Jantar Mantar is very popular among tourists and the people of Delhi. The structure is another great masterpiece of Indian architecture which shows the scientific acumen of ancient India. Jantar Manter is situated at Parliament Street, very close to Connaught Place. Jantar Mantar is also called Delhi Observatory. It is maintained by the Jaipur government because it was built by Maharaja Sawai Jai Singh II of Jaipur in 1710 A.D.
It is a remarkable structure which consists of fourteen geometric devices used for measuring time, forecasting weather changes, predicting behaviour of planets and finding extraterrestrial altitude. All these devices are fixed structures and point to a specific direction. The largest device or instrument is the Samrat Jantar which is 90 feet high and its shadow is plotted in such a manner so that is shows the exact time of the day. Any weather change or the onset of monsoons can be ascertained by the Hindu Chhatri, which is a small domed structure.
The whole structure is made of stone and marble with each of then having an engraved astronomical scale. Jantar Mantar finally got the status of a national monument in 1948. It has always attracted architects, historians and scientists from all over the world.
Maharaja Jai Singh was a fanatical astronomer himself who studied various works from Hindu, Muslim and European astronomy. He had the perception that the tables used by the pundits were deceptive and the actual planetary changes and predictions of eclipses would not have been possible through these measuring parameters. So he thought that he would find an improved and efficient means through which exact prediction could be made. It was his own inspiration and foresightedness that gave shape to such an instrument. He built other observatories at Jaipur, Ujjain, Benares and Mathura to have an exact calculation. It took almost seven years before the whole structure was fully operational because he wanted to be fully satisfied with the accuracy of the instruments at Jantar Mantar.
The Samrat Yantra 'Prince of Dials' (the largest device)
The Ram Yantra - two circular buildings
The Jai Prakash
The Misra Yantra (north-west to the Samrat Yantra)
Pillars on the southwest of Mishra Yantra used to measure the shortest and longest days of the year.
The Samrat Yantra measured the accurate time of the day. It also measured the declination of the sun which can be seen by the shadow moving around the structure.
The Jai Prakash shows the sun's position at the time of equinox. There is a hole near the bottom of the structure which witnesses sunshine only once in a year that is on 21 march, called vernal eqinox.
Another important structure called the Ram Yantra, consists of two large buildings with open top. Both these two buildings form a complete device. The device is used to measure the altitude of stars which is equivalent to the latitude and the longitude on the earth.
To the north-west of the Prakash Yantra, there is a structure or instrument called Mishra Yantra. It consists of five instruments. Pillars on the southwest of Mishra Yantra are used to measure the shortest day (21 December) and the longest day (21 June) of the year.
It is no denying the fact that the structure does represent the scientific heritage of India, though not being used in the modern scientific research. Having said that, we must give accreditation to the Jantar Mantar for its scientific acumen which could have reaped more fruits had there been appropriate motivation and resource given for research and development.