This Jantar Mantar observatory of New Delhi had different instruments named as the Samrat Yantra, Mishra Yantra, Jayaprakash yantra, and Ram yantra.
Samrat Yantra: With sundial of equal hour, a giant triangle shaped yantra is said to be Samrat Yantra. The basic height of this yantra is about 70 feet along with length 114 feet, and breadth 10 feet. This yantra is attached with the hypotenuse that has a length of 128 foot present parallel to the axis of earth and pointed to the North Pole. There is quadrant in association with graduation on both sides that indicates hours, minutes, and seconds. There is one sundial that already existed at the time of construction of Samrat yantra, but this was changed into a precision tool for the measurement of declination and for associated bodies of heaven.
Jayaprakash Yantra:This yantra of Jayaprakash is made up of hemispheres that are hollow having different markings on the surface concave. On the rim, all the points were stretched crosswire. From the yantra of Ram, different markings were made on the edge of window, setting position of a star by the observer.
Misra Yantra:In order to detrmine the year’s shortest and longest day, this Misra Yantra was designed. To determine the actual noon moment in different cities by detecting distance from Delhi, this Yantra is used. This yantra was not the invention of Jail Singh II and it is used to determine the time of noon in different cities in the whole world.