{{Short description|Five early C18 observatories in India}} {{Other uses|Jantar Mantar (disambiguation)}} {{Use dmy dates|date=June 2016}} {{Use Indian English|date=June 2016}} [[File:Jantar Mantar at Jaipur.jpg|thumb|[[Jantar Mantar (Jaipur)|Jantar Mantar]] in [[Jaipur]]]] [[File:Prakash Yantra Jantar Mantar Jaipur.jpg|thumb|Jai Prakash Yantra Jantar Mantar Jaipur]] [[File:Jantar Mantar at Jaipur - 1928.JPG|thumb|[[Jantar Mantar (Jaipur)|Jantar Mantar]] in [[Jaipur]]. 1928]] [[File:Jantar Mantar Delhi 27-05-2005.jpg|thumb|[[Jantar Mantar (Delhi)|Jantar Mantar]] in [[New Delhi]]]] A '''''Jantar Mantar''''' (जंतर मंतर, [[Hindustani language|Hindustani]] pronunciation: [[Help:IPA/Hindi and Urdu|[d͡ʒən̪t̪ər mən̪t̪ər]]] ‘calculation instruments’) is an assembly of stone-built astronomical instruments, designed to be used with the naked eye. There were five Jantar Mantars in [[India]], built between 1724 and 1735. All were built at the command of the [[Sawai Jai Singh II]], who had a keen interest in [[mathematics]], [[architecture]] and [[astronomy]]. A total of five ''Jantar Mantars'' were constructed across North India: [[Jantar Mantar, Jaipur|Jaipur]], [[Jantar Mantar, New Delhi|Delhi]], [[Jantar Mantar, Ujjain|Ujjain]], [[Jantar Mantar, Varanasi|Varanasi]], and [[Mathura]] (the last of which no longer exists).{{cite journal |last=Sharma |first=Virendra Nath |year=1994 |title=Míshra Yantra of the Delhi observatory |journal=Indian Journal of History of Science |volume=29 |issue=3 |pages=477–487 |issn=0019-5235 }} These compilations or ''[[Mishra Yantra]]'' (‘mixed instruments’) gather up to 19 different [[List of astronomical instruments|astronomical instruments]].{{refn|group=note|The four instruments of Jantar Mantar are Samrat Yantra (a large [[sundial]] for calculating time), Jay Prakash Yantra (2 [[Lens (optics)#Types of simple lenses|concave]] [[hemispherical]] structures, used to ascertain the position of Sun and other heavenly bodies), Ram Yantra (two large [[cylindrical]] structures with open top, used to measure the altitude of stars based on the [[latitude]] and the [[longitude]] on the earth). }} The largest example is the [[equinox|equinoctial]] [[sundial]] belonging to [[Jantar Mantar, Jaipur|Jaipur]]'s assembly of instruments, consisting of a gigantic triangular [[gnomon]] with the [[hypotenuse]] parallel to the [[Earth]]'s [[Axial tilt|axis]]. On either side of the gnomon is a [[Circular sector|quadrant]] of a circle, parallel to the plane of the [[equator]]. The instrument can be used with an accuracy of about 20 seconds by a skilled observer to determine the time of day, and the [[declination]] of the [[Sun]] and the other [[Astronomical object|heavenly bodies]]. It is the world's largest stone sundial, and is known as the Samrat Yantra.{{cite book|last1=Smithsonian|title=Timelines of Science|year=2013|publisher=Penguin|isbn=978-1465414342|page=136}}Archaeological Survey of India, various authors, Nomination of The Jantar Mantar, Jaipur, for inclusion on World Heritage list, p.14 [https://whc.unesco.org/uploads/nominations/1338.pdf]The Jaipur Jantar Mantar is a [[UNESCO]] [[World Heritage Site]].[https://whc.unesco.org/en/list/1338/ Unesco listing for Jantar Mantar] accessed July 30 2021 ==History== [[Image:Vedh Shala, Ujjain 01.jpg|thumb|The [[Sundial|Sun Dial]] at the Vedh Shala in [[Ujjain]]]] In the early 18th century, [[Sawai Jai Singh]] of [[Jaipur]] constructed five Jantar Mantar in total, in [[Jantar Mantar, New Delhi|New Delhi]], [[Jantar Mantar, Jaipur|Jaipur]], [[Jantar Mantar, Ujjain|Ujjain]], [[Mathura]] and [[Jantar Mantar, Varanasi|Varanasi]]; they were completed between 1724 and 1735. The observatory at Mathura and the fort that protected it were destroyed before 1857.{{Cite web|url=http://www.jantarmantar.org/learn/observatories/sites/index.html|title=The Observatory Sites|access-date=2024-01-29|language=en}} As part of Jantar Mantar there were many instruments like Samrat Yantra, Jai Prakash Yantra, Disha Yantra, Rama Yantra, Chakra Yantra, Rashiwalya Yantra, Dingash Yantra and Utaansh Yantra. The primary purpose of the instruments was to compile astronomical tables and to predict the times and movements of the [[Sun]], [[Moon]] and [[Planet|Planets]]. ==Name== The name "Jantar Mantar" is at least 200 years old, being mentioned in an account from 1803. However, the archives of [[Kingdom of Amber]], such as accounts from 1735 and 1737–1738, do not use this as ''Jantra'', which in the spoken language is corrupted to ''Jantar''. The word ''Jantra'' is derived from ''[[yantra]]'', meaning instrument, while the suffix ''Mantar'' is derived from mantrana meaning consult or calculate. ==See also== *[[Jantar Mantar, Jaipur]] *[[Jantar Mantar, New Delhi]] *[[Jantar Mantar, Varanasi]] *[[Jantar Mantar, Ujjain]] *[[List of archaeoastronomical sites by country]] *[[List of astronomical observatories]] *[[Yantra]] *[[Mantra]] == Notes == {{reflist|group=note}} ==References== {{Reflist|refs= {{citation | last = Sharma | first =V‌irendra Nath | year = 1995 | pages = 98–99 | title = Sawai Jai Singh and His Astronomy | publisher = Motilal Banarsidass Publishers Pvt. Ltd. | isbn = 81-208-1256-5 | url = https://books.google.com/books?id=QRA2mgZnXXMC&pg=PA98 }} }} * {{citation |author=Anisha Shekhar Mukherji |title=Jantar Mantar: Maharaja Sawai Jai Singh's Observatory in Delhi |url=https://books.google.com/books?id=QyI6tKjRhdgC |access-date=23 July 2013 |year=2010 |publisher=Ambi Knowledge Resource |isbn=978-81-903591-1-5}} ==External links== {{commons category|Jantar Mantars}} * [http://www.jantarmantar.org/ Jantar Mantar - The Astronomical Observatories of Jai Singh II], "a project initiated by [[Cornell University]] Professor of Art, Barry Perlus" * [http://perso.orange.fr/cadrans.solaires/cadrans/cadrans-jaipur.html Pictures with French text] * [http://7thtraveler.com/jantar-mantar-jaipur-history-timings-entry-fee-images-information/ Jantar Mantar Jaipur Timings, Entry Fee] * [https://www.bbc.com/travel/article/20220530-jantar-mantar-indias-mysterious-gateway-to-the-stars India's mysterious gateway to the stars] [[BBC_Online#International-only_site|BBC Travel]] (2022-05-31) {{Indian astronomy}} {{Telescopes and Observatories in India}} {{Indian mathematics}} {{Portal bar|India|Astronomy|Stars|Spaceflight|Outer space|Solar System|Education|Science}} {{Coord|26|55|28|N|75|49|29.5|E|source:dewiki_region:IN|display=title}} [[Category: Ancient astronomical observatories]] [[Category: Archaeoastronomy]] [[Category: Astronomical observatories in India]] [[Category: Buildings and structures in Delhi]] [[Category: History of science and technology in India]] [[Category: Rajput architecture]]