Innovations in Architectural Astronomy: The Jantar Mantar Observatory

Jantar Mantar is a huge observatory in Delhi. It was completed in 1724 by Maharaja Jai Singh II of Jaipur, who was fascinated by the movement of celestial bodies.

The Maharaja designed four similar observatories in Jaipur, Ujjain, Mathura and Varanasi to help and improve upon the studies of space and time. The Jantar Mantar in Jaipur is now the largest among them.

This particular view is from the Man Singh Observatory in Varanasi.

The Jantar Mantar was used for the observation of astronomical positions with the naked eye, a part of the tradition of the Ptolemaic positional astronomy, which was a common practice in 18th-century society.

The Delhi monument, red in colour, comprises of 13 architectural astronomy instruments that could be used to predict the timings and movements of the sun, moon and planets by charting astronomical tables.

Jantar Mantar's striking combinations of geometric forms have caught the attention of architects, artists and art historians from around the world.

On a visit to the Jantar Mantar in Delhi, the top four instruments that should not be missed are:
- the Ram yantra, used to observe celestial objects
- the Samrat yantra, an enormous sundial
- the Jai Prakash yantra, two elaborate hemispherical sundials
- the Misra yantra, which is a composite of five instruments

The two large open-top cylindrical structures of the Ram yantra are used to measure the altitude of stars based on the Earth’s latitude and longitude.

The Samrat yantra stands parallel to the Earth's axis, and is a large hour sundial that helps tell the time.

The Jai Prakash yantra are two highly innovative hemispherical structures and used for aligning the positions of stars to markings.

Meanwhile, the Misra yantra is used to determine the shortest and the longest days of the year.

All of these instruments have been made out of brick and rubble, and plastered with lime, and must be repaired from time to time.

When visiting the Man Singh Observatory in Varanasi, you can even enjoy a beautiful view of River Ganges, stretching into the distance.