Jantar Mantar, Jaipur

The name jantar is derived from "yantra" a Sanskrit word, meaning "instrument, machine", and mantar from "mantrana" also a Sanskrit word meaning "consult, calculate").{{cite web|last1=mantraNa, yantra|title=Sanskrit - English Dictionary|url=http://spokensanskrit.de/index.php?script=HK&beginning=0+&tinput=&trans=Translate&direction=AU|website=Spoken Sanskrit Germany|publisher=Koln University|access-date=15 April 2015}} Therefore, Jantar Mantar literally means 'calculating instrument'.

File:Jaipur, Jantar Mantar, Brihat Samrat Yantra (9713595658).jpg

Jai Singh noticed that the Zij, which was used for determining the position of celestial objects, did not match the positions calculated on the table. He constructed five new observatories in different cities in order to create a more accurate Zij. The astronomical tables Jai Singh created, known as the Zij-i Muhammad Shahi, were continuously used in India for a century. (However, the table had little significance outside of India.) Also, it was used to measure time.{{Cite book|title=Sawai Jai Singh and his astronomy|last=Nath.|first=Sharma, Virendra|date=2016|publisher=Motilal Banarsidass Publishers|others=Jai Singh II, Maharaja of Jaipur, 1686-1743.|isbn=978-81-208-1256-7|edition= 2nd|location=Delhi|oclc=32699670}}

Exactly when Raja Jai Singh began construction in Jaipur is unknown, but several instruments had been built by 1728, and the construction of the instruments in Jaipur continued until 1738. During 1735, when construction was at its peak, at least 23 astronomers were employed in Jaipur, and due to the changing political climate, Jaipur replaced Delhi as Raja Jai Singh's main observatory and remained Jai Singh's central observatory until his death in 1743. The observatory lost support under Isvari Singh (r.1743-1750) because of a succession war between him and his brother. However, Mado Singh (r. 1750–1768), Isvari Singh's successor, supported the observatory, although it did not see the same level of activity as under Jai Singh. Although some restorations were made to the Jantar Mantar under Pratap Singh (r.1778-1803), activity at the observatory died down again. During this time, a temple was constructed and Pratap Singh turned the site of the observatory into a gun factory.{{Cite journal |last=Johnson-Roehr |first=Susan N. |date=2014 |title=Observatories of Sawai Jai Singh II |url=https://www.academia.edu/43023913/Observatories_of_Sawai_Jai_Singh_II |journal=Handbook of Archaeoastronomy and Ethnoastronomy |pages=2017}}

File:Bhairav Temple Jantar Mantar Jaipur.jpg

Ram Singh (r. 1835–1880) completed restoring the Jantar Mantar in 1876, and even made some of the instruments more durable by inserting lead into the instruments' lines and using stone to restore some of the plaster instruments. However, the observatory soon became neglected again, and was not restored until 1901 under Madho Singh II (r. 1880–1922)

File:Ecliptic equator galactic anim.gif

File:Kapali Yantra.jpg

File:Laghu samrat yantra.JPG

The observatory consists of nineteen instruments for measuring time, predicting eclipses, tracking location of major stars as the Earth orbits around the Sun, ascertaining the declinations of planets, and determining the celestial altitudes and related ephemerides. The instruments are (alphabetical):

1. Chakra Yantra (four semicircular arcs on which a gnomon casts a shadow, thereby giving the declination of the Sun at four specified times of the day. This data corresponds to noon at four observatories around the world (Greenwich in UK, Zurich in Switzerland, Notke in Japan and Saitchen{{clarify|date=August 2021}} in the Pacific); this is equivalent of a wall of clocks registering local times in different parts of the world.){{cite book|last1=David Kelly|title=Exploring Ancient Skies: A Survey of Ancient and Cultural Astronomy|date=2011|publisher=Springer|isbn=978-1441976239|page=82}}
2. Dakshin Bhitti Yantra (measures meridian, altitude and zenith distances of celestial bodies)
3. Digamsha Yantra (a pillar in the middle of two concentric outer circles, used to measure azimuth of the sun and to calculate the time of sunrise and sunset forecasts){{cite book|last1=Lindsay Brown|title=Rajasthan, Delhi & Agra|date=2008|isbn=978-1741046908|page=157}}
4. Disha Yantra (used to detect the direction)
5. Dhruva Darshak Pattika (observe and find the location of pole star with respect to other celestial bodies)
6. Jai Prakash Yantra (two hemispherical bowl-based sundials with marked marble slabs that map inverted images of sky and allow the observer to move inside the instrument; measures altitudes, azimuths, hour angles, and declinations)
7. Kapali Yantra (measures coordinates of celestial bodies in azimuth and equatorial systems; any point in sky can be visually transformed from one coordinate system to another)
8. Kanali Yantra
9. Kranti Vritta Yantra (measures longitude and latitude of celestial bodies)
10. Laghu Samrat Yantra (the smaller sundial at the monument, inclined at 27 degrees, to measure time, albeit less accurately than Vrihat Samrat Yantra)
11. Misra Yantra (meaning mixed instrument, it is a compilation of five different instruments)
12. Nadi Valaya Yantra (two sundials on different faces of the instrument, the two faces representing north and south hemispheres; measuring the time to an accuracy of less than a minute)
13. Palbha Yantra
14. Rama Yantra (an upright building used to find the altitude and the azimuth of the Sun)
15. Rashi Valaya Yantra (12 gnomon dials that measure ecliptic coordinates of stars, planets and all 12 constellation systems)
16. Shastansh Yantra (next to Vrihat Samrat Yantra) This instrument has a 60-degree arc built in the meridian plane within a dark chamber. At noon, the Sun's pinhole image falls on a scale below enabling the observer to measure the zenith distance, declination, and the diameter of the Sun.){{cite book|last1=Andreas Volwahsen|title=Cosmic architecture in India|date=2001|publisher=Prestel|isbn=978-3791325064|pages=48–73}}
17. Unnatamsa Yantra (a metal ring divided into four segments by horizontal and vertical lines, with a hole in the middle; the position and orientation of the instrument allows measurement of the altitude of celestial bodies) File:Unnatamsa Yantra.jpg
18. Vrihat Samrat Yantra (world's largest gnomon sundial, measures time in intervals of 2 seconds using shadow cast from the sunlight)
19. Yantra Raj Yantra (a 2.43-metre bronze astrolabe, one of the largest in the world, used only once a year, calculates the Hindu calendar){{cite book|last1=SC Bhatt|title=Land and People of Indian States and Union Territories|date=2006|isbn=978-8178353791|page=362}} File:Yantra Raj.jpg

The Vrihat Samrat Yantra, which means the "great king of instruments", is {{convert|88|ft|m}} high, making it one of the world's largest sundials. {{cite news|title=Largest sundial world record|url=http://www.heraldo.es/noticias/aragon/zaragoza_provincia/zaragoza/2013/10/01/el_gigante_del_tiempo_vadorrey_guinness_world_record_251195_301.html}} Its face is angled at 27 degrees, the latitude of Jaipur. It is purported to tell the time to an accuracy of about two seconds in Jaipur local time.{{cite web |url=http://www.jantarmantar.org/Architecture_Science_web.pdf |title=Architecture in the Service of Science: The Astronomical Observatories of Jai Singh II |author=Barry Perlus |publisher=Jantarmantar.org |access-date=2012-11-11 |archive-date=5 February 2009 |archive-url=https://web.archive.org/web/20090205014353/http://jantarmantar.org/Architecture_Science_web.pdf |url-status=dead }} Its shadow moves visibly at 1 mm per second, or roughly a hand's breadth (6 cm) every minute, The Hindu chhatri (small cupola) on top is used as a platform for announcing eclipses and the arrival of monsoons.

File:JaiPrakashYantraJaipur20080213-3.jpg

The instruments are in most cases huge structures. The scale to which they have been built has been alleged to increase their accuracy. However, the penumbra of the sun can be as wide as 30 mm, making the 1mm increments of the Samrat Yantra sundial devoid of any practical significance. Additionally, the masons constructing the instruments had insufficient experience with construction of this scale, and subsidence of the foundations has subsequently misaligned them.{{citation needed|date=August 2023}}

File:Jantar Mantar in Jaipur giant sundial.jpg

Built from local stone and marble, each instrument carries an astronomical scale, generally marked on the marble inner lining. Bronze tablets, bricks and mortar were also employed in building the instruments in the monument spread over about 18,700 square metres. It was in continuous use until about 1800, then fell in disuse and disrepair. Restored again several times during the British colonial rule, particularly in 1902, the Jantar Mantar was declared a national monument in 1948. It was restored in 2006. The restoration process in early 20th century replaced some of the original materials of construction with different materials.

Jantar Mantar is managed under the Archeological Sites and Monuments Act of Rajasthan since 1961, and protected as a National Monument of Rajasthan since 1968.[http://museumsrajasthan.gov.in/pdf/rules.pdf THE RAJASTHAN MONUMENTS ARCHAEOLOGICAL SITES AND ANTIQUITIES RULES, 1968]

The Vedas mention astronomical terms, measurement of time and calendar, but do not mention any astronomical instruments. The earliest discussion of astronomical instruments, gnomon and clepsydra, is found in the Vedangas, ancient Sanskrit texts.{{cite book|last1=David Edwin Pingree|title=A History of Indian Literature, Vol 6|date=1981|publisher=Otto Harrassowitz Verlag|isbn=978-3447021654|pages=52–54}} The gnomon (called Śaṅku, शङ्कु){{cite web|last1=gnomon|title=Sanskrit - English Dictionary|url=http://spokensanskrit.de/index.php?script=HK&beginning=0+&tinput=&trans=Translate&direction=AU|website=Spoken Sanskrit Germany|publisher=Koln University|access-date=15 April 2015}} found at Jantar Mantar monument is discussed in these first millennium BCE Vedangas and in many later texts such as the Katyayana Sulbasutras. Other discussions of astronomical instruments are found in Hinduism texts such as the fourth century BCE Arthashastra, Buddhist texts such as Sardulakarna-avadana, and Jainism texts such as Surya-prajnapti. The theories behind the instruments are found in texts by the fifth century CE Aryabhatta, sixth century CE Brahmagupta and Varahamihira, ninth century Lalla, eleventh century Sripati and Bhaskara. The texts of Bhaskara have dedicated chapters on instruments and he calls them Yantra-adhyaya.

The theory of chakra-yantra, yasti-yantra, dhanur-yantra, kapala-yantra, nadivalaya-yantra, kartari-yantra, and others are found in the ancient texts.

The full extent of how Jai Singh's instruments were used for astronomical observation remains unclear. While the instruments themselves were impressive, there is limited evidence of a dedicated observational program or a team of trained astronomers. This raises the question of whether the observatory's primary purpose was purely scientific or also served other symbolic or cultural functions.

The Zij Muhammad-Shahi, an astronomical handbook compiled under Jai Singh's patronage, does not appear to rely heavily on data collected from his observatories. Instead, it primarily utilizes existing tables from sources like the Zij-i Ulugh Beg and Philippe de la Hire's astronomical tables. The Zij Muhammad-Shahi essentially adapts these tables by incorporating adjustments for the precession of the equinoxes and the difference in longitude between Paris and Delhi.{{Cite journal |last=Yavari Ayin |first=Mostafa |year=2023 |title=Defenseless eyes against the sky. A narrative of some astronomical observations before the invention of the telescope |journal=Nojum Magazine [Iranian Magazine of Astronomy] |volume=32 |issue=04 |pages=36-41}}

It was used as a filming location for the 2006 film The Fall as a maze.

Storm Thorgerson photographed the sundial for the cover of Shpongle's DVD, Live at the Roundhouse 2008.{{cite web |url=http://www.twistedmusic.com/news/news_shpongle_live_in_concert_twsdvd002/ |title=Twisted Music |publisher=Twisted Music |date=2009-10-23 |access-date=2012-11-11 |url-status=dead |archive-url=https://web.archive.org/web/20120220113633/http://www.twistedmusic.com/news/news_shpongle_live_in_concert_twsdvd002/ |archive-date=20 February 2012 |df=dmy-all }}

It was photographed by Julio Cortázar with the collaboration of Antonio Gálvez for the book Prosa del Observatorio (Editorial Lumen: Barcelona, 1972).

; General

• Jantar Mantar
• Yantra
• Mantra
• Tantra
• Gyarah Sidi
• UNESCO Intangible Cultural Heritage Lists

; Research stations

• Indian Antarctic Program
• Bharati (research station)
• Dakshin Gangotri First Indian station 1983, converted to support base
• Maitri Second Indian station 1989
• Defence Research and Development Organisation
• Defence Institute of High Altitude Research
• Indian Astronomical Observatory
• National Centre for Polar and Ocean Research
• Siachen Base Camp (India)
• List of Antarctic research stations
• List of Antarctic field camps
• List of astronomical observatories
• List of highest astronomical observatories

{{Reflist}}

• Sharma, Virendra Nath and Aditya Sharma (1995). [https://books.google.com/books?id=QRA2mgZnXXMC Sawai Jai Singh and his astronomy]. Motilal Banarsidass Publishers Pvt. Ltd. {{ISBN|81-208-1256-5}}.

{{Commons category|Jantar Mantar (Jaipur)}}

• [http://museumsrajasthan.gov.in/mounment_Jantar-Mantar.htm Official website of Rajasthan government, India], Jantar Mantar
• [https://web.archive.org/web/20161220201045/http://www.math.nus.edu.sg/aslaksen/gem-projects/hm/0203-1-07-jantar_mantar.pdf Jantar Mantar - Section III] Theory, Construction and Limitations, National University of Singapore
• [https://web.archive.org/web/20161104173817/http://www.panoramio.com/user/4942042/tags/Jantar%20mantar%20jaipur Photos of Jantar Mantar]
• [https://web.archive.org/web/20151210085654/http://www.bomhard.de/englisch/jaipur/00.html Jantar Mantar (Jaipur)]
• [http://www.jantarmantar.org Jantar Mantar] Articles and History
• [http://www.jantarmantar.org/Architecture_Science_web.pdf Architecture in the Service of Science] {{Webarchive|url=https://web.archive.org/web/20090205014353/http://jantarmantar.org/Architecture_Science_web.pdf |date=5 February 2009 }}
• [https://www3.astronomicalheritage.net/index.php/show-entity?idunescowhc=1338 The Jantar Mantar at Jaipur, India] at {{url|www3.astronomicalheritage.net}}
• {{OSM|n|542886857}}

{{World Heritage Sites in India}}

{{Indian mathematics}}

{{Indian astronomy}}

{{Telescopes and Observatories in India}}

{{Authority control}}

{{Portal bar|India|Astronomy|Stars|Spaceflight|Outer space|Solar System|Education|Science}}

Category:Tourist attractions in Jaipur

Category:World Heritage Sites in India

Category:History of science and technology in India

Category:1738 establishments in India

Category:Rajput architecture

Category:Ancient astronomical observatories

Category:Astronomical observatories in India

Category:Buildings and structures in Jaipur