Jantar Mantar

With foreign invasions and internal unrest, India in the 18th century had to endure one of the most chaotic periods in its entire history. Still, one man remained focused on the stars. Maharaja Sawaii Jai Singh II was a kingdom ruler with great interest in astronomy. Along with his political contributions, his legacy endures through the Jantar Mantar.

After witnessing an argument in the court of India’s Emperor on how to make astronomical calculations for travel, Jai Singh II sought to educate the country on astronomy. Between 1724 and 1730, he constructed five astronomical observatories, commonly known as Jantar Mantar, in the cities of Jaipur, Ujjain, Mathura, Varanasi, and Delhi – however, the Mathura observatory no longer stands.

The Jantar Mantar are known for their large-scale geometric forms, or instruments. When designing the observatories, Jai Singh wanted instruments that were more accurate than the popular brass ones at the time. Using stone and masonry, he included seven different types of instruments in the Jantar Mantar. To this day, their measurements of celestial movements remain unequalled.

The main instrument – “”Samrat Yantra”” – is an equinoctial sundial with a gigantic triangular gnomon (the part that casts the shadow) and the hypotenuse parallel to the Earth’s axis. On each side is the quadrant of a circle, parallel to the plane of the equator.

Now nearly 300 years old, the Jantar Mantar has survived history and time. Through the Archeological Survey of India, which aims to preserve India’s cultural heritage sites, the country is divided into 24 Circles, or regions, where protected monuments, including Delhi’s Jantar Mantar, can be regulated and restored when needed.