There have been many instances of use of telescopes for observing astronomical events in India through the eighteenth century. The Century saw some significant, even though sporadic, efforts in astronomy in terms of facilities, literature and observations, and in related sciences. The most notable beginning was made when, at the instance of the then Mughal Emperor Muhammad Shah (r. 1719-48), the king Sawai Jai Singh II (1688-1743) of Amber built an observatory at Delhi in 1724. This was followed by similar structures at Varanasi (probably a renovation of an old observatory), Mathura, Ujjain and Jaipur with unique, large-sized instruments of masonry, stone and metal to measure time and angles. The observatories were patterned after Ulugh Beg’s at Samarkand. ‘From the observations made in this observatory, the celebrated Astronomical Tables, known by the name of Muhammad Shah, were drawn up by Mirza Khairullah and Shaikh Muhammad Muhaddis, under the supervision of Jai Singh, and the accuracy of the Tables was proved by the conjunction of two planets in 1154 A.H. (1741 A.D.) as recorded therein. In the observatory at Delhi there is a big equatorial dial which for its accuracy and magnitude was called Samrat Jantra by Jai Singh himself. The gnomons and the periphery of the circle are marked with degrees for determining altitudes and azimuths of the heavenly bodies. Besides this, there are two circular buildings open at the top and a small altitude-meter’ (quote from Law N N 1916 Promotion of learning in India during Muhammadan rule). At the Delhi vedhshala, Jai Singh had determined in 1729 the obliquity of the ecliptic at 23°28′.

Sawai Jai Singh II was a great scholar of mathematics and astronomy. He had made observations with a glass telescope also, acquired standard Persian and European monographs on sciences, and initiated their translations to Sanskrit from Persian. The astronomical treatises and tables that he received from Arabia and Europe included Pere de la Hire`s Tabulae Astronomicae, Historia Coelestis Britannica by John Flamsteed and Ulugh Beg`s tables Zij Ulugh Begi. Pandit Jagannatha Samrat (1652- 1744) who was his chief court astronomer translated the classic works, Tahrir al-Majisti (Nasir al-Din al-Tusi’s recension of Ptolemy’s Almagest) and Elements of Euclid, from their Arabic versions into Sanskrit that were given Sanskrit names as Siddhanta Sara Kaustubha and RekhaGanita respectively. The work Samrat Siddhanta was his own. Availability of the western knowledge subsequently led scholars to write monographs in Persian on the European sciences, particularly astronomy. Jai Singh’s endeavours died out with him. Notably, his observatory at Delhi suffered severe damage in 1764 at the hands of Jawahar Singh, son of the king Suraj Mal of Bharatpur as he plundered Delhi while the one at Jaipur (itself founded by him in 1727), that was completed in 1734, was converted by his grandson Pratap Singh into a gun factory for casting and boring cannons. An extensive restoration work of the Jaipur Observatory was taken up in 1901-02 by the then Maharaja Sawai Madho Singh II of Jaipur that was carried out under the supervision of Liutt. Arthur Ffolliott Garrett and in which the famous scholar and writer Pt Chandradhar Sharma Guleri (1883-1922), best known for his classic Hindi story Usne Kaha Tha, too had lent technical assistance. The Delhi observatory was restored by the Maharaja in 1910, preparatory to the 1911 Delhi Durbar of King George V.This epitome of Indian science is a milestone in the history of India. It received its name from Yantra-Mantra (instrument and theory). The degradation of its name to Jantar Mantar undermines its scientific meaningfulness. The Delhi Vedhshala has served as a venue for civil expressions. It would be good if it is introduced as Sawai Jai Singh Vedhshala.

This article was published in 2011: Jantar Mantar or Vedhashala? The Hawk, in Hindi and in English, Jun 5. http://prints.iiap.res.in/handle/2248/5493