“Great Work of Astronomy”
Jantar Mantar was constructed by Maharaja Jai Singh II of Jaipur in 1724. It consists of 13 architectural astronomy instruments.
Maharaja Jai Singh who built this observatory went on to build other observatories in Jaipur, Ujjain, Varanasi and Mathura. Jai Singh had found the existing astronomical instruments too small to take correct measurements and so he built these larger and more accurate instruments.
Jantar Mantar of Delhi is an astronomical observatory with masonry instruments. The primary purpose of the observatory was to compile astronomical tables and to predict the times and movements of the sun, moon and planets. Some of these purposes nowadays would be classified as astronomy.
There are three instruments within the observatory:
Samrat Yantra: The Samrat Yantra, or Supreme Instrument, is a giant triangle that is basically an equal hour sundial. It is 70 feet high, 114 feet long at the base, and 10 feet thick. It has a 128-foot-long (39 m) hypotenuse that is parallel to the Earth's axis and points toward the North Pole. On either side of the triangle is a quadrant with graduations indicating hours, minutes, and seconds. At the time of the Samrat Yantra's construction, sundials already existed, but the Samrat Yantra turned the basic sundial into a precision tool for measuring declination and other related coordinates of various heavenly bodies.
Jayaprakash Yantra: The Jayaprakash consists of hollowed out hemispheres with markings on their concave surfaces. Cross wires were stretched between points on their rim. From here, an observer could align the position of a star with various markings or a window's edge.
Misra Yantra: The Misra Yantra was designed as a tool to determine the shortest and longest days of the year. It could also be used to indicate the exact moment of noon in various cities and locations regardless of their distance from Delhi – quite remarkable!
While the purpose of the Jantar Mantar is astronomy and astrology (Jyotish), they are also a major tourist attraction and a significant monument of the history of astronomy. It is located near to well know Connaught Place, one can easily reach at Jantar Mantar without much hassle. If you are visiting the national capital, do not miss to have a glimpse of Jantar Mantar-a beautiful creation of the Jaipur King Maharaja Jai Singh II.
Open: All Days, 9:30am to 4:30pm
Entry Fee: Rs. 5/- (Indians), Rs. 100/- (Foreigners)
Video camera fee: Rs. 25/-