Jayaprakāśa-yantra





A Jayaprakasa-yantra, or Jai Prakash Yantra, is an instrument of astronomy.

Some say it was invented by Sawai Jai Singh, the famous builder of observatories in the 1700s AD.

Hartley says that the yantra can be used for finding the celestial latitude and longitude of the Sun. There are actually two Jayaprakasa at Jaipur; the red portions are passageways where an astronomer could stand to closely examine the shadow, and one Jaya was the reversed-image of the other.