Samrat Yantra in Jantar Mantar, Delhi Observatory
Samrat Yantra or the king of instruments is the largest and the most imposing device in Jantar Mantar, the observatory of Delhi. It is used to measure the accurate time of day and also to measure the declination of the sun. It consists of a triangular indicator with the hypotenuse parallel to earth’s axis.
Built by Jai Singh II of Jaipur, Jantar Mantar is also called Delhi Observatory. It is located in the Parliament Street near Connaught Place. This observatory represents one of the last links with the old school of astronomy.