86 Sentences With "sextants" | Random Sentence Generator

Only radio communication is allowed; sextants are used for navigation.

"If you like compasses and sextants, the GPS has made those obsolete," Heffernan said.

If you like compasses and sextants, the GPS technology has really seemingly made those obsolete.

The successful first voyage between Hawai'i and Tahiti, without maps, compasses or sextants, helped spark a renaissance of Hawaiian culture and language.

The building itself is a stony colonial relic; inside its centuries-old confines, artifacts on display range from traditional costumes to sailors' sextants.

In fact they cannot do this, in the same way that sextants could help crews know their own ships' positions but could not enable others to track the ships.

And all the satellites and cell phones we have now are derived entirely from people plying the trackless ocean with sextants and confidence in their ability to sail, so this idea that the Earth could be flat is so weird.

Because China's done the math, taken out its calipers and sextants, and made sure the features they've built into islands (and their EEZs) form a loose patchwork quilt in the sea that defines almost unbroken ownership of the entire South China Sea.

Southeast Portland is one of the sextants of Portland, Oregon.

It enabled sextants to be used for taking "star shots" from a projected display of the night sky.

Arctic explorer Charles Francis Hall owned a Spencer, Browning & Rust sextant. The Smithsonian Institution houses four navigational instruments manufactured by Spencer, Browning & Rust in its National Museum of American History. The items include two sextants, an octant, and a telescope. American Arctic explorer Charles Francis Hall (1821–1871) owned one of the sextants.

Sextants for astronomical observations were devices depicting a sixth of a circle, used primarily for measuring the positions of stars. They are of significant historical importance, but have been replaced over time by transit telescopes, astrometry techniques, and satellites such as Hipparcos. There are two types of astronomical sextants, mural instruments and frame-based instruments.

So the modern instruments are technically bubble octants, but they may be labeled bubble sextants. Byrd developed the first bubble sextant.

Ships had long used sextants for navigation, but sextants had problems in aircraft navigation. A ship at sea is on a relatively flat surface and can use the horizon to measure the altitude of celestial objects. An aircraft may not have the sea's horizon as a flat reference surface. It may be flying over land where the horizon is formed by mountains of unknown height.

Since the spacers looked like little pillars, these were also called pillar sextants. Troughton also experimented with alternative materials. The scales were plated with silver, gold or platinum. Gold and platinum both minimized corrosion problems.

Maine Maritime Museum galleries, with Mark 48 torpedo hull The collection contains "many sextants, spyglasses, captain's chests". Over the period of 2001 through to 2007 the museum's collection of objects grew from 16,000 to 20,000.

The Bris sextant is not a true sextant, but it is a true reflecting instrument based on the principle of double reflection and subject to the same rules and errors as common octants and sextants. Unlike common octants and sextants, the Bris sextant is a fixed angle instrument capable of accurately measuring a few specific angles unlike other reflecting instruments which can measure any angle within the range of the instrument. It is particularly suited to determining the altitude of the sun or moon.

Furnished with a list produced by Charles Pierre Claret de Fleurieu, Monneron also bought scientific instruments from some of the largest English firms, particularly Ramsden. He even surpassed Fleurieu's directives by acquiring two sextants of a new type.

The collection consist of a variety of models and miniature boats, drawings and engravings, maps, nautical instruments (sextants, compasses, etc.) and fishing tackle (lobster pots, long lines, hooks, needles for mending nets, etc.), which were once used by fishermen the length of the Catalan coast.

Large frame quadrants were used for astronomical measurements, notably determining the altitude of celestial objects. They could be permanent installations, such as mural quadrants. Smaller quadrants could be moved. Like the similar astronomical sextants, they could be used in a vertical plane or made adjustable for any plane.

This is followed by nautical devices such as compasses, chronometers and sextants. Although displaced by modern technology such as GPS, these devices are still mandatory on board. If they fail or do not work correctly, threaten penalties. Furthermore, nautical charts and logarithm tables are needed to determine the exact position of the ship.

The best sextants at the very beginning of the lunar distance era could indicate angle to one-sixth of an arc-minute and later sextants (after ) to 0.1 arc-minutes, after the use of the vernier was popularized by its description in English in the book Navigatio Britannica published in 1750 by John Barrow, the mathematician and historian. In practice at sea, actual errors were somewhat larger. Experienced observers can typically measure lunar distances to within one-quarter of a minute of arc under favourable conditions, introducing an error of up to one quarter degree in longitude. If the sky is cloudy or the Moon is new (hidden close to the glare of the Sun), lunar distance observations could not be performed.

The Fakhrı sextant, stood on top of a rock into which some of it was carved, so the edifice would not be tall given the soft bricks of the area. Al-Kashi compares this to Maragha, saying that the sextant is positioned higher there but also notes the flat roof present in Samarkand should facilitate scientific improvement given the fact that “instruments may be placed on it”. This information, about the sextants in Maragha is contradictory to other sources that state there were no sextants at Maragha. This contradiction was revealed by the translation. Moreover, the scientific atmosphere of Samarkand was one of general isolation because Al-Kashi describes the stout adherence to Ptolemy’s methodologies and lack of awareness for happenings of the Maragha observatory.

Herd charted both Port Nicholson and Port Otago.From Sextants to Satellites: A cartographic time line for New Zealand, Brian Marshall, New Zealand Map Society Journal No 18, Auckland, 2005, page 10 In January 1827 Hongi Hika was shot and wounded in a minor engagement. This prompted fears for safety of the Missionaries in Northland.

Pihl developed a large collection of self-made astronomical instruments, and also made telescopes and sextants for others. He designed Vang church which had burned down and was rebuilt between 1804 and 1810. He started large-scale production of pendulum clocks. The rectory became the largest employer in Vang, with up to 140 persons employed.

In 1976, the average annual growth of the GDP was approximately five percent. This made the East German economy the richest in all of the Soviet Bloc until reunification in 1990. Notable East German exports were photographic cameras, under the Praktica brand; automobiles under the Trabant, Wartburg, and the IFA brands; hunting rifles, sextants, typewriters and wristwatches.

In 1795 when he started engraving he set up shop on North Main Street directly next door to St. John's church in Providence. He then made bank note plates. Hamlin published the first view of Providence, Rhode Island, in one of his engravings. Hamlin was a manufacturer and repairer of optical instruments, telescopes, sextants, and quadrants as a business.

There are examples of sextants made with wood, however most are made from brass. In order to ensure the frame was stiff, instrument makers used thicker frames. This had a drawback in making the instrument heavier, which could influence the accuracy due to hand-shaking as the navigator worked against its weight. In order to avoid this problem, the frames were modified.

Frame designs were modified over time to create a frame that would not be adversely affected by temperature changes. These frame patterns became standardized and one can see the same general shape in many instruments from many different manufacturers. In order to control costs, modern sextants are now available in precision-made plastic. These are light, affordable and of high quality.

Instead of a handle on the frame, they had a socket to allow the attachment of a surveyor's Jacob's staff. ;Box or pocket sextants:These are small sextants entirely contained within a metal case. First developed by Edward Troughton, they are usually all brass with most of the mechanical components inside the case. The telescope extends from an opening in the side.

South Portland in 2020. Portland, Oregon is divided into six sections, as of May 1, 2020: North Portland, Northeast Portland, Northwest Portland, South Portland, Southeast Portland, and Southwest Portland. There are 95 officially recognized neighborhoods, each of which is represented by a volunteer-based neighborhood association. No neighborhood associations overlap the Willamette River, but a few overlap the addressing sextants.

Thereafter, he relocated to 131 South Water Street, and the business was called "At the Sign of the Quadrant" advertising compasses, quadrants, sextants, spyglasses, telescopes, and microscopes. The business was there from 1847 until Hamlin's death in 1869. It was at this business that he became inspired to become an engraver. His first attempts at engraving were done on copper.

If they separate there is collimation error. As modern sextants rarely use adjustable telescopes, they do not need to be corrected for collimation error. ;Index error:This occurs when the index and horizon mirrors are not parallel to each other when the index arm is set to zero. To test for index error, zero the index arm and observe the horizon.

He moved to Detroit for this purpose. Burt & Bailey company of Detroit built his first prototype by the early part of 1855. Burt had obtained an accurate reading within five degrees on board the ship Illinois on its historic first journey through the Soo Canal on June 18, 1855. In March 1856 Burt sent a sample of one of his Equatorial Sextants to the Navy Department.

Francis Barker & Son is a trademark of Pyser Optics, a British design and manufacturing company based in Edenbridge, Kent, which provides military-grade electro-optical products, search and location equipment, educational material and radio electronics.Pyser Optics company information The trademark became notable as a supplier of precision equipment to allied forces in Europe during the Great War and Second World War, particularly compasses and sextants.

Several makers offered instruments with sizes other than one-eighth or one-sixth of a circle. One of the most common was the quintant or fifth of a circle (72° arc reading to 144°). Other sizes were also available, but the odd sizes never became common. Many instruments are found with scales reading to, for example, 135°, but they are simply referred to as sextants.

In 1676, the British Parliament declared that navigation was the greatest scientific problem of the age and in 1714 offered a substantial financial prize for the solution to finding longitude. This spurred the development of the marine chronometer, the lunar distance method and the invention of the octant after 1730. By the late 18th century, navigators replaced their prior instruments with octants and sextants.

Al Khujandi's instrument was larger than previous instruments; it had a radius of about twenty meters.Tekeli, Sevim (1958), 'Nasiruddin, Takiyuddin ve Tycho Brahe'nin Rasat Aletlerinin mukayesesi'. Ankara Universitesi Dil ve Tarih-Cografya Fakültesi Dergesi, XVI, p. 4\. The main improvement incorporated in al-Fakhri sextants over earlier instruments was bringing the precision of reading to seconds while older instruments could only be read in degrees and minutes.

More modern mural instruments would use a telescope with a reticle eyepiece to observe the object. Many mural quadrants were constructed, giving the observer the ability to measure a 90° range of elevation. There were also mural sextants that read 60°. Mural quadrants of the 17th century were noted for their expense, with Flamsteed's costing 120 pounds (1689), and Edmund Halley's costing over 200 pounds (1725).

Beamish dial ;Beamish museum: There are two London dials, the first is in 'town' by the Solicitors Office. It is dated 1649. The second is in the garden of Pockerley Manor, this is a dial produced by Spencer, Browning & Co, more noted for their production of sextants and navigational instruments. St Michael's Mount ;St Michael's Mount, Cornwall: There is a dial engraved by Troughton and Simms.

Kinji Imanishi and Takeo Kuwabara were among Nishibori's mountain-climbing friends. Nishibori also led negotiations with the Nepal government to send a Japanese expedition to climb Manaslu. It would become the first mountain above 8000 m in height to be first summoned by Japanese climbers. Nishibori also backed the Japanese adventurer, Naomi Uemura, and taught him how to use scientific observation equipment, sextants, and other instruments.

While most people think of navigation when they hear the term sextant, the instrument has been used in other professions. ;Navigator's sextant:The common type of instrument most people think of when they hear the term sextant. ;Sounding sextants:These are sextants that were constructed for use horizontally rather than vertically and were developed for use in hydrographic surveys. ;Surveyor's sextants:These were constructed for use exclusively on land for horizontal angular measurements.

The index and other parts are completely covered when the case cover is slipped on. Popular with surveyors for their small size (typically only in diameter and deep), their accuracy was enabled by improvements in the dividing engines used to graduate the arcs. The arcs are so small that magnifiers are attached to allow them to be read. In addition to these types, there are terms used for various sextants.

It could measure altitudes of up to about 120 degrees. That allowed the navigator to sight the horizon in front of him and measure the altitude of a star that was behind him. The first bubble instruments were bubble sextants; they were copying the features of an ordinary sextant. However, a bubble instrument does not look at the horizon, and so it never needs to measure an angle more than 90°.

Northwest Portland is one of the sextants of Portland, Oregon. Northwest Portland includes the Pearl District, most of Old Town Chinatown, the Northwest District, and various residential and industrial neighborhoods. A range of streets primarily in Northwest Portland is named alphabetically from Ankeny through York (the street following York is Reed Street). The street between Wilson and York was called "X Street" until it was renamed as Roosevelt Street.

Sextants are used to measure the angle of the sun or stars with respect to the horizon. Using trigonometry and a marine chronometer, the position of the ship can be determined from such measurements. Historically, trigonometry has been used for locating latitudes and longitudes of sailing vessels, plotting courses, and calculating distances during navigation. Trigonometry is still used in navigation through such means as the Global Positioning System and artificial intelligence for autonomous vehicles.

The master and third officer had rescued sextants, a chronometer, charts and navigation books from Primrose Hills bridge. However, the boats proved to be very short of rations and water for the number of men who had survived. On the morning of 30 October the four lifeboats, keeping close together, set sail and steered eastwards for the Cape Verde Islands. However, by the morning of 31 October wind and currents had taken them westwards.

The transit circle was capable of determining both right ascension and declination of a star, unlike the more simple and common transit instrument that can only determine the right ascension. Such an instrument could also be used to set the Observatory's clocks by observing standard stars whose position was precisely known. In addition there were three other smaller transit telescopes, two clocks by Clemens Riefler of Munich, and other accessories including sextants, chronometers, and teaching tools.

It gave buyers in the 21st century the opportunity to compose complete dinner sets with Qing porcelain. Further items such as mercury, sextants, pocket watches, cannons, coins and other merchandise were also salvaged. The recovery was the largest in salvage history. It is the story of an incredible shipping disaster with more than 1600 dead (and was consequently entitled the “Titanic of the East” by Spiegel news magazine), involving economic difficulties and mass emigration in the early 19th century.

The effect of smoked glass can be incorporated into glass manufacture by adding darkening materials, such that light passing through the glass is decreased in brightness. It can be used aesthetically, for example, in the manufacture of coffee tables with smoked glass tops. It can also be used in scientific instruments as a filter, as in the use of smoked glass in cross-staves and sextants, allowing operators to make sun sightings without damaging their eyesight.

The navigator's sextant uses mirrors to bring the image of the sun, moon or a star to the horizon and measure the altitude of the object. Due to the use of the mirrors, the angle measured is twice the length of the instrument's arc. Hence, the navigator's sextant measures 120° on an arc with an included angle of 60°. By comparison, the astronomical sextants are large and measure angles directly — a 60° arc will measure at most 60°.

These large sextants are made primarily of wood, brass or a combination of both materials. The frame is heavy enough to be stiff and provide reliable measures without flexural changes in the instrument compromising the quality of the observation. The frame is mounted on a support structure that holds it in position while in use. In some cases, the position of the sextant can be adjusted to allow measurements to be made with any instrument orientation.

The firm manufactured a variety of navigational instruments, including octants, sextants, telescopes, and compasses, for both domestic and international markets. Nautical instruments marked with the SBR logo are found in the museums of a number of countries. One of the oldest items in the collection of the United States Geological Survey Museum is a quintant sextant or lattice sextant (pictured) that was manufactured by Spencer, Browning & Rust. The last surviving original partner, Samuel Browning, died in about 1819.

Spencer, Browning & Rust was a London firm that manufactured instruments for navigational use during the 18th and 19th centuries. The predecessor company of Spencer and Browning was established by William Spencer and Samuel Browning in 1778, before they entered into partnership with Ebenezer Rust in 1784. After the death of Ebenezer Rust's son, the successor business was known as Spencer, Browning & Co. The firm of Spencer, Browning & Rust made a variety of navigational instruments, including octants and sextants.

Spencer, Browning & Rust manufactured a variety of navigational instruments, including octants, sextants, telescopes, and compasses. One of the earliest instruments for nautical use was the quadrant; this was followed by the octant. Also referred to as a reflecting quadrant or Hadley quadrant, the octant had small mirror(s) that permitted alignment of the reflected image of the sun with the horizon. It was easier to use than the Davis quadrant and thus generally had fewer errors.

Harriot started to study navigation shortly after receiving a bachelor's degree from Oxford University. The study of navigation that Harriot studied concentrated on the idea of the open seas and how to cross to the New World from the Atlantic Ocean. He used instruments such as the astrolabe and sextants to aide his studies of navigation. After educating himself by incorporating ideals from his astronomic and nautical studies, Harriot taught other captains his navigational techniques in Raleigh.

After a sight is taken, it is reduced to a position by looking at several mathematical procedures. The simplest sight reduction is to draw the equal-altitude circle of the sighted celestial object on a globe. The intersection of that circle with a dead-reckoning track, or another sighting, gives a more precise location. Sextants can be used very accurately to measure other visible angles, for example between one heavenly body and another and between landmarks ashore.

In the early 1850s, the facility began performing a role in assessing and rating barometers, thermometers, chronometers, watches, sextants and other scientific instruments for accuracy; this duty was transferred to the National Physical Laboratory in 1910. An instrument which passed the tests was awarded a "Kew Certificate", a hallmark of excellence. As marine navigation adopted the use of mechanical timepieces, their accuracy became more important. The need for precision resulted in the development of a testing regime involving various astronomical observatories.

The first fusion with Western music was Tibetan Bells, a 1972 release by Nancy Hennings and Henry Wolff. The soundtrack to Kundun, by Philip Glass, has helped to popularize Tibetan music. Foreign styles of popular music have also had a major impact within the Tibetan diaspora, where Indian ghazal and filmi are very popular and American rock has produced the India-based Rangzen Shonu. Within Tibet itself, among rock groups the bilingual Vajara (Tian Chu) sextants are the oldest and most famous act.

The new building was constructed in a quiet side of the city inside the university's botanical gardens. It consisted of a number of offices, living quarters for astronomers, and a number of observing domes containing telescopes. In 1873 two new rooms were added to the building in order to house the tools required to verify nautical instruments; tools used to test compasses, sextants and other instruments. Two of the domes were rebuilt, one in 1875 and the other in 1889.

The exhibit is divided into the following thematic collections — electrical, optics, pneumatics, thermology, mechanics and geodesy. Some of these instruments include solar microscope, a Silbermann device, a Foucault pendulum, a Thomson ammeter, a Regnault hypsometer as well an Atwood machine, various coils, resistors, capacitors, electromagnets, electrometers, spectrometers, photometers, sextants, theodolites and rings. This section also includes a hyperbaric chamber designed and used by Carlo Forlanini between 1901 and 1918 for inducing artificial pneumothorax — which was the first successful cure for tuberculosis.

While Sir Isaac Newton (1642–1727) invented the principle of the octant, it was two other men who developed the octant independently, one in England and the other in America. The octant was patented by English mathematician John Hadley (1682–1744) in 1734, and soon thereafter was utilized by most British navigators. American optician Thomas Godfrey (1704–1749) developed the octant about the same time in Pennsylvania. Also among the nautical instruments that the company of Spencer, Browning & Rust made were sextants.

St. Johns Bridge North Portland is one of the six sextants of Portland, Oregon. North Portland is a diverse mixture of residential, commercial, and industrial areas. It includes the Portland International Raceway, the University of Portland, and massive cargo facilities of the Port of Portland. Nicknames for it include "NoPo" and "the Fifth Quadrant" (for having been the odd-one out from the four-cornered logic of SE, NE, SW, and NW, prior to the 2020 arrival of South Portland).

It differs from other sextants primarily in being a fixed angle sextant, capable of measuring a few specific angles. Sven Yrvind (Lundin) developed his Bris sextant as part of his quest for low-cost, low-technology equipment for ocean crossings. The Bris is a low-technology, high-precision, fixed-interval instrument. It is made of two narrow, flat pieces of glass (microscope slides) permanently and rigidly mounted in a V-shape to a third flat piece of #12 welding glass to make viewing the sun eye safe.

U.S. Secretary of State upright After the riot, the U.S. government hesitated to make amends to the Chinese for the massacre.Waley-Cohen, The Sextants of Beijing, pp 176–77. In China, the governor-general of the Guangdong region suggested that Americans in China might be the target of revenge for the events in Rock Springs. The American envoy to China, Charles Harvey Denby, and others in the diplomatic corps reported rising anti-American sentiment in Hong Kong and in Canton, Guangdong, following the riot.

Such an arrangement can go to a higher resolution by using a higher scale ratio, known as the vernier constant. A vernier may be used on circular or straight scales where a simple linear mechanism is adequate. Examples are calipers and micrometers to measure to fine tolerances, on sextants for navigation, on theodolites in surveying, and generally on scientific instruments. The Vernier principle of interpolation is also used for electronic displacement sensors such as absolute encoders to measure linear or rotational movement, as part of an electronic measuring system.

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.

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.

Marine Infantry Room: Contains collected tables that show the actions and battles in which the marine infantry actions throughout Spanish history. There are also photographs of the marines and a section dedicated to their bands, weapons and uniforms. Cartography and Navigation Room: Copies of manuscripts of maps, letters and objects such as a rudder of a nineteenth-century war steamer, telegraphs, sextants, navigation publications, a collection of logs, and two ships. The Navy Diving Room: Reviews the history of diving in the Navy, and displays various objects on this subject and its evolution.

It was decided to go beyond the budget boundaries, so the crews also bought two chronometers by inventor Arnold John (№ 518 and 2110), and two – by (№ 920 and 922), three- and four-foot refractors with achromatic lenses, a 12-inch reflecting telescope, and for Simonov – a transit instrument and an attitude indicator. Repeating circles by Edward Troughton proved to be inconvenient for use at sea. For ‘Vostok’ they bought sextants by Troughton and Peter Dollond; officers bought some of the instruments with their own money. Thermometers were designed with the Réaumur scale used in Russia, but Simonov also used the Fahrenheit temperature scale.

A sector with the central angle of 180° is called a half- disk and is bounded by a diameter and a semicircle. Sectors with other central angles are sometimes given special names, these include quadrants (90°), sextants (60°) and octants (45°), which come from the sector being one 4th, 6th or 8th part of a full circle, respectively. Confusingly, the arc of a quadrant can also be termed a quadrant. The angle formed by connecting the endpoints of the arc to any point on the circumference that is not in the sector is equal to half the central angle.

In November 1863, aged 16, Forrest took up an apprenticeship with Thomas Campbell Carey, the government surveyor at Bunbury. He had already been taught celestial navigation by his father, and under Carey learned the basic techniques of surveying, becoming proficient in traversing and the use of surveyors' tools, including Gunter's chains, prismatic compasses, sextants, and transit theodolites. He was also a skilled horseman and able to endure long periods in the bush without access to fresh meat and vegetables. After two years as an apprentice to Carey, Forrest was appointed as a government surveyor on a provisional basis.

However, he also continued to write on theology (see below). Riccioli built an astronomical observatory in Bologna at the College of St. Lucia, equipped with many instruments for astronomical observations, including telescopes, quadrants, sextants, and other traditional instruments. Riccioli dealt not only with astronomy in his research, but also with physics, arithmetic, geometry, optics, gnomonics, geography, and chronology. He collaborated with others in his work, including other Jesuits, most notably Francesco Maria Grimaldi (1618–1663) at Bologna, and he kept up a voluminous correspondence with others who shared his interests, including Hevelius, Huygens, Cassini, and Kircher.

He also used highly refined lenses and optical equipment in conjunction with other instruments, such as sextants and armillary spheres. To increase the accuracy of his readings further, he utilized the equatorial coordinate system instead of the zodiacal coordinate system with his specially designed instruments. In 1580, Brahe created the Great Globe, a hollow, wooden sphere layered with brass plates to document the stars and planets he observed. By the year 1595, over 1,000 stars had been etched onto the globe; 777 of these were placed over the majority of Brahe's time at Uraniborg, and the last 223 just before he left.

She received her B.A. and M.A. degrees in Chinese Studies from Cambridge University, then took a degree in law. When she moved with her husband to the United States, she could not practice law, and enrolled in the Ph.D. program at Yale University, receiving her degree in 1987 Waley-Cohen's books include The Culture of War in China: Empire and the Military under the Qing Dynasty (I.B. Tauris, 2006); The Sextants of Beijing: Global Currents in Chinese History (W.W. Norton, 1999); and Exile in Mid-Qing China: Banishment to Xinjiang, 1758-1820 (Yale University Press, 1991).

The sextant and octant are most accurate because they measure angles from the horizon, eliminating errors caused by the placement of an instrument's pointers, and because their dual mirror system cancels relative motions of the instrument, showing a steady view of the object and horizon. Navigators measure distance on the globe in degrees, arcminutes and arcseconds. A nautical mile is defined as 1852 meters, but is also (not accidentally) one minute of angle along a meridian on the Earth. Sextants can be read accurately to within 0.2 arcminutes, so the observer's position can be determined within (theoretically) 0.2 miles, about 400 yards (370 m).

When set on a pedestal or other mount, they could be used to measure the angular distance between any two celestial objects. The details on their construction and use are essentially the same as those of the astronomical sextants; refer to that article for details. Navy: Used to gauge elevation on ships cannon, the quadrant had to be placed on each gun's trunnion in order to judge range, after the loading. The reading was taken at the top of the ship's roll, the gun adjusted, and checked, again at the top of the roll, and he went to the next gun, until all that were going to be fired were ready.

Anita McConnell, Instrument Makers to the World Pp. 43 In 1860, Troughton & Simms opened a new works at Charlton. There were many requests from around the world for standard measure bars, and in 1876, they supplied the Imperial Standards Of Length gauges mounted at Trafalgar Square and the Greenwich Royal Observatory. The firm produced hundreds of astronomical instruments such as mural circles, transit circles, sextants, and other astronomical instruments for observatories around the world. Towards the end of this period other countries such as France, Germany and the United States were able to make instruments themselves so Troughton & Simms made more of their product for the British market.

Astrolabe, used for navigation until around 1730, when they were replaced with sextants From the sixth to the eighteenth centuries, the maritime history of Europe had a profound impact on the rest of the world. The broadside-cannoned full-rigged sixteenth-century sailing ship provided the continent with a weapon to dominate the world. During this time period, Europeans made remarkable inroads in maritime innovations. These innovations enabled them to expand overseas and set up colonies, most notably during the sixteenth and seventeenth centuries.1588 map of Northern Europe by Nicolo Zeno They developed new sail arrangements for ships, skeleton-based shipbuilding, the Western “galea” (at the end of the 11th century), sophisticated navigational instruments, and detailed charts.

One common training task involves the Eagle crew covering all Global Positioning System receivers on board and requiring trainees to navigate between ports using sextants, a compass, and the tools of celestial navigation. A Coast Guard officer candidate uses a sextant to shoot a sun line and help determine Eagles position in 2012. A Coast Guard officer candidate leads a group of future Boatswain Mate Petty Officers in handling a line on Eagles mizzenmast in 2013. On a normal training day, Eagle will set 'sail stations' once or twice and all cadets and crew members will take their positions on deck to set or douse sail, or conduct a sailing maneuver such as tacking or wearing.

Meridian Circle, at Gotha Observatory till 1936 Around 1800, the observatory became an international center for astronomy, being the most modern astronomical institute primarily for its instruments. The instruments came from London, England, the standard place to acquire them in the 18th century. These included an eighteen-inch quadrant, a two-foot transit instrument, three Hadley sextants, an achromatic heliometer, a two-foot achromatic refractor, a Gregorian reflector and many clocks. By the start of the nineteenth century improved instrumentation was acquired from Munich, the standard place to acquire them in the 19th century: consisting of a theodolite (Reichenbach, Utzschneider & Liebherr), a different heliometer (Fraunhofer), new mounting, and three-foot meridian circle (Ertel, Utzschneider & Fraunhofer).

Contains images and video clip of Meridian idents. The unusual logo design was reportedly inspired by maritime images (the sun/moon face is a recurring feature on compasses, sextants and other nautical artefacts used in the navigation of ships), appropriately reflecting the south's long seafaring history. The name "Meridian", which derives from the Latin meridionālis meaning "of the south", may also be linked to the Prime Meridian (the boundary between the Western and Eastern Hemispheres of the globe, and a key landmark in the measurement of time), which passes through the middle of the region, although this has not been confirmed. On 2 September 1996, this ident was replaced by one with a deep purple/blue background and an emphasis on the deep colours of the logo, as well as a smoother form-up.

The Hughes family were originally clockmakers in the east end of London who progressed into supplying sextants and marine chronometers to ships coming into the River Thames. In 1712 Thomas Hughes became a member of the Worshipful Company of Clockmakers at the age of 26 and was elected as Master of the Worshipful Company of Clockmakers in 1742. His son, Thomas Hughes (junior) had his business at 25 New Bond Street London and was elected as Master of the Worshipful Company of Clockmakers in 1762. In 1781 William Hughes, believed to be the son of Thomas Hughes Junior, was elected freeman of the Worshipful Company of Clockmakers and sold a cabin clock to Captain Cook. Joseph Hughes, believed to be the son of William born in 1781, lived and worked at 16 Queen Street, Ratcliffe.

It includes the Lair Hill, Johns Landing and South Waterfront districts and Lewis & Clark College as well as the Riverdale area of unincorporated Multnomah County south of the Portland city limits. In 2018, the city's Bureau of Transportation finalized a plan to transition this part of Portland into South Portland, beginning on May 1, 2020 to reduce confusion by 9-1-1 dispatchers and delivery services. With the addition of South Portland, all six addressing sectors (N, NE, NW, S, SE and SW) are now officially known as sextants. The Pearl District in Northwest Portland, which was largely occupied by warehouses, light industry and railroad classification yards in the early to mid-20th century, now houses upscale art galleries, restaurants, and retail stores, and is one of the wealthiest neighborhoods in the city.

Omega cal. 1861 movement In 1968, American insurance salesman Ralph Plaisted and three companions were the first confirmed expedition to reach the North Pole by land on snowmobiles. The team successfully used the same reference 145.012 Omega Speedmasters as the Apollo program along with sextants for navigation. Also in 1968, Omega transitioned the caliber 321 movement to the new caliber 861, also designed by Albert Piguet, with the introduction of the reference 145.022 Speedmaster. The 861 was very similar to the 321, but replaced its column wheel switching mechanism with a cam and increased the beat rate from 18,000 to 21,600 vibrations per hour. Most Speedmaster Professional watches from 1968 to the present have used variants of this movement, including the modern rhodium-plated caliber 1861 and decorated exhibition calibers 863 and 1863.

Woolaroc flew a great-circle route, flying at an altitude of , above the cloud cover. The navigator, Davis, used sextants and smoke bombs to calculate course and wind drift; although the radio beams from the picket ships stationed along the route helped guide the aircraft, Davis used it only to check the course plotted via traditional instruments. Of the four aircraft headed to Hawaii, only Woolaroc had a two-way radio capable of sending and receiving messages. In fact, Davis had packed a spare radio and repair parts based on Bronte's prior experience in July. The crew radioed Wahiawa Radio Station, next to Wheeler Field, when they were approximately out with an estimated remaining time of 2 hours. They were greeted in Hawaii by a crowd estimated between 25,000 and 30,000, and escorted by a Boeing PW-9 out of Wheeler Field. Goebel and Davis won the race in 26 hours, 17 minutes, earning them the US$25,000 first prize. After their sponsors were paid, Goebel and Davis split the remainder, earning them each US$7,500.