A unique structure raised in 1724, now lies in the heart of Delhi's commercial centre near Connaught place. This is the Jantar Mantar, one of several astronomical observatories raised by Maharaja Jai Singh II of Jaipur. The various abstract structures within the Jantar Mantar are, in fact, instruments that were used for keeping track of celestial bodies.

Yet, Jantar Mantar is not only a timekeeper of celestial bodies, it also tells a lot about the technological achievements under the Rajput kings and their attempt to resolve the mysteries regarding astronomy. The Jantar Mantar of Delhi is only one of the five observatories built by Sawai Jai Singh II, the other four being located at Jaipur, Varanasi, Ujjain and Mathura.

All of these were built as far back as AD 1724-1730 during the period generally known as the dark age of Indian history, when the last great Mughal emperor Aurangzeb had died and the Mughal Empire was rapidly declining. During this period of turmoil, Muhammad Shah ascended the throne of the Mughal Empire.
As many enemies surrounded him, he sought the alliance of the Hindu rulers. Of these, the most notable was Sawai Jai Singh II of Amber, who came into limelight since the days of Aurangzeb. When Jai Singh ascended the throne of Amber in 1699, he was barely eleven, but sharp and shrewd far beyond his years. The then Mughal emperor Aurangzeb was so impressed with the young ruler that he gave Jai Singh II the title of 'Sawai', meaning one and a quarter of an average man in worth.

As Jai Singh repeatedly proved himself a worthy ally of the Mughals, Muhammad Shah, who was seeking a dependable ally, zeroed in on Jai Singh and duly raised him to the rank of governor of Agra and later, of Malwa. Legend Behind Jantar Mantar Jai Singh was passionate about two things-arts and the sciences, chiefly astronomy.
Once, at the court of Muhammad Shah, he found the Hindu and Muslim astrologers embroiled in a heated argument over certain planetary positions. It was imperative that the positions be known accurately to determine an auspicious hour for the emperor to set out on an expedition. Jai Singh offered to rectify the then available astronomical tables, an offer that was readily accepted by the Mughal emperor.

The result was an onsite Jantar Mantar in Delhi, an astronomical observatory where the movements of sun, moon and planets could be observed.

Jai Singh's idea was to create a rebirth of practical astronomy among the Indian masses and practicing astronomers. However, the lofty ideals of the Jantar Mantar remained unfulfilled as the country at that time was in chaos and the full potential of this observatory was never realized. In the beginning, Jai Singh tried to use brass instruments in this observatory, but soon gave them up because of several inherent flaws. They were too small, for one thing, their axes were unstable so the center often got displaced. He then decided to follow the style adopted by the renowned Arab astronomer, Prince Ulugh Beg, builder of the famous 15th century observatory at Samarkand, Uzbekistan. The massive masonry instruments at Samarkand suited Jai Singh's architectural tastes and promised to be more accurate because of sheer size. In 1730, Jai Singh sent a mission to the king of Lisbon. On its return to Jaipur, the mission brought back a telescope and the court astronomer by the name of Xavier de Silva. The Observatory This unique observatory was completed in 1724 and remained operational only for seven years.

Astronomical observations were regularly made over here and these observations were used for drawing up a new set of tables, later compiled as Zij Muhammad Shahi dedicated to the reigning monarch. Jai Singh named his observatory Jantar Mantar, which is actually pronounced, as 'Yantra Mantra', yantra for instrument and mantra for formula. A huge sundial known as "Samrat Yantra" or 'Prince of Dials', meant to measure accurate time of the day within half a second and the declination of the sun and other heavenly bodies dominates it.

Jai Singh himself designed this yantra. Other yantras were also meant for the study of heavenly bodies, plotting their course and predicting eclipses. The two pillars on the southwest of Mishra Yantra are meant to determine the shortest and longest days of the year. Interestingly, in December one pillar completely covers the other with its shadow while in June it does not cast any such shadow at all. After the completion of the first Jantar Mantar and with a view to verifying astronomical observations made at Delhi, Jai Singh built similar, even if smaller observatories, at other important Indian cities-Jaipur, Varanasi, Ujjain, and Mathura. The Jantar Mantars may have fallen into disuse but they remain an integral part of India's scientific heritage. It presents that the spirit of scientific enquiry was not dead in India and would have yielded rich results if only an opportunity of research and development had been given to it. This monument situated just a stroll away on the Parliament Street, still remains one of the most intriguing structures of the capital, one that burst in a flood of questions inside the curious mind of the tourist. Timing : Daily 9.00am - 7.00pm.