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38-675: The Natal Observatory was an astronomical observatory in the Colony of Natal (now the KwaZulu-Natal province of the Republic of South Africa) from 1882 to 1911. The most important work carried out there was a study of the motion of the moon . In 1882 David Gill , director of the Royal Observatory, Cape of Good Hope , requested the government of Natal to establish an astronomical observatory at Durban , in anticipation of

76-444: A clock by Dent keeping sidereal time , and some precision clocks and other minor instruments. A mean time clock by Victor Kullberg was added in 1892 and a 75 mm portable equatorial refractor in 1896. In December 1883 meteorological instruments were received from England and regular meteorological observations initiated at the observatory. Instruments to measure magnetic declination arrived in 1892. Nevill remained director of

114-702: A large percentage of clear nights per year, dry air, and are at high elevations. At high elevations, the Earth's atmosphere is thinner, thereby minimizing the effects of atmospheric turbulence and resulting in better astronomical " seeing ". Sites that meet the above criteria for modern observatories include the southwestern United States , Hawaii , Canary Islands , the Andes , and high mountains in Mexico such as Sierra Negra . Major optical observatories include Mauna Kea Observatory and Kitt Peak National Observatory in

152-520: A particular subject (such as public health observatory ) or for a particular geographic area ( European Audiovisual Observatory ). Astronomical observatories are mainly divided into four categories: space-based , airborne , ground-based, and underground-based. Historically, ground-based observatories were as simple as containing an astronomical sextant (for measuring the distance between stars ) or Stonehenge (which has some alignments on astronomical phenomena). Ground-based observatories, located on

190-592: A president, regional vice-presidents, secretary, treasurer, and additional council members. The presidents: The Pretoria Branch of the Association arranges monthly public lectures on scientific subjects. The Association annually publishes the Rudolf Marloth Brochure , named after the former president Rudolf Marloth . It contains information about the recipients of the annual awards, summaries of their lectures, and other information relating to

228-596: A remote 5,640 m (18,500 ft) mountaintop in the Atacama Desert of Chile. The oldest proto-observatories, in the sense of an observation post for astronomy, The oldest true observatories, in the sense of a specialized research institute , include: Space-based observatories are telescopes or other instruments that are located in outer space , many in orbit around the Earth. Space telescopes can be used to observe astronomical objects at wavelengths of

266-467: A routine nature and included analyses of geological samples for gold and other metals, analyses of soil samples for agricultural purposes, the examination of high explosives and detonators , and toxicological investigations. Following the formation of the Union of South Africa in 1910 the post of government astronomer of Natal was abolished and the observatory closed down. Some of the equipment went to

304-613: A shelf until such time as a vote can be obtained to publish it… The next year disaster struck when the manuscript was damaged during a rainstorm owing to a leak in the observatory's roof. In subsequent years similar work was done by others, notably E.W. Brown in the United States, M. Radau in France, and P.H. Cowell in Britain, who received the credit. In 1907 Nevill related this sad history in his presidential address to Section A of

342-419: A week at the absolute reference point calibration measurements are performed. Example magnetic observatories include: Example seismic observation projects and observatories include: Example gravitational wave observatories include: A volcano observatory is an institution that conducts the monitoring of a volcano as well as research in order to understand the potential impacts of active volcanism. Among

380-833: Is a facility which precisely measures the total intensity of Earth's magnetic field for field strength and direction at standard intervals. Geomagnetic observatories are most useful when located away from human activities to avoid disturbances of anthropogenic origin, and the observation data is collected at a fixed location continuously for decades. Magnetic observations are aggregated, processed, quality checked and made public through data centers such as INTERMAGNET . The types of measuring equipment at an observatory may include magnetometers (torsion, declination-inclination fluxgate, proton precession, Overhauser-effect), variometer (3-component vector, total-field scalar), dip circle , inclinometer , earth inductor, theodolite , self-recording magnetograph, magnetic declinometer, azimuth compass. Once

418-444: Is a scientific institution whose main task is to make observations in the fields of meteorology, geomagnetism and tides that are important for the navy and civil shipping. An astronomical observatory is usually also attached. Some of these observatories also deal with nautical weather forecasts and storm warnings, astronomical time services, nautical calendars and seismology. Example marine observatories include: A magnetic observatory

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456-658: Is that, because of their location above the Earth's atmosphere, their images are free from the effects of atmospheric turbulence that plague ground-based observations. As a result, the angular resolution of space telescopes such as the Hubble Space Telescope is often much smaller than a ground-based telescope with a similar aperture . However, all these advantages do come with a price. Space telescopes are much more expensive to build than ground-based telescopes. Due to their location, space telescopes are also extremely difficult to maintain. The Hubble Space Telescope

494-613: Is the Mauna Kea Observatory , located near the summit of a 4,205 m (13,796 ft) volcano in Hawaiʻi. The Chacaltaya Astrophysical Observatory in Bolivia, at 5,230 m (17,160 ft), was the world's highest permanent astronomical observatory from the time of its construction during the 1940s until 2009. It has now been surpassed by the new University of Tokyo Atacama Observatory , an optical-infrared telescope on

532-632: The Natal Agricultural Journal , in which he identified an 18-year rainfall cycle. Rendell also published a paper on the rainfall at Durban in the Quarterly Journal of the Royal Meteorological Society in 1906. The staff also analysed tidal observations made during 1884–1888 and compiled tidal tables for Durban Harbour . By 1903, these had still not been printed and by that time the entrance to

570-564: The Royal Astronomical Society (1885), describing the corrections required by Hansen's tables. He next studied all available lunar observations since the middle of the 17th century and reduced them to a uniform basis. Comparing these observations to Hansen's tables, he used the discrepancies to derive the amplitudes and periods of appropriate correction terms. After all these improvements the tables provided an excellent fit to all lunar observations made since 1650. The work

608-424: The Royal Observatory, Cape of Good Hope , who was elected its first president. All scientific disciplines were accommodated, with the result that membership rose to over 1000. For many years S2A3 was the largest and most influential scientific society in southern Africa. Members met once a year in different southern African cities to present papers and tend to the business of the Association. The first annual meeting

646-544: The South African Association for the Advancement of Science . Nevill's other astronomical work included the accurate determination of the observatory's latitude and longitude, first for astronomical purposes and then for the geodetic survey of southern Africa, and regular transit observations for the provision of time signals. A larger collaborative project, carried out from 1886 to 1896, involved

684-478: The Stratospheric Observatory for Infrared Astronomy use airplanes to observe in the infrared , which is absorbed by water vapor in the atmosphere. High-altitude balloons for X-ray astronomy have been used in a variety of countries. Example underground, underwater or under ice neutrino observatories include: Example meteorological observatories include: A marine observatory

722-663: The transit of Venus on 4 December that year. Mr Robert T. Pett, third assistant at the Royal Observatory, visited Durban in June that year to expedite matters. A site for the observatory was chosen in the southwest corner of the Natal Botanic Gardens. Gill invited the British astronomer Edmund Neville Nevill (also known as Edmund Neison) to take up the post of government astronomer of Natal and director of

760-447: The Advancement of Science The Southern Africa Association for the Advancement of Science ( S2A3 or S 2 A 3 ) is a learned society , originally known as the South African Association for the Advancement of Science ( SAAAS ). Established in 1902, its principal aim is to increase the public awareness and understanding of science, engineering and technology, and their role in society, by means of various awards and by communicating

798-453: The Advancement of Science in 1905. In addition to the regular meteorological observations made at the observatory the staff was responsible also for analysing and publishing meteorological observations made elsewhere in Natal. Thus by 1900 there were 31 stations that submitted their observations to the observatory on a monthly basis. In 1908 Nevill wrote an article on the rainfall in Natal for

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836-631: The US, Roque de los Muchachos Observatory in Spain, and Paranal Observatory and Cerro Tololo Inter-American Observatory in Chile . Specific research study performed in 2009 shows that the best possible location for ground-based observatory on Earth is Ridge A  — a place in the central part of Eastern Antarctica. This location provides the least atmospheric disturbances and best visibility. Beginning in 1933, radio telescopes have been built for use in

874-782: The Union Observatory in Johannesburg. During the nineteen-twenties the Natal Astronomical Association repaired the observatory and opened it to the public for some time. Later the 200 mm refractor came under the control of the Natal Technical College Astronomical observatory The term observatoire has been used in French since at least 1976 to denote any institution that compiles and presents data on

912-728: The best known are the Hawaiian Volcano Observatory and the Vesuvius Observatory . Mobile volcano observatories exist with the USGS VDAP (Volcano Disaster Assistance Program), to be deployed on demand. Each volcano observatory has a geographic area of responsibility it is assigned to whereby the observatory is tasked with spreading activity forecasts, analyzing potential volcanic activity threats and cooperating with communities in preparation for volcanic eruption . South African Association for

950-479: The comparison of the declination of stars based on observations made in the northern and southern hemispheres . During his early years in Natal, under the name E.N. Neison, he published a popular book entitled Astronomy: a simple introduction to a noble science (London, 1886). He also made a study of ancient eclipses , on which he read a paper at the joint meeting of the British and South African Associations for

988-463: The electromagnetic spectrum that cannot penetrate the Earth's atmosphere and are thus impossible to observe using ground-based telescopes. The Earth's atmosphere is opaque to ultraviolet radiation, X-rays , and gamma rays and is partially opaque to infrared radiation so observations in these portions of the electromagnetic spectrum are best carried out from a location above the atmosphere of our planet. Another advantage of space-based telescopes

1026-406: The entire upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes usually do not have domes. For optical telescopes, most ground-based observatories are located far from major centers of population, to avoid the effects of light pollution . The ideal locations for modern observatories are sites that have dark skies,

1064-670: The field of radio astronomy to observe the Universe in the radio portion of the electromagnetic spectrum. Such an instrument, or collection of instruments, with supporting facilities such as control centres, visitor housing, data reduction centers, and/or maintenance facilities are called radio observatories . Radio observatories are similarly located far from major population centers to avoid electromagnetic interference (EMI) from radio , TV , radar , and other EMI emitting devices, but unlike optical observatories, radio observatories can be placed in valleys for further EMI shielding. Some of

1102-405: The harbour had changed so much that more recent tidal observations needed to be analysed, for which there were no funds. From 1893 daily observations of the magnetic declination were made at the observatory. In November 1887 Nevill was appointed also as Government Chemist and Official Assayer for Natal, which further reduced the time available for astronomical research. His chemical work was mainly of

1140-581: The nature, processes, ethics, and excitement of science. Membership is open to all. The South African Association for the Advancement of Science was founded in 1902 and modelled on the British Association for the Advancement of Science (BA), now known as the British Science Association . One of the most prominent scientists involved in the movement to establish S2A3 was Dr (later Sir) David Gill (1843–1914), director of

1178-567: The observatory until it was closed in 1911, following the incorporation of Natal into the Union (now the Republic ) of South Africa in 1910. He was assisted by, among others, the following persons: During the 1880s the discrepancies between the best available lunar tables (published by Hansen in 1857) and observations had become so large that navigators could no longer use the moon's position to determine their longitude accurately. Nevill tackled

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1216-483: The observatory, urging him to arrive in time to observe the transit. Nevill landed in Durban on 27 November and despite problems with the available equipment managed to observe the transit successfully. The Natal Observatory was initially equipped with a 200 mm Grubb equatorial refracting telescope donated by the Natal lawyer and politician Harry Escombe , a 75 mm Troughton & Simms transit instrument ,

1254-454: The problem by first verifying Hansen's treatment of lunar perturbations caused by the direct action of the sun . He then devised an improved method for calculating perturbations caused by Venus . The remaining errors he ascribed to the gravitational pull of the other planets, whose effects were very difficult to calculate. This work was published, among others, in a paper in the Memoirs of

1292-414: The surface of Earth, are used to make observations in the radio and visible light portions of the electromagnetic spectrum . Most optical telescopes are housed within a dome or similar structure, to protect the delicate instruments from the elements. Telescope domes have a slit or other opening in the roof that can be opened during observing, and closed when the telescope is not in use. In most cases,

1330-795: The world's major radio observatories include the Very Large Array in New Mexico , United States, Jodrell Bank in the UK , Arecibo in Puerto Rico , Parkes in New South Wales , Australia, and Chajnantor in Chile . A related discipline is Very-long-baseline interferometry (VLBI). Since the mid-20th century, a number of astronomical observatories have been constructed at very high altitudes , above 4,000–5,000 m (13,000–16,000 ft). The largest and most notable of these

1368-483: Was able to be serviced by the Space Shuttles while many other space telescopes cannot be serviced at all. Airborne observatories have the advantage of height over ground installations, putting them above most of the Earth's atmosphere. They also have an advantage over space telescopes: The instruments can be deployed, repaired and updated much more quickly and inexpensively. The Kuiper Airborne Observatory and

1406-601: Was held in Cape Town in 1903. Two years later the Association met jointly with the British Science Association in South Africa. A second joint meeting was held in South Africa in 1929. The annual meetings were discontinued in the nineteen-seventies, whereupon the Association's membership declined to its present level of around 100. The Association is governed by a National Council, consisting of

1444-487: Was ready for publication by the end of 1894, but no funds were available to have it printed. Each year Nevill urged the Natal government in his annual Report of the Government Astronomer to provide funds for publication, but to no avail. In his report for 1898 he wrote despairingly: The investigations of the errors in the lunar tables have been wrapped up in brown paper, tied up with red tape, and put away on

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