Raja Sawai Jai Singh II: An 18th century medieval astronomer

The early 18th-century observatories constructed in five North Indian cities by the Raja Jai Singh represent the last historical attempt to carry out a major program in observational astronomy using naked eye methods alone. The major instruments are described and the precision of each is estimated. An attempt is then made to discern the motives which led Jai Singh to construct these observatories more than a century after Galileo first used the telescope for astronomical purposes. It is concluded that Jai Singh's astronomical program can only be understood in terms of the place which science occupied in the social and political matrix of late Moghul India.