Singh’s Chief Architect.
     Though Jai Singh was engaged in much desultory warfare, and had many
opportunities of distinguishing himself in the field, his talent for civil
government and intrigue appears to have served him far better than his
military attainments.
                  OBSERVATORIES OF JAI SINGH
  Maharaja Sawai Jai Singh II read the works of Ptolemy, Euclid and
  Persian astronomers. Wanting to improve the Indian calendar and the
  ability to precisely locate the Sun, for purposes of map-making, he built
  five astronomical observatories in India. The instruments at these
  observatories, based on Muslim design, perhaps copies of the large 15th
  century instruments at Samarkand, Uzbekistan built by Ulgh Beg, were
  large masonry structures equipped with protractors and marked grids to
  aid in the precise measurements of the location of celestial objects.
  The Jantar Mantar or “House of Instruments” at Jaipur is the largest of the
  observatories and contains eighteen instruments. The largest instrument is
  the Samrat Yantra or equatorial sundial. It consists of a straight 90 foot
  high ramp, or gnomon, which is aligned north-south and elevated at an
  angle of 27 degrees above the northern horizon. The latitude of Jaipur is
  27 degrees north, thus the ramp points toward the celestial pole. On each
  side of the ramp there are two quarter circles, or quadrants, fashioned in
  masonry. The quadrants are centered on the nearest edge of the ramp.
  One of the more interesting instruments is the Jai Prakash Yantra. It is
  attributed to Sawai Jai Singh II. There are a number of sundials; one of
  which a beautiful vertical sundial. There is a smaller equitorial sundial as
  well as two large masonry instruments built to help read the altitude and
  azimuth of celestial bodies.
     Besides constructing astronomical observatories and building palaces, Jai
Singh had built sara is dr inns for travellers in various parts of his dominions
and did much to improve his province. Jai Singh seemed to have collected
treasures of learning from all parts of the world and had amassed a valuable