first sight, the Jantar Mantar appears like a gallery of modern
art. It is, however, an observatory. Sawai Jia Singh II of Jaipur
(1699-1743), a keen astronomer and a noble in the Mughal court,
dissatisfied by the errors of brass and metal astronomical instruments.
Under patronage from the emperor, he set on himself the task of
correcting the existing astronomical tables and updating the almanac
with more reliable instruments.
Jantar Mantar is the first of the five observatories that he built
with large masonry instruments. The observatory has the Samrat
Yantra, a simple equal hour sun dial, the Ram yantra for reading
altitudinal angles; Jai Prakash for ascertaining the position of
the sun and other celestial bodies, and the Misra Yantra which is
a combination of four scientific gadgets.