Abstract:
In 1724 AD, Maharaja Sawai Jai Singh II of Jaipur built a large observatory at Delhi comprising of huge masonry instruments, with which he made careful observations of the celestial objects. He then built four other similar observatories at Jaipur, Ujjain, Benaras (now Varanasi) and Mathura, so that the accuracy of his observations could be improved. The surviving ones of these observatories, in due course of time, acquired the now well known name of Jantar Mantar. The masonry instruments at Delhi Jantar Mantar, though fairly well maintained as historical monuments, are unfortunately in such a condition that they cannot be used for astronomical observations anymore. Most of the scales and markings on various surfaces of these instruments are now either erased or mutilated. Thus, considering various historical and scientific aspects, the Astronomical Society of India launched a program for the restoration of these three-century old instruments in collaboration with the Archaeological Survey of India. This program is actively supported by the Department of Science & Technology, Government of India. A description of the masonry instruments at Delhi Jantar Mantar and the program for their restoration are briefly outlined here.
