The Jantar Mantar in Jaipur is the largest and one of the best preserved of five observatories constructed by Maharaja Sawai Jai Singh all over northern India. For being a reputed astronomer, Jai Singh was commissioned by Emperor Muhammad Shah, to correct the astronomical tables and to confirm the data that was available on the planetary positions. He took nearly seven years to finish the Jantar Mantar. It was restored in 1901 and in 1948 the famous observatory was declared a national monument. The Jantar Mantar observatory in Jaipur constitutes the most significant and best preserved set of fixed monumental instruments built in India in the first half of the 18th century; some of them are the largest ever built in their categories. Designed for the observation of astronomical positions with the naked eye, they embody several architectural and instrumental innovations. The observatory forms part of a tradition of Ptolemaic positional astronomy which was shared by many civilizations. It contributed by this type of observation to the completion of the astronomical tables of Zij. It is a late and ultimate monumental culmination of this tradition.
Through the impetus of its creator, the prince Jai Singh II, the observatory was a meeting point for different scientific cultures, and gave rise to widespread social practices linked to cosmology. It was also a symbol of royal authority, through its urban dimensions, its control of time, and its rational and astrological forecasting capacities. The observatory is the monumental embodiment of the coming together of needs which were at the same time political, scientific, and religious.
History – During early 18th century, Jaipur was ruled by Maharaja Sawai Jai Singh II who was also the founder of Jaipur. He was a very brilliant astrologer who loved to study philosophy, astrology and architecture. In 1718, the king desired to build an observatory on renown. So he thoroughly studied the subject of astronomy and then started this task. It took him seven years to complete this task. He constructed five different observatories in North India including Jaipur, New Delhi, Ujjan, Varanasi and Mathura. The first stone observatory was constructed in 1724 in Delhi. He built The Jaipur observatory of Rajasthan in 1728. Along with other scholarly astronomers, such as Pt. Kedarnath, He utilized these places for astronomical observations. Being the largest stone observatory in India, the Jantar Mantar at Jaipur has been renovated and again. The place contains several instruments which are used for time measurement, the azimuth, sun declination and much more. The Jaipur observatory was functional for seven years only, as the Maharaja was not very successful in deriving accurate, astronomical observations. The sad thing is that Jantar Mantar at Jaipur was active for just seven years as the King could not derive accurate astronomical calculations and observations.