{{Short description|Observatory in Varnasi, India}}
{{Other uses|Jantar Mantar (disambiguation)}}
{{Use dmy dates|date=June 2016}}
{{Use Indian English|date=June 2016}}
{{Infobox historic site
| name = Jantar Mantar
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| image = Digansa Yantra.JPG
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| caption = Digansh Yantra
| pushpin_map = India
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| coordinates = {{coord|25.307721|83.010701|type:landmark_region:IN|display=inline, title}}
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| type = [[Observatory]]
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| location = [[Varanasi]], [[Uttar Pradesh]], India
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| elevation = {{cvt|75.6|m}}
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| founder = [[Jai Singh II|Maharaja Jai Singh II]]
| built = 1737
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'''Jantar Mantar''' in [[Varanasi]] is an [[observatory]] designed to be used with the naked eye. It is one of the five [[Jantar Mantar]] in India and was built in 1737 by [[Jai Singh II|Maharaja Jai Singh II]] of [[Amber, India|the Kingdom of Amber]] (later called [[Jaipur]]).[{{cite news|title=Coordinates|publisher=latlong.net|access-date=16 August 2015|url=http://www.latlong.net/|archive-date=7 August 2017|archive-url=https://web.archive.org/web/20170807151635/http://www.latlong.net/|url-status=dead}}]
- {{cite news|title=Altitude|publisher=daftlogic.com|access-date=16 August 2015|url=http://www.daftlogic.com/}}
- {{cite news|title=Places Of Interest|publisher=Varanasi.nic|access-date=16 August 2015|url=http://varanasi.nic.in/tourist/tourist4.html}}
- {{cite news |title=Jantar Mantar information |publisher=visitinvaranasi.com |access-date=16 August 2015 |url=http://www.visitinvaranasi.com/jantar-mantar-varanasi.aspx |url-status=dead |archive-url=https://web.archive.org/web/20150915155657/http://visitinvaranasi.com/jantar-mantar-varanasi.aspx |archive-date=15 September 2015 }}
- {{cite news|title=Jantar Mantar in Varanasi|publisher=hoteltravel.com|access-date=16 August 2015|url=http://www.hoteltravel.com/india/varanasi/jantar-mantar-in-varanasi.htm|archive-url=https://web.archive.org/web/20150924031405/http://www.hoteltravel.com/india/varanasi/jantar-mantar-in-varanasi.htm|archive-date=24 September 2015|url-status=dead}}[{{cite news|title=History|publisher=Varanasi.org|access-date=16 August 2015|url=http://www.varanasi.org.in/jantar-mantar-varanasi|archive-date=15 March 2016|archive-url=https://web.archive.org/web/20160315084810/http://www.varanasi.org.in/jantar-mantar-varanasi|url-status=dead}}]
- {{cite news|title=Jantar Mantar|publisher=[[Varanasi]] city website|access-date=16 August 2015|url=http://www.varanasicity.com/jantar-mantar.html}}
- {{cite news|title=About Jantar Mantar|publisher=holidayiq.com|access-date=16 August 2015|url=http://www.holidayiq.com/Jantar-Mantar-Varanasi-Sightseeing-588-2740.html|archive-date=9 January 2016|archive-url=https://web.archive.org/web/20160109172438/http://www.holidayiq.com/Jantar-Mantar-Varanasi-Sightseeing-588-2740.html|url-status=dead}}
==History==
[[Jai Singh II|Maharaja Jai Singh II]] was also an [[astronomer]] and had a deep interest in science and astronomy. In the early 18th century, he sent his scholars to several countries to study design, construction and technology of the observatories and also the prevalent technology. The scholars returned with their observations and many manuals on astronomy. Subsequently, between 1724 and 1737, [[Jai Singh II|Maharaja Jai Singh II]] had five [[observatory|observatories]] constructed in [[Jantar Mantar (Jaipur)|Jaipur]], [[Mathura]], [[Jantar Mantar, New Delhi|New Delhi]], [[Ujjain]] and in [[Varanasi]].[{{cite book|url=http://voiceofdharma.org/books/tbt/|title=Collected writing of Dharampal|volume=1|page=39}}] [[Sir Robert Barker, 1st Baronet|Sir Robert Barker]], in 1772, wrote that the observatory was built about 200 years before by Raja Mawnsing, son of Jaysing. He states, "The principal curiosity here is the observatory, built by Mawnsing, the son of Jysing, about 200 years ago; there is an exceedingly good mural arch cut upon a fine plaister of chunam, so fine and smooth, that it has the appearance of marble; and though it is certainly very old, it still is perfect, but the index is wanting; that is a loss which could very easily be supplied by a person who has a taste for these studies; for the centres are left in the wall." It clearly indicates that the observatory was built centuries before the British came to India.
A rather curious point arises here out of this chronology about the dating of the Benares observatory: [[Sir Robert Barker, 1st Baronet|Barker]] along with Pearse, and A. Campbell visited the observatory in 1772. If the observatory was actually built in 1737, it was only 35 years old at this date. Both Barker and Pearse specifically state that it had been there for some two centuries. They must have arrived at this statement after meeting and conversing with people who, if the observatory had been constructed only 35 years previously, must have been eyewitnesses to its construction. As there was no controversy in 1772 about the date of the construction of the observatory, it is inconceivable that Barker's informants misled him on this point. The conversion of two centuries into 35 years
is the most fabulous aspect of this controversy.
==Purpose==
Jantar Mantar was constructed with an aim of measuring [[Time zone|local time]], [[altitude]] (of the place) and also to measure [[Position of the Sun#Declination of the Sun as seen from Earth|declination of Sun]], [[star]]s and [[planet]]s and to determine [[eclipse]]s. Motion, speed and properties of stars and planets were also recorded using several special instruments.