It was the year 1719, the illustrious rural of Jaipur Sawai Jai Singh II was witness to a noisy discussion in the court of Mughal Emperor Muhammad Shah. The heated debate regarded how to make astronomical calculations to determine auspicious date when the emperor could start journey. This discussion led Jai singh to think that the nation needed to educate on the subject of astronomy.
Astronomy however was maharaja’s real passion. He was a scholar, with a miscellaneous collection of astronomical manuscripts and tables from Arabia and Europe. He also acquired different kinds of telescopes from Europe, and started to research on observations using astrolabes and other instruments.
Five observatories were built at Delhi, Mathura, Varanasi, Ujjain and his own capital Jaipur, in between 1732 to 1734. Maharaja called these observatories Jantar-Mantars, and in Sanskrit it translates to ‘the formula of Instruments’. Relying primarily on Indian astronomy, these buildings were well equipped with drafting devices and grid indicators and used to accurately measured the planetary positions and read the time accurate to one second. Among five, Jaipur’s was big and still operational.
Jantar Mantar also consists some of the instruments designed by King Jai Singh II himself, like ‘Ram Yantra’, ‘Samrat Yantra’, and ‘Jai Prakash Yantra’.