This book, attempting to study the history of astronomical science in India, focuses on the observatories built by Maharaja Jai Singh II of Jaipur (1686-1743), discussing the reasons for their construction and their significance. It takes up in detail planning, models for building and construction methods used for observatories at Delhi, Jaipur, Ujjain, Benaras and Mathura, pointing out their special features, like their showing no similarity with contemporary Mughal architecture. Illustrated with rich colour photographs and technical drawings, it argues that in building the observatories, the Maharaja aimed to create a representation of his own earthly powers thus underlining his claim to worldly power.