, Book 4: North of the gap is Angle Tarn, a feeder of the Langstrath.
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Direction was maintained with solar and magnetic compasses. Two of the vehicles each carried several altimeters and a proton magnetometer, and traveled such that one led the other by 8 km. Every 8 km they paused for simultaneous readings of the altimeters and magnetometers; and for measurements of gravity, surface slope, and snow density, and for weather observations. The surface slope was measured by scanning the horizon with a theodolite and recording the azimuth and vertical angle of the highest and lowest points.
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This gyrostabilization system, while never implemented on a massive scale, laid the foundation for his son's autopilot system. In 1916, Sperry joined Peter Hewitt to develop the Hewitt-Sperry Automatic Airplane, one of the first successful precursors of the UAV. In 1917, Sperry solved the issue of magnetic compasses indicating the opposite position when an aircraft is turning, inventing the Gyro Turn Indicator. This turn indicator was later modified into what is known now as the Turn and Slip Indicator.
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Chinese geomantic compass c. 1760 from the National Maritime Museum in London The compass was invented in China during the Han Dynasty between the 2nd century BC and 1st century AD where it was called the "south-governor" (sīnán ). The magnetic compass was not, at first, used for navigation, but for geomancy and fortune-telling by the Chinese. The earliest Chinese magnetic compasses were possibly used to order and harmonize buildings in accordance with the geomantic principles of feng shui.
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Magnetic compasses are prone to errors in the neighborhood of such bodies. Some compasses include magnets which can be adjusted to compensate for external magnetic fields, making the compass more reliable and accurate. A compass is also subject to errors when the compass is accelerated or decelerated in an airplane or automobile. Depending on which of the Earth's hemispheres the compass is located and if the force is acceleration or deceleration the compass will increase or decrease the indicated heading.
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Natural ore deposits are located in synclines and up against mafic dikes. Beneficiation commenced in 1954 and this concentration of iron into pellets accounted for 73 percent of production by 1965. Early mining used open-pit mining methods, but was replaced with underground mining by 1880. The Marquette Iron Range was discovered in 1844 by a party of surveyors led by William A. Burt, who found that their sensitive magnetic compasses produced skewed results because of the concentration of iron in the land they were surveying.
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Users of a smartphone compass should carefully calibrate their devices and run several tests against traditional magnetic compasses in order to understand the limitations of their chosen program. There are several different digital geological compasses now available, including the listerCompass . This is based on software that bypasses the inherent inaccuracy of the 'Heading' function by recording data from the magnetometers and to the accelerometers, and then computing the orientation of the iPhone using vector algebra. The accelerometers record vibration, so the iPhone needs be held still.
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Lodestone attracting some iron nails Hall of Gems of the Smithsonian Lodestone attracting small bits of iron A lodestone is a naturally magnetized piece of the mineral magnetite. They are naturally occurring magnets, which can attract iron. The property of magnetism was first discovered in antiquity through lodestones. Pieces of lodestone, suspended so they could turn, were the first magnetic compasses, and their importance to early navigation is indicated by the name lodestone, which in Middle English means "course stone" or "leading stone", from the now-obsolete meaning of lode as "journey, way".
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An incredibly extensive array of precise instrumentation had to be readily available for Humboldt's terrestrial physicist. The expansive amount of scientific resources that characterized the Humboldtian scientist is best described in the book Science in Culture, > Thus the complete Humboldtian traveller, in order to make satisfactory > observations, should be able to cope with everything from the revolution of > the satellites of Jupiter to the carelessness of clumsy donkeys.Cannon, > Science in Culture, p. 76 Just some of such instruments included chronometers, telescopes, sextants, microscopes, magnetic compasses, thermometers, hygrometers, barometers, electrometers, and eudiometers.
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Meanwhile, in 1913, C. Plath (a Hamburg, Germany-based manufacturer of navigational equipment including sextants and magnetic compasses) developed the first gyrocompass to be installed on a commercial vessel. C. Plath sold many gyrocompasses to the Weems’ School for Navigation in Annapolis, MD, and soon the founders of each organization formed an alliance and became Weems & Plath.The Invention of Precision Navigational Instruments for Air and Sea Navigation , Weems & Plath. The 1889 Dumoulin-Krebs gyroscope Before the success of the gyrocompass, several attempts had been made in Europe to use a gyroscope instead.
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The Airy Glacier () is a glacier long and wide, flowing west to the northeast portion of Forster Ice Piedmont, near the west coast of the Antarctic Peninsula. The glacier was first roughly surveyed by British Graham Land Expedition of 1936-37, then photographed from the air by the Ronne Antarctic Research Expedition in 1947, and surveyed by Falkland Islands Dependencies Survey in 1958. It was named by United Kingdom Antarctic Place-Names Committee for George Biddell Airy, British Astronomer Royal, who in 1839 introduced a method of correcting magnetic compasses for deviation.
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Classic geological compass (Brunton), sideview Classic geological compass (Brunton), topview There are a number of different (specialised) magnetic compasses used by geologists to measure orientation of geological structures, as they map in the field, to analyse (and document) the geometry of bedding planes, joints, and/or metamorphic foliations and lineations.The Mapping of Geological Structures (Geological Society of London Handbook Series) [Paperback] K. R. McClayStatistics of Earth Science Data: Their Distribution in Time, Space and Orientation [Paperback] Graham J. Borradaile (Author) In this aspect the most common device used to date is the analogue compass.
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Iron ore was first discovered in Michigan's Upper Peninsula on September 19, 1844, by William A. Burt, who was then employed to lead a party engaged in surveying the Upper Peninsula on behalf of the United States government. Variations in the readings of magnetic compasses employed suggested that something was disturbing the local magnetic fields, and, on investigation of part of the Marquette Iron Range, ore was found as close to the surface as just below the sod. Development of this find was ongoing throughout the 1840s and early 1850s. The initial focus was on producing iron locally, as shipping was difficult.
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Flinders Peak () is a conspicuous triangular peak, high, on the west end of the Bristly Peaks. The peak overlooks Forster Ice Piedmont near the west coast of the Antarctic Peninsula. It was photographed from the air by the British Graham Land Expedition (February 1937) and the Ronne Antarctic Research Expedition (December 1947). It was surveyed from the ground by the Falkland Islands Dependencies Survey in December 1958, and was named by the UK Antarctic Place-Names Committee after Matthew Flinders, an English navigator who discovered the cause of deviation in magnetic compasses, and pointed the way to a solution, 1805–14.
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The foundations of the company were laid on November 24, 1755, when flag, sail and compass maker Iver Jensen Borger set up his own maritime supplier business in Copenhagen, Denmark. Iver Jensen Borger specialized in the production of nautical instruments, mainly magnetic compasses, as well as flags and sails for sailing vessels. He gradually expanded the business into one of the main maritime suppliers in Copenhagen and laid the basis of a long-lasting family firm. When Borger died in 1799, his son-in-law, Johan Philip Weilbach, took over the business and during the nineteenth century it passed to subsequent generations of the Weilbach family.
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During the nineteenth century steam ships and iron hulled vessels started to replace wooden sailing vessels, and technological changes in shipping provided new business opportunities for Weilbach. Magnetic compasses were sensitive to the magnetic fields of iron and steel hulls and needed regular corrections by professional compass correctors. Such corrections were done during sea trials for new vessels, but they were also performed on regular intervals on existing vessels. Weilbach's employees specialized in this activity as a supplement to the making of nautical instruments. Iver C. Weilbach In 1887, Weilbach's business was split between two brothers, Iver Christian Weilbach and Johannes Sophus Vilhelm Weilbach.
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Wassuc spent the next two years operating in the 5th Naval District, primarily plying the waters of the Chesapeake Bay region and occasionally ranging as far north as the Washington Navy Yard and as far south as Cape Hatteras. She operated principally in BuOrd testing programs at the Naval Mine Warfare Proving Grounds at Solomons Island, Maryland, and at Yorktown, Virginia. She also served two tours of duty as a training ship, providing instruction for officers in the compensation of magnetic compasses. Although her duties appear to have been largely experimental and test-oriented, records indicate that the ship laid a small minefield off Cape Hatteras on 22 May 1942.
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The first HVDC Cross-Channel scheme was built by ASEA and went into service in 1961 Compendium of HVDC schemes, CIGRÉ, Compendium of all HVDC projects between converter stations at Lydd in England (next to Dungeness Nuclear Power Station) and Echinghen, near Boulogne-sur-Mer, in France. This scheme was equipped with Mercury arc valves, each having four anodes in parallel.Cory, B.J., Adamson, C., Ainsworth, J.D., Freris, L.L., Funke, B., Harris, L.A., Sykes, J.H.M., High voltage direct current converters and systems, Macdonald & Co. (publishers) Ltd, 1965, p175-218. In order to keep the disturbances of the magnetic compasses of passing ships as small as possible, a bipolar cable was used.
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In his letter of 1269,The letter of Petrus Peregrinus on the magnet, A.D. 1269 Translated by Brother Arnold (New York, McGraw Publishing, 1904) (online) Peregrinus explains how to identify the poles of the compasses. He also describes the laws of magnetic attraction and repulsion. The letters also contain a description of an experiment with a repaired magnet, as well as a number of compasses, one of which "you will be able to direct your steps to cities and islands and to any place whatever in the world." Indeed, the increasing perfection of magnetic compasses during the thirteenth century allowed navigators such as Vandino and Ugolino Vivaldi to strike out on voyages to unknown lands.
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The first section is prefaced by Mercator's ideas on magnetism, the central thesis being that magnetic compasses are attracted to a single pole (not a dipole) along great circles through that pole. He then shows how to calculate the position of the pole if the deviation is known at two known positions (Leuven and Corvo in the Azores): he finds that it must be at latitude 73°2' and longitude 169°34'. Remarkably, he also calculates the longitude difference between the pole and an arbitrary position: he had solved the longitude problem—if his theory had been correct. Further comments on magnetism may be found in an earlier letter to Perrenot and on the later world map.
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NOAA personnel launch a Slocum glider Gliders typically make measurements such as temperature, conductivity (to calculate salinity), currents, chlorophyll fluorescence, optical backscatter, bottom depth, and sometimes acoustic backscatter or ambient sound. They navigate with the help of periodic surface GPS fixes, pressure sensors, tilt sensors, and magnetic compasses. Vehicle pitch is controllable by movable internal ballast (usually battery packs), and steering is accomplished either with a rudder (as in Slocum) or by moving internal ballast to control roll (as in SeaExplorer, Spray and Seaglider). Buoyancy is adjusted either by using a piston to flood/evacuate a compartment with seawater (Slocum) or by moving oil in/out of an external bladder (SeaExplorer, Seaglider, Spray, and Slocum Thermal).
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Lacaille's designations were kept in the offspring, so Carina has α, β, and ε; Vela has γ and δ; Puppis has ζ; and so on. As a result of this breakup, Argo Navis is the only one of the 48 listed by Ptolemy in his Almagest no longer officially recognized as a single constellation. In addition, the constellation Pyxis (the mariner's compass) occupies an area near that which in antiquity was considered part of Argo's mast. Some recent authors state that modern Pyxis was part of the ancient Greek conception of Argo Navis, but magnetic compasses were unknown in ancient Greek times, nor does it appear that the stars now in Pyxis were included in the original conception of Argo Navis.
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The Kelvin Crests () are a line of steep-sided elevations with ice-covered cliffs long, on the north side of Airy Glacier near its junction with Forster Ice Piedmont on the west side of the Antarctic Peninsula. Roughly surveyed by the British Graham Land Expedition in 1936–37, they were photographed from the air by the Ronne Antarctic Research Expedition in 1947. They were surveyed from the ground, from the southwest only, by members of the Falkland Islands Dependencies Survey, December 1958, and completely mapped by the United States Geological Survey, 1974. The feature was named by the UK Antarctic Place-Names Committee for William Thomson, 1st Baron Kelvin, a British physicist and engineer who made substantial improvements in the design of magnetic compasses, 1873–78, and invented the Thomson sounding machine in 1878.
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The direction of the induced magnetic field is also sometimes remembered by the right-hand grip rule, as depicted in the illustration, with the thumb showing the direction of the conventional current, and the fingers showing the direction of the magnetic field. The existence of this magnetic field can be confirmed by placing magnetic compasses at various points round the periphery of an electrical conductor that is carrying a relatively large electric current. The thumb shows the direction of motion and the index finger shows the field lines and the middle finger shows the direction of induced current. If an external magnetic field is applied horizontally, so that it crosses the flow of electrons (in the wire conductor, or in the electron beam), the two magnetic fields will interact.
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At the very end of the 19th century, in response to the development of battleships with large traversable guns that affected magnetic compasses, and possibly to avoid the need to wait for fair weather at night to precisely verify one's alignment with true north, the gyrocompass was developed for shipboard use. Since it finds true, rather than magnetic, north, it is immune to interference by local or shipboard magnetic fields. Its major disadvantage is that it depends on technology that many individuals might find too expensive to justify outside the context of a large commercial or military operation. It also requires a continuous power supply for its motors, and that it can be allowed to sit in one location for a period of time while it properly aligns itself.
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The first gyroscope for scientific use was made by the French physicist Léon Foucault (1819–1868) in 1852, who also named the device, while researching in the same line that led him to use the eponymous pendulum, for which he was awarded a Copley Medal by the Royal Society. The gyrocompass was patented in 1885 by Marinus Gerardus van den Bos in The Netherlands after continuous spinning was made possible by small electric motors, which were in turn a technological outcome of the discovery of magnetic induction. Yet only in 1906 was the German inventor Hermann Anschütz-Kaempfe (1872–1931) able to build the first practical gyrocompass. It had two major advantages over magnetic compasses: it indicated true north and was unaffected by ferromagnetic materials, such as the steel hull of ships.
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Other innovations included the square-pallet bilge pump, which was adopted by the West during the 16th century for work ashore, the western chain pump, which was adopted for shipboard use, being of a different derivation. Junks also relied on the compass for navigational purposes. However, as with almost all vessels of any culture before the late 19th century, the accuracy of magnetic compasses aboard ship, whether from a failure to understand deviation (the magnetism of the ship's iron fastenings) or poor design of the compass card (the standard drypoint compasses were extremely unstable), meant that they did little to contribute to the accuracy of navigation by dead reckoning. Indeed, a review of the evidence shows that the Chinese embarked magnetic pointer was probably little used for navigation.
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These bearings are then converted on a pre-flight plan by adding or subtracting the local variation displayed on a sectional. Radionavigation aids located on the ground, such as VORs, are also checked and updated to keep them aligned with magnetic north to allow pilots to use their magnetic compasses for accurate and reliable in-plane navigation. Runways are designated by a number between 01 and 36, which is generally one tenth of the magnetic azimuth of the runway's heading: a runway numbered 09 points east (90°), runway 18 is south (180°), runway 27 points west (270°) and runway 36 points to the north (360° rather than 0°).Federal Aviation Administration Aeronautical Information Manual, Chapter 2, Section 3 Airport Marking Aids and Signs part 3b However, due to magnetic declination, changes in runway designators have to occur at times to keep their designation in line with the runway's magnetic heading.
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Peter G. Hoare and Caroline S. Sweet, "The orientation of early medieval churches in England" in Journal of Historical Geography 26, 2 (2000) 162–173 Similarly, a survey of a total of 32 medieval churches with reliable metadata in Lower Austria and northern Germany discovered only a few aligned in accordance with the saint's feast, with no general trend. There was no evidence of the use of compasses; and there was a preferred alignment towards true east, with variations due to town and natural topography.Patrick Arneitz, Andrea Draxler, Roman Rauch, Roman Leonhardt, "Orientation of churches by magnetic compasses?" in Geophysical Journal, Volume 198, Issue 1, p.1-7 A notable example of an (approximately) oriented church building that – to match the contours of its location and to avoid an area that was swampy at the time of its construction – bends slightly in the middle is Quimper Cathedral in Brittany.
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There he did his first scientific work with Ivan de Collong on Deviation of magnetic compasses. The theory of magnetic and gyro-compasses fascinated him for all of his life; later he published important works related to the dynamics of the magnetic compass and proposed the dromoscope, a device that would automatically calculate the deviation of a compass. He also was a pioneer of the gyrocompass, being the first to create a full theory of it. After spending several years at the Main Hydrographic Administration and at a shipbuilding plant (French-Russian shipbuilding company), in 1888 he continued his study in the Naval Academy of Saint Petersburg. He was a talented and promising student and after graduating ahead-of-schedule from the Academy in 1890, stayed on as mathematics and ship- theory lecturer. Fame came to him in the 1890s, when his pioneering Theory of oscillating motions of the ship, significantly extending William Froude's rolling theory, became internationally known.
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To avoid problems with magnetic compasses at that latitude, one of the destroyers would point towards the coast and once three Hurricane pilots had formed a vic, they were to line up along it and keep going until they reached the coast, then turn right for Vaenga a few miles inland. The squadron commanders briefed their pilots that 134 Squadron would take off first and that they were to keep a sharp lookout for German fighters but that they would carry only six of their twelve machine-guns to save weight. The first Hurricanes came up on the lift into a grey overcast day and the fight deck began to vibrate as the ship picked up speed into a light headwind and the Hurricane engines were started. Tony Miller, the 134 Squadron leader, went first, hit the ramp as suggested by the navy pilots and got airborne, despite the undercarriage being too damaged to retract.
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