Mishra Yantra
Mishra Yantra is an ancient instrument in Jantar Mantar constructed between 1724 and 1730. A total of five Jantar mantars were constructed across North India in Jaipur, Delhi, Ujjain, Varanasi, and Mathura. They are one of the four astronomical instruments of the Jantar Mantar observatory located in New Delhi, India. Each instrument at Jantar Mantar are architecturally constructed based on mathematical observations, and help calculate celestial objects and time. The Mishra Yantra (mixed instrument), is a compilation of five different instruments). Historical and cultural importance 
The Mishra (composite) Yantra is composed of five instruments. This Yantra is one of the special instruments in Delhi observatory. It is believed to have been constructed by Maharaja Madho Singh (1751–68), the son of Maharaja Sawai Jai Singh II. The five yantras are the Dakshinottar Bhitti, Samrat Yantra (a smaller version of the large sundial, attached to Mishra Yantra, in two halves), Niyat Chakra, Kark Rashivalaya, and the Western Quadrant. The Dakshinottar Bhitti was built in the Jaipur, Ujjain, Varanasi and Mathura observatories. It is a modified version of the Portable Meridian Dial present in Greek, Arabic, Hindu and European systems. The Dakshinottar Bhitti of the Mishra Yantra is in the form of a graduated semicircle located on the eastern wall. Notes

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Archaeoastronomy